close

Вход

Забыли?

вход по аккаунту

?

183.Журнал Сибирского федерального университета. Сер. Химия №4 2008

код для вставкиСкачать
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
?????? ?????????? ???????????? ????????????
Journal of Siberian Federal University
2008
1 (4)
?????
Chemistry
???????????? ?????
???????? ??? ?.?.???????
???????? ??? ?.?.???????????
???????? ??? ?.?.?????????
???????? ??? ?.?.???????
??.-?. ???, ?-? ???.-???.????
?.?.???????????
??.-?. ???, ?-? ???.-???. ????
?.?.???????
??.-?. ???, ?-? ????. ????
?.?.??????
??.-?. ???, ?-? ???.-???. ????
?.?.????????
??.-?. ???, ?-? ???.-???. ????
?.?. ???????
Editorial Advisory Board
Chairman:
Eugene A. Vaganov
Members:
Kirill S. Alexandrov
Josef J. Gitelzon
Vasily F. Shabanov
Andrey G. Degermendzhy
Valery L. Mironov
Gennady L. Pashkov
Vladimir V. Shaidurov
Veniamin S. Sokolov
Editorial Board:
Editor-in-Chief:
Mikhail I. Gladyshev
Founding Editor:
Vladimir I. Kolmakov
Contents / ??????????
Dmitry V. Kazachkin, David R. Luebke,
Vladimir I. Kovalchuk, and Julie L. d?Itri
Hydrogen-Assisted 1,2-Dichloroethane Dechlorination Catalyzed
by Pt-Cu/SiO2: Insights into the Nature of Ethylene-Selective
Active Sites
? 303 ?
Alexey N. Lukianov, Olga N. Kononova
and Sergey V. Kachin
Calculation of Protolytic Equilibria Parameters on a Surface of
Some Carbon Adsorbents According to Potentiometric Titration
Data
? 326 ?
Tatiana G. Shendrik, Valentina V. Siminova,
Nikolai V. Chesnokov and Boris N. Kuznetsov
Properties of Active Carbons Produced by Thermochemical
Transformation of Lignin, Brown Coal and Oil Slime Mixtures
? 336 ?
Anatoly I. Rubailo and Andrey V. Oberenko
Polycyclic Aromatic Hydrocarbons as Priority Pollutants
? 344 ?
Irina G. Sudakova, Boris N. Kuznetsov,
Natalia V. Garyntseva, Nina I. Pavlenko
and Natalia M. Ivanchenko
Functional and Thermal Analysis of Suberin Isolated from Birch
Bark
? 355 ?
Managing Editor:
Olga F. Alexandrova
Executive Editor for Chemistry:
Boris N. Kuznetsov
???????? ?.?. ?????? ????????? ?.?. ??????????
???????????? ??????? ?.?. ?????????, ?.?. ?????????
????????? ? ?????? 22.12.2008 ?. ?????? 19?27. ???. ???. ?. 6,6.
??.-???. ?. 10,5. ?????? ???. ?????? ????????. ????? 1000 ???. ????? 1/215.
?????????? ? ??? ???. 660041 ??????????, ??. ?????????, 79.
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Editorial board for Chemistry:
Nikolai V. Chesnokov
Lubov? K. Altunina
Natalia G. Bazarnova
Vasiliy A. Babkin
Vicente Cebolla
Viktor M. Denisov
Zinfer R. Ismagilov
Sergey V. Kachin
Sergey D. Kirik
Wolfgang Klose
Vladimir I. Kovalchuk
Vladimir A. Likholobov
Yuri L. Mikhlin
Gennady L. Pashkov
Anatoly I. Rubailo
Tatyana V. Ryazanova
Vladimir A. Sobyanin
Valeri E. Tarabanko
Tatyana G. Shendrik
Maxim L. Shchipko
Jean V. Weber
????????????? ? ??????????? ???
?? ? ??77-28-726 ?? 29.06.2007 ?.
Valeri E. Tarabanko, Olga A. Ulyanova,
Galina S. Kalachova, Valentina V. Chuprova
and Nikolai V. Tarabanko
Study of Plant Growth Promoting Activity and Chemical Composition of Pine Bark after Various Storage Periods
? 363 ?
???????? ?. ??????????, ????????? ?. ??????????,
????? ?. ????????
??????? ????????????? ??????? ?? ?????????? ???????????
?????????? ? ????????, ??????????? ? ???????? ???????
? 369 ?
???????? ?. ???????, ???????? ?. ????????,
??????? ?. ????????, ?????? ?. ?????
????????? ???????????? ???????? ??????????????????????
??????????? ????????? ???-41 ? ?????????? ????????????????? ?????????
? 376 ?
???????? ?. ????????, ????????? ?. ??????,
????? ?. ??????????, ??????? ?. ????????,
????? ?. ????????
??????? ?????????????? ??????? ?? ???????????? ??????
????????? ?????? ? ??????????????? ?????
? 389 ?
???????? ?. ??????????, ??????? ?. ??????????
?????? ???????????? ???? ????? ?????????
? 399 ?
??????? ????????????? ?????? ??? ??????????
? 405 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Journal of Siberian Federal University. Chemistry 4 (2008 1) 303-325
~~~
??? 546
Hydrogen-Assisted 1,2-Dichloroethane Dechlorination Catalyzed
by Pt-Cu/SiO2: Insights into the Nature
of Ethylene-Selective Active Sites
Dmitry V. Kazachkin, David R. Luebke,
Vladimir I. Kovalchuk* and Julie L. d?Itri
Department of Chemical Engineering, University of Pittsburgh,
Pittsburgh, Pennsylvania 15261 1
Received 24.11.2008, received in revised form 15.12.2008, accepted 22.12.2008
Differently pretreated silica-supported Pt, Cu, and Pt-Cu catalysts with Cu to Pt atomic ratio of 1 to 6
have been investigated by a combination of reaction kinetics and FTIR spectroscopic studies in order
to understand the factors that control the selectivity toward ethylene and ethane in the CH2ClCH2Cl+H2
reaction. Carbon monoxide adsorption was used to probe the electronic modification of Pt and Cu as
well as the nature of ethylene-selective active sites. It was shown that there is a very limited, if any,
electronic interaction between Pt and Cu in the bimetallic catalysts reduced at 493 K. However, the
Pt-Cu catalysts, for which no dipole-dipole coupling shift was observed in the IR spectra of adsorbed
CO suggesting extremely small Pt ensembles on the catalyst surface, demonstrated high ethylene
selectivity in the 1,2-dichloroethane dechlorination. Electronic interactions between Pt and Cu have
been discovered for the Pt-Cu/SiO2 catalysts reduced at 773 K. The interactions manifested themselves
by a higher stability of Cu0-CO adsorption complexes in vacuum and by an increase in intensity of the
Pt-CO band in the FTIR spectra upon evacuation of CO from the gas phase suggesting the formation
of Pt-Cu solid solutions. The higher temperature reduction resulted in the dipole-dipole coupling shift
of 6 to 19 cm-1 in the FTIR spectra of adsorbed CO. The initial ethylene selectivity of the catalysts was
inversely proportional to the dipole-dipole coupling shift. The observations are consistent with the
idea that the nature of the Pt-Cu species, viz., alloy particles as opposed to Cu/Pt overlayers, does
not control the reaction selectivity, which is a function of the Pt ensemble size on the surface of Pt-Cu
moieties.
Keywords: hydrogen-assisted dechlorination, 1,2-dichlorothane, ethylene, Pt-Cu catalysts, infrared
spectroscopy, singleton frequency, dipole-dipole coupling.
Introduction
It has been discovered a decade ago
that a combination of Pt or Pd with another
metal deposited on a solid support catalyzes
hydrodechlorination of vicinal dichloroalkanes
such
as
1,2-dichloroethane
and
1,2*
1
dichloropropane toward the formation of the
corresponding alkene, viz., ethylene or propylene
[1-3]. Such a chemistry looks surprising because
any catalyst that activates H2 should also
hydrogenate the product olefin. As chloroalkanes
are common environmental pollutants and alkenes
Corresponding author E-mail address: vkovalchuk@mckasd.net
й Siberian Federal University. All rights reserved
? 303 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Dmitry V. Kazachkin, David R. Luebke,.. Hydrogen-Assisted 1,2-Dichloroethane Dechlorination Catalyzed by?
have a greater commodity value than alkanes,
this chemistry has drawn a continuous interest of
researchers [4-17]. It is referred in literature as to
hydrogen-assisted dechlorination as opposed to
classic hydrodechlorination when alkane and HCl
form from 1,2-dichloroalkane and H2 [18].
Among different noble and non-noble metal
combinations, the Pt-Cu system has been studied
the most thoroughly [1, 2, 4, 11, 12, 15, 17]. The
main question addressed in these publications
was about the role of Pt and Cu in the conversion
of 1,2-dichloroethane. Based on the experimental
evidence, it was concluded that even though the
electronic state of Pt and Cu in the supported
bimetallic catalysts is modified as compared to
the corresponding monometallic catalysts this
modification is not a key factor in controlling
the catalyst selectivity toward ethylene [4, 12].
Instead, the kinetics performance depends on the
size of Pt ensembles in the Cu matrix. The catalysts
with relatively large Pt ensembles that exhibited
a dipole-dipole coupling shift in the spectra of
adsorbed CO catalyzed the CH2ClCH2Cl+H2
reaction toward ethane, whereas the catalysts
that did not show dipole-dipole coupling shift in
the spectra of adsorbed CO were highly selective
toward ethylene. Nevertheless, some aspects of
this chemistry still remain undisclosed.
It has been assumed a priori that the reduction
of supported Pt-Cu catalysts at the temperature
as low as 493 K results in the formation of alloy
Pt-Cu particles on the support surface [2,4,11,12].
Initially, the concentration of Cu in the alloy PtCu particles was suggested to be low because
of the chromatographic separation of the Pt and
Cu precursors on the support surface during
catalyst preparation and, as a consequence, the
ethylene selectivity was low [11]. As the reaction
proceeded, additional amounts of Cu alloyed with
Pt because of the high mobility of the chloride Cu
precursors over the support surface [19] resulting
in a continuous increase in the ethylene selectivity
[2,11,12]. However, the suggestion that Pt-Cu solid
solutions form during the few hour reduction by
H2 at 493 K is dubious. It has been shown that for
a Cu monolayer on the Pt(111) surface there is an
energy barrier of ~ 110 kJ mol-1 for the interlayer
mixing and the noticeable diffusion of Cu
adatoms into Pt was observed at the temperatures
above 550 K [20-23]. Thus, only Cu overlayers on
the surface of Pt particles would form during the
few hour catalyst reduction at 493 K. If this is the
case, the transient behavior of supported Pt-Cu
catalysts in terms of the ethylene selectivity could
be explained by the continuous conversion of Cu
overlayers to Pt-Cu solid solutions assuming that
the latter moieties are ethylene selective in the
CH2ClCH2Cl+H2 reaction, whereas the former
ones are not.
The objectives of the present investigation
were to compare the catalytic performance of
Cu/Pt overlayer moieties in the CH2ClCH2Cl+H2
reaction to that of Pt-Cu solid solutions in the
effort to elucidate the factors that control the
reaction selectivity. It was assumed that the
reduction of Pt-Cu/SiO2 catalysts at 493 K favors
the formation of Cu overlayers on the surface of
Pt particles, while the reduction at 773 K ensures
the formation of Pt-Cu alloy moieties on the
silica surface. The nature of the active sites was
probed by the infrared spectroscopy of adsorbed
CO. Earlier research has shown that a strong
intensity redistribution occurs between the bands
of CO adsorbed on adjacent sites of a different
nature when the difference between vibrational
frequencies of the two types of oscillators is
relatively small [24,25]. In application to infrared
spectra of CO adsorbed on Pt-Cu catalysts,
the redistribution phenomenon results in a
suppression in the integral intensity of the Pt-CO
band and in an enhancement in that of the Cu-CO
one if Cu and Pt sites are located in close vicinity
to each other. Thus, removing CO adsorbed on
Cu by evacuation should result in an increase in
? 304 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Dmitry V. Kazachkin, David R. Luebke,.. Hydrogen-Assisted 1,2-Dichloroethane Dechlorination Catalyzed by?
the integral intensity of the Pt-CO band if Pt and
Cu form a solid solution.
The information regarding the geometric
and electronic properties of the active site can
also be derived from the vibrational frequency
of non-interacting CO molecules adsorbed in a
linear mode and from the shift of the absorption
band maximum that results from dipole-dipole
interactions between adjacent CO molecules
on the metal surface [26-28]. The vibrational
frequency of a CO molecule sufficiently isolated
from the other CO molecules that dipole-dipole
coupling does not occur, the so-called singleton
frequency, depends on the electron density on
the atom with which CO forms the adsorption
complex. In other words, the singleton frequency
depends on the degree to which the d-orbitals
of the metal atom donate electron density to
the unoccupied 2?*-orbital of the adsorbed
CO molecule and the degree to which the 5?orbital of the adsorbed CO donates electron
density to the metal atom. Thus, the singleton
frequency characterizes the electronic state of
the adsorption site [29]. The dipole-dipole shift
at saturation coverage characterizes the size of
an ensemble consisting of the same metal atoms,
as it is determined by the number of the adjacent
vibrating dipoles [30].
Experimental
Catalysts preparation and routine
characterization
The catalysts were prepared by pore volume
impregnation of SiO2 (Aldrich, 99+%, 60-100
mesh, 300 m2 g-1, average pore diameter, 150 ┼)
with a 0.1 N aqueous HCl solution containing
H2PtCl6╖6H2O (Alfa, 99.9%) or CuCl2╖2H2O
(MCB Manufacturing Chemists, 99.5%) or a
mixture of H2PtCl6╖6H2O and CuCl2╖2H2O. The
concentrations of the metal precursors in the
impregnating solution were adjusted to obtain
a metal loading of 2.7% Pt and 0.5% Cu for the
monometallic catalysts. For the bimetallic Pt-Cu
catalysts, the concentration of the Pt precursor
in the impregnating solutions was essentially the
same as in case of the monometallic Pt catalyst,
but the corresponding amount of CuCl2╖2H2O
was added to the solution to obtain the desired Cu
to Pt atomic ratio.
After impregnation the materials were
allowed to equilibrate overnight before drying at
ambient temperature and pressure for 24 h and
then at 373 K for 2 h in vacuum (?25 Torr). To
eliminate possible chromatographic separation
[31] of Pt and Cu ions on the surface of silica,
the dry materials were repeatedly impregnated
with distilled water in the amount of 20% of
the H 2O volume required to reach the incipient
wetness point. Prior to use, the ?wet? samples
were stored in tightly closed vials. The catalysts
compositions are shown in Table 1. The catalyst
nomenclature is defined according to the Pt to
Cu atomic ratio. For example, a catalyst with Pt
to Cu atomic ratio of 1:3 is referred to as Pt1Cu3
(Table 1).
The carbon monoxide chemisorption
measurements were conducted with a volumetric
sorption analyzer (Micromeritics, ASAP 2010
Chemi) to determine the fraction of Pt atoms
exposed. The procedure is described in detail
elsewhere [2]. The measurements were performed
at 308 K, and the adsorption stoichiometry, CO/
Ptsurface, was assumed to be equal to 1. Prior to
measurements, the catalyst was exposed to
flowing He (Praxair, 99.999%, 30 ml min-1) while
it was heated from ambient temperature to 403
K at the rate of 5 K min-1 and then held at 403
K for 1.5 h. Then the gas stream was switched
to H2 (Praxair, 99.999%, 30 ml min-1). Next, the
catalyst was heated from 403 K to the reduction
temperature (493 or 773 K) at the rate of 5 K
min-1 and held at this temperature for 2 h. After
reduction, the catalysts was evacuated at the
reduction temperature for 1.5 h and cooled to
? 305 ?
a
? 306 ?
2.7%Pt
2.8%Pt+0.9%Cu
2.7%Pt+1.8%Cu
2.7%Pt+2.7%Cu
2.7%Pt+3.5%Cu
2.7%Pt+4.2%Cu
2.6%Pt+5.1%Cu
0.5%Cu
Pt
PtCu1
PtCu2
PtCu3
PtCu4
PtCu5
PtCu6
Cu
0.008/0.016
0.18/0.025
773
1.7/1.5
493
1.2/2.1
773
1.7/1.6
773
493
2.6/3.1
493
2.1/1.9
2.9/1.5
773
2.3/2.0
493
2.5/2.4
773
2.6/2.3
773
493
1.9/1.6
2.4/2.0
773
493
1.7/1.6
10.8/3.1
773
493
17.7/4.0
Conversion, %
(Initialc /Steady-State)
493
Tred, K b
100/100
100/100
85/97
100/96
38/97
100/95
15/98
99/96
20/85
98/95
6/42
89/77
0/3
54/55
0/0
0/0
C2H4
0/0
0/0
15/3
0/4
62/3
0/5
85/2
1/4
80/15
2/5
94/58
11/23
95/93
46/45
90/92
93/89
C2H6
0/0
0/0
0/0
0/0
0/0
0/0
0/0
0/0
0/0
0/0
0/0
0/0
5/4
0/0
10/8
7/11
C2H5Cl
Selectivity, mol.% (Initialc /Steady-State)
0.0008
0.003
1.1
1.0
1.6
1.4
1.3
1.3
1.4
1.2
1.6
1.1
1.9
1.8
4.8
4.8
Activity,
╡molDCE gcat-1 s-1
n/a e
n/a e
2.3
1.9
2.0
1.7
1.5
2.3
1.1
1.4
0.76
1.1
0.68
0.96
0.13
0.13
TOFd, s-1
Reaction conditions: T = 473 K; P = 1 atm (7,000 ppm 1,2-C2H4Cl2, 35,000 ppm H 2, balance He). bCatalyst reduction temperature. cIn 1 hour on stream. d Turnover frequency. eNot applicable.
Catalyst
Composition
Catalyst
Table 1. Composition and catalytic performance of Pt-Cu/SiO2 catalysts reduced at 493 and 773 K in the reaction of 1,2-dichloroethane (DCE) dechlorination a
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Dmitry V. Kazachkin, David R. Luebke,.. Hydrogen-Assisted 1,2-Dichloroethane Dechlorination Catalyzed by?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Dmitry V. Kazachkin, David R. Luebke,.. Hydrogen-Assisted 1,2-Dichloroethane Dechlorination Catalyzed by?
the measurement temperature. The fraction of
exposed Cu atoms was not measured.
Carbon monoxide uptakes of Pt-Cu/SiO2
catalysts reduced at 493 K were too small for
precise volumetric measurements; thus, Pt
dispersions of these catalysts were calculated as
follows:
D(Pt-Cu) = DPt ╫ [I(CO/Pt-Cu) / I(CO/Pt)],
where D(Pt-Cu) ? Pt dispersion of a Pt-Cu/SiO2
catalyst reduced at 493 K; DPt ? dispersion of Pt
in the 2.7%Pt/SiO2 reduced at 493 K measured
volumetrically; I(CO/Pt-Cu) ? integral intensity
of the absorption bands in the IR spectra of
CO irreversibly adsorbed on Pt in the Pt-Cu/
SiO2 catalyst reduced at 493 K; I(CO/Pt) ? integral
intensity of the absorption bands in the IR spectra
of CO irreversibly adsorbed on Pt in the 2.7%Pt/
SiO2 catalyst reduced at 493 K.
Kinetics experiments
The dechlorination of CH2ClCH2Cl was
conducted at ambient pressure in a stainlesssteel flow reaction system connected to a quartz
microreactor (10 mm i.d.) in which the catalyst
was supported on a quartz frit. The reactor zone
containing the catalyst was heated by an electric
furnace. The temperature of the catalyst was
measured and controlled with an accuracy of
▒ 1 K with a temperature controller (Omega,
model CN2011). Gaseous reactants were metered
with mass flow controllers (Brooks, 5850E) and
mixed prior to entering the reactor. The liquid
CH2ClCH2Cl (Sigma-Aldrich, 99.8%) was
maintained at 273 K and metered into the reaction
system via a saturator; He was the carrier gas.
Saturation was confirmed by varying the flow
rate of He through the saturator and quantifying
the CH2ClCH2Cl in the gas phase by a gas
chromatograph (GC) (Varian 3300 series).
The effluent from the reactor was analyzed
on-line by GC. The GC was equipped with a 3
m 60/80 Porapak Q packed column (Supelco) and
a flame ionization detector capable of detecting
concentrations > 1 ppm for all chlorocarbons and
hydrocarbons involved in this study. Hydrogen
chloride, a reaction product, was not quantified.
Prior to reaction, the catalyst was exposed to
flowing He (Praxair, 99.999%, 30 ml min-1) while
it was heated from the ambient temperature to
403 K at the rate of 5 K min-1 and then held at 403
K for 1.5 h (the drying step). Then the gas stream
was switched to a 10% H2/Ar mixture (Airgas,
99.99%, 30 ml min-1). Next, the catalyst was
heated from 403 K to the reduction temperature
(493 or 773 K) at the rate of 5 K min-1 and held
at this temperature for 2 h (the reduction step).
The catalyst was then cooled in He (30 ml min-1)
to the reaction temperature and the He flow was
switched to the reactant mixture.
For a typical dechlorination reaction, 0.1 g of
catalyst was used and the total flow of the reactant
mixture through the reactor was 41 ml min-1. The
flow consisted of 7,000 ppm of CH2ClCH2Cl,
36,000 ppm of H2, and He (balance). The reaction
temperature was 473 K. The reaction was run
for 40 h or longer until steady-state performance
with respect to activity was achieved. Steady
state was defined as a change in conversion of
less than 0.2% within a 10 h interval. In order
to compare selectivities, the weight of the each
bimetallic catalyst was adjusted to maintain the
steady-state conversion at comparable levels (1 to
3%). However, for Cu/SiO2 the conversion could
not be raised beyond 0.03% even with 0.3 g of
catalyst.
FTIR spectroscopic investigation
of CO adsorption
Infrared spectra were recorded with a
Research Series II FTIR spectrometer (Mattson)
equipped with a liquid N2 cooled MCT detector
(Judson Technologies) and an IR cell used in
previous research [32]. The cell volume was
? 307 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Dmitry V. Kazachkin, David R. Luebke,.. Hydrogen-Assisted 1,2-Dichloroethane Dechlorination Catalyzed by?
200а cm3, and the light path-length was 12 cm.
The cell was equipped with glass stopcocks (Ace
Glass Inc.) connected to gas inlet/outlet ports.
The spectra of adsorbed CO were measured with
a resolution of 4 cm-1. To obtain a satisfactory
signal to noise ratio, 64 scans were accumulated
per spectrum.
The infrared spectra were collected in the
transmission mode, which mandates the use of
thin wafers of catalyst. Such self-supporting
catalyst wafers (~20 mg cm-2 thick) were prepared
by powdering the catalyst in an agate mortar and
13
C, 95+% 18O). Initially, the pretreated catalyst
wafer was exposed to 12C16O for 15 min at room
temperature and an equilibrium pressure of 10
Torr. Then, the gaseous 12C16O was evacuated, and
a mixture of 13C18O+12C16O of known composition
(10 Torr) was admitted to the IR cell. After 15
min the spectrum of adsorbed CO in the presence
of the gas phase was recorded. Then, the gaseous
CO was evacuated for 15 min, and the spectrum
of adsorbed CO was recorded in the absence of
gas phase. By repeating this procedure while
systematically varying the composition of the
then pressing the powder at 830 atm for 3 min.
Subsequently, the wafers were mounted into the
IR cell, evacuated at room temperature for 15
min, heated to 403 K at 5 K min-1, evacuated at
403 K for 1.5 h, heated to 493 K at 5 K min-1 in a
5% H2/Ar mixture flowing at 30 ml min-1, and held
at 493 K for 2 h while the gas mixture continued
to flow. Finally, the temperature was lowered to
473 K, the gas phase was evacuated to a pressure
of ?10 -6 Torr, and the wafer was allowed to cool
down to ambient temperature under continuous
evacuation.
After the CO adsorption experiments
described below were performed, the catalyst
wafer was evacuated at ambient temperature for
15 min, heated to 773 K at 5 K min-1 in a 5% H2/Ar
mixture flowing at 30 ml min-1, and held at 773 K
for 2 h under the same gas mixture flow. Then the
temperature was lowered to 473 K, the gas phase
was evacuated to a pressure of ?10 -6 Torr, and
the wafer was allowed to cool down to ambient
temperature under continuous evacuation. After
this pretreatment, another set of CO adsorption
experiments was conducted.
The frequency shift that results from dipoledipole coupling and the singleton frequencies
of CO adsorbed on the catalyst were measured
by the isotopic dilution method [29,33] using
mixtures of different compositions of 12C16O
(Praxair, 99.99+%) with 13C18O (Isotec, 99+%
isotopic mixture, the spectra of adsorbed CO as
a function of 13C18O+12C16O mixture composition
were determined. Similar to the procedure
described elsewhere [24,34], the singleton
frequencies, ?Pt(12C16O), for the Pt-12C16O linear
complexes were determined from the spectra of
the adsorbed 13C18O+12C16O mixtures with very
low 13C18O concentrations by increasing the
frequency of the Pt-13C18O absorption band by 100
cm-1, a difference between vibrational frequencies
of 13C18O and 12C16O molecules [35]. The dipoledipole shifts, ??Pt(12C16O), were determined as the
difference between the frequency of the Pt-12C16O
absorption band in the spectra of 13C18O+12C16O
mixtures with very low 13C18O concentrations and
the Pt-12C16O band singleton frequency.
Temperature programmed desorption
(TPD) and reduction (TPR)
The TPD and TPR experiments were
carried out in the IR cell described above. In all
experiments, 0.02-0.05 g catalyst wafers were
used.
Prior to the TPD experiment, the wafer was
evacuated at ambient temperature for 2 h. Then
the cell was disconnected from the vacuum pump
by means of a valve and the wafer temperature
was increased from ambient temperature to 403
K at a rate of 4 K min-1 while FTIR spectra of gas
phase in the cell were recorded every 2-5 min.
? 308 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Dmitry V. Kazachkin, David R. Luebke,.. Hydrogen-Assisted 1,2-Dichloroethane Dechlorination Catalyzed by?
Results
Dispersion measurements
The dispersion of Pt in the monometallic
2.7%Pt/SiO2 catalyst was essentially independent
of the catalyst reduction temperature. The
fractions of Pt atoms exposed determined by
volumetric measurements of irreversibly adsorbed
CO were 27 and 26.5% after the reduction at 493
and 773 K, respectively (Fig. 1). Addition of Cu to
Pt resulted in a dramatic decrease in the apparent
Pt dispersion of bimetallic catalysts reduced
at both temperatures. The fraction of Pt atoms
exposed of the PtCu1/SiO2 reduced at 773 K was
approximately 2%, and the fraction of surface Pt
atoms in Pt-Cu/SiO2 catalysts gradually decreased
further as the Cu to Pt ratio increased to reach
0.4% for the PtCu6/SiO2 (Fig. 1). This trend is
consistent with the results reported elsewhere [2,
13, 36].
For bimetallic Pt-Cu/SiO2 catalysts reduced
at 493 K, the amounts of CO adsorbed irreversibly
28
26
24
3
2
1
Pt
Cu
6
Pt
Cu
5
Pt
Cu
4
Pt
Cu
3
Pt
Cu
2
Pt
Cu
1
0
Pt
493 K for 1.5 h similar to the procedure described
in the previous section. Then, the temperature
was lowered to 473 K and the cell was evacuated
for 0.5 h. Next, 600 Torr of H2 was admitted to the
IR cell and the temperature was increased to 773
K at a rate of 4 K min-1. During the heating, FTIR
spectra of gas phase in the cell were recorded
every 2-5 min.
30
Dispersion, %
Temperature-programmed
reduction
experiments were conducted according to two
different protocols. According to the first protocol,
the catalyst wafer after the TPD experiment was
evacuated at 403 K for 1.5 h and cooled to room
temperature under continuous evacuation. Then
600 Torr of H2 were admitted to the IR cell and
the wafer was heated to 773 K at a rate of 4 K
min-1 while the composition of the gas phase in
the IR cell was monitored with FTIR.
According to the second TPR protocol, a
fresh catalyst wafer was reduced in the IR cell at
Fig. 1. Dispersions of Pt/SiO2 and Pt-Cu/SiO2 catalysts
reduced at 493 (black bars) and 773 K (gray bars).
Platinum dispersions of Pt/SiO2 reduced at both
temperatures and Pt-Cu/SiO2 reduced at 773 K were
determined volumetrically from the irreversibly
adsorbed CO whereas Pt dispersions of Pt-Cu/SiO2
reduced at 493 K were calculated based on volumetric
and FTIR measurements
were too small to be measured reliably with the
ASAP 201 Chemi Micromeritics instrument.
Thus, the Pt dispersions of these catalysts were
calculated using results of volumetric and FTIR
measurements (see Experimental section).
According to the calculations, the Pt dispersion of
the PtCu1/SiO2 was only 1.3% and the dispersion
decreased as the Cu to Pt ratio increased, so that
the fraction of Pt atoms exposed of the PtCu6/
SiO2 was 0.4% (Fig. 1). It is worth noting that
Pt dispersions calculated with FTIR data can be
used as an estimate only because the extinction
coefficients for CO adsorbed on Pt in mono- and
bimetallic catalysts might be quite different.
Kinetics experiments
The kinetics results for the catalysts reduced
at 493 and 773 K are shown in Table 1. The Pt/SiO2
permanently deactivated as the 1,2-dichloroethane
conversion decreased by a factor of 3 to 4 during
the first 50 hours on stream. In contrast, the
? 309 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Dmitry V. Kazachkin, David R. Luebke,.. Hydrogen-Assisted 1,2-Dichloroethane Dechlorination Catalyzed by?
conversion for the Pt-Cu catalysts decreased
only slightly during the first 1-2 hours on stream
and remained essentially constant thereafter.
However, the 1,2-dichloroethane conversion
for the Cu/SiO2 reduced at 773 K decreased by
an order of magnitude during the first 80 hours
on stream, whereas the conversion for the same
catalyst reduced at 493 K was increasing with
time on stream to exceed the initial conversion by
a factor of 2 at steady-state (Table 1).
The Pt/SiO2 exhibited the highest catalytic
activity on per mass of catalyst basis; the activities
of the Pt-Cu/SiO2 were lower by a factor of 3-5.
The bimetallic catalysts with the Cu to Pt ratio
greater than 1 did not show a clear dependence
of catalytic activity on Cu loading. The activity
of Cu/SiO2 was negligible. The Pt/SiO2 had
the turnover frequency (TOF) of 0.13 s-1, being
the lowest one among Pt-containing catalysts.
Upon addition of copper, the TOFs of bimetallic
catalysts increased to exceed that of the Pt/SiO2
by an order of magnitude. It is worth noting, that
the TOFs of the Pt-Cu/SiO2 reduced at 493 K
were close to those of the catalysts reduced at 773
K (Table 1).
The product selectivities for the Pt/SiO2 and
Cu/SiO2 catalysts did not depend on the reduction
temperatures and were also independent of
time on stream. The latter catalyst was 100%
selective toward ethylene, while the former one
catalyzed 1,2-dichloroethane dechlorination
to form approximately 90% of ethane and 10%
of monochloroethane (Table 1). However, the
selectivities for the Pt-Cu catalysts were a function
of reduction temperature and time on stream as
well as a function of catalyst composition.
The characteristic features of the bimetallic
catalysts were catalyzing the CH2ClCH2Cl + H2
reaction toward the formation of C2H4 and the
absence of monochloroethane among the reaction
products (Table 1). The initial selectivity for the
PtCu1/SiO2 reduced at 493 K toward C2H4 was
54% and it did not change with time on stream. For
the PtCu2/SiO2 reduced at 493 K, the initial C2H4
selectivity was 89%. The selectivity decreased
with time on stream to drop to 77% in 65 h. The
initial ethylene selectivities for the other Pt-Cu
catalysts reduced at 493 K were close or equal to
100% and decreased to 95-97% at steady-state.
The PtCu1/SiO2 reduced at 773 K exhibited
no ethylene selectivity initially and this selectivity
increased to only 3% in 40 h on stream when the
catalyst reached the steady state. Even though the
other Pt-Cu catalysts reduced at 773 K showed
initial ethylene selectivities, they were much
lower than those for the catalysts reduced at
493 K (Table 1). However, ethylene selectivities
increased with time on stream, and the steady
state selectivity figures for the catalysts with Cu
to Pt atomic ratio greater than 3 were virtually
the same as those for the catalysts reduced at
493аK (Table 1).
Temperature programmed desorption
(TPD) and reduction (TPR)
The TPD and TPR experiments were
conducted with Pt/SiO2, PtCu1/SiO2, PtCu3/
SiO2, PtCu6/SiO2, and Cu/SiO2 catalysts.
The objective of the TPD experiments was to
elucidate chemical processes occurring during
the drying step of the catalyst treatment prior to
the kinetics testing. Temperature programmed
desorption experiments demonstrated that all
catalyst samples start releasing H2O at ~340 K
(not shown). The onset of the HCl evolution by
the Pt and PtCu samples was observed at ~370
K whereas the monometallic Cu sample started
releasing HCl at ~390 K (not shown). The
evolution of H2O and HCl would have been an
indication of the decomposition of Cu and Pt
hydroxides/hydroxychlorides, which may form
during catalyst preparation and/or storage [19].
Another source of water could be a temperature
stimulated desorption of H2O that was not
? 310 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Dmitry V. Kazachkin, David R. Luebke,.. Hydrogen-Assisted 1,2-Dichloroethane Dechlorination Catalyzed by?
removed by a prolonged sample evacuation at
room temperature prior to the TPD experiments.
The TPR experiments were performed to
probe the reducibility of the bimetallic Pt-Cu
and the corresponding monometallic catalysts.
During the heating in hydrogen of a 2.7%Pt/SiO2
wafer dried in vacuum at 403 K, the onset of
the HCl formation was observed at ~360 K (not
shown). This temperature is consistent with that
of the Pt chlorides reduction reported elsewhere
[19]. Only trace amounts of HCl were evolved
by the catalyst wafer above 420 K whereas
the H2O evolution was observed in the whole
temperature range of the TPR experiments (not
shown). Probably, the water released because of
temperature stimulated desorption of strongly
bound H2O as well as because of dehydroxylation
of the SiO2 surface. In addition, the evolution of
trace amounts of CO and CH4 was detected with
the onset of the formation at ~520 and ~570 K,
respectively (not shown). The emerging of CO
was assigned to the decomposition of carbonatecarboxylate species formed from the metal
chlorides during the catalyst preparation/storage
while the appearance of CH4 was attributed to the
Pt-catalyzed hydrogenation of these species and/
or CO.
In the TPR experiment with a 0.5%Cu/
SiO2 wafer, hydrogen chloride evolution began at
~440 K. The IR-TPR profile for the HCl evolution
had two different slopes in the range of 450-490
and 490-550 K (not shown). These slopes were
attributed to the reduction of Cu(II) to Cu(I) and
Cu(I) to Cu(0), respectively [37,38]. Similar to the
TPD experiment with Pt/SiO2, the Cu/SiO2 wafer
released water in the whole temperature range
of the experiment. The onset of CO evolution
was observed at ~550 K. No CH4 formation was
detected for the Cu/SiO2.
The TPR of PtCu1/SiO2, PtCu3/SiO2 and
PtCu6/SiO2 bimetallic samples showed the onset
of HCl formation at ~400 K. At 520 K CO became
detectable in the gas phase. A continuous increase
in the water concentration in the gas phase was
observed throughout the whole temperature range
for all bimetallic samples. Similar to the Cu/SiO2,
no CH4 was detected in the TPD experiments
with the bimetallic Pt-Cu catalysts.
The TPR experiments with the catalysts
preliminary reduced at 493 K for 2 h showed that
the reduction of the Pt and Cu compounds on the
silica surface does not occur completely. For the Pt/
SiO2, H2O and HCl along with CH4 were detected
in the gas phase at 570 K (not shown). However,
the amount of HCl released was approximately
100 times less then that for the wafer without
preliminary reduction. This suggests that after
reduction at 493 K the Pt/SiO2 catalyst holds
~1% of the initial Cl content. Hydrogen chloride,
H2O, and CO were also detected in the gas phase
during the TPR experiments with the reduced
at 493 K Cu/SiO2 and bimetallic Pt-Cu wafers,
with the HCl amounts being 6 times greater in
comparison with the pre-reduced Pt/SiO2. No
product in the gas phase was detected in the
TPD experiments with Pt, Cu, and Pt-Cu catalyst
wafers pre-reduced at 773K.
FTIR spectroscopy of adsorbed CO
For the Pt/SiO2 catalyst reduced at 493 K,
the addition of 12C16O at room temperature to
the IR cell resulted in the IR bands at 1835 and
2077 cm-1 (Fig. 2A). These bands are assigned to
CO adsorbed on metallic Pt in the bridging and
linear forms, respectively [39,40]. When the gas
phase was removed by evacuation, the intensity
of both bands decreased by approximately 10%
and peak maxima shifted to 1815 and 2069 cm-1.
Room temperature adsorption of 12C16O on the
Pt/SiO2 catalyst reduced at 773 K resulted in the
bands at 1764 and 2075 cm-1 (Fig. 2B). Evacuation
of the gas phase decreased the band intensity for
the linear CO mode by less than 10% and shifted
the band position to 2071 cm-1 whereas the band
? 311 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Dmitry V. Kazachkin, David R. Luebke,.. Hydrogen-Assisted 1,2-Dichloroethane Dechlorination Catalyzed by?
100
10 Torr CO
Evacuation 15 min
2069
2077
A
B
10 Torr CO
Evacuation 15 min
80
2
Absorbance, O.D. x cm x g
-1
80
40
0
1835
20
2250
2100
1950
1800
Wavenumber, cm
60
40
20
0
1650
1764
60
2075
2071
2
Absorbance, O.D. x cm x g
-1
100
2250
2100
-1
1950
1800
Wavenumber, cm
1650
-1
Fig. 2. IR spectra of 12C16O adsorbed on Pt/SiO2 reduced at 493 (A) and 773 K (B) in the presence and in the
absence of the gas phase
B
2
0
6
4
2
1750
2049
4
2037
2136
6
10 Torr CO
Evacuation 30 sec
Evacuation 15 min
2052
2125
8
2
8
Absorbance, O.D. x cm x g
10 Torr CO
Evacuation 30 sec
Evacuation 15 min
-1
10
A
2
Absorbance, O.D. x cm x g
-1
10
0
2250
2100
1950
1800
Wavenumber, cm
1650
2250
-1
2100
1950
1800
Wavenumber, cm
1650
-1
Fig. 3. IR spectra of 12C16O adsorbed on PtCu1/SiO2 reduced at 493 (A) and 773 K (B) in the presence and in the
absence of the gas phase
intensity and position for the bridging CO mode
remained invariable (Fig. 2B).
When 10 Torr CO was present in the gas phase,
the spectrum of CO adsorbed on the PtCu1/SiO2
catalysts reduced at 493 K consisted of the bands at
2037 and 2136 cm-1 (Fig. 3A). Bands in the range of
2030-2050 cm-1 have been previously assigned to
12 16
C O adsorbed linearly on Pt atoms embedded into
the Cu matrix [33,41,42], whereas the band at 2136
cm-1 is attributed to 12C16O adsorbed on metallic Cu
[33,42-44]. The 2136 cm-1 band is asymmetric and
can be fitted to two Gaussian peaks with maxima
at 2142 cm-1 and 2131 cm-1. Thus, it is reasonable
to suggest that there are two kinds of Cu(0) sites.
Evacuation of the 12C16O at room temperature for
15 min resulted in the disappearance of the high
frequency band at 2136аcm-1 and in the shift of the
2037 cm-1 band to 2049 cm-1 with an insignificant
increase in the absolute intensity (Fig. 3A).
However, the integral intensity of the band did
? 312 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Dmitry V. Kazachkin, David R. Luebke,.. Hydrogen-Assisted 1,2-Dichloroethane Dechlorination Catalyzed by?
B
10 Torr CO
Evacuation 30 sec
Evacuation 15 min
2
2031
2044
4
0
6
2020
2129
2137
6
2052
8
2
8
Absorbance, O.D. x cm x g
10 Torr CO
Evacuation 30 sec
Evacuation 15 min
-1
10
A
2
Absorbance, O.D. x cm x g
-1
10
4
2
0
2250
2100
1950
1800
Wavenumber, cm
1650
2250
-1
2100
1950
1800
Wavenumber, cm
1650
-1
Fig. 4. IR spectra of 12C16O adsorbed on PtCu2/SiO2 reduced at 493 (A) and 773 K (B) in the presence and in the
absence of the gas phase
not change. The disappearance of the band at 2136
cm-1 upon room temperature evacuation highlights
thermal instability of the complexes of CO with
Cu(0) [33, 42-44].
Exposure of the PtCu1/SiO2 catalysts reduced
at 773 K to 10 Torr CO resulted in a spectrum with
the band of CO adsorbed on metallic Cu at 2125
cm-1 and in the bands of CO adsorbed on metallic
Pt in the linear and bridging modes at 2051 and
1750 cm-1, respectively (Fig. 3B). When gas-phase
CO was removed by evacuation, the intensity of
the high-frequency band decreased significantly
and shifted to 2123 cm-1, while the band of linear
Pt-CO complexes increased in integral intensity
by approximately 40% and shifted to 2052 cm-1.
The spectrum of PtCu2/SiO2 reduced at 493
K consisted of the band of Cu-CO complexes at
2137 cm-1 and that of linear Pt-CO complexes at
2031 cm-1 when 10 Torr CO were present in the gas
phase (Fig. 4A). Evacuation for 15 min resulted
in a virtual disappearance of the high frequency
band and in a shift of the low frequency band to
2044 cm-1 with insignificant decrease in integral
intensity.
When the PtCu2/SiO2 catalyst wafer was
reduced at 773 K, the bands at 2129 and 2050 cm-1
because of linear CO complexes with metallic
Cu and Pt sites appeared in the spectrum in
the presence of 10 Torr CO in the gas phase. In
addition, the low frequency band had a distinct
shoulder at 2020 cm-1 (Fig. 4B). Room temperature
evacuation caused a sharp decrease in intensity
of the 2129 cm-1 band and its shift to 2127 cm-1. As
well, the band at 2050 cm-1 showed a considerable
increase in intensity encompassing thereby the
shoulder at 2020 cm-1 and shifted to 2052 cm-1.
The assignment of the 2020 cm-1 band is
ambiguous. The low frequency peak of the two
bands observed in the region of 2030-2045 cm-1
in the spectra of CO adsorbed on silica-supported
cluster-derived Pt-Cu catalysts was assigned
to a bridging or semi-bridging mode between
Pt and Cu [45]. It has been reported also that
CO adsorption on a Cu/Al 2O3 reduced at 173550 K and the CO pressure of 75 Torr resulted
in a band in the 2000-2010 cm-1 spectral region
assigned to bridged species [43,46]. However,
these assignments are questionable because the
spectral region where bridged Pt [39,40] and
Cu [47,48] carbonyls are detected is well below
1900 cm-1. In addition, bridged carbonyls on Cu
were observed only at low temperatures and
? 313 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Dmitry V. Kazachkin, David R. Luebke,.. Hydrogen-Assisted 1,2-Dichloroethane Dechlorination Catalyzed by?
2029
2042
4
2149
2
0
6
2016
2139
6
10 Torr CO
Evacuation 30 sec
Evacuation 15 min
2044
8
2
2
Absorbance, O.D. x cm x g
-1
8
B
2124
10 Torr CO
Evacuation 30 sec
Evacuation 15 min
-1
10
A
Absorbance, O.D. x cm x g
10
4
2
0
2250
2100
1950
1800
Wavenumber, cm
1650
2250
2100
-1
1950
1800
Wavenumber, cm
1650
-1
B
2
2149
2030
0
2045
6
2016
4
2042
2140
6
10 Torr CO
Evacuation 30 sec
Evacuation 15 min
8
2
8
Absorbance, O.D. x cm x g
10 Torr CO
Evacuation 30 sec
Evacuation 15 min
-1
10
A
2
Absorbance, O.D. x cm x g
-1
10
2127
Fig. 5. IR spectra of 12C16O adsorbed on PtCu3/SiO2 reduced at 493 (A) and 773 K (B) in the presence and in the
absence of the gas phase
4
2
0
2250
2100
1950
1800
Wavenumber, cm
1650
2250
-1
2100
1950
1800
Wavenumber, cm
1650
-1
Fig. 6. IR spectra of 12C16O adsorbed on PtCu4/SiO2 reduced at 493 (A) and 773 K (B) in the presence and in the
absence of the gas phase
high coverages [47-49]. In another investigation,
a stable in vacuum band at 2018 cm-1 developed
after exposure of a reduced Cu/SiO2 to CO was
assigned to linear Cu0 -CO adsorption complexes
formed with low coordinated Cu atoms [50].
Nevertheless, the nature of this band requires
further investigation. It is worth noting that the
band at approximately 2020 cm-1 was present also
in the spectrum of CO adsorbed on the PtCu1/
SiO2 reduced at 773 K but much less pronounced
(Fig. 3B).
The IR spectra of CO adsorbed on the PtCu3/
SiO2, PtCu4/SiO2, PtCu5/SiO2, and PtCu6/SiO2
reduced at 493 and 773 K are shown in Fig. 5-8.
For each of the catalyst reduced at 493 K, the
spectrum recorded in the presence of gas phase
consisted of the bands of linear Cu-CO and PtCO complexes at 2139-2144 and 2029-2030 cm-1,
? 314 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
B
10 Torr CO
Evacuation 30 sec
Evacuation 15 min
8
2
2040
2029
4
2149
0
6
2017
2142
6
2042
2
8
Absorbance, O.D. x cm x g
10 Torr CO
Evacuation 30 sec
Evacuation 15 min
-1
10
A
2
Absorbance, O.D. x cm x g
-1
10
2127
Dmitry V. Kazachkin, David R. Luebke,.. Hydrogen-Assisted 1,2-Dichloroethane Dechlorination Catalyzed by?
4
2
0
2250
2100
1950
1800
Wavenumber, cm
1650
2250
-1
2100
1950
1800
Wavenumber, cm
1650
-1
B
10 Torr CO
Evacuation 30 sec
Evacuation 15 min
8
2
2149
2030
2043
4
0
6
2015
2144
6
2042
2
8
Absorbance, O.D. x cm x g
10 Torr CO
Evacuation 30 sec
Evacuation 15 min
-1
10
A
2
Absorbance, O.D. x cm x g
-1
10
2125
Fig. 7. IR spectra of 12C16O adsorbed on PtCu5/SiO2 reduced at 493 (A) and 773 K (B) in the presence and in the
absence of the gas phase
4
2
0
2250
2100
1950
1800
Wavenumber, cm
1650
2250
-1
2100
1950
1800
Wavenumber, cm
1650
-1
Fig. 8. IR spectra of 12C16O adsorbed on PtCu6/SiO2 reduced at 493 (A) and 773 K (B) in the presence and in the
absence of the gas phase
respectively (Fig. 5A-8A). The high frequency band
is asymmetric and split into two poorly resolved
bands at 2149 and 2132-2134 cm-1 resulting from
30 second evacuation. After 15 min evacuation of
the gas phase, the Cu-CO band disappeared while
the band of Pt-CO experienced a blue shit by 1113 cm-1 with the intensities remaining essentially
invariable (Fig. 5A-8A).
For the catalysts reduced at 773 K, there
were three bands in the spectra at 2124-2127,
2036-2038, and 2015-2017 cm-1, respectively,
when CO was present in the gas phase. The
latter band manifested itself as a low-frequency
shoulder of the 2036-2038 cm-1 band (Fig. 5B8B). Evacuation of the gas phase caused a sharp
decrease of the Cu-CO band in intensity but it did
not disappear as it was observed for the reduction
temperature of 493 K. Evacuation did not result
in a shift of the band position either. However,
15 min evacuation affected both the intensity
? 315 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Dmitry V. Kazachkin, David R. Luebke,.. Hydrogen-Assisted 1,2-Dichloroethane Dechlorination Catalyzed by?
Table 2. Singleton frequencies and dipole-dipole coupling shifts of the 12C16O complexes with Pt a for the silicasupported Pt and Pt-Cu catalysts reduced at 493 and 773 K
Catalyst
a
?Pt(12C16O)b, cm-1
??Pt(12C16O)c, cm-1
Tred = 493 K
Tred = 773 K
Tred = 493 K
Tred = 773 K
Pt
2035
2032
42
37
PtCu1
2042
2032
7
19
PtCu2
2042
2035
1
10
PtCu3
2041
2034
0
10
PtCu4
2043
2035
0
8
PtCu5
2040
2037
0
7
PtCu6
2040
2037
0
6
In the absence of the gas-phase CO. Singleton frequency. Dipole-dipole coupling shift.
b
c
and the position of the Pt-CO band. It shifted to
the higher wavenumbers by 4-6 cm-1 with a twofold increase in intensity. This increase worsened
the resolution of the 2036-2038 cm-1 band and its
shoulder at 2015-2017 cm-1, but an asymmetry of
the shifted band at 2042-2045 cm-1 suggested that
the band at 2015-2017 cm-1 was still present in the
spectra (Fig. 5B-8B).
Singleton frequencies and dipole-dipole
shifts of the 12C16O complexes with Pt in silicasupported Pt and Pt-Cu catalysts are listed
in Table 2. The spectra of the 12C16O+13C18O
isotopic mixtures used for the measurements
of these characteristics of the CO adsorbed are
not shown. The singleton frequency of Pt-12C16O
complexes for the Pt/SiO2 reduced at 493 K was
2035 cm-1. It was 5-8 cm-1 greater for the Pt-Cu
catalysts, but there was no correlation between
the singleton frequency and the Cu to Pt atomic
ratio (Table 1). For the Pt/SiO2 and PtCu1/SiO2
reduced at 773 K, the singleton frequency was
2032 cm-1. The frequency increased with an
increase in the Cu to Pt atomic ratio, but the
trend was very weak. The difference between
singleton frequencies for Pt/SiO2 and PtCu6/
SiO2 was 5 cm-1 only (Table 2). The singleton
frequencies for the bimetallic catalysts reduced
at 773 K were 3-10 cm-1 lower than those for the
catalysts reduced at 493 K.
The dipole-dipole shift for the Pt/SiO2
reduced at 493 K was 42 cm-1. It reduced to 7 cm-1
for the PtCu1/SiO2 and remained virtually zero
for the other bimetallic catalysts (Table 2). While
the dipole-dipole shift for the Pt/SiO2 reduced at
773 K was close to that for the catalyst reduced at
493 K, the shifts for the Pt-Cu catalysts reduced at
773 K exceeded those for the bimetallic catalysts
reduced at 493 K. The shift was 19 cm-1 for the
PtCu1/SiO2 and it decreased gradually as the Cu
to Pt atomic ratio increased to reach 6 cm-1 for the
PtCu6/SiO2 (Table 2).
Discussion
The present investigation provides evidence
that active sites of different nature form on the
surface of the silica support for the Pt-Cu/SiO2
catalysts reduced at 493 and 773 K. The FTIR
spectroscopy results of adsorbed CO presented
in this work are consistent with the formation of
surface particles of Pt-Cu solid solutions after the
reduction at 773 K and with the formation of Cu
overlayers on the surface of Pt particles after the
catalyst reduction at 493 K.
Even though the Pt-Cu/SiO2 catalysts were
repeatedly impregnated with distilled water to
eliminate possible chromatographic separation
[31] of Pt and Cu ions during the first impregnation
of the support with aqueous solutions of H2PtCl6
? 316 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Dmitry V. Kazachkin, David R. Luebke,.. Hydrogen-Assisted 1,2-Dichloroethane Dechlorination Catalyzed by?
and CuCl2, the Pt and Cu chlorides may still be
separated on the silica surface. Because both Pt
and Cu chlorides/oxychlorides are relatively stable
in an inert atmosphere and migrate readily over
the surface of oxide and carbon supports at higher
temperatures [19,51], the drying of the Pt-Cu/SiO2
catalysts in He flow at 403 K (see Experimental
section) would lead to a redistribution of Pt and
Cu chloride moieties on the support by surface
diffusion. As Pt chlorides are thermally unstable
at temperatures above 370 K [52] it is expected that
some Pt chlorides will decompose to the Pt metal.
The Pt metal sites could serve as a trap for the
mobile CuClx moieties by catalyzing dissociation
of Cu-Cl bonds on the Pt surface. The driving
force of this process is the energy of cohesion
between Pt and Cu [53]. Thus, after the drying
step of the Pt-Cu/SiO2 catalyst pretreatment, the
metal-containing moieties on the support surface
would consist of microcrystals of partially
decomposed Pt chlorides encompassed by CuClx
species. Of course, a fraction of Cu chlorides may
crystallize apart of Pt-containing moieties.
Both thermodynamics and kinetics favor
the reduction of platinum chlorides by H2 to
the metallic state [19,31]. Hence, at higher
temperatures the life time of Pt chloride moieties
in the presence of H2 is not expected to be long.
Copper chlorides are more stable and need higher
temperature or longer time at lower temperature
to be reduced to the metal. Indeed, according to
the TPD/TPR results, in monometallic catalysts
the reduction of Pt starts at 360 K, while reduction
of Cu chlorides requires the temperature of 440
K. In the presence of platinum, copper chloride
should also reduce rapidly. Silica supports favor
hydrogen spillover [19], and there would not be
a shortage of dissociated H in close proximity to
the CuClx moieties even if Pt clusters, the source
of dissociated H, are quite distant. However, the
TPR results show that the reduction of Pt-Cu/SiO2
catalysts starts at 400 K, 40 K higher than the
temperature of the Pt/SiO2 reduction. This fact
provides an indirect support to the suggestion
that in the Pt-Cu/SiO2 catalysts, after the drying
step, microcrystals of partially decomposed Pt
chlorides are covered by CuClx moieties. If this
is the case, molecular hydrogen has to diffuse
through the CuClx layer to be activated on the
Pt sites. If the H2 diffusion is slower than the
kinetics of the Pt and Cu chloride reduction by
dissociated hydrogen, the onset temperature of
the Pt-Cu/SiO2 catalysts reduction will be higher
than that of the Pt/SiO2 reduction.
Thus, the reduction of the Pt-Cu/SiO2
catalysts at 493 K will result in the metallic
particles consisted of the Pt core covered with
multilayers of Cu along with the particles of
metallic Cu consistent with the two peaks for the
Cu-bonded CO in the IR spectra (Fig. 3A-8B).
Alloying of Cu and Pt is not expected because of
high energy barrier for the diffusion of Cu into Pt
[20]. Previous studies showed that alloy formation
takes place after annealing Cu/Pt overlayers to the
temperatures above 550 K [20,21,54]. It is worth
noting that alloying between Pt and Cu in PtCu/C catalysts reduced at 493 K was not detected
by HRTEM even though catalytic properties of
Cu and Pt were significantly modified [55].
The suggestion about the formation of
multilayers of Cu over Pt particles is supported
by the results of the IR investigation of adsorbed
CO. A low stability of the Cu-CO adsorption
complexes in vacuum (Fig. 3A-8A) similar to
that of pure Cu [33,42-44] is consistent with a
very weak, if any, electronic modification of Cu;
hence, alloying of Pt-Cu does not take place.
On the other hand, a very small dipole-dipole
coupling shift of the Pt-CO band for the PtCu1/
SiO2 and the absence of it for the other Pt-Cu
catalysts (Table 2) along with a very low apparent
Pt dispersion suggest that Pt in the catalysts
reduced at 493 K is blocked by Cu. A blue shift
of Cu-CO bands by 45-50 cm-1 for the Pt-Cu/SiO2
? 317 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Dmitry V. Kazachkin, David R. Luebke,.. Hydrogen-Assisted 1,2-Dichloroethane Dechlorination Catalyzed by?
as compared to silica- and alumina-supported Cu
[33,42] can be explained by electron withdrawal
effect of the residual Cl (see TPR results) as well
as by the roughness of the Cu surface due to a
relatively low catalyst reduction temperature. It
was shown previously that the frequencies of CO
adsorbed on ?smooth? Cu(100) and Cu(111) single
crystals are lower than those on ?rough? Cu(211)
and Cu(311) [56].
Removing the CO adsorbed on Cu of the PtCu/SiO2 catalysts reduced at 493 K by evacuation
does not result in a change in integral intensity
The singleton frequencies of Pt-CO
complexes for the reduced at 493 K Pt-Cu/SiO2
catalysts do not allow one to make an insightful
conclusion about the electronic modification of
Pt. The frequencies for the bimetallic catalysts are
greater that that for the Pt/SiO2, but the difference
is 5-8 cm-1 only (Table 2). This difference could
be attributed to an electron withdrawal effect
of chlorine atoms rather than to an electronic
modification of Pt by Cu, as the TPD/TPR results
show that after the reduction at 493 K the Pt-Cu/
SiO2 catalysts retain 6 times as much Cl as the
of the Pt-CO band (Fig. 3A-8A) suggesting that
there are limited, if any, electronic interactions
between Pt and Cu [24,25,53,57,58]. However, a
possibility of some electronic interaction between
Pt and Cu is inferred from a blue shift of the PtCO band by 11-13 cm-1 when the CO adsorbed on
Cu sites was removed (Fig. 3A-8A). Similar shifts
were observed for CO on Pt(111) surfaces covered
with 0.12-0.29 monolayer of Cu after the CO
adsorbed on Cu was removed, but the shift was
only two wavenumbers [57]. Much greater shift
of 22 cm-1 was reported for reduced at 873 K PtCu/Al2O3 catalysts [58]. The shift was explained
in terms of electronic modification of Pt and Cu
under assumptions that CO adsorption on Cu
results in an electron transfer from CO to Cu and
that alloying Cu and Pt increases the population
of the Pt(d) orbitals. Such explanation is hardly
valid. It has been shown that CO adsorption on
Cu(100) produces a shift of +0.5 eV in the Cu(3d)
and Cu(2p3/2) levels [59] indicating electron
transfer from Cu to CO. As well, according to
the UPS and XPS results reported elsewhere
[54], electron transfer from Pt to Cu takes place
when Cu deposited on the Pt(111) migrates into
Pt(111) to form surface alloys (vide infra). Hence,
it is very difficult, if possible at all, to explain the
CO frequency shift observed (Fig. 3A-8A) within
simple models of molecular orbital theory. This
effect requires further investigation.
Pt/SiO2.
The formation of alloy Pt-Cu particles in
the catalysts reduced at 773 K is evident from the
spectra of CO adsorbed on Pt. Evacuation of CO
from the gas phase over the catalyst wafers results
in a sharp decrease in intensity of the Cu-CO
absorption band and in a significant increase in
intensity of the Pt-CO band (Fig. 2B-7B). Similar
intensity redistribution was observed in infrared
reflection absorption spectra of CO adsorbed on
ultrathin Cu films supported on Pt(111) and has
been assigned to the formation of heteronuclear
metal-metal bonds [53,57]. An increase in
intensity of the Pt-CO absorption band after the
gas-phase CO is removed by evacuation was also
reported for the Pt-Cu/Al2O3 catalysts reduced
at 873 K [58]. Thus, the intensity redistribution
between the Cu-CO and Pt-CO bands observed
in the present investigation is consistent with the
formation of Pt-Cu moieties in which Pt and Cu
atoms are in an intimate contact, namely, with the
formation of Pt-Cu alloys.
The formation of alloy Pt-Cu particles for
the Pt-Cu/SiO2 catalysts reduced at 773 K is also
evident from the analyses of the spectra of CO
adsorbed on Cu. There is a single absorption band
with a maximum at 2124-2129 cm-1, independent
of CO surface coverage (Fig. 3B-8B). This
frequency is ~30 cm-1 higher than that for CO
linearly adsorbed on metallic Cu supported
? 318 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Dmitry V. Kazachkin, David R. Luebke,.. Hydrogen-Assisted 1,2-Dichloroethane Dechlorination Catalyzed by?
on alumina [33] or silica [42]. Even though CO
adsorption complexes with Cu(0) decompose
readily in vacuum [33, 42-44] and the band at
2124-2129 cm-1 does not disappear during 15 min
evacuation (Fig. 3B-8B), it cannot be assigned to
stable in vacuum at room temperature complexes
of CO with Cu+ ions [43,44,46,50]. Indeed, if
copper in the Pt-Cu/SiO2 catalysts reduces to
the metallic state at 493 K (vide supra), it should
definitely reduce at 773 K, the temperature that
is 280 K higher. Thus, the increased stability of
the Cu0-CO complexes in vacuum is due to the
that C-O stretch frequency is more sensitive to
the charge on the metal to which the molecule is
bonded than to the electron population of the CO
2?-orbitals [53,57].
The electronic state of Pt alloyed with Cu is
also modified. For example, the CO desorption
temperature from Pt in Pt-Cu surface alloys is
decreased by as much as 100 K as compared to
pure Pt [20]. This is indicative of the Pt(d) ?
Cu electron transfer. The increase in the CO
singleton frequencies for the reduced at 773 K
Pt-Cu/SiO2 catalysts (Table 2) is consistent with
peculiarities of electronic interactions between
Cu and Pt in Pt-Cu alloys.
The results of UPS and XPS investigations
of surface alloys formed after migration of
Cu multilayer into Pt(111) indicate electron
transfer from Pt to Cu [54,60-62]. Theoretical
calculations with a cluster model showed that
electronic interactions between Pt and Cu result
in a Cu(s,p) ? Pt charge transfer accompanied
by Pt ? Cu(d) and Cu(s,p) ? Cu(d) electron
transfers [63]. Thus, electronically modified
surface Cu atoms of Pt-Cu surface alloys should
bind CO stronger than the surface of bulk Cu due
to an increased donation of the electron density
from the d-orbitals of Cu to the 2?*-orbital of
CO adsorbed. Indeed, the temperature of CO
desorption from a Cu monolayer deposited on
Pt(111) is ~70 K higher than that from Cu(111) [53,
61]. This change in the desorption temperature
corresponds to an enhancement of ~20 kJ mol-1
in the strength of the Cu-CO bond [61,64]. The
fact that an enhancement in the stability of the
Cu-CO adsorption complexes does not result in
a red shift in the C-O stretch frequency for PtCu/SiO2 catalysts (Fig. 3B-8B) as compared to
that for supported Cu [33,42] is not surprising. A
blue shift in the C-O stretch frequency resulting
from an increase in ?-backdonation was reported
elsewhere for fractional monolayer coverages of
Cu over Pt(111) [53,57]. It has been concluded
a reduction in the Pt(5d) population. However,
the effect is very weak. The maximum difference
between the singleton frequencies of Pt/SiO2
and Pt-Cu/SiO2 does not exceed 5 cm-1 (Table
2). It might be due to the fact that, according
to previous theoretical studies, CO vibrational
shifts on metals and metal oxides depend not only
on the extent of ?-backdonation, but also on the
interaction between the CO dipole momentum
and the charge on the metal center and on the
repulsion arising when the CO molecule stretches
in the presence of the rigid surface to which it is
bound (the so-called Wall effect) [65, 66].
Even though IR spectra of CO adsorbed
on Pt provide little to no information about
the electronic modification of Pt in the Pt-Cu/
SiO2 catalysts for both reduction temperatures,
important information can be derived from
the dipole-dipole coupling shifts of the Pt-CO
complex frequency (Table 2). The shift allows one
to judge on the relative sizes of Pt ensembles on the
surface of Pt-Cu moieties [30]. The dipole-dipole
coupling shift is absent for the reduced at 493 K
Pt-Cu/SiO2 catalysts with Cu to Pt atomic ratio
greater than 1 (Table 2). The absence of dipoledipole coupling suggests that Pt is blocked by Cu
almost completely, and the exposed Pt consists of
very small ensembles, maybe even of isolated Pt
atoms. At higher reduction temperatures the rate
of the Cu overlayer diffusion into Pt increases
? 319 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Dmitry V. Kazachkin, David R. Luebke,.. Hydrogen-Assisted 1,2-Dichloroethane Dechlorination Catalyzed by?
and, as a consequence, the concentration of Cu
on the surface of Pt-Cu moieties decreases while
that of Pt increases. In addition, hydrogen in
the gas phase favors an enrichment of the Pt-Cu
surface in Pt. The driving force for this chemistry
to occur is the different energies of H adsorption
on Pt and Cu [67]. The heats of H2 chemisorption
on Pt and Cu are 109 and 34 kJ mol-1, respectively
[19]. The enrichment in Pt results in a relatively
large dipole-dipole coupling shifts of the Pt-CO
band for the Pt-Cu/SiO2 catalysts reduced at
773аK (Table 2).
with the reactants and products. Hydrogen and
ethylene have a greater heat of adsorption on
Pt [19] favoring an enrichment of the bimetallic
surface in Pt; Cl atoms, the product of 1,2dichloroethane dissociation, have greater affinity
for Cu when compared to Pt [68-70] favoring a
surface enrichment in Cu. Thus, the transient
performance of the Pt-Cu/SiO2 catalysts in terms
of the ethylene selectivity infers that the average
size of Pt ensembles when the equilibrium
between the catalysts and the reaction mixture is
reached is intermediate between the sizes of the
Characteristic feature of the catalytic
performance of the reduced at 493 K Pt-Cu/SiO2
catalysts that do not exhibit dipole-dipole coupling
of CO adsorbed on Pt is the high initial selectivity
toward ethylene in the CH2ClCH2Cl + H2 reaction
(Table 1). The initial ethylene selectivity of the
catalysts reduced at 773 K is much lower and
this selectivity is inversely proportional to the
dipole-dipole coupling of CO adsorbed on Pt
(Table 1) or, in the other words, to the size of
Pt ensembles on the surface of Pt-Cu moieties.
Thus, the results of the present investigation are
consistent with the suggestion that the extent of
electronic modification of Pt and Cu does not
control the ethylene selectivity of the catalysts
in the hydrogen-assisted dechlorination of 1,2dichloroethane. Instead, the size of Pt ensembles
plays a crucial role for the ethylene selectivity.
It has been shown that isolated Pt atoms do
not bind ethylene, the primary product of 1,2dichloroethane dechlorination, strongly favoring
thereby its desorption rather than hydrogenation
toward ethane [18].
As the CH2ClCH2Cl + H2 reaction proceeds,
the ethylene selectivity of the reduced at 493
K Pt-Cu/SiO2 catalysts with Cu to Pt atomic
ratio greater than 1 decreases whereas that of
the catalysts reduced at 773 K increases (Table
1). Such catalytic performance is explained
by the equilibration of the catalysts? surface
Pt ensembles in the catalysts reduced at 493 and
773 K.
The steady-state turnover frequencies (TOFs)
of Pt-Cu/SiO2 catalysts in the CH2ClCH2Cl
+ H2 reaction are approximately one order of
magnitude greater than those of Pt/SiO2, being
virtually independent of the Cu loading and the
reduction temperature (Table 1). The difference
in catalytic activity between bimetallic Pt-Cu
and monometallic Pt catalysts is approximately
the same as the difference between the rates
of stoichiometric dechlorination of 1,2dichloroethane over silica-supported Cu and Pt
[71]. These observations are consistent with the
hypothesis that for Pt-Cu/SiO2 catalysts 1,2dichloroethane dissociate on Cu sites to form
ethylene and adsorbed Cl atoms. As hydrogen
dissociative adsorption on Cu is an activated
process with a relatively low adsorption energy,
the concentration of H atoms on the Cu surface
would be low [19]. Thus, monometallic Cu/SiO2
catalyst possesses very low activity in the reaction
under consideration (Table 1) as the surface Cl
can not be removed easily due to a lack of surface
hydrogen. Therefore a noble metal is needed
to provide an abundant source of dissociated
hydrogen which upon spilling over from Pt sites
reduces surface CuCl species followed by HCl
desorption. The independence of the activity of
the Pt-Cu/SiO2 catalysts on per surface Pt atom
? 320 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Dmitry V. Kazachkin, David R. Luebke,.. Hydrogen-Assisted 1,2-Dichloroethane Dechlorination Catalyzed by?
basis on Cu loading (Table 1) suggests that the
rate-determining step of the CH2ClCH2Cl + H2
reaction is H diffusion from Pt to Cu sites or
reduction of surface CuCl species rather than
the dissociation of the first C-Cl bond of the 1,2dichloroethane as it has been proposed elsewhere
[7] for Pd-Ag/SiO2 catalysts.
The results of the present investigation
suggest that the different temperature of the
Pt-Cu/SiO2 catalysts reduction results in the
manifests itself by an increased stability of the
Cu0-CO adsorption complexes in vacuum and by
an intensity redistribution between Pt-CO and
Cu-CO bands in the IR spectra of adsorbed CO.
As well, a significant dipole-dipole coupling shift
of the linear Pt-CO band suggests relatively large
Pt ensembles on the surface of Pt-Cu moieties.
Such moieties exhibit relatively low ethylene
selectivity in the CH2ClCH2Cl + H2 reaction and
this selectivity is inversely proportional to the
dipole-dipole coupling shift.
Initial ethylene selectivity of the Pt-Cu/
formation of different active sites on the surface
of the silica support. The characteristic features
of the active sites of the catalysts reduced
at 493 K are a very weak, if any, electronic
interaction between Pt and Cu and the absence
of the dipole-dipole coupling shift of the linear
Pt-CO band in the IR spectra of adsorbed CO.
These are consistent with the idea that metallic
Cu blocks physically the surface of Pt particles
making thereby the size of Pt ensembles
exposed very small. Such active sites are 100%
selective toward ethylene in the CH 2ClCH 2Cl +
H 2 reaction.
The alloy Pt-Cu particles form in the catalysts
reduced at 773 K. In these particles, there is an
electronic interaction between Pt and Cu, which
SiO2 catalysts reduced at 493 K decreases with
the course of the reaction, whereas the initial
selectivity of the catalysts reduced at 773 K
increases with time on stream. The steadystate ethylene selectivities of the Pt-Cu catalyst
with Cu to Pt atomic ratio greater than two
reduced at different temperatures are very close
suggesting the similar surface composition of
the Pt-Cu moieties independent of the reduction
temperature. Thus, the nature of the Pt-Cu
species formed upon catalyst reduction does not
control the reaction selectivity. The selectivity
is a function of the composition of the Pt-Cu
particle surface, which, in turn, is a result of
chemical equilibration between the catalyst and
the reaction mixture.
Conclusion
Acknowledgement
Financial support from the Department of Energy ? Basic Energy Sciences (DE-FG02-95ER14539)
is gratefully acknowledged.
References
1.
Ito, L. N.; Harley, A. D.; Holbrook, M. T.; Smith, D. D.; Murchison, C. B.; Cisneros, M. D. Catalytic
conversion of 1,2-dichloropropane to propylene. WO 9407819, 1994.
2. Vadlamannati, L. S.; Kovalchuk, V. I.; d?Itri, J. L., Dechlorination of 1,2-dichloroethane
catalyzed by Pt-Cu/C: unraveling the role of each metal. Catalysis Letters 1999, 58, (4),
173-178.
3. Heinrichs, B.; Delhez, P.; Schoebrechts, J.-P.; Pirard, J.-P., Palladium?Silver Sol-Gel Catalysts for
Selective Hydrodechlorination of 1,2-Dichloroethane into Ethylene. Journal of Catalysis 1997,
172, (2), 322-335.
? 321 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Dmitry V. Kazachkin, David R. Luebke,.. Hydrogen-Assisted 1,2-Dichloroethane Dechlorination Catalyzed by?
4. Borovkov, V. Y.; Luebke, D. R.; Kovalchuk, V. I.; D?Itri, J. L., Hydrogen-Assisted 1,2-Dichloroethane
Dechlorination Catalyzed by Pt-Cu/SiO2: Evidence for Different Functions of Pt and Cu Sites.
Journal of Physical Chemistry B 2003, 107, (23), 5568-5574.
5. Srebowata, A.; Stefanowicz-Pieta, I.; Juszczyk, W.; Karpinski, Z., Chlorine removal from 1,2dichloroethane over Ni/C catalysts Polish Journal of Chemistry 2007, 81, (8), 1521-1529.
6. Srebowata, A.; Juszczyk, W.; Kaszkur, Z.; Karpinski, Z., Hydrodechlorination of 1,2-dichloroethane
on active carbon supported palladium-nickel catalysts. Catalysis Today 2007, 124, (1-2), 28-35.
7. Heinrichs, B.; Schoebrechts, J.-P.; Pirard, J.-P., Palladium?Silver Sol?Gel Catalysts for Selective
Hydrodechlorination of 1,2-Dichloroethane into Ethylene. III. Kinetics and Reaction Mechanism
Journal of Catalysis 2001, 200, (2), 309-320.
8. Srebowata, A.; Juszczyk, W.; Kaszkur, Z.; Sobczak, J. W.; Kepinski, L.; Karpinski, Z.,
Hydrodechlorination of 1,2-dichloroethane and dichlorodifluoromethane over Ni/C catalysts: The
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
effect of catalyst carbiding. Applied Catalysis A: General 2007, 319, 181-192.
Srebowata, A.; Sadowska, M.; Juszczyk, W.; Kaszkur, Z.; Kowalczyk, Z.; Nowosielska, M.;
Karpinski, Z., Hydrogen-assisted dechlorination of 1,2-dichloroethane over silica-supported
nickel-ruthenium catalysts. Catalysis Communications 2006, 8, (1), 11-15.
Lambert, S.; Ferauche, F.; Brasseur, A.; Pirard, J.-P.; Heinrichs, B., Pd-Ag/SiO2 and Pd-Cu/SiO2
cogelled xerogel catalysts for selective hydrodechlorination of 1,2-dichloroethane into ethylene.
Catalysis Today 2005, 100, (3-4), 283-289.
Luebke, D. R.; Vadlamannati, L. S.; Kovalchuk, V. I.; d?Itri, J. L., Hydrodechlorination of 1,2dichloroethane catalyzed by Pt-Cu/C: effect of catalyst pretreatment. Applied Catalysis B:
Environmental 2002, 35, (3), 211-217.
Vadlamannati, L. S.; Luebke, D. R.; Kovalchuk, V. I.; d?Itri, J. L.; Avelino Corma, F. V. M. S. M.
a. J. L. G. F., Olefins from chlorocarbons: Reactions of 1,2-dichloroethane catalyzed by Pt-Cu. In
Studies in Surface Science and Catalysis, Elsevier: 2000; Vol. 130A, pp 233-238.
Rhodes, W. D.; Lazar, K.; Kovalchuk, V. I.; d?Itri, J. L., Hydrogen-Assisted 1,2-Dichloroethane
Dechlorination Catalyzed by Pt-Sn/SiO2: Effect of the Pt/Sn Atomic Ratio. Journal of Catalysis
2002, 211, (1), 173-182.
Rhodes, W. D.; Margitfalvi, J. L.; Borbath, I.; Lazar, K.; Kovalchuk, V. I.; d?Itri, J. L., Hydrogenassisted 1,2-dichloroethane dechlorination catalyzed by Pt-Sn/SiO2 catalysts of different
preparations. Journal of Catalysis 2005, 230, (1), 86-97.
Avdeev, V. I.; Kovalchuk, V. I.; Zhidomirov, G. M.; d?Itri, J. L., Ethylene adsorption on the Pt-Cu
bimetallic catalysts. Density functional theory cluster study. Surface Science 2005, 583, (1), 46-59.
Avdeev, V. I.; Kovalchuk, V. I.; Zhidomirov, G. M.; d?Itri, J. L., Models of active sites in supported
Cu metal catalysts in 1,2-dichloroethane dechlorination. DFT analysis. Journal of Structural
Chemistry 2007, 48, (Supplement), S160-S170.
Avdeev, V. I.; Kovalchuk, V. I.; Zhidomirov, G. M.; d?Itri, J. L., DFT analysis of the mechanism of
1,2-dichloroethane derchlorination on supported Cu-Pt bimetallic catalysts. Journal of Structural
Chemistry 2007, 48, (Supplement), S171-S183.
Kovalchuk, V. I.; d?Itri, J. L., Catalytic chemistry of chloro- and chlorofluorocarbon dehalogenation:
from macroscopic observations to molecular level understanding. Applied Catalysis A: General
2004, 271, (1-2), 13-25.
? 322 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Dmitry V. Kazachkin, David R. Luebke,.. Hydrogen-Assisted 1,2-Dichloroethane Dechlorination Catalyzed by?
19. Anderson, J. R., Structure of Metallic Catalysts. Academic Press: London, 1975; p 478.
20. Yeates, R. C.; Somorjai, G. A., The growth and alloy formation of copper on the platinum(111) and
stepped (553) crystal surfaces; characterization by LEED, AES, and carbon monoxide thermal
desorption. Surface Science 1983, 134, (3), 729-744.
21. Paffett, M. T.; Campbell, C. T.; Taylor, T. N.; Srinivasan, S., Copper adsorption on platinum(111)
and its effects on chemisorption: a comparison with electrochemistry. Surface Science 1985, 154,
(1), 284-302.
22. Leung, L. W. H.; Gregg, T. W.; Goodman, D. W., Electrochemical and ultrahigh vacuum
characterization of ultrathin copper films on platinum(111). Langmuir 1991, 7, (12), 3205-3210.
23. Tsay, J. S.; Mangen, T.; Wandelt, K., Kinetic study of the formation of a surface-confined Cu50Pt50
alloy. Thin Solid Films 2001, 397, (1-2), 152-156.
24. Borovkov, V. Y.; Kolesnikov, S. P.; Kovalchuk, V. I.; d?ItriJ.L, Probing Adsorption Sites of Silica-
25.
26.
27.
28.
29.
30.
31.
32.
33.
34.
35.
36.
Supported Platinum with 13C16O + 12C16O and 13C18O + 12C16O Mixtures: A Comparative Fourier
Transform Infrared Investigation. Journal of Physical Chemistry B 2005, 109, (42), 1977219778.
Persson, B. N. J.; Hoffmann, P. M., Vibrational phase relaxation at surfaces: The role of lateral
interaction. Journal of Electron Spectroscopy and Related Phenomena 1987, 45, 215-225.
Mahan, G. D.; Lucas, A. A., Collective vibrational modes of adsorbed CO. Journal of Chemical
Physics 1979, 68, (4), 1344-1348.
Persson, B. N. J.; Liebsch, A., Collective vibrational modes of isotopic mixtures of CO on Cu(111)
and Cu(001) Surface Science 1981, 110, (2), 356-368.
Persson, B. N. J.; Ryberg, R., Vibrational interaction between molecules adsorbed on a metal
surface: The dipole-dipole interaction. Physical Review B 1981, 24, (12), 6954-6970.
Hammaker, R. M.; Francis, S. A.; Eischens, R. P., Infrared study of intermolecular interactions for
carbon monoxide chemisorbed on platinum. Spectrochimica Acta 1965, 21, (7), 1295-1309.
Crossley, A.; King, D. A., Infrared spectra for CO isotopes chemisorbed on Pt (111): Evidence for
strong absorbate coupling interactions. Surface Science 1977, 68, 528-538.
Ponec, V.; Bond, G. C., Catalysis by Metals and Alloys. Elsevier: Amsterdam, 1995; p 734.
Deshmukh, S. S.; Borovkov, V. Y.; Kovalchuk, V. I.; d?Itri, J. L., FTIR Spectroscopic and Reaction
Kinetics Study of the Interaction of CF3CFCl2 with ?-Al2O3. Journal of Physical Chemistry B
2000, 104, (6), 1277-1284.
Toolenaar, F. J. C. M.; Stoop, F.; Ponec, V., On electronic and geometric effects of alloying. An
infrared spectroscopic investigation of the adsorption of carbon monoxide on platinum-copper
alloys. Journal of Catalysis 1983, 82, (1), 1-12.
Borovkov, V. Y.; Kolesnikov, S. P.; Koval?chuk, V. I.; d?Itri, J. L., The state of metals in the Pt/
Al2O3 and (Pt-Cu)/Al2O3 catalysts as indicated by IR spectroscopy with isotope dilution of 12C16O
with 13C18O molecules. Russian Chemical Bulletin 2007, 56, (5), 863-869.
Pinchas, S.; Laulicht, I., Infrared Spectra of Labelled Compounds. Academic Press: London New York, 1971; p 371.
Early, K. O.; Rhodes, W. D.; Kovalchuk, V. I.; d?Itri, J. L., Hydrogen-assisted 1,2,3-trichloropropane
dechlorination on supported Pt-Sn catalysts. Applied Catalysis B: Environmental 2000, 26, (4),
257-263.
? 323 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Dmitry V. Kazachkin, David R. Luebke,.. Hydrogen-Assisted 1,2-Dichloroethane Dechlorination Catalyzed by?
37. Rouco, A. J., TPR study of Al2O3- and SiO2-supported CuCl2 catalysts. Applied Catalysis, A:
General 1994, 117, (2), 139-149.
38. Rouco, A. J., Low-temperature ethylene oxyhydrochlorination: effects of supports and promoters
on the mobilities of active species in CuCl2 catalysts. 1995; Vol. 157, p 380-387.
39. Sheppard, N.; Nguyen, T. T., The vibrational spectra of carbon monoxide chemisorbed on the
surfaces of metal catalysts - a suggested scheme of interpretation. Advances in Infrared and
Raman Spectroscopy 1978, 5, 67-148.
40. De La Crus, C.; Sheppard, N., An exploration of the surfaces of some Pt/SiO2 catalysts using CO
as an infrared spectroscopic probe. Spectrochimica Acta 1994, 50A, (2), 271-285.
41. Stoop, F.; Toolenaar, J. C. M.; Ponec, V., Geometric and ligand effects in the IR spectra of carbon
monoxide adsorbed on a platinum-copper alloy. Journal of the Chemical Society, Chemical
Communications 1981, (20), 1024-1025.
42. Toolenaar, F. J. C. M.; Reinalda, D.; Ponec, V., Adsorption of carbon monoxide on platinumcopper alloys. On the possible role of atomic and collective properties of metals in chemisorption:
observations by infrared spectroscopy. Journal of Catalysis 1980, 64, (1), 110-115.
43. Dandekar, A.; Vannice, M. A., Determination of the dispersion and surface oxidation states of
supported Cu catalysts. Journal of Catalysis 1998, 178, (2), 621-639.
44. Hadjiivanov, K. I.; Kantcheva, M. M.; Klissurski, D. G., IR study of CO adsorption on Cu-ZSM-5
and CuO/SiO2 catalysts: ? and ? components of the Cu+-CO bond. Journal of the Chemical
Society, Faraday Transactions 1996, 92, (22), 4595-4600.
45. Chandler, B. D.; Pignolet, L. H., DRIFTS studies of carbon monoxide coverage on highly dispersed
bimetallic Pt-Cu and Pt-Au catalysts. Catalysis Today 2001, 65, (1), 39-50.
46. Dulaurent, O.; Courtois, X.; Perrichon, V.; Bianchi, D., Heats of Adsorption of CO on a Cu/Al 2O3
Catalyst Using FTIR Spectroscopy at High Temperatures and under Adsorption Equilibrium
Conditions. Journal of Physical Chemistry B 2000, 104, (25), 6001-6011.
47. Hayden, B. E.; Kretzschmar, K.; Bradshaw, A. M., An Infrared Spectroscopic Study of CO on
Cu(111): The Linear, Bridging and Physisorbed Species. Surface Science 1985, 155, (2-3), 553-566.
48. Raval, R.; Parker, S. F.; Pemble, M. E.; Hollins, P.; Pritchard, J.; Chesters, M. A., FT-RAIRS,
EELS and LEED studies of the adsorption of carbon monoxide on copper(111). Surface Science
1988, 203, (3), 353-377.
49. Hollins, P., The influence of surface defects on the infrared spectra of adsorbed species. Surface
Science Reports 1992, 16, (2), 51-94.
50. Hadjiivanov, K.; Venkov, T.; Knozinger, H., FTIR spectroscopic study of CO adsorption on Cu/
SiO2: formation of new types of copper carbonyls. Catalysis Letters 2001, 75, (1-2), 55-59.
51. Stevenson, S. A.; Dumesic, J. A.; Baker, R. T. K.; Ruckenstein, E., Metal-Support Interactions in
Catalysis, Synthering, and Redispersion. Van Nostrand Reinhold Co.: New York, 1987; p 315.
52. Lide, D. R., CRC Handbook of Chemistry and Physics. 83rd ed.; CRC Press LLC: Boca Raton,
2002; p 2664.
53. Rodrigues, J. A.; Goodman, D. W., The Nature of the Metal-Metal Bond in Bimetallic Surfaces.
Science 1992, 257, (5072), 897-903.
54. Shek, M. L.; Stefan, P. M.; Lindau, I.; Spicer, W. E., Electronic structure of different Pt-Cu
surfaces. Physical Review B 1983, 27, (12), 7288-7300.
? 324 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Dmitry V. Kazachkin, David R. Luebke,.. Hydrogen-Assisted 1,2-Dichloroethane Dechlorination Catalyzed by?
55. Chakraborty, D.; Kulkarni, P. P.; Kovalchuk, V. I.; d?Itri, J. L., Dehalogenative oligomerization of
dichlorodifluoromethane catalyzed by activated carbon-supported Pt?Cu catalysts: effect of Cu to
Pt atomic ratio Catalysis Today 2004, 88, (3-4), 169-181.
56. Hollins, P.; Pritchard, J., In Vibrational spectroscopy of adsorbates, Willis, R. F.; Agarwal, B. K.,
Eds. Springer-Verlag: Berlin, 1980; Vol. 15.
57. Rodriguez, J. A.; Truong, C. M.; Goodman, D. W., Infrared Vibrational Studies of CO Adsorption
on Cu/Pt(111) and CuPt(111) Surfaces. Journal of Chemical Physics 1992, 96, (10), 7814-7825.
58. Sokolova, N. A.; Barkova, A. P.; Furman, D. B.; Borovkov, V. Y.; Kazansky, V. B., IR-spectroscopic
study of the state of Cu and Pt in copper-platinum-alumina catalysts for paraffin dehydrogenation
subjected to different reductive and oxidative treatments. Kinetics and Catalysis (Translation of
Kinetika i Kataliz) 1995, 36, (3), 434-440.
59. Egelhoff, W. F., Surface electronic structure and screening of 3d-band holes in Cu(100). Physical
60.
61.
62.
63.
64.
65.
66.
67.
68.
69.
70.
71.
Review B 1984, 29, (8), 4769-4771.
Santra, A. K.; Rao, C. N. R., Interaction of Carbon Monoxide with Bimetallic Overlayers. Journal
of Physical Chemistry 1994, 98, (23), 5962-5965.
Shek, M. L.; Stefan, P. M.; Lindau, I.; Spicer, W. E., CO chemisorption on Cu adlayers on Pt(111).
Physical Review B 1983, 27, (12), 7301-7312.
Shek, M. L.; Stefan, P. M.; Lindau, I.; Spicer, W. E., Photoemission study of the adsorption of Cu
on Pt(111). Physical Review B 1983, 27, (12), 7277-7287.
Rodriguez, J. A.; Kuhn, M., Electronic and Chemical Properties of Ag/Pt(111) and Cu/Pt(111)
Surfaces: Importance of Changes in the d Electron Populations. Journal of Physical Chemistry
1994, 98, (44), 11251-11255.
Rodrigues, J. A.; Campbell, R. A.; Goodman, D. W., The nature of metal-metal bonding at
bimetallic interfaces Surface Science 1994, 307-309, (1), 377-383.
Ryberg, R., Infrared Spectroscopy of Molecules Adsorbed on Metal Surfaces. In Advances in
Chemical Physics, Lawley, K. P., Ed. John Wiley & Sons: Chichester, 1989; Vol. 76, p 1.
Pacchioni, G.; Cogliandro, G.; Bagus, P. S., Characterization of oxide surfaces by infrared
spectroscopy of adsorbed carbon monoxide: a theoretical investigation of the frequency shift of
CO on MgO and NiO. Surface Science 1991, 255, (3), 344-354.
Ponec, V., Selectivity in Catalysis by Alloys. Catalysis Reviews - Science and Engineering 1975,
11, (1), 41-70.
Yang, M. X.; Sarkar, S.; Bent, B. E.; Bare, S. R.; Holbrook, M. T., Degradation of MultiplyChlorinated Hydrocarbons on Cu(100). Langmuir 1997, 13, (2), 229-242.
Erley, W., Chlorine adsorption on the (111) faces of Pd and Pt. Surface Science 1980, 94, (2-3),
281-292.
Erley, W., Chlorine adsorption on the (110) faces of Ni, Pd and Pt Surface Science 1982, 114, (1),
47-64.
Anju, Y.; Mochida, I.; Yamamoto, H.; Kato, A.; Seiyama, T., The Dehalogenation of Haloalkanes
on SiO2-supported Metals. Bulletin of the Chemical Society of Japan 1972, 45, (8), 2319-2323.
? 325 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Journal of Siberian Federal University. Chemistry 4 (2008 1) 326-335
~~~
??? 541.183
Calculation of Protolytic Equilibria Parameters
on a Surface of Some Carbon Adsorbents According
to Potentiometric Titration Data
Alexey N. Lukianov, Olga N. Kononova*
and Sergey V. Kachin
Siberian Federal University
79 Svobodny, Krasnoyarsk, 660041 Russia 1
Received 24.11.2008, received in revised form 15.12.2008, accepted 22.12.2008
Constants and Gibbs energy values of neutralization were calculated for protolytic equilibria on
carbon adsorbents based on anthracite, charcoal and brown coal. A proposal regarding composition
of surface functional groups of these sorbents was made.
Keywords: Activated Carbon, Protolytic equilibria, Adsorption properties, Chemical Structure,
Surface Properties.
Introduction
An
investigation
of
acid-base
characteristics of adsorbents is a matter of
practical interest, since they are involved into
the technological schemes for separation and
concentration of metal ions. It is known that
adsorbents synthesized on the basis of natural
materials show a high selectivity to individual
components during recovery from solutions
[1]. We have already shown that the natural
oxidized coals of Kuznetsk and Kansk-Achinsk
deposits of Siberia are promising to be used
as a basis for synthesis of sorbents, which can
selectively recover some non-ferrous metal ions
and iron (III) from industrial manganese sulfate
solutions [2]. That is why the presentation of
equilibrium phenomena on a surface of such
sorbents is important for investigators. It should
*
1
2
be noted that a number of publications related
with this question is rather limited [2-4].
A consideration of acid-base characteristics
of sorbents is frequently accomplished with
data of potentiometric titration of samples by
acid and (or) base [5]. The particular values
of dissociation constants and of surface
concentration of reaction centers (RC) are
obtained by a treatment of a potentiometric
titration curve within the limits of any model of
acid-base equilibrium in the system ?solution ?
sorbent?.
K a For instance, a widespread approach to
calculation
of RC ionization constants K a .1
Ka
RH l R H RH l R H is based on the Henderson?s
equations [5]:
D
p K a pH lg
D
p K a pH lg 1 D 1D
pK a
Corresponding author E-mail address: cm2@bk.ru
pK a
й Siberian Federal University. All rights reserved
Here and further, the line over the symbol indicates the sorbent phase.
? 326 ?
pH
pH
pK a
pK a
D
pH m lg
,
D
pH m lg 1 D ,
1D
D
f (lg
D )
f (lg 1 D )
1D
(1)
(2)
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
RH l R H Ka
D N. Kononova and Sergey V. Kachin. Calculation of Protolytic Equilibria Parameters on?
Alexey N. Lukianov, Olga
K
pK
a a
or
pH lg
1 l
D R H RH
RH l R H D
D
p K a pH mp K
lg a pH
, lg
1D
1D
D
(3)
(4) and (5), i.e. we have used both models ? MI
and DEL, aiming to ascertain, which of the
limiting cases is the closest to the real state of the
adsorption layer.
lg
wherep K?a is pH
the neutralization
degree of the
1D
D
D
adsorbent;
pH f (lg p K) a pH m lg
,
1D
D
1
Experimental
m is tangent of the slope Dangle of a curve plotted
p K a pH m lg
,
We have investigated the carbon adsorbents
1D
D
pK a
) ; the value of synthesized on the basis of brown coals from
on the coordinates pH f (lg
1D
Ka
Kansk-Achinsk deposit (AUIS), anthracite from
D
)
pH fp(lg
H
K
a
m characterizes
a1 force
D of electrostatic interaction Kuznetsk deposit (LKAU-2 and LKAU-7) and
pK a
between
(reaction centers).
industrial charcoal made in Perm region (BAU).
RH functional
l R Hgroups
K K H / M
p K al R the
However,
pK a
calculation in All the adsorbents were synthesized from
RH
H
pH p H
D
accordance
equations (2) and (3) implies coals according to the following technological
p K a with
pH
lg RH
M
l
R1
assumption
DM H is in conflict scheme: preparation, carbonization (600-640░C),
D
that pH
.
Such
p
H
p K a pH lg
K KH /M
1 D representations and activation of the carbonized material in a steamwith both the theoretical
D
RH
M
l
R
H
.
K
experimental
In our
it is hardly
gas medium at 830-850░C with the further
p K a K H pH
m lgM
,opinion,
/ data
M [6].
RH 1
DMD l R M H
possible
p K to
pH m lg the p,K a values directly, modification by air oxygen at 400-410░C.
a determine
1D
E f ( pH
)
i.e. using
data,
The conditioning of sorbents was carried out
RH only
M the
lDRpotentiometric
M H titration
RH) M l R M H .
(lg case
pH in fthis
K a alternate treatment by HCl and NaOH
because
the additional information by their
* 1
DlgDJ ,
pH pH
(lg
)
pH
f
of solution
concerning
the pH
values
in the sorbent solutions (each of 5%) and by 10% ammonia
RH M
l
1 R
D Mf ( pHH) .
E
micropores
That is why we consider solution.
TheR metal
RH l
H content in the conditioned
p K a is required.
1/ 2
1/ 2
lg
J
0
.
5
I
(
1
3
.
29
aI
)
bI
.
Ep K alternative
f ( pH )
that an
approach to the estimation sorbents was determined by titration with EDTA
a
pH pH * lg J ,
D desorption of mineral
of acid-base properties is quite reasonable. Our in solutions obtained after
p K a pH lg
pH
E i 1 E i
dE p H'*E
D M HCl, exposure time
approach
is basedon
, of exchange
pH
Juse
, equilibrium impurities (desorbent1?0.1
pH |pH
p'
HpH lg
lg JpH i 1 0.5pH
I 1 / i2 (1 3.29aI 1 / 2 ) bI .
dpH
constants
K KKH / =M K H / M in accordance with the ? 72 h). This content does not exceed 0.03 mmol
D
following
equations:
per 1 pgKofa sorbent.
lg
0.5 I 1 / 2 (1 3.29aI 1/ 2 ) bI .
pH m lg
,
KJ K
E
E
H /M
'
E
ndE
i
1D
K ci [ Na ]E oi i 1
|
,
The
physical-chemical
characteristics
of the
E
)
dpH
RH f (MpH
lж
R
M ' pH
H pH i 1) , pH(4)
i
i 1 K ci [ Na ] M ( pH
E 1 E i carbon adsorbents investigated are presented in
'E
dE
RH |M l R iM
H ,
D
)
f (lg
or dpH 'pH pH i1 pH
TablepH
1.
i n
1
D
[
]
K
Na
E
pH H .
M
RH
M
l
R
ci
oi
нM ( pH ) E Ш 10
, The potentiometric titration of sorbents
E f ;( pH )
(5)
оRH M l R M H . ж
(
)
M
pH
i 1 K ci [ Na ] K ti J ( Nan ) JK( H[ Na
); ]E
пEK ci f ( pH
in H + -form was carried out at (25▒0.5)░C
ci
oi
pK a
,
E f ( pH )) ж
These
] Mlimiting
( pH ) cases by method of individual weighed samples [5]
K ci [ Na two
1 present
E f (equations
pH ) нipH
pH
M (; pH ) E Ш+10 ;
нMstate
( pH )of*10
for the
counter-ions
the sorbent using 0.01 M and 0.1 M NaOH as a titrant in the
о
lg
pH
pH
J , K JM( Na in
pH p H
о
K
) J ).( H );
ci
ti ) Ш J ( Na
п
pH
K
K
J
(
Na
)
J
(
H
phaseнпM
[7].
The
presence of NaCl as a background electrolyte (the
* E Ш 10of a ;strong bonding (fixing)
cipH
tistate
(
)
pH pH lg J ,
о
*
of double electric
of counter-ions
in /a2 dense
part
ionic K
strength
2
); 1/pH
K H / MI was about 1). The pHа values (see
пlgKJci K0.ti5JI(1Na
(1) J3(.H
29aI
) bI .
нM ( pH )
10
;
layer J(DEL)
in Stern
in (5). below) were measured using universal ionometer
( Na )and
J (H
) | 1 ,layer
[ Na is]1 described
/|
21
lg J 0.5 I 1 / о2 K(1 3K
.29JaI( Na
) bI
.H ) Ш J ( Na ).
)
J
(
ci
ti
п
But ifнMthe
counter-ions
able to move freely EV-74 (Russia).
The experimental error was in
10 pH ; E are
dE( pH ) 'E
i 1 E i
RH M l R M H |
,
о
in thedpH
surface
gel
film,
the ).chemical this case not more than 0.03 logarithmic units.
in this
K
K''tipH
JE( Na
)EJi (1H E
)icase
Ш Ji ( Na
pH
pH
ci
пdE
| correspond
J ( Nato
)the
J (equation
H ), | 1 ,(4),
[ Nawhich
] |1
interactions
The integral
potentiograms of the sorbents
dpH 'pH
pH i 1 pH i
RH M l R M H .
includes a mobile
ion (MI) in sorbent
phase.
were plotted on the coordinates
[ Na
J ( Na ) J ( H )n | 1 ,K[ciNa
] |]E
1 oi
(
)
,
E
f
pH
жn KisK[focused
The present paper
on calculation
E f ( pH ) ,
]E( oipH )
]M
i 1
ci [ Na
ci Na
(
)
,
E
f
pH
ж
of the exchange constants using
the equation
i 1 K ci [ Na ] M ( pH )
нM ( pH ) E Ш 10 pH ;
о
нпMK(cipH )K ti JE( Na
Ш 10)pHJ; ( H );
о
п K ci K ti J ( Na ) J ( H );
нM ( pH ) 10 pH ;
? 327 ?
pH
pH * lg J ,
lg J
0.5 I 1 / 2 (1 3.29aI 1 / 2 ) bI .
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
D
p K al RpH
,
RH
D
Hmlg
) 1D
pH f (lg
1D
D
D
p KpaK a pH lg
p K a pH 1mlg
,
D
1D
D
Alexey
pH pofHProtolytic Equilibria Parameters on?
p K aN. Lukianov,
pH Dlg Olga N. Kononova and Sergey V. Kachin. Calculation
pH f (lg
1) D
D
pK a
p K a pH mDlg
,
1D
(lg
)
pH
f
1
Table 1. Physical-chemical characteristics of carbon adsorbents investigated 1 D D
K KH /M
D
p
K
pH
m
lg
,
a
Sorption capacity for
ppH
K a pH
D
D
Basis1for
Specific surface area Total pore volume
Trade name
)
pH
p
K
2
3af (lg synthesis
(m /g)
(cm /g)
RH
M 1 l
M H methylene blue
D RI2 (mmol/g)
(mg/g)
K
/M
pH K pH H
D
AUIS
Brown
coal
420
0.38
3.4
25
)
pH f (lg
pH M
p H l R M H .
1D
p KRH
LKAU-7
Anthracite
K
RH KM l R M H LKAU-2 H / M Anthracite
pK a
BAU
Charcoal
680
a0.86
4.8
29
600
?
4.5
?
6.0
47
530
RH M l R M
M H H. Ka
pH p H
whereEE isfsorption
capacity
to Naа+ ions (mmol/g)
( pH
)
RH M
l
R
M
H
.
and RH l R H K K
H /M
*
pH f (pH
E
pH ) lg J ,
D
lg p K a MpH
RH
l R 1 DM H where pHа* is pH
measured (see above);
* 1value
lg
0.5 I /lg2 J(1, 3.29aI 1 / 2 ) bI .
pHJ pH
? is a coefficient of activity for H + ( H 3 O + ) ions:
RH M l R M D H .
pdE
KJ a pH
2 lg E
,EaIi 1 / 2 ) bI .
'E1 /m
(6)
lg
(11i31D
.29
| 0.5 I
,
'pH
dpH f ( pH
pH i 1 pH i
E
)
In accordance with the work [8], for
'E D E i 1 E i
dE
|f (lg
, =а?0.25.
) b = 0.22;lgа?
pHNaCl,
I=1M
a* = 4.20;
Na i ]E oi
'pH
dpH
1lgDnJpH
, i K1 ci[ pH
pH pH
(
)
E
f
pH
жpotentiograms
The differential
were, plotted
i 1 K ci [ Na ] M ( pH )
by methods of 1 /numerical
differentiation
in
p KJ a 0.5 I 2 n (1 3K.29
lg
aI 1 / 2])Eoi bI .
ci [ Na
(
)
,
E
f
pH
approximation
жKpH ;[ Na ] M ( pH )
нM ( pH ) E Ш 10
i 1
ci
о
E);i
E
pH
p
H
K
K
J
(
Na
)
J
'
dE
E
i (1H
п ci | ti
,
(7)
pH
нdpH
M ( pH )'pH
E Ш 10pH
i;1 pH i
оK K
pH
нMK( pHH)K/ MJ10
( Na
;) J ( H );
whereпо Ecii and tipHi are
exchange
capacity
and pH
K
K ti J ( Nan ) JK( H
) Ш J (]E
Na
ci [ Na
oi ).
)
,
f ( pH
valueпEin ciexperimental
point
i,
respectively.
ж
] M ( pH )
M) 10
lR
ciM[ Na
H
ipH1 ;K
нRH
M ( pH
All
the
results
were
processed
statistically
о
K
K
J
(
Na
)
J
(
H
)
J
(
Na
Ш
J
(
Na
)
J
(
H
)
|
1
,
[
Na
]
|
1
ci
ti
п
according to the
standard
methods
[9] ).
for n = 3
pH нRH
M) l
R M ;H .
M ( pH
E Ш 10
and pа=а0.95.
о
K J ( Na
Jп K
( Na
) Jti( H ) |)1J, ([HNa); ] | 1
ci
E f ( pH )
Results and Discussion
нM ( pH
) 10 pH the
; integral potentiograms
Fig.
presents
*
оpH 1 pH
lg
J
,
K ti Jadsorbents
( Na ) J ( H investigated.
) Ш J ( Na ). These
ci
п Kcarbon
of the
curves have some1 / 2(n) inflection1 / points,
and the
lg J 0.5 I (1 3.29aI 2 ) bI .
J ( Na )potentiograms
J ( H ) | 1 , [ Na
| 1 accordingly,
differential
(Fig.а] 2),
show n peaks. Therefore, these experimental data
E i 1 E i
'E
dE
|
can be interpreted
within the law ,of mass action
dpH 'pH
pH i 1 pH i
for n types of RC:
E
f ( pH )
n
жK
i 1
K ci [ Na ]E oi
ci
[ Na ] M ( pH )
нM ( pH ) E Ш 10 pH ;
о
п K ci K ti J ( Na ) J ( H );
нM ( pH ) 10 pH ;
K K /M )
pHE1.20pfH(HpH
,
(8)
pHK M
pH *l
lgRJ , M H K RH
H /M
where Kci is exchange concentration constant for
RC of type i ; 1 / 2 1/ 2
RH
M
H
. ) bI .
lg
IR R(M
1M3.29
0.5l
J M lcapacity
HaIof type
Eoi RH
is exchange
of RC
i;
а+
[Na ]Eis equilibrium
concentration of Naа+ ions in
'E) E i 1 E i
dE f ( pH
RH M
| l R M H .
,
solution,
mmol/mL;
dpH 'pH
pH i 1 pH i
?( pH)pH is pH
a * parameter determined by a
E f ( pH ) lg J ,
neutralization model
chosen for study. In
n
K ci [ Na ]E oi
(
)
,
E
f
pH
approximation
2 DEL model
1 / 2 (see
lg J *0.5 Iof1 / ж
(
1
3
29aI
bI equation
.)
] M)(pH
K
pH pH lg J i, 1 ci [.Na
(5)):
E i;1 E
dE ) '1E/E2 Ш 10 pH
lg JнM ( pH
0|.5 I
(1 3.29
aI 1 /i2 ) , bI .
оdpH 'pH pH i 1 pH i
п K ci K ti J ( Na ) J ( H );
(9)
E i 1 E i
dE K 'Eis thermodynamic
where
| ti
n
K ci [ Na, ]E oiequilibrium
pH
нEM ( pH
dpH
) 10
;i 1 pH
) pH
,
f'(pH
pH
i
ж
constant;
о
)
i 1 K ci [ Na ] M ( pH
K ci K ti Jа+( Na ) J ( H ) Ш J ( Na ).
?(Naа+п) and
?(H ) are coefficients of activity for
n
K ci [ Na ]E oi
а+
а+
NaEandf H
ions,
respectively.
pH
)
pH
ж
нM ((pH
)
E
10
; ] M ( pH ) ,
Ш
[
K
Na
i 1 )
JIn
(
Na
)
J
(
H
|
1
,
[ Namodel
] | 1(see equation
ci
о approximation of MI
п K ci K ti J ( Na ) J ( H );
(4)):
нM ( pH ) E Ш 10 pH ;
о нM ( pH ) 10 pH ;
(10)
п Kоci K ti J ( Na ) J ( H ); п K ci K ti J ( Na ) J ( H ) Ш J ( Na ).
нM ( pH
10 pHof
; DEL model, the values of
Within
the) scope
о J ( Na ) J ( H ) | 1 , [Na ] | 1
Na ) J ( Hassuming
) Ш J ( Na the
). following
pKпti K
and
ci EoiKare
ti J (calculated
simplifications:
a) J ( Na ) J ( H ) | 1 , [ Na ] | 1;
b) overlaps of RC neutralization processes can be
neglected.
E oi
н
░ E f ( pH ) | K ci [ Na ]
K ci [ Na ] M ( pH )
░
░ н0, i 1
о ░ i 1
(11)
░ о E , i 2, 3, n
ж
oij
░ ░? j 1
░ pH П [ pH ; pH ]
i
i 1
п
? 328 ?
pH П [ pH i 1 ; pH i ] [ pH i 1 ; pH i 2 ]
E
f ( pH )
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Alexey N. Lukianov, Olga N. Kononova and Sergey V. Kachin. Calculation of Protolytic Equilibria Parameters on?
E (Na+), 1,8
mmol/g
1,6
LKAU-7
1
LKAU-2
2
н
E E oi
н н E░ E f ( pH
f ( pH
K[ Na
ci[ Na
|) K|[ Na
)K
] ] E oi oi
ci
|
E
f
(
pH
)
]
░
M
K
[
Na
]
(
pH
)
ci
░
ci
E
M
K
[
Na
]
(
pH
)
н
E]oi M ( pH )
н ░ ░
oi
ci
1,2 ░ E f ( pH )BAU
| K ci [ Na ]
) | K ci [ Na ] K ci [ Na
░
░ E ░f (нpH
K ci [ Na ]░ M░н(0оpH
)0, i 1
K ci [ Na ] M (4pH )
░
░о о ,н░i0i ,░1ii11 1
░
i
1
о
░
1,0 ░ н0, i 1
░░░он0,оi ж
E , i 32,,
3, n
о ░ i 1
E░?oij1jE1,oiji ,oiji 2, 32,,
n n
░1 ж
о ░░ж
i ░?
░?
░
j
1
░ о
░░о j░1pH
, i[ pH
2,i ;3,pH
]ni 1 ]
0,8 ░ ░?ж E oij , i 2, 3, n
ж
oij
░ pH
п [EПpH
[ПpH
i ; pH
i 1
п░?pH
j 1
jП
1
i ; pH
i 1 ]
2 ░
п
░ pH П [ pH ; pH ]
░ pH П [ pH ; pH ]
i
i
1
i
i 1
п
0,6 п
pH [ПpH
[ pH;i pH
[ pH;i pH
1 ; pH
i ][
1 ; pH i] 2 ]
i
1
i ][
1
pHpH
П [ПpH
;
pH
pHpH
i 1
i]
i 1 ;i pH
i 2 i] 2
0,4 pH П [ pH i 1 ; pH i ] [ pH i 1 ; pH i 2 ]pH П [ pH i 1 ; pH i ] [ pH i 1 ; pH i 2 ]
3
E ( pH
f ( pH
)
E E f ( fpH
) )
0,2
4
E f (3pH )
E f ( pH )
[ pH
pH [ПpH
i ; pH i 1 ]
i ; pH ]i 1 ]
0,0
; pH
pHpH
П [ПpH
1,4
AUIS
pH
2 П [ pH i ; pH i 4
1 ]
i
i 1
6 pH П [ pH i ;8pH i 1 ]
10
12
D(i1 (1D D
lg(
н pK ti pHpH
i ))
D
lg(
))
pK
н
D i (i1 D i ))i
н pK
░ ti pH E lg(
pH
( pH
) (EpH
( pH i ) .
░ ░о tiоD E|(EpH
)lg(
Ei(EpH
)D
н pK ti pH lg(D i (1 D i ))
(1 i )Di i))). .
ноDpKD|ti░i |i pH(pH
░
()pH
)E(EpH
( pH )
░░ ░i п 2E?E( BAU;
(EpH
)i?E(1LKAU-7;
) E (adsorbents.
pH i ) . 1 ? LKAU-2;
pH
Fig. 1. Integral potentiograms
carbon
i
3
1E
(pH
pHi )i ) i )4. i ? AUIS
оD | E (ofpH
i 1 )
поDп | E ( pH
i
░п
░п i E ( pH i 1 ) E ( pH i )
E ( pH i 1 ) E ( pH i )
E oi
н
Jcalculation
)
( pH
) | K i+1[ Na
] pointsof i and (i ( Na
( Na
where
are the
+ 1)
this
is unachievable, since well░ E fpH
i and pHci
J
( JNa
) )
M
K
[
Na
]
(
pH
)
ci
░
J ( Na ) potentiogram (Fig. 2).
minima
substantiated
theory of activity coefficients is not
J ( Na )
░ н0, i ofн1 the differential
pK ci yet [10]. That is why the pK values are
E oi E oi
н1 should
о ░ iIt
[ Na the
pK
|
E
f
(
pH
)
K
]
be
noted
that
simplifying
developed
ci
pK ci ci
K ci [ Naci ]
E M ( pH
░ о ░ EE
н ░ f, i( pH2,)3|, K ci[ ]Na
)
nK [ Na K]ci [ Na
Moi (] pH
) oij
░ (b)
E
f ( pHpK
)|
pK
assumption
is
verified
after
processing
calculated
assuming
(a)
and
(b)
as
well
as
░
ci
░ ░?ж
ci
░
ci
j 1
K ci [ Na ] M ( pH )
░ ░н0░о, i н01, i 1
H ) Ш J( Na
░
J
(
Na
)
J
(
)
|
const
,
pH [ПpH
[ pH
i ; pH ]i 1 ]
( Na) J) ( JH( H) Ш J) (Ш JNa
( Na) |) const
| const
, pH
experimental
since the exchange c)
;░ pH
i ; pH
i 1results,
J ( JNa
, pH
П [ПpH
i 1 ]
п pH оП [░░pH
i ; pH
i 1 ]i 1
i 1 i0, i
1
н
о
░
E
н
E
,
i
2
,
3
,
n
о
░
oi
о
ж
oij
J
(
Na
)
J
(
H
)
Ш
J
(
Na
)
|
const
,
pH
П
[
pH
;
pH
]
░ iE1 Efor
capacity ж
value
in the
3,of
) in|type
J ( Na ) J (i H ) iШJ1 (.Na ) | const , pH П [ pH i ; pH i 1 ]
f2(, pH
K ci [ Na
] interval
░j 1, i RC
░ ░░?░j о1 ░?oij
f ( pH
K ci [ Nanot
] M ( pH
)E f ( pH
E oij ], i [ pH
2, 3, n
ж
░
) ) scope of MI model, the curve
░
pH П░[ pH
;
pH
;
pH
]
does
E E Within
f ( pH ) the
░?ipH
░ пП
1j 1 П [i pH i ; pHi i11 ]
i2
pH
[
pH
;
pH
]
i
i
1
п
░ нE0, i f 1( pH )
E f ( pH ) is approximated on each interval
exceed ░п0.03?0.04
pH По[ pH
pH i 1 ] i.e. these values
░ i i 1;mmol/g,
pH [ПpH
[ pH
i ; pH ]i 1 ]
о
░
E comparable
f ( pHpH
) П [ pH
E oij the
,i ]
2error
, 3, nof; pH
i ; pH
pHpH
П [ПpH
are
with
capacity
i ; pH
i 1 ]i 1by the following expression:
i 1 ; ]pH
i pH [ pH
i 1
i2 ]
pH П [ pH
pH
[
;
pH
]
░ i 1░?;ж
i 1
i2
j 1 i
pH
П
pH
pH
[
;
]
pH
П
pH
pH
[
;
i
i
1
determination.
i
i 1 ]
pH П [░pH
[ pH i]1 ; pH i 2 ]
1 ; [pH
pHi П
pHi i];pH
(13)
lg E pK
pK ci pHpH
lg(D (1 D )). i 1
п
E
lg(
lg
; pH 1 ] )with the equation (11), the lg E pK ci ci pH lg(
pH ПIn[ pH
D i D(i1 (i1Di D)).i )).i
E
E accordance
fi ( pHf ()i pH
pK ci pH lg(D
D i )). lg E The
pKequilibrium
pH lg(constants
D i (1 D i values,
)).
ci
pHlg
)E
curve E f (pH
oni (1each
obtained
П
[ is
pH iapproximated
m
z
1
1 ; pH i ] [ pH i 1 ; pH i 2 ]
m
z
1
D
D
lg(
(
1
))
pK
pH
н
m
z
1
i i ; pH i i1 ] by the following
П [;pH
interval
by statistical processing of experimental data
[ pH
pH
░ tipHEП(pH
i 1 ]
)pH
( zpH
pH
i E
.
m
1
i)]
m z 1 0 to (12) and (13), are presented in Table
о
[
;
pH
П
pH
dependencies:
according
D |
i
i 1
'0GT
░п i E ( pH i E1 ) Ef (( pH
0G
pH i))
T
'G'
lg((1Di D(1))
D i ))
2.
ItT can
be seen from Table 2 that the standard
ti
lg(0 D
pH
н pK н░ti pKpH
i
i
0
'
G
░ н pK
'
G
(
)
(
)
E
pH
E
pH
T
T
lg(
pH
i .i )) .
(12) deviation
( pH
) D
E (DpH
S for the constants
calculated
within MI
i i1
n
n
П) [pH
о оD tiE|pH
i ; pH
i 1 ]
n
n
0
)
(
)
EE((pH
E
pH
J ( Na░D)░оi |░п Ei ( pH
0G | 2.3nRT ж pK En
)
(
)
pH
E
pH
.
'
E
i
0
ж
i
1
i
Ti oi ж E based
oi
model
for
constants
on DEL
.3RT
i 1 ) E ( pH i )
жpKipK
п Di |
Ti E
oi ж E oi oi
'G'TG|T is2|T.higher
32RT
жn than
n
Ti
1 E oi
n i 1i 1
░п
i 1
E ( pH i 01 ) E ( pH in)
0
i
i
1
1
it Tican
that DEL
We haveн pK
used
model
'GT the
| 2.3MI
RT
pK
E oi model.
'GT | 2Therefore,
.3RT ж pK
E oi beжconcluded
E oi
lg(Dж
(1 TiDEonly
)) жfor
pH
oi
pK
░ ) ti E ( pH ) Ei i(1 pH ) i
i 1
i 1
i 1
( Na
J
model
fits
the
experimental
data
better.
Moreover,
the ci calculation
of
concentration
equilibrium
.
J ( Na ) оD |
i
no
f
no
no
ff
J ( Na
░п) i the
E ( pH
it is likely that the sodium ions are mainly fixed in
constants,
because
thermodynamic
i 1 ) E ( pH i ) constant
of
J ( NapK
) JpK
( Hci ) Ш Jn( Na
) | const , pH П [ pH i ; pH i 1n] o f
f
x
a surface layer.fIndeed,
the
of countercan not
f
x migration
cibe calculated without the coefficients
x 10
[ Na
10
[ Na
] ] * * f * ( x)dx,
10
[
Na
]
E
f
(
pH
)
pK ci
│
E
f
(
pH
)
f( x)(dx
x),dx,
x
E
f
(
pH
)
f
│
of activity J ( Na ) in sorbent
phase.
But ions can be discouraged
x xby
the
f
Na
( pH
(MpH
f
│ 10
xf10
[[Na
[ Na
]M(]]following
)* ) factors:
MpH
10 x [ Na ]
*
f1010
[
Na
]
)
E f ( pHJ)( Na ) EJ ( Hf()pH
f
)
f
(
x
)
dx
,
Ш J ()Na
) | const
П [;pH
E? i ; pH
f ( pH
f ( x)dx,
i 1 ])
J ( Na ) J ( H ) Ш J ( Na
| │const
pH, ]ПpH
[M
pH
│ x ?pH
i )
i 1 ]
10 x [, Na
( 329
pH
J ( Na pK
) J ( H ) Ш J ( Na ) f| const , pH П [ pH i ; pHxi 1 ] pK f10 [ Na ] M ( pH )
ci
c
x x pKpK
pH П [ pHEi ; pH
c c
i pH
1] )
f
(
E f ( pH ) x pK
x pK c
c
E f (J pH
)
*
( Na ) J ( H ) Ш J ( Na ) | const , pH П*[f pH
* f ;( x
pH
) i 1 ]
lg(
D i (1] D i )).
lg E pK cipH ПpH
f ( x)( xi )
pH
pH
[
;
pH П [ pH ; pHi ] i 1
? 330 ?
0,0
0,2
0,4
0,6
0,8
1,0
1,2
1,4
2
1
4
2
6
LKAU-2
LKAU-7
8
10
1
pH
12
dE/dpH
0,0
0,2
0,4
0,6
0,8
1,0
1,2
1,4
1,6
2
4
4
Fig. 2. Differential potentiograms of carbon adsorbents. 1 ? LKAU-7; 2 ? LKAU-2; 3 ? AUIS; 4 ? BAU
dE/dpH
1,6
BAU
AUIS
6
3
8
10
12
pH
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Alexey N. Lukianov, Olga N. Kononova and Sergey V. Kachin. Calculation of Protolytic Equilibria Parameters on?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
E oi
н
з x 4 x░3 E╖ f ( pH ) | K ci [ Na ]
K ci [ Na ] M ( pH )
╕
и
░
иx x ╕
й 3 Calculation
░2 ╣ aq
Alexey N. Lukianov, Olga N. Kononova and Sergey V. Kachin.
Equilibria Parameters on?
0, i of Protolytic
1
о н░ i 1
░ он E , i 2, 3, n
E oi
oij
ззpK
╖
ззxx4 xx3equilibria
xx4on
:x(3 x╖╖, x ) of carbon
░?░ж
░ adsorbents
E
f ( pH
) | K ci [ Na ]
Table 2. Parameters of protolytic
investigated
j 1
j aq
и
ии 4
3 ╕╖
4aqaxsurface
3 ╕i
╕
и
╕
╕
и
ииx x ╕╕
M
K
[
Na
]
(
pH
)
░
ci
E
н
x
x
░ П [ pH ; pH ]
oi
pH
йй x33 x22 ╣╣s йий x33 x22 ╣╕╣aq
s
aq
░ E пf ( ░pHн)0|, iKici1[ Nai 1]
Gibbs energy
M0 ( pH )
K
[
Na
]
ci
о
░
DEL
model
MI
model
?
G
(kJ/mol)
)
E
E
S
pK
░
Total ( ж oi )
ж oi ░
298
Ti i 1
i
i
, i ░П
1 [оpH
calculated
by
E1oij; pH
, i i ]2
, 3[,pH
ni 1 ; pH
н0pH
pK
ж
i
i2 ]
aq ::((xxi ,,xxj ))aq
о
pK
░ i 1 ░ ░? j 1
i
j aq
RC E0 for RCaq concentration
░ о E░ , i 2, 3, n
Trade
(total
oijpH П [ pH ; pH
type of i type,
░ ░?ж
i
i 1 ]
name
j 1 п
E
f
(
pH
)
(i)
(mmol/g)
Dispersion
Dispersion
)
E
E
S
pK
░
(
)
ж
Eoioi ж
Eoioi S )
pKTTi i п pH П2[ pH i ; pH
pKai i1 ]
MPE
RA
ж
ж
i
i
S2
S
i
i
pH П [ pH i 1 ; pH i ] [ pH i 1 ; pH i 2 ]
concentration)
pH П [ pH i ; pH i 1 ]
(mmol/m 2)
pH П [ pH i 1 ; pH i ] [ pH i 1 ; pH i 2 ]
1
0.90
4.91
0.01 E f 5.31
0.30
( pH )
1.80
D
lg(
(1 D i ))+41.77 +42.64
pK
pH
н
LKAU-2
2
0.64
8.99
0.04
8.88
i0.08
E f░( pHti )
(3.0?10 -3)
(
)
(
E
pH
E
pH
.
i)
оD | 11.42
3
0.26
11.64
<0.01
pH i ; pH 0.01
i 1 ]
░п i pHEП( [pH
( pH i )
1
0.40
3.74
0.01
4.59i 1 ) E0.04
pH П [ pH i ; pH i 1 ]
2
0.45
7.15
0.02
7.37
0.04
1.40
pH lg(D i (1 D+41.75
н pK
LKAU-7
+41.39
i ))
-3
ti
(2.0?10
)
░
J ( Na ) 8.95
3
0.31
9.01
<0.01
0.04
(
)
(
)
E
pH
E
pH
.
D
D
lg(
(
1
))
i
н pK ti оpH
i
i
i |11.37
4
0.24
11.50 ░ 0.70E░D
( pH
)1.08
(EpH
оD | п( pH ) E
i 1i ) E .( pH i )
1
1.06
7.16 ░ i <0.01
pK
1.35
) E ( pH 0.10
E (cipH i 17.63
i)
п
AUIS
+45.55 +47.13
ззxx3 xx2 ╖╖
иии 3
2╕
╕╕
йий xx22 xx11 ╣╕╣s
s
2
BAU
0.29
1
0.90
2
0.20
3
0.37
ззx 3 xx2 ╖╖
ии x 43
23 ╕ .
╕╕ .
и
йи xx22 xx11 ╣╕aq
2 ╣ saq
й 3
(3.2?10 -3)
11.06
0.90
10.97
1.05
1.47
(2.8?10 -3)
10.35
?
10.30
?
J ( Na )
5.41
0.10
( Na ) J5.87
J
( H ) Ш J (0.21
Na ) | const , pH П [ pH i ; pH i 1 ]
J ( Na )
pK ci
11.40
0.03
11.30
pK ci E f ( pH )
hydrophobic surface of carbon adsorbents;
effect of RC electrostatic field at low surface
concentration (see Table 2);
? steric impediments.
It should be noted that, on the one hand,
in some cases the S 2 values are expressed by
relatively large magnitudes: 0.70 and 0.90 for
weak acidic RC (pK ~ 11?12) of LKAU-7 and
AUIS, respectively (Table 2). On the other hand,
the pK values calculated according to the equation
(12), decrease in these cases with the increase
in the neutralization degree ? (Fig. 3). That can
be caused by electrostatic interaction between
the reaction centers or by exhibition of sorbents
inhomogeneity effect [11].
Aiming to express the experimental data
more adequately, we have used the Henderson?s
equation (3) with m ? 1 here. For LKAU-7 we
have determined mа=а0.113; pKa = 11.34 and for
AUIS m = 0.145; pKa = 11.38 ( S 2 values do not
exceed 0.01 in this case).
?
?
+43.26
+43.40
0.09
J ( Na ) J ( H ) Ш J ( Na ) | const , pH П [ pH i ; pH i 1 ]
pH
[ pH
J ( Na ) JП( H
) iШ;JpH
( Nai 1 ]) | const , pH П [ pH i ; pH i 1 ]
The data obtained allow to calculate
E f ( pH )
somelgthermodynamic
characteristics
E ) pK ci pH lg(
D i (1 D i )). of the
E f ( pH
equilibria investigated, in particular, the Gibbs
pH П [ pH i ; pH i 1 ] 0
energy
?GT . Within the DEL
zof1 ineutralization
pH Пm[ pH
; pH i 1 ]
model, the Gibbs energy can be calculated as a
E pK ci pH lg(D i (1 D i )).
lg
0
sum
partial
values
of partial energy
'G
pK
pH
lg(D(method
lg E of
T ci
i (1 D i )).
? MPE) [12]:
m z1
n
n
m z1 0
(14)
'GT | 2.3RT ж pK Ti E oi ж E oi i 1
i 1
'GT0
0
'Gusing
or
the
model
of
inhomogeneous
sorbents
T
n o f approximation
(Roginskiy?s
? RA) [13].
n
n
0
n 2.3RT
n E
'
G
|
pK
E[7],
ж
ж
T
Tisorbents
oi
oi
inhomogeneous
the
0 For
'GT | 2.3RT ж pKfTi Eioi1 ж xE oi i 1
10
[
Na
]
*
i
i
1
1
potentiogram
expression
E f ( pHis) approximated
f ( x)dx,
│ x [ Na ]by Mthe
( pHat) n ? ?
f10
obtainednby
means
of
a
limiting
process
of
no
f
in
equation
(8):
x pK c
f
x
10
[ Na ]
E f f
( pH ) 10 │ x [ Na
f * ( x)dx,
]
x
f * ( x ) dx, (15)
E f ( pH ) │ x f10
[
Na
]
(
pH
)
M
f * ( x) f10 [ Na ] M ( pH )
where x pK c , f * ( x) is the differential
x pK c [ Na of
] |the
1 RC distribution in equilibrium
function
constants
f *K( xc).
f * ( x)
J ( Na ) J ( H ) | 1
? 331 ?
[ Na ] | 1
[ Na ] | 1
J ( Na ) JJ((Na
H )) |J1( H ) | 1
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
E
f ( pH )
E
pH П [ pH i ; pH i 1 ]
f ( pH )
Alexey N. Lukianov, Olga N. Kononova
Kachin.
pHand
ПSergey
[ pH ;V.pH
] Calculation of Protolytic Equilibria Parameters on?
lg E pK ci
pK
m z1
13,0 lg E pK ci
1
pH lg(D i (1 D i )).
LKAU-7
'G | 2.3RT ж pK Ti E oi
i 1
nof
f ( pH )
x
10 [ Na ]
f ( x)
[ Na ] | 1
nof
f
│ 10 x [ Na ] 10,5
M ( pH )
E
*
( x)dx,
f ( pH )
10,0
pK c
│ 10 xT
f
f
10 xT
E f ( pH ) │ x
f * ( xT )dxT ,
pH T
xT pK Tf
xTT 10
ж E oi
10
f
10
n
n
*
i 1
11,5
E Ef ( pH ) E │ x
'GT0 | 2.3RT ж pK
ж oif10 T 10 pH f T ( xT )dxT ,
Ti oi
i 1
* i 1
) T
xfT ( xTpK
f
*
f ( pH )
n
11,0
f
10 xT
f * ( xT )dxT ,
pH T
10
AUIS f
E
0
12,0 'GT 2
n
0
T
x
i 1
12,5 m z 1
'GT0
E
i
pH lg(D i (1 D i )).
0,0
x pK0,2
c
xT
pK T
*
зf TdE
( x(TpH
) )╖
╕╕
ии
# f T* ( xT ),
* йx dpH
f
╣
( xT )[ Na ] pH *xT
f T10
f ( x)dx,
│ 10 x [ Naз dE] ( MpH( pH
)╖)
f
╕╕
ии
# f T* ( xT ),
*
dpH
(
E
(
pH
))
|
)
╣
й
з dE ( pH ) ╖ pH pHxT xT * T ( xT ),
╕
и
#
f
(
x
0,4и 0,6 ╕ 0,8
1,0
T
T ),
й dpH ╣ pH x
( E*( pH )) pHfxT *|D
) * ( x ),
) T ( xT ) │ f T ( xT )TdxTT.
*
f ( x)
*
Fig. 3. Dependence
pK = f(?).
? LKAU-7;
? AUIS
( E1( pH
))
|2 f)
( x ),
pH xT
In an approximation that [ Na ] | 1 and
J ( Na ) J ( H ) | 1, the following expression
takes place for DEL model:
T
*
T
wherexT xT pKpK
f T* ( xT ) is the differential
T T,
xT pK T
f
function of distribution
thermodynamic
T
10 xxin
E * *f ( pH ) f
10 T pH f T** ( xT )dxT ,
│
x
(
)
f
x
constants
K
.
T
ET f TfT((xpH
f ( xT )dxT ,
TT ) )
│f10 xT 10 pH T
f T* ( xT )
10
f10
According to Roginskiy?s
approximation:
╖
зxTdE
( pH
pK
з dE
( pH
* *
T) ) ╖
(17)
ииxT( иpHpK
xT ),
з dE
) ╖ T ╕╕ ╕╕ #* f#T (fxT T(),
и
╕╕ ╣ pH╣ pH
ии й йdpH
dpH
#
f
(
x
),
T
xT xTT
╣ pH xT are replaced (pHа=аX T), the
й dpH
* coordinates
when
(
)
fthe
x
*
f TT ( xTT )
differential
potentiogram
into the
(E( E
pH
)) pH)) pH
)|*)(isx* transformed
( pH
(),
x ),
xT x|
T* T TT T
(
E
(
pH
))
|
)
(
x
),
curveз dE
of (differential
function, and
pH )x╖
Tdistribution
T
T
pH
*
зии dE ( pH ) ╖╕╕
#
f
(
x
),
*
T
T
the integral
is transformed
╕╕╣f f # f Tin( xturn,
иий dpHpotentiogram,
T ),
pH *xT *
* dpH
( xT* T()xf
f
(
x
)
dx
.
)╣│pH
f
(
x
)
dx
.
x
T)
T
T
T
T
to the*й)integral
function:
T distribution
T
T
T
) T ( xT ) │ fTf* (x│fT )dxT .
f
(18)
( E ( pH )) pH xT | ) **T ( xT ), ( E ( pH )) pH xT f
|)
( xT ),
fT
0 0
*
f
) E .
2RT
.3RT
where'0G'T GT (2.3(f
│ xT xf T (fxT*T()xdx
T )Tdx T ) f E f .
'GT * (2.3RTf│ x*Tf fT│f* ( xT )dxT ) E f .
) T* ( xT ) │ ff T* ( xT )dxT .
(19)
) T ( xT ) │f f T ( xT )dxT . T
T
*
Tf T
f
f
J ( Na ) J ( H ) | 1
xT xT
f f
10 10
E E f ( pH
f T* (fxT*T()xdx
,
)f ) │ │10 x xTx pH* pH
f ( pH
T )Tdx T ,
T T
(16)
10
E f ( pH ) │ f10
f
(
x
)
dx
,
10
10
T
T
T
f
xT
10 pH
f10
f
) ( xT ) │ f ( x )dxT .
f
*
f
'G 0 (2.3RT
│ xTT . f T ( xT )dxT ) E f . (20)
) ( xT ) T │ f T* ( xT )dx
*
T
f
This0 formula is
an integral analog of the
'
(2.3RT │ xT f T* ( xT )dxT ) E f .
fGT
equation (14).
f
*
( x T )xdxTf f* ( x )dx ) E .
│ x(T2.f3TRT
'GT0 Since
│ T T T T f
f
f
f
│x
f
f
f
*
│ xT )f ((xxTT))dxT │ ) T ( xT )dxT ,
f
*
T T
**
TT
f
f
f ( x T )dxT
f
f
f
xT ) T* ( x T ) │ ) T* ( xT pH
)dxT ,
(21)
f
f
f
╖
f RT з f
0
*
*
и
'G | 2.3 │ )pH
T ,using
E ( pH
)dpH ╕
(
x
dx
fTE)f
│
T ) T (Tx T ) equation
T
thexfollowing
is
derived
expressions
╕
f E и
f
pH 0
fй
╣
(18), (20) and (21): з
pH f
╖
RT
и pH f E f E ( pH )dpH ╕
'GT0 | 2.3
│
0
и
╕
pH f
╖
'G 298 RT з E f й
pH 0
╣
0
и
╕
(22)
'GT | 2.3
pH f E f │ E ( pH )dpH
╕
E f ий
pH 0
╣
0
'G 298
whereRE ? is saturation exchange capacity of the R
0
'G 298
sorbent,
mmol/g;
COOH
OH
pH? isRsaturation pH value;
R
pH
the point of zero capacity (E(pH0)а?а0).R
R0 ispK
a ( pK ) aq b
COOH
OH
s
Gibbs
energy values of neutralization,
OH at T = 298 K according to theCOOH
calculated
formulas
pK
) зaqby
bMPE
з
x
xa2 (╖pK
x3 x 2 ╖ and RA methods,
(14) иand3s (22),
i.e.
╕╕ .
ии
и x x ╕╕
xagreement
2( pK1) ╣ s in
2 x1 ╣ aq with each other
й
й
pK
a
b
are
satisfactorily
f f
s
aq
f
* *
f
╖
з x 3 for
xT│* xf Tenergy
(fxT T()xdx
з x2),
x 2 about
x 2 ╖account
)TdxTan inhomogeneous sorbent (Table
Gibbs
│
T for
╕╕ . (40?50) kJ/mol
╕╕
ии
ии 3 and
xTf fT0f( x T )dxT f
│
*
f
x
x
x
x
'
G
(
2
.
3
RT
x
f
(
x
)
dx
)
E
.
╖+-form of the carbon
з
╖
з
2 ╖ xNa
1 ╣
is calculated
from the following formula:
for
з╣ sx 3 й xx2(i.e.
з x 3different
й xx242 ╖ x13sorbents
f
и 4 ╕ .3 ╕ aq
╕
и ╕
'GTT0 *(2*.3RT f││ffxfTTff TT*f*( xTT* )dxTT ) E ff .
и
ии
╕
и
╕
и
╕
╕
и
xT )
,
xTT)( xTT(f)x T ) f │) T)( xTT()xdx
T )Tdx T ,
? 332 й?x 2 й x13 ╣s x 2 й╣ sx 2 й x13 ╣aqx 2 ╣ aq
xT ) T* ( x T ) f │ f) fT* (│fxT )dxT ,
f
з x 4 x3 ╖
з x 4 x3 ╖
f
f
╕
и
╕
и
*
f
╕
и
x3aq╖ :x(2xз╣i ,sxx j pK
)ийaqxx3 ╖ x 2 ╕╣ aq
T
││ xxTT ff TT* (( xxTT ))dx
й
з
x
x
pH
pH
dx
f
f
3
3
╖ ╖ и 4
Tз з
f 0 0
RTRT
╕
и 4
╕
pH f
╕ ╕ и
и pHE f E
иx x ╕
╕
'
f │ E│( E
pH
)dpH
fG'
G| 2|.32.3з и pH
( pH
)╖dpH
x
x
0 T T RT и fи и ff f
3
2
3
2
╣ aq
й
╣
й
╕
╕
╕
s
E fpH
E f fEf f * EpH( pH
'GT | 2.3*
)
dpH
pH
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Alexey N. Lukianov, Olga N. Kononova and Sergey V. Kachin. Calculation of Protolytic Equilibria Parameters on?
Table 3. Supposed composition of native analogs of carbon adsorbents*
Chemical formula
Trade name
a
(xi)aq value
OH
BAU
OH
OH
8.30
CH3
LKAU-2
OH
HO
COOH
HO
8.00
COOH
OH
12.56;
9.96
0.95
OCH3
8.0
HO
1.17
4.50
COH
OH
0.91
2.87
COH
10.27
OH
COOH
COH
9.45
LKAU-7
OH
4.41
OH
AUIS
COOH
1.00
COH
4.10
8.00
* pKTi values for RC of i type on a surface of sorbent, calculated in accordance with DEL model, were taken for
comparison
adsorbents is thermodynamically unstable). It
0
should be noted that ?G 298
values obtained are
apparent values and give estimation from below
for the true values of Gibbs energy, since the
presence of RC, neutralized at pH > 12 on the
surface of the sorbent is not excluded.
It is known [14] that the reaction centers,
existing on carbon adsorbent surface, are
protolytes and they can be viewed as phenolic
and carboxylic functional groups localized on a
system of condensed aromatic rings (the presence
of aldehyde or ether groups on a surface is also
possible). That is why we assume that the nature of
RC can be elucidated by comparison of acid-base
equilibrium constants for the reaction centers of
sorbent and for organic acids (native analogs) in
aqueous solution. These acids have the following
composition:
R
R
OH COOH (23)
where R is ?H, ?CH3, ?OCH3, ?OH, ?COOH,
?COH
? 333 ?
'GxTT ) T*((2x.3T RT
) │fxT│ f)T T*( x( xT T)dx
)dxT T) , E f .
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
f f
f
з x3 x 2 ╖
з x3 x 2 ╖
*
╕ .
и
╕╕
ии
x
f
(
x
)
dx
T
T
T
│ * RT з
pH f
x 2 x1 ╣ s ий x 2 x1 ╕╣ aq
╖
й
x f T Lukianov,
( x )dxTи Olga N. Kononova and Sergey V.
'│G N.
| 2.3T
pH f E f │ E ( pH )dpH ╕ Kachin. Calculation of Protolytic Equilibria Parameters on?
╕
E f fий f *
*
╣
xT ) T ( x T ) f │f) T ( xT )pHdx0 T ,
f
з x 4 x3 ╖
╖
x 4 four
x3 indexes
WexTcompared
accordance
are satisfied for the combinationзиof
) T* ( x T ) the
│fpK
) T*values
( xT )dxin
,
T
╕
и
╕
f
╕
и
f energy linear relation
x3 x 2 ╣ s ий x3 x 2 ╕╣ aq
0
with 'a Ghypothesis
of free
of equilibrium constants, and so on.
й
298
f
observance
[15], RT
i.e. зexistence of pH
linear
correlation
The search for combinations was carried out
╖
'GT0 | 2.3 RT из pH f E f pH│fE ( pH )dpH ╕╖
between 0 logarithms
of protolytic equilibrium as follows. Any two values of pK aq : ( xi , x j ) aq
'R
GT | 2.3 E f иий pH f E f pH│ 0E ( pH )dpH ╕╕╣ R
и
╕
E
constants on a sorbent
surface
were arbitrarily chosen from a table of acid
f й
pH 0 (pK s) and ╣ in
aqueous 0solution
(pKaq).
E oi S )
pK Ti
ж Eoi[16] жwith
COOH constants of organic compounds
'G 298 OH
i
i
0
If
compositions
(23).
The
other
values
were
'G 298
f
f T
f T0
Alexey
f T
pK s a ( pK ) aq b (24)
R
R
R
R
where a and b are constants for the given sorbent,
╖
з
╖
з x 3 xOH
x
x
COOH
2
2
╕╕ . for combination
ии 3is satisfied
╕╕
ии
the following
relation
COOH
OH
x
x
x
x
2
1
2
1 ╣ aq
╣s й
й
of three indexes of equilibrium constants (x1, x2,
pK
a ( pK ) b
x3): pK s a ( pK ) aq b
s
зaqx 4 x3 ╖
з x 4 x3 ╖
╕
и
╕
и
зий x3 x 2 ╖╕╣ s зий x 3 x 2 ╖╕╣ aq
(25)
изи x x ╕╖╕ . изи x x ╕╖╕
ийи x32 x21 ╕╣╕ s ийи x32 x21 ╕╣╕ aq .
x 2 x1 ╣ s й x 2 x1 ╣ aq
йpK
: ( xi , x j ) aq(25) and
aqexpression
The
з x 4 x3 ╖
з x 4 x3 ╖
и x ╕╖
из x x ╕╖
и x 4E x 3 ╕ Eзи xx 4 S
)x 3 ╕╕ pK T
(26)
иoi
ийж 3 oi 2 ╕╣ж
s
иi x x ╕ i йи x3 x 2 ╣╕ aq i
2 ╣s
2 ╣ aq
й 3
й 3
pK aq : ( xi , x j ) aq
pK aq : ( xi , x j ) aq
1.
2.
3.
4.
5.
6.
7.
8.
9.
calculated using relations (25) and (26) and were
compared with table data. We have considered only
those variants where the discordance with table
data was not more than 0.1 logarithmicаunits.
The structures of native analogs are given
in Table 3. The acid constants of compounds
corresponding to (23) are comparable with
values obtained for reaction centers of a surface
of a sorbent according to the hypothesis of free
energy linear relation. This can be considered
as an indirect confirmation of the assumption
[14], that carboxylic and phenolic groups are the
reaction centers of carbon adsorbents.
References
Goba
I.A.,
Tomashevskaya A.N. Chemical properties of different fossil coals
E oi S )
pK
ж Eoi V.E.,жTarkovskaya
Ti
i E
i E
)
S
pK
ж scope
ж
Ti
oi
oi
and
for their
use as sorbents.
Khimiya i tekhnologiya vody 1991. V. 13(4). P. 307 -309.
i
i
Kononova O.N., Kholmogorov A.G., Lukianov A.N., Kachin S.V., Pashkov G.L., Kononov Y.S.
Sorption of Zn (II), Cu (II), Fe (III) on carbon adsorbents from manganese sulfate solutions.
Carbon 2001. V. 39. P. 383-387.
Golovin G.S., Lesnikova E.V., Artyomova N.I., Lukicheva V.P. Ion exchange properties of cation
exchangers synthesized on the basis of brown coal from Kansk-Achinsk basin. Khimiya tverdogo
topliva 2000. V. 4. P. 30-35.
Kholmogorov A.G., Kononova O.N., Lukianov A.N., Pashkov G.L., Kononov Y.S., Kachin S.V.
Carbon adsorbents for purification of manganese (II) sulfate solutions . Khimiya tverdogo topliva
2000. V. 5. P. 55-59.
Saldadse K.M., Kopylova-Valova V.D. Complex-Forming Ion Exchangers. Moscow: Nauka, 1980.
P. 256-270.
Helfferich F. Ionenaustauscher. Moscow: Inostrannaya Literatura, 1962. P. 245-320.
Kholin Y.V. Function Able Materials. Book 2. Quantitative Physical-Chemical Analysis of
Equilibria on the Surface of Complex-Forming Silica Sorbents. Kharkov: Oko, 1997. P. 138-139.
Komar N.P. Chemical Metrology. Book 1.Homogeneous Ionic Equilibria. Kharkov: Vishcha
shkola, 1983. P. 208-230.
Pollard J.H. A Handbook of Numerical and Statistical Techniques. Cambridge: Cambridge
University Press, 1977. P.342.
? 334 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Alexey N. Lukianov, Olga N. Kononova and Sergey V. Kachin. Calculation of Protolytic Equilibria Parameters on?
10. Parfit G., Rogister K. Adsorption from Solutions on Solids Surface. Moscow: Mir, 1986. P. 230368.
11. Alekseev O.A., Ovcharenko F.D. Electrical Surface Phenomenon and Hydrophility of Dispersed
Systems. Kiev: Naukova Dumka, 1992. P. 153-172.
12. Stepanov N.F., Erlykina M.E., Filippov G.G. Methods of Linear Algebra in Physical Chemistry.
Moscow: Izdatelstvo MGU, 1976. P. 232-360.
13. Roginsky S.Z. Adsorption and Catalysis on Inhomogeneous Surfaces. Moscow: Izdatelstvo AN
SSSR, 1948. P. 353-455.
14. Tarkovskaya I.A. Oxidized Carbon. Kiev: Naukova Dumka, 1981. P. 165-198.
15. Advances in Chemistry. Series 244. Aquatic Chemistry, Interfacial and Interspecies Processes.
Washington : ASC, DC, 1995.
16. Temnikova T.I. Theoretical Principles of Organic Chemistry. Leningrad: GNTI Khimicheskoy
Literatury, 1962. P. 378-457.
? 335 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Journal of Siberian Federal University. Chemistry 4 (2008 1) 336-343
~~~
??? 547.9:661.183.2
Properties of Active Carbons Produced by Thermochemical
Transformation of Lignin, Brown Coal and Oil Slime Mixtures
Tatiana G. Shendrika, Valentina V. Siminovaa,
Nikolai V. Chesnokovb,c and Boris N. Kuznetsovb,c*
a
Institute of Physical-Organic and Coal Chemistry NAS,
70 R. Luxemburg st., Donetsk, 83114 Ukraine,
b
Institute of Chemistry and Chemical Technology SB RAS,
42 ?. ??rx st., Krasnoyarsk, 660049 Russia,
c
Siberian Federal University,
79 Svobodny, Krasnoyarsk, 660041 Russia 1
Received 24.11.2008, received in revised form 15.12.2008, accepted 22.12.2008
The yield and properties of active carbons (AC) produced by combined pyrolysis and activation of the
mixtures: hydrolytic lignin ? oil slime, brown coal ? oil slime and hydrolytic lignin ? brown coal ? oil
slime have been compared. The yield of AC from a triple mixture is lower than that from brown coal ?
oil slime, but higher than that of lignin ? oil slime mixtures. The reached yield (15-20 %) and surface
area (about 400 m2/g) of AC from triple mixture hydrolytic lignin ? oil slime ?brown coal are enough
for their industrial using.
Keywords: mixtures, hydrolytic lignin, brown coal, oil slime, pyrolysis, activation, active carbons,
yield, surface area.
Introduction
Increasing scale of using carbon sorbents
in technological processes and in environmental
protection stimulates the research in the field of
sorbents producing from cheap and available
natural raw material.
Cheap carbon sorbents can be obtained
by co-carbonization of different mixtures
of carbon-containing waste materials [1, 2].
Interaction of the mixture components in cocarbonization processes is exhibited through
non-additive changes in the product yield and
structural characteristics of the produced active
carbons.
*
1
In the process of hydrolytic lignin, and oil
slime carbonization, the oil slime can play the
role of binding and pore-forming agent. [3, 4].
The present paper compares the yield
and properties of active carbons, produced
by pyrolysis and activation of the mixtures:
hydrolytic lignin ? oil slime, brown coal ? oil
slime and hydrolytic lignin ? brown coal ? oil
slime.
Experimental
To produce AC the hydrolytic lignin (L) from
Krasnoyarsk Biochemical Plant (Russia) with the
following composition (%): Wa ? 3.6, Ad ? 1.8,
Corresponding author E-mail address: bnk@icct.ru
й Siberian Federal University. All rights reserved
? 336 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Tatiana G. Shendrik, Valentina V. Siminova,.. Properties of Active Carbons Produced by Thermochemical Transformation?
Vdaf ? 63.4, C ? 60.2, H ? 6.0, O ? 33.0, (S+N)
? 0.8; brown coal from Alexandryisky deposit
(Ukraine) with the composition (%): Wa ? 12.4,
Ad ? 11,7, Vdaf ? 57.6, C ? 70.4, H ? 6.0, O ? 17.8,
N ? 2.0, S ? 3.8 and oil slime (OS) i.e. waste of
cleaning cisterns at wash-curing station (?dessa),
being a aqueous emulsion of heavy oil fractions
with surface-active substance admixtures were
used .
The mixtures lignin ? oil slime, lignin
? brown coal, and lignin ? brown coal ? oil
slime were produced by mechanical mixing at
room temperature during 5 minutes without
the consequent forming. The oil slime content
was 20-50 wt. %, corresponding to the most
effective interaction between carbon-containing
components of the mixture [5].
Active carbons were produced in a vertical
reactor with a fixed layer under simultaneous
processes of pyrolysis and steam activation
according to the method described in paper [4].
The value of specific surface area (SBET, ?2/g)
was estimated with the use of low-temperature
argon desorption at ?Sorptomatic-1900? [6]. The
definition error SBET was ▒ 7 % rel.
The study of AC permolecular structure
was conducted by diffractometer DRON-1UM
(radiation CuK? , 4 ?V, 20 mA).
Results and Discussion
Earlier the thermal destruction peculiarities
of hydrolytic lignin (L) and oil slime (OS)
mixtures under different temperatures have
been studied under conditions of non-isothermic
heating, pyrolysis and steam gaseous activation
[4]. The interaction of lignin and oil slime
components was exhibited in non-additive
changes in the mixture functional composition,
displacement of the temperature interval of
thermal decomposition areas, increase in the rate
of thermal transformations in the maximum points
of thermal decomposition areas in comparison
with of the initial lignin and oil slime samples.
The changes in permolecular structure are evident
already on the stage of mixing hydrolytic lignin
with oil slime with the following progress under
thermal processing of the mixture.
In the present paper the yield and textural
characteristics of active carbons, produced by
pyrolysis and activation of lignin ? oil slime
mixtures, and hydrolytic lignin ? brown coal ?
oil slime mixtures were compared.
The effect of the mutual influence of
the components in lignin ? oil slime mixture
is exhibited in non-additive changes in the
carboneous materials yield and there textural
characteristics. The observed changes depend
on the activation temperature, which is the
most important in the interval of 800-900 ░?,
when the active carbon yield from the mixture
is approximately equivalent to the active carbon
yield from lignin (Fig. 1). Under these conditions
oil slime components are involved in a maximum
degree into the active carbon space lattice
formation. The specific area of active carbons
from the lignin ? oil slime (1:1) mixture is higher
than that of the active carbons produced from
lignin (Fig. 2).
Oil slime components taking part in active
carbon formation influence on the characteristics
of AC porous structure. The amount of
mesopores in AC from ligninа?аoil slime mixture
is considerably (up to 3 times) higher than that of
AC produced from lignin [4].
The differences in porous structure of
AC from lignin and ligninа ?а oil slime mixture
correspond to their peculiarities in their
permolecular structure, studied by X-ray
technique. The higher degree of AC space lattice
disorder in the presence of oil slime can be a
possible reason for the increased mesoporosity
of AC obtained from lignin ? oil slime mixture.
The increased amount of mesopores in AC
from lignin ? oil slime mixture after activation
? 337 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Tatiana G. Shendrik, Valentina V. Siminova,.. Properties of Active Carbons Produced by Thermochemical Transformation?
Fig. 1. The influence of activation temperature on yield of active carbons from lignin (1) and from lignin ? oil
slime mixture (2). Estimated yield of AC from lignin ? oil slime mixture
Fig. 2. The influence of activation temperature on the specific surface area of active carbons from lignin (1) and
lignin ? oil slime mixture (2)
under 800-900 ░? results in the higher adsorption
activity in methylene blue than that of AC
produced from lignin.
Thus, the co-activation of lignin with oil
slime makes it possible to produce AC with a
well developed BET surface area (? 800 ?2/?).
Probably, the interaction of lignin with the oil
slime components creates an additional number
of reactive centers, promoting the formation of
micro- and mesopores in AC during gasification
reactions. Functional groups of lignin containing
O, S, N atoms can be referred to these reactive
centers [7].
It is possible to suggest that to convert
oil slimes into AC effectively, the presence
of components with a high content of oxygen
functional group, being an intermediary product
of topochemical reactions during steam activation
is necessary [8].
In case of lignin ? oil slime mixture
activation, lignin, having a high amount of
oxygen (?daf 33.0 %), becomes a supplier of the
mentioned functional groups: methoxyl, carboxyl,
ether, carbonyls and others [7].
Thermochemical transformations of lignin
? oil slime mixture have been studied in the
? 338 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Tatiana G. Shendrik, Valentina V. Siminova,.. Properties of Active Carbons Produced by Thermochemical Transformation?
presence of another solid carbon substance ?
brown coal, which as well as lignin, has a high
content of oxygen functional groups (?daf 17.8 %).
But coal is more thermostable and it has stronger
rigidity of a carbon framework due to the presence
of condensed 2-3 ringed arenes and larger number
of three dimensional linkages between structural
elements [9].
Table 1 compares the yield and specific
surface area for ACs, produced from brown coal
and brown coal ? oil slime mixture.
In case of brown coal, the largest surface
area development is registered after 15 minute
activation, while in case of lignin activation, only
after 30 minutes [4]. The maximum of surface
area (290 ?2/?) of AC from brown coal is several
times lower than that of AC produced from lignin
(650 m2/g according to [4]).
Let us compare AC yield from the mixture
of brown coal and oil slime (Tableа1) with the AC
yield from brown coal. Taking into account the
low AC yield from oil-slime, the estimated AC
yield from brown coal ? oil slime is two times
lower than of experimental yield. Thus, nonadditive effect based on oil slime participation
in AC structure formation while brown coal ?
oil slime mixture activation is observed.
The value of specific surface area of AC
produced from brown coal is not high (Tableа1)
and reaches 290 m 2/g. Activated carbons from
brown coal ? oil slime mixture have less
developed surface (230 m 2/g), which is much
lower the surface values for AC produced from
lignin ? oil slime mixtures.
We can suppose that the observed differences
are the consequence of structural peculiarities of
lignin and coals.
Lignin
consists
of
low-branched
phenylpropane chains, aggregated into a threedimensional framework with easily destructed
intermolecular bonds [7]. Because of this, lignin
structure acquires a high conformation mobility
and can easier transform under the action of oil
slime components both during mixing and under
conditions of AC framework formation during
activation.
Brown coals structural elements have
lower conformation mobility, are more densely
packed, resulting in a less porous structure of
the produced AC. Besides, the composition of
oxygen functional groups for brown coal and
lignin is qualitatively different [7, 9], thus making
influence on the interaction of brown coal and
lignin with oil slime during activation.
The behavior of triple mixture lignin ? brown
coal ? oil slime (1:1:1) was compared in the aspect
of estimation of mutual influence of mixture solid
components on AC formation. AC yield from a
triple mixture is lower than that from brown coal
? oil slime, but higher than that of lignin ? oil
slime mixture.
This result shows the lack of mutual influence
of lignin and brown coal in the mixture during
activation process. For a triple mixture under
the conditions of a one-stage activation process
the high AC yield, typical for brown coal ? oil
slime mixture was not reached. Nevertheless, it
is possible to produce AC with the surface area
about 400 m2/g (Fig. 3) and yield of 15-20 % from
a triple mixture. It is necessary to stress that the
reached yield and surface area values are enough
for the industrial use of AC produced from the
studied carbon-containing waste.
The comparison of lignin and ligninа ?а oil
slime samples microstructure before and after
their thermal activation was made (Fig. 4). The
microstructure of the initial hydrolytic lignin was
presented in fragments of lignified walls of cells,
observed from different cuts ? horizontal, vertical
an diagonal, cell cavity being empty.
In the cross cut the pore diameter is from 5
to 20 mkm, cell wall thickness is from 2 to 10
mkm, the inner cell wall surface is characterized
by the presence of ultrathin pyritization and
? 339 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Tatiana G. Shendrik, Valentina V. Siminova,.. Properties of Active Carbons Produced by Thermochemical Transformation?
Table 1. Yield and specific surface area of active carbons produced by one-stage activation of brown coal and
brown coal ? oil slime mixture
Activation temperature, ??
Activation time,
min.
AC yield,
wt. %
Specific surface area,
m 2/g
170
Brown coal
600
15
39.8
650
15
36.2
210
700
15
33.0
220
750
15
28.6
270
800
15
22.8
290
850
15
20.9
290
900
15
17.1
280
800
0
32.1
120
800
10
27.3
230
800
15
22.8
290
800
30
18.5
280
800
45
16.1
270
60
15.7
260
800
Brown coal ? oil slime mixture (1:1)
800
0
32.0
100
800
10
26.8
210
800
15
23.7
225
800
30
23.0
220
800
45
18.1
220
800
60
16.3
220
pyrite single crystals 2-3 mkm. Lignin color in
different cuts is dark brown, dark grey, black.
Lignin reflection indices are 0.26 ? 0.37%, mean
value is 0.30%.
Under a microscope observation ligninа?аoil
slime mixture looks in a different way in
comparison with pure lignin: cell walls are thicker
with occluded cell cavities. Some cell cavities are
occluded with a dark substance (oil slime), while
lignin in a sample has a higher reflection index R
(0.38 %).
Lignin in the lignin ? oil slime mixture,
heated at 240 ░? during 3 hours is characterized
by irregular changes in microstructure and a
wide range of R values in different fragment
points. About 50 % of lignin is characterized
by R values from ?? 0.27 up to 0.60 %, the
rest values are up to 1.70 %, single fragments?
1.9-2.00 %.
With increasing R index the peculiarities
of lignin microstructure become more evident:
differences in color gradations disappear;
aggregations of fine-fragmented lignin gets
a denser structure with pores of irregular
shape taking place of cavities between lignin
fragments containing some bitumen inclusions.
In some areas the thermolignin homogenous
structure replaces fine-fragmented lignin
aggregations.
Ligninа ?а oil slime mixture, thermolyzed
at 400 ░? during 3 hours, is characterized by
the presence lignin of light grey color with a
variety of colors from grey to white and bright
white. Accordingly, lignin in the sample has
? 340 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Tatiana G. Shendrik, Valentina V. Siminova,.. Properties of Active Carbons Produced by Thermochemical Transformation?
Fig. 3. Dependence of activated carbon specific surface area on the burn-off degree: 1 ? brown coal ? oil slime
mixture (1:1); 2 ? triple mixture of lignin ? brown coal ? oil slime (1:1:1); 3 ? lignin? oil slime mixture (1:1)
1
2
3
4
5
Fig. 4. Lignin and lignin ? oil slime mixture microstructure before and after thermolysis: 1 ? lignin; 2 ? (lignin
? oil slime mixture); 3, 4 ? (lignin?oil slime mixture) at 240 ?? after 3 h; 5 ? (lignin?oil slime mixture),
at 400 ??, after 3 h
? 341 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Tatiana G. Shendrik, Valentina V. Siminova,.. Properties of Active Carbons Produced by Thermochemical Transformation?
high reflection indices, raised in comparison
with the initial values from 0.57-0.55 up to 1.24
and 1.13 % and are equal to R of coking coals.
Thermally changed lignin is isotropic, porous
substance with dense smooth cell walls and pore
walls. Lignin fragments with equal reflection
values prevail, a number of lignin fragments
with higher or lower reflection indices being
rather small. There are two different pore types
in lignin fragments. The first of them is present
by natural pores of empty cell cavities and larger
pores with sizes from 10 up to 100 mkm. The
second type of pores is likely formed as a result
of thermolysis. They have rounded, of irregular
shape and rather homogeneously distributed and
substantially smaller in size (from 2 to 40 mkm).
Accordingly, the pores of the first type have
thicker cell walls of 10-50 mkm as compared to
pores of the second type ? 2-15 mkm. The ratio
of these two types of porosity is more or less
equal in all samples.
Conclusion
As a result of the accomplished research
it was found that oil-slimes can play the role
of binding and structure forming component
in thermal transformation of lignin and
brown coal. Active carbons, produced from
oil slime ? lignin ? brown coal mixtures are
coked particles, considerably different from
powdery active carbons produced from lignin
and brown coal.
AC produced from double mixture oil slime
? lignin has highest specific surface area. The
observed differences in yield and specific surface
area between AC from lignin ? oil slime mixtures
and lignin ? brown coal mixtures are likely to be
the result of different content of oxygen functional
groups, providing interaction of components
in mixtures during thermal transformation
processes, as well as availability of arenes in
brown coal, which are more condensed than in
lignin, and a larger number of three-dimension
bonds, providing a higher rigidity of a carbon
framework in coal.
The following benefits of active carbons,
produced from hydrolytic lignin, oil slime, brown
coal mixtures ? well developed mesoporous
structure with narrow range of mesopores sizes,
high rather specific surface area, the possibility to
produce AC of different geometric shape ? open
good perspectives to use the considered above
active carbons as carbon sorbents, carriers and
catalyst supports.
References
1.
Shendrik ?.G., ?utcherenko V.?., Paschenko L.V., Khabarova ?.V. Problems of Processing the
Carbon-containing Industrial Waste into Adsorbents. Problems of Waste Collection, Processing
and Utilization. Proceedings TsNTEPI ?dessa, 2003. P. 167-171 (in Russian).
2. Shendrik ?.G., ?utherenko V.?., Tamarkina Yu.V., Khabarova ?.V Brown coal and oil waste
thermolysis. Coal Chemistry Journal, 2005. ?1-2. P. 45-49 (in Russian).
3. Shendrik ?.G., Paschenko L.V., Simonova V.V., Drozdov V.A., ?utcherenko V.?., Khabarova ?.V.
Adsorbents from Lignin and Wash oil Waste. Chemistry of Solid Fuel. 2007. ?2. P. 62-67 (in Russian).
4. Siminova V.V., Shendrik T.G., Kucherenko V.A., Chesnokov N.V., Kuznetsov B.N. Study of
Thermochemical Transformation of Hydrolytic Lignin and Properties of the Produced Active
5.
Carbons. Journal of Siberian Federal University: Chemistry. 2008. N2. P. 107-117.
Yatsenko ?.M, Prokopik Z.V., Tchebenko Yu.N., Vorobiov ?.?. Use the Waste of Petrochemical
and Oil Refinery Enterprises. Eco-technologies and Resource Saving. 2000. ?3. P. 47-50 (in
Russian).
? 342 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Tatiana G. Shendrik, Valentina V. Siminova,.. Properties of Active Carbons Produced by Thermochemical Transformation?
6. Fenelonov V.B., Porous Carbon. Institute of Catalysis SB RAS, Novosibirsk, 1995. 518 p (in
Russian).
7. Shorygyna N.N., Reznikov V.?., Yelkin V.V. Lignin Reactive Ability, Nedra, Moscow, 1976. 368
p (in Russian).
8. Zhuang Q., Kyotani T., Tomita A. Dynamics of surface oxygen complexes during carbon
gasification with oxygen. Energy & Fuels .1995. V.9. N 4. P. 630-634.
9. Saranchuk V.I., Butuzova L.F., ?inkova V.N. Thermochemical Destruction of Brown coal .
Naukova Dumka, ?iev, 1993. 224 p (in Russian).
? 343 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Journal of Siberian Federal University. Chemistry 4 (2008 1) 344-354
~~~
??? 547
Polycyclic Aromatic Hydrocarbons
as Priority Pollutants
Anatoly I. Rubailoa* and Andrey V. Oberenkob
a
Siberian Federal University,
79 Svobodny, Krasnoyarsk, 660041 Russia
b
Institute of Chemistry and Chemical Technology SB RAS,
42 K.Marx st., Krasnoyarsk, 660049 Russia 1
Received 24.11.2008, received in revised form 15.12.2008, accepted 22.12.2008
Many countries pay increasing attention to problems of environmental safety and control of pollutants
emission. Thereat the problem of presence of polycyclic aromatic hydrocarbons (PAHs) in environment
becomes urgent because this substances are ubiquitous pollutants and some of them have carcinogenic
properties. PAHs and their derivatives appears in the processes of incomplete combustion of organic
substances. PAHs concentrations vary considerably in urban and rural places under influence of
vehicular traffic, heat power plant and industrial activity. Some countries set non-mandatory ambient
air quality standards for the PAHs. This fact shows pollutants of this class is to be given significant
attention. This paper presents some up-to-date data related with sources of atmospheric PAHs,
methods of their determination and processes affecting their concentration.
Keywords: PAH, benzo[a]pyrene, sources.
Introduction
Polycyclic aromatic hydrocarbons (PAHs)
are organic compounds constituting only carbon
and hydrogen, arranged in two or more aromatic
rings. The biggest part of PAHs are hydrophobic
substances which have low solubility in water.
The best known PAH is benzo[a]pyrene (B[a]
P) which contains 5 rings. Because of their low
vapor pressure, some PAHs are present at ambient
temperature in air, both as gas and associated
with particles [1]. The lighter PAHs, such as
phenanthrene, are found almost exclusively in
gas phase whereas the heavier PAHs, such as
B[a]P, are almost totally adsorbed on to particles.
Seventeen priority PAH were chosen by Agency
*
1
for Toxic Substances and Disease Registry (USA)
on the base of their toxicological profile[2].
Substances were included in priority List of PAH
were chosen by following reasons: 1) there are
more information on them than on others; 2) they
are suspected to be more harmful than others, and
they exhibit harmful effects that are representative
of PAHs in general; 3) there is a greater chance
for exposure to these PAHs than to the others; 4)
these PAHs more abundant and have the highest
concentrations in environment; 5) these PAHs
are characteristic for some sources.
Sixteen PAHs have been specified by the
United States Environmental Protection Agency
(EPA) as priority pollutants. Table 1 lists the
Corresponding author E-mail address: rai@icct.ru
й Siberian Federal University. All rights reserved
? 344 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Anatoly I. Rubailo and Andrey V. Oberenko. Polycyclic Aromatic Hydrocarbons as Priority Pollutants
Table 1. USA EPA priority list of PAH
Total molecular
formula
Molecular weight
Carcinogenic activity
Naphthalene
C10H 8
128
+
Phenanthrene
C14H10
178
-
Substance
Anthracene
C14H10
178
▒
Fluoranthene
C16H10
202
-
Pyrene
C16H10
202
-
Chrysene
C18H12
228
▒
Benzo(a)anthracene
C18H12
228
+
Benzo(b)fluoranthene
C20H12
252
++
Benzo(k)fluoranthene
C20H12
252
+
Benzo(e)pyrene
C20H12
252
▒
Benzo(a)pyrene
C20H12
252
+++
Perylene
C20H12
252
▒
Benzo(ghi)perylene
C22H12
276
▒
Dibenzo(ah)anthracenes
C22H14
278
+++
Indeno(cd)pyrene
C22H12
276
+
Coronene
C24H12
300
▒
+ (++) - there is sufficient evidence that substance is carcinogenic to experimental animals;
▒ - the available data are inadequate to permit an evaluation of the carcinogenicity of substance to experimental
animals.
- the available data provide no evidence that substance per se is carcinogenic to experimental animals.
priority PAHs their total molecular formulas and
carcinogenic activity.
Adequacy of benzo[a]pyrene
as indicator substance
of total PAH concentration
Benzo[a]pyrene seems to be a reasonable
choice, albeit an imperfect indicator, due to the
strong correlation between B[a]P and other PAHs
for a given set of conditions and due to the relative
abundance of B[a]P exposure measurements [3].
Although B[a]P presents only 3-20% of total
airborne PAH its part among carcinogenic PAHs
is considerably higher - about 30-100 %. Role of
B[a]P as indicator also is due to its characteristic
and intensive fluorescence spectrum in visible
spectral region.
But ratio of B[a]P to the other PAH varies
considerably inn different places. Furthermore
can?t be reliable indicator because it is relatively
unstable, poorly soluble in water and presents in
low concentrations in emissions. For example its
concentration in industrial exhausts usually is
less then 10 %[4].
Formation
The principle formation mechanism for P??
occurs as part of the combustion process present
in many different types of sources. Formation
mechanism is not studied in details well enough
today. Conventional theory claims that PAHs are
formed by free radical mechanism in gas phase
[5]. The biggest part of evidences shows that PAHs
exist in the atmosphere as solids. It means that
transformation of vapor into solid is to take place
between point of of PAHs formation and point of
their release in atmosphere. It has been recognized
that soot (a product of coal combustion) is similar
? 345 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Anatoly I. Rubailo and Andrey V. Oberenko. Polycyclic Aromatic Hydrocarbons as Priority Pollutants
in some structural characteristics to polycyclic
aromatic molecules and that both soot and
PAH are products of combustion Comparisons
of the two types of molecules give rise to the
first clue as to how PAH may be formed in
combustion, namely by incomplete combustion
and degradation of large fuel molecules such
as coal. It is also known, however, that carbon
black and soot are produced by burning methane
(CH). Thus, it is believed that PAHs are not only
produced by degrading large fuel molecules, but
are also produced by polymerizing small organic
fragments in rich gaseous hydrocarbon flames
[6]. The question of how the polyacetylenes (that
are produced by a sequence of rapid reaction
steps) cyclize still remains. One theory is that
the polyacetylene chain bends around the carbon
atoms and eventually bonds into the condensed
ring structures. The association shown requires
minimum atomic rearrangements. Also, the
formation of polyacetylene cycles is highly
exothermic, thereby providing sufficient energy to
dissociate terminal groups and the free valences
to produce reactive and stable PAHs [7].
Sources of PAHs
PAHs are mostly formed during the
incomplete combustion and pyrolysis of fossil
fuels or wood, and from the release of petroleum
products. Other sources of PAHs include
petroleum spills, oil seepage, and diagenesis of
organic matter in anoxic sediments. PAHs are also
found in coal tar, crude oil, creosote, and roofing
tar, and a few are used in medicine or to make
dyes, plastics, and pesticides. PAHs produced for
commercial use, include naphthalene, fluorene,
anthracene, phenanthrene, fluoranthene, and
pyrene. These pure PAHs usually exit as colorless,
white or pale yellow?green solids. In general,
there are five major emission sources of PAHs,
i.e. domestic, mobile, industrial, agricultural, and
natural [8]. Furthermore, some cosmic sources
of PAHs have also been proposed [9]. Different
sources of PAHs are presented in Table 2 [10].
Source identification
Source markers. Some PAH were
suggested to be indicators for some processes
which form PAH. These special PAH are called
source markers, tracers, or signatures. Profiles
of concentrations and relative abundance
concentrations could be used to determine the
impact of different sources on total concentration.
This approach makes possible to distinguish the
sources in case when the lesser sources source
contributed more than 10% of the total [11]. Table
3 presents PAHs groups which are suggested in
literature as source markers [12].
Diagnostic ratio. Diagnostic ratio method
means comparing ratios of pairs of frequently
found PAH emissions. For example value of 0.350.7 of Ind/(Ind+B[ghi]P) ratio has been used for
diesel emissions. The higher ratio (>0.5) of Flu/
(Flu+Pyr) has been used for diesel emission,
while a lower ratio (<0.5) for gasoline emission.
The B[a]P/B[ghi]P ratio higher than 0.6 refers to
the presence of traffic emission and contribution
from other PAH sources. The PAH profile was
also seen to perform as reliably as inorganic
compound profiles in a multivariate PAHs source
apportionment study. The diversity in PAHs
sources could be described in terms of diagnostic
ratios. At the same time Diagnostic ratio method
should be used with caution because it is often
difficult to discriminate between some sources.
Ratio could change due to different reactivity of
PAH against other atmospheric species, such as
ozone and/or oxides of nitrogen. In addition to
the atmospheric reactivity, degradation that may
occur during the sampling process and can also
modify the atmospheric PAHs levels and thus
the ratios between PAHs. The other limitation
of diagnostic ratio is that their interpretation
greatly depends on the ratio considered and on
? 346 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Anatoly I. Rubailo and Andrey V. Oberenko. Polycyclic Aromatic Hydrocarbons as Priority Pollutants
Table 2. Amount of PAHs emission from different industrial sources
B[a]P concentration
Source
Heat power engineering Products of coal and
fuel oil combustion
1. лBig╗ (50 ?W),
2. лMedium╗ (5-50 ?W)
3. лSmall╗ (?? 5 ?W)
4. Oil-burning boiler
Aluminum industry Products of combustion,
excretion, decomposition of coal-tar pitch
1. Electrolysis workshop
2. Ventilation skylight
3. Anodic mass workshop
Building technology
Products of combustion, excretion,
decomposition of fuel oil, bitumen
1. Perlite burning furnace
2 Asphalt-concrete installations
Petrochemical industry
Products of combustion, excretion,
decomposition of natural gas, fuel oil, coke
Combustion, pyrolysis and other installations.
Vehicle emissions
gasoline engines
diesel engines
Mass
concentration
?g /m3
Mass
emission
?g/s
In fly ash
?g /?g
In nonvolatile
ashe ?g /?g
0,005-0,150
0,6-50
1-10000
0,1-1
0,2-8
4-250
0,1-6000
1-6
0,1-0,3
(3-50)103
(1,2-9)105
5╖103
1,4
3100
-
200-3000
0,9-67
10-100
(7-50)103
(4-8)104
(0,7-12)102
(9-10)105
7╖105
(3-8)103
-
0,05-50
20-300
2-80
80-1100
(1-200)102
(2-30)104
1-2
(2-3)103
0-15
0-40
-
-
0,09-0,23
0,20-0,70
-
(4-10)103
-
Table 3. Source markers
Source
Characteristic PAHs
Coal Burning
Phenanthrene , Fluoranthene and Pyrene
Coking
Anthracene, Phenanthrene and B[a]P
Incineration of garbage
Pyrene , Phenanthrene and Fluoranthene
Wood burning
B[a]P and Fluoranthene ;
Fuel oil burning
Fluoranthene , Pyrene and Chrysene
Gasoline engines
Fluoranthene , Pyrene with high ratio of Benzo[b]fluoranthene
Diesele engines
Fluoranthene, Pyrene with high ratios of Benzo[b]fluoranthene ? ? Benzo[k]
fluoranthene
? 347 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Anatoly I. Rubailo and Andrey V. Oberenko. Polycyclic Aromatic Hydrocarbons as Priority Pollutants
the source profile chosen. This may be a case,
when the sampling is carried out in the vicinity
of sources of particulate PAHs and for highly
reactive compounds. Furthermore, the difference
in chemical reactivity, volatility, and solubility of
PAH species may introduce bias but to minimize
this error, the diagnostic ratio with similar
physico-chemical properties of PAHs should be
used.
Principal component analysis (???).
Using PCA, it is possible to simplify the
interpretation of complex systems and to reduce
the set of variables to few new ones, called
factors. Each of these factors can be identified
as either an emission source, or a chemical
interaction. Many of these factors indicate
more than one possible cause. In general, each
factor from PCA is associated with a source
characterization by its most representative
PAH compound(s).
Radiocarbon analysis. Carbon has two
stable, nonradioactive isotopes: carbon-12 (12C),
and carbon-13 (13C). In addition, there are trace
amounts of the unstable isotope carbon-14
(14C) . Carbon-14 is constantly generated in the
atmosphere under impact of radiation (the main
source of radiation is cosmic rays) . Proportion of
radioactive to non-radioactive carbon is constant
in the atmosphere and biosphere at defined point
and time, because all living organisms take part
in carbon exchange and consume carbon from
environment, and isotopes through their chemical
identity take part in biochemical reaction by the
same way. Once organism dies, this exchange
stops, and the amount of carbon-14 gradually
decreases through radioactive beta decay. This
process determines difference in isotopic ratios
in products of combustion of fossil fuels and
biomass. Isolation of PAH and subsequent analysis
by the method accelerative mass spectrometry
makes possible to determine concentration of
carbon isotopes in this substances and calculate
contribution of combustion of fossil fuels and
biomass [13, 14].
Sampling artifacts
Representative PAHs sample should
demonstrate their real concentration in ambient
air. PAH monitoring is usually performed using
high- or low-volume samplers (HVS, LVS) and
is complex because of the reactive breakdown of
PAHs between the gas and particulate phases.
In HVS or LVS the particulate phase is first
trapped on a filter and the gaseous phase is
trapped on a solid adsorbent (e.g. polyurethane
foam) located downstream from the filter.
However, these sampling procedure have also
been shown to be affected by several sampling
artifacts. In the particulate phase, positive
artifacts (overestimationа of the particle phase
concentrations) are mainly due to sorption of
gaseous compounds on the filter, while negative
artifacts (underestimation of the particle phase
concentrations) result from the volatilization of
particulate PAH from the filter. Moreover, chemical
degradations of PAHs by oxidizing compounds
such as nitrogen oxides (NOx =NO+NO2),
hydroxyl radical (OH), halogens, nitric acid
(HNO3), hydrogen peroxide (H2O2), and ozone
(O3) may occur during sampling reported that
the atmospheric PAH concentrations measured
using conventional samplers not equipped
with an ozoneа trap can underestimate the PAH
concentration by more than 200%.
This was especially found when the samples
were collected in the vicinity of a point source
of particulate PAHs and for highly reactive
compounds such as B[a]P. To reduce artifacts
induced by conventional samplers, denuder
sampling devices were developed. The denuder
sampler systems were designed to trap the gas
phase on a solid sorbent coated on the surface of
the trap prior to collecting the particulate phase on
a filter. This methodology avoids the phenomenon
? 348 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Anatoly I. Rubailo and Andrey V. Oberenko. Polycyclic Aromatic Hydrocarbons as Priority Pollutants
of adsorption of the gas phase on the filter and
reduces the desorption artifact by collecting the
volatilized fraction on a sorbent cartridge placed
downstream from the filter. Finally, the chemical
degradation of particulate PAHs may be reduced
as the sorbent coated on the denuder tubes can
remove the oxidizing species included in the gas
phase.
Change of PAHs concentration
in the atmosphere
PAHs concentration depends on a variety
of factors like temperature, humidity, pressure,
winds speed and direction, precipitation and so
on [15]. Polycyclic organic matter emitted as
primary pollutants present on particulate matter
can be subject to further chemical transformation
through gas-particle interactions occurring either
in exhaust systems, stacks, emission plumes, or
during atmospheric transport.
These include highly reactive intermediates
(both free radicals and excited molecular species)
and stable molecules. Seasonal variation in
transformation reactions of PAH have been
observed. During winter, with conditions of
low temperature and low irradiation, the major
pathway for PAH degradation is probably
reactions with nitrogen oxides, sulfur oxides and
with the corresponding acids.
Reactions with the ozone and free
radicals have the most important influence on
concentration of PAH in gaseous phase, while
photolysis plays a minor role [16]. Seasonal
variation in concentrations of particle phase PAH
have similar trend in some large cities over the
world. During winter PAHs concentrations are
higher compared with those during summer[17].
Higher concentrations during winter (a) reduced
vertical dispersion due to inversion[18]; (b) lower
mixing layer and less intensive atmospheric
reactions; (c) enhanced sorption to particles
at lower temperature (d) increased emissions
from domestic heating and power plants during
winter with low temperature [19]; (e) alteration
of prevailing wind direction [20, 21]. Besides
some big cities have diurnal variations of PAHs
concentrations related with traffic [22].
It was found that PAHs transformation goes
by different ways if it takes place on the surface of
particles, in the solution or in the solid phase [23].
Gas/particles distribution depends on molecular
mass of substance and ambient temperature. Usually,
2 to 4-ring PAHs are mainly gas-phase compounds,
while PAHs with five or more rings tend to be mainly
associated with particulate. It should be noticed that
about 75% of total PAH accumulated with particles
lesser than 0.6 ?m [24].
Organic substances resulted from human
activities could undergo long-range atmospheric
transport to remote sites [25]. Water in clouds
absorbs those substances and precipitation could
lead to pollution of distant regions.
PAH are eventually removed from the
atmosphere by sedimentation or washout, or due
to their decomposition in surface of particles. It
was found that dry sedimentation was usual for
hydrophobic substances. For example up to 70%
of B[a]P is present in precipitations in the surface
of particles, while naphthalene due to its high
solubility in water is present in precipitations as
a solution.
Although the biggest part of pyrogenic
PAHs precipitate near their source, considerable
amounts of this substances could be transferred
in atmosphere to distant regions. They are found
in water of highland lakes and arctic ice [26].
Decrease of PAHs concentration in the
atmosphere has three principal reasons:
1) photochemical modifications of PAH
under irradiation from different sources;
2)
non-photochemical
degradation
(spontaneous oxidation in the dark);
3) chemical modifications induced by
reactions between atmospheric gas (NOx,
? 349 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Anatoly I. Rubailo and Andrey V. Oberenko. Polycyclic Aromatic Hydrocarbons as Priority Pollutants
Table 4. Half-life of selected PAHs under simulated atmosphere conditions
Half life in hours
PAHs
Simulated sunlight
Simulated sunlight and ozone
(0.2 ppm)
Dark reaction ozone
(0.2 ppm)
Anthracene
0.20
0.15
1.23
Benzo(a)anthracene
4.20
1.35
2.88
Dibenzo(a,h)anthracene
9.60
4.80
2.71
Dibenzo(a,c)anthracene
9.20
4.60
3.82
Pyrene
4.20
2.75
15.72
Benzo(a)pyrene
5.30
0.58
0.62
Benzo(e)pyrene
21.10
5.38
7.60
Benzo(b)fluroanthene
8.70
4.20
52.70
Benzo(k)fluroanthene
14.10
3.90
34.90
S?x,аO3) and various PAH adsorbed onto different
substrates, in the absence or the presence of
radiation.
It was found that PAHs could react with
molecular oxygen in absence of irradiation,
but speed of such reactions is very slow and
they have no considerable effect on total
degradation process. It seems that the ozone
is the most important gaseous pollutant
influencing PAHs concentration [27]. Ozone
concentrations occurring in natural conditions
lead to considerable decrease of half life of
PAHs (Tableа4).
Regulations and current levels
of PAHs in different countries
Many countries have added PAHs to their
hazardous air pollutants lists but till date there is
no strict ambient air quality standard for PAHs
(Table 5). The EPA (1994) has classified PAHs
as a probable human carcinogen with sufficient
evidence from animal studies but inadequate
evidence from human studies and hence PAHs
are among the list of hazardous air pollutants
to be regulated under the US Clean Air Act
Amendment, 1990. The Occupational Safety and
Health Administration (OSHA) has set a limit
of 0.2 mg/m?3 of PAHs. National Institute for
Occupational Safety and Health recommended s
limit of 0.1 mg/m?3 of PAHs [28].
European union directive has proposed
a target value of 1 ng/m?3 B[a]P for the total
content in the PM10 fraction averaged over a
calendar year. Furthermore, this directive also
suggest to assess the contribution of B[a]P in
ambient air, each Member State shall monitor
other relevant PAHs, i.e. benzo(a)anthracene,
benzo(b)fluoranthene,
benzo(j)fluoranthene,
benzo(k)fluoranthene, indeno(1,2,3-cd)pyrene,
and dibenz(a,h)anthracene. Monitoring sites for
these PAHs should be selected in such a way that
geographical variation and long-term trends can
be identified.
Netherlands introduced an interim goal of
reducing the annual average B[a]P concentration
to below 5 ng/m?3 (Smith and Harrison, 1998),
while a guideline of 10 ng/m?3 for the annual
average B[a]P has been proposed by the German
Federal Environmental Agency. The Dutch
National Institute of Public Health and the
Environment (DNIPHE) has determined values
of maximum permissible concentrations (MPCs)
and negligible concentrations (NCs) for about 200
toxic compounds including some PAHs (RIVM,
1999?). The MPCs and NCs represent risk limit
of the substances in different compartments
? 350 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Anatoly I. Rubailo and Andrey V. Oberenko. Polycyclic Aromatic Hydrocarbons as Priority Pollutants
Table 5. Non-mandatory ambient air quality standards for the PAHs
Countries
Limit value (ng/m?3)
Guide value (annual average) (ng/m?3)
Australia
?
1.0
Belgium
1.0
0.5
Croatia
2.0
0.1
Germany
?
10.0
India
?
5.0
Netherlands
1.0
0.5
France
0.7
0.1
Italy
1.0
?
Sweden
?
0.1
UK
?
0.25
WHO
?
1.0
EU*
6.0
?
* To be met in 2010.
of the environment-surface water, soil, air,
groundwater, and sediments, and are calculated
from available eco-toxicological data. These
risk limits are used to derive environmental
quality standards in the Netherland. Setting
integrated environmental quality standards:
environmental quality standards for soil, water
and air. Dutch National Institute of Public
Health and the Environment. However, ecotoxicological data available for only B[a]P out
of the 7 PAHs has been reported. These MPCs
and NCs for air were not available for the other 6
PAHs (anthracene, benz[a]anthracene, benzo[k]
fluoranthene, fluoranthene, naphthalene, and
phenanthrene) but DNIPHE has assigned a
critical concentration value for each of these
compounds. Critical concentrations are normally
calculated for air and/or rainwater. They are
theoretically derived steady state concentrations
of the pollutants in air and/or rainwater that will
not lead to exceedance of MPCs value for soil.
Russian Federation set up MPC for B[a]
P 1 ng/m?3[29]. This value is lower than
corresponding European standards, but only B[a]
P is under control. Limitations of this approach
described above. Nowadays there is exceeding of
B[a]P concentrations in some industrial cities in
Russia [30-32].
Conclusions
Today biosphere suffers increasing
anthropogenic influence. Considerable efforts are
applied in the field of research and monitoring of
hazardous or potentially hazardous substances To
control, predict and if possible to avoid negative
effects of PAHs pollution it is necessary to have
exact information about their nature, sources
and amount of emission. Western countries pay
increasing attention to problems of environment
and living standards. Because Russia has largescale industrial projects in the field of aluminum
and petrochemical industry as well annually
increasing traffic, analysis and use of up-todate data about priority pollutants appears one
of the chief elements of environmental safety
ensuring.
? 351 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Anatoly I. Rubailo and Andrey V. Oberenko. Polycyclic Aromatic Hydrocarbons as Priority Pollutants
References
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
National Air Toxics Program: the integrated urban strategy Report to Congress United States
Office Of Air Quality EPA-453/R-99-007 Environmental Protection Planning And Standards July
2000 Agency Research Triangle Park, NC 27711
Toxicological profile for polycyclic aromatic hydrocarbons (PAHs). ATSDR (Agency for Toxic
Substances and Disease Registry), 1995. US Department of Health and Human Services, Public
Health Service. Atlanta, GA.
Friesen M.C. Adequacy of Benzo(A)Pyrene and Benzene Soluble Materials as Indicators of
Exposure to Polycyclic Aromatic Hydrocarbons in a Soderberg Aluminum Smelter/ Melissa
C. Friesen, Paul A. Demers, John J. Spinelli and Nhu D. Le// Journal of Occupational and
Environmental Hygiene. ? 2008. - ? 5 - P. 6?14
Rovinsky F.J. Background Monitoring of Polyciclic Aromatic Hydrocarbons / F.J. Rovinsky, ?.?.
Teplitskaya, ?.?. ?lekseeva. ? Leningrad: Hydrometeoizdat, 1988. (in russian)
Crittenden B.D. Carcinogenesis - A Comprehensive Survey Volume I. Polynuclear Aromatic
Hydrocarbons: Chemistry, Metabolism and Carcinogenesis. / B.D.Crittenden, R. Long., R.
Freudenthal and P.W. Jones, New York: Raven Press. ? 1976, P. 209-223.
Skjoth-Rasmussen M. S. Formation of polycyclic aromatic hydrocarbons and soot in fuel-rich
oxidation of methane in a laminar flow reactor / M. S. Skjoth-Rasmussen, P. Glarborga, M.
Ostbergb, J. T. Johannessena, H. Livbjerga, A. D. Jensena and T. S. Christensenb // Combustion
and Flame. - 2004 ? V. 136, ?1 - P. 91-128
Howard J.B. Polynuclear Aromatic Hydrocarbons: Formation, Mechanism, and Measurement /
J.B. Howard, J.P. Longwell // Proceedings of the Seventh International Symposium on Polynuclear
Aromatic Hydrocarbons. - Columbus, Ohio: Battelle Press. - 1983. - P. 27-61.
Ambient air pollution by Polycyclic Aromatic Hydrocarbons (PAH). Position Paper Luxembourg:
Office for Official Publications of the European Communities, 2001 ISBN 92-894-2057-X
Naraoka H. Isotopic evidence from an Antarctic carbonaceous chondrite for two reaction pathways
of extraterrestrial PAH formation / Hiroshi Naraoka, Akira Shimoyama, Kaoru Harada // Earth
and Planetary Science Letters. ? 2000. ? V. 184, ?1. ? P. 1-7
Belih L.I. Benzo[a]pyrene in atmospheric exhausts of industrial Pribaikalye / L.I. Belih, U.M.
Malih, A.A. Penzina, ?.N. Smagunova // Luminescence and laser physics. - Irkutsk: Publishing
house of Irkutsk State University - 2003. - P. 45-50 (in russian)
Ravindra K. Atmospheric polycyclic aromatic hydrocarbons: Source attribution, emission
factors and regulation / Khaiwal Ravindra, Ranjeet Sokhi, and Renщ Van Grieken // Atmospheric
Environment ? 2008. ? V. 42, ?13. ? P. 2895-2921
Polycyclic Aromatic Hydrocarbons (PAHs) in air and their effects on human Health / Central
Pollution Control Board, Ministry of Environment & Forests, 2003 , 42.
Mandalakis M. Radiocarbon apportionment of fossil versus biofuel combustion sources of
polycyclic aromatic hydrocarbons in the Stockholm metropolitan area. / M. Mandalakis; ╓.
Gustafsson; C. M. Reddy; L. Xu // Environ. Sci. Technol. ? 2004. ? V. 38, ? 20. ? ?. 5344-5349
Zdenek Z. Source apportionment of atmospheric PAHs in the western Balkans by natural
abundance radiocarbon analysis / Zdenek Zencak, Jana Klanova, Ivan Holoubek, Orjan Gustafsson
// Environ. Sci. and Technol. - 2007. - V. 41. - N 11. - P. 3850-3855.
? 352 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Anatoly I. Rubailo and Andrey V. Oberenko. Polycyclic Aromatic Hydrocarbons as Priority Pollutants
15. Ravindra K. Seasonal and site-specific variation in vapour and aerosol phase PAHs over
Flanders (Belgium) and their relation with anthropogenic activities / Khaiwal Ravindra,
Lсszlє Bencs, Eric Wauters, Johan de Hoog, Felix Deutsch, Edward Roekens, Nico Bleux,
Patrick Berghmans and Renщ Van Grieken // Atmospheric Environment. ? 2006. ? V. 40, ?а4.
? P. 771-785
16. Vione D. Polycyclic Aromatic Hydrocarbons in the atmospher: monitoring, sources, sinks and
fate / Davide Vione, Silvia Barra, Gianluigi De Gennaro, Massimo De Riezo, Stefania Gilarbody,
Maria Grazia Perrone, Luca Pozzoly // Annali di Chimica. ? 2004. - ?94. - ?. 17-32.
17. Sadykova G.D. Concentration of 3,4-benzoapyrene ? in the atmosphere of city Almaty / G.D.
Sadykova // Hydrometeorology and Ecology. - 2000. - N 3-4. - P. 169-178
18. Mazquiarсn M. A. B. Organic composition of atmospheric urban aerosol: Variations and sources
of aliphatic and polycyclic aromatic hydrocarbons / Miguel A. Barrero Mazquiarсn, Lourdes
Cantєn Ortiz de Pinedo // Atmospheric Research. ? 2007. - ? 85. ? ?. 288?299
19. Schnelle-Kreisa J. Analysis of particle-associated semi-volatile aromatic and aliphatic
hydrocarbons in urban particulate matter on a daily basis / Juergen Schnelle-Kreisa, Martin
Sklorza, Anette Petersb, Josef Cyrysb, Ralf Zimmermanna // Atmospheric Environment. ? 2005.
? V. 39, ?40. ? ?. 7702?7714
20. Tao S. Vertical distribution of polycyclic aromatic hydrocarbons in atmospheric boundary layer
of Beijing in winter / Shu Tao, Yi Wang, Shiming Wu, Shuzheng Liu, Han Dou, Yanan Liu,
Chang Lang, Fei Hu and Baoshan Xing // Atmospheric Environment. ? 2007. ? V. 41, ? 40. ? P.
9594-9602
21. Sandersona E.G. Comparison of particulate polycyclic aromatic hydrocarbon profiles in different
regions of Canada / E.G. Sandersona, A. Raqbib, A. Vyskocilb, J.-P. Faranta // Atmospheric
Environment. ? 2004. - V. 38, ?21. ? P. 3417?3429
22. Qi S. Distribution of polycyclic aromatic hydrocarbons in aerosols and dustfall in Macao / Shihua
Qi, Jun Yan, Gan Zhang, Jiamo Fu, Guoying Sheng, Zhishi Wang, Tong S.M., Tang U.W., Yunshun
Min // Environ. Monit. and Assess. - 2001. - V. 72. - N 2. - P. 115-127.
23. Pagni1 R. M. Recent Developments in the Environmental Photochemistry of ??? and PCBs in
Water and on Solids / Richard M. Pagni1, Reza Dabestani. // Hdb Env Chem. - 2005. - V. 2, Part
M. - P.193?219
24. Gutierrez-Daba A. Particle-size distribution of polycyclic aromatic hydrocarbons in urban air
in southern Spain / A. Gutierrez-Daban, J. Fernandez-Espinosa, M. Ternero-Rodr?guez, F.
Fernandez-Alvarez // Anal Bioanal Chem. ? 2005. ? V. 381, 33. ? P. 721?736
25. Lang C. Atmospheric Transport and Outflow of Polycyclic Aromatic Hydrocarbons from China /
Chang Lang, Shu Tao, Wenxin Liu, Yanxu Zhang, and Staci Simonich // Environ. Sci. Technol. ?
2008. ? V. 42, ?14. ? P. 5196?5201
26. Masclet P. Polycyclic aromatic hydrocarbon deposition on the ice sheet of Greenland / P.Masclet,
V. Hoyau, J.L. Jaffrezo, H. Cachier // Atmos. Environ. - 2000. - Vol. 34, N 19. - P. 3195-3207.
27. Valerio F.Chemical and photochemical degradation of polycyclic aromatic hydrocarbons in the
atmosphere / Federico Valerio, Patrizia Bottino, Donatella Ugolini, Maria Roberta, Cimberle
Giulio Andrea Tozzi, Alberto Frigerio // The Science of The Total Environment. ? 1984. ? V. 40,
?1. ? P. 169-188
? 353 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Anatoly I. Rubailo and Andrey V. Oberenko. Polycyclic Aromatic Hydrocarbons as Priority Pollutants
28. Pocket Guide to Chemical Hazards. / Cincinnati: National Institute for Occupational Safety and
Health (NIOSH). U.S. Department of Health and Human Services, Public Health Service, Centers
for Disease Control and Prevention, 1997.
29. Hygienic regulations HR 1.1.725-98 ?List of substances, products and industrial processes,
residential and natural factors, carcinogenic for human? HR 1.1.725-98 (approved by decree of
Chief state health officer of Russian Federation 23 December 1998 ?. N 32) (in russian)
30. Bykova N.V. PAHs concentration in snow cover of city Abakan, Republic of Khakasia / N.V.
Bykova, S.?. Kirova // Ecology of South Syberia and neighboring territory. - Abakan: Publishing
house of Khakasian State University, 2004. - V. 2 - P. 7-8 (in russian)
31. Zentsova S.V. Polycyclic aromatic hydrocarbons ? persistent toxic environmental pollutants
/ S.V. Zentsova, N.V. Zhuravleva // International theoretical and practical conference лRussian
metallurgy ? at the turn of the XXI century?. - Novokuznetsk: Publishing house SybSIU, 2005. V. 2 - P. 329-335 (in russian)
32. Belan B.D. Investigation of chemical composition of atmospheric aerosol in Syberian cities / B.D.
Belan, G.?. Ivlev, I.I. Marinaite, ?.?. Rasskazchikova, D.V. Simonenkov, ?.V. Fononov // Optics
of atmosphere and ocean - 2005. - V. 18. - N 8. - P. 670-677 (in russian)
? 354 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Journal of Siberian Federal University. Chemistry 4 (2008 1) 355-362
~~~
??? 547
Functional and Thermal Analysis
of Suberin Isolated from Birch Bark
Irina G. Sudakovaa, Boris N. Kuznetsova,b, Natalia V. Garyntsevaa,
Nina I. Pavlenkoa and Natalia M. Ivanchenko*
a
Institute of Chemistry and Chemical Technology SB RAS,
42 K. Marx, Krasnoyarsk, 660049 Russia
b
Siberian Federal University,
79 Svobodniy, Krasnoyarsk, 660041 Russia 1
Received 24.11.2008, received in revised form 15.12.2008, accepted 22.12.2008
The functional composition and the process of thermal degradation of suberin samples obtained by
water-alkaline and alcohol-alkaline hydrolysis of outer birch-bark were studied by IR-spectroscopy,
TGA and DTA methods. It was shown that the partial hydrolysis of birch bark occurs in water-alkaline
solution, while alcohol-alkaline hydrolysis of bark yields the mixture of suberinic acids. The alcoholalkaline suberin destruction occurs at higher temperatures than that of water-alkaline suberin. The
basic weight loss is observed at 340-400 ░? and 410-440 ░?. At these temperatures the loss of weight
is 64 % and 91 % for samples of suberin, obtained by water-alkaline and alcohol-alkaline hydrolysis
of outer birch-bark accordingly. It was shown that method of suberin isolation from birch-bark defines
the composition, properties and areas of the use of suberinic products.
Keywords: suberin, birch-bark outerlayer, water-alkaline and alcohol-alkaline hydrolysis, filmforming materials, binding agent.
The outer bark birch contains up to
35-40 % of pentacyclic triterpenoids with
the domination of betulin, which possesses
biologically active characteristics. The
known ways of the betulin separation are
based on the solvent extraction of birch
bark, as well as on the birch bark alkaline
hydrolysis [1].
The by-product of betulin separation
from outer birch-bark is suberin - a complex of
hydroxy-acids and phenolic acids, connected
with each other by ether and other bonds with the
formation of polymeric network.
*
1
There is information in literature about
perspective trends of suberin and suberinic acid
use. It was shown [2] that the mixture of suberinic
and phthalic acids are a good glue. Their melts
can be used for gluing heated metal. It is also
found out that suberinic acids show antibacterial
and antifungal activity [3].
There has been investigated the possibility
of obtaining film-forming resins by the thermal
polycondensation of suberin, separated by the
birch bark alkaline extraction. Film-forming
materials with technological features similar
to those of commercial varnish PF-060 have
Corresponding author E-mail address: inm@icct.ru
й Siberian Federal University. All rights reserved
? 355 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Irina G. Sudakova, Boris N. Kuznetsov,.. Functional and Thermal Analysis of Suberin Isolated from Birch Bark
been produced by means of the follow-up
dissolution of condensed suberin in styrene
and turpentine [4].
The possibility of obtaining fire-proof
mixtures on the suberin base has been shown. The
impregnation of wood samples with the suberin
solution in turpentine, as well as the application
of suberin coating makes wood nonflammable
material [5].
There have been proposed the methods
of production of pressed materials with
perfected ecological, physico-mechanical and
performance characteristics which have been
made of milled wood waste with the use of
suberinic binder [6].
The suberin reactivity is determined by the
conditions of its extraction from the outer birch
bark. So, in order to choose the most rational
ways of the suberin use the influence of the
extraction methods on suberin composition and
its characteristics should be studied.
The purpose of this work is to determine
functional composition of suberin samples,
produced by the method of alcohol-alkaline and
water-alkaline hydrolysis of the outer birch bark
and to study their thermo-chemical conversions.
Experimental Part
The water-alkaline suberin was obtained by
outer birch-bark hydrolysis in the glass reactor
with the volume of 600 ml. 15 g of birch bark
(fr. ?0.315 mm) were loaded into the reactor
and 300 ml of 3 % KOH solution were added;
the temperature was raised up to 87 ░? and the
mixture was agitated for 60 minutes. The hot
solution was filtered through the cloth filter. The
cooled filtrate was acidified by 1 M solution of
HCl up to pH = 4-5. The precipitated suberin was
filtered and washed on the filter with distilled
water till the neutral reaction of washing water.
After that the washed sediment was dried in
vacuum till the constant weight.
In order to obtain alcohol-alkaline suberin,
300 ml of 40 % KOH solution were added to
15а g (fr. ?0.315 mm) of birch bark and boiled
in the flask with the backflow condenser for
120 minutes. The solution cooled to 70а░C, then
300 ml of isopropyl alcohol were added to the
reaction mixture and boiled for 15 minutes. The
hot solution was filtered, the isopropyl alcohol
was evaporated, the remainder was watered down
and betulin was separated by filtering. The water
solution was acidified by 1 M solution of HCl till
pH =4-5. The precipitated suberin was filtered
and washed on the filter with distilled water till
the neutral reaction, then it was dried in vacuum
till the constant weight.
The elemental analysis of suberin was
accomplished with the analyzer Fl?she EA?1112 Thermo Quest (Italia).
The IR-spectra were recorded on the
?Spekord 75 JR? in the range of 400 - 4000аcm-1.
The samples were mixed and pressed with
potassium bromide [8].
Derivatograph
?Paulik-Paulik-ErdeyQ-1000D? was used for the thermal analysis in
the temperature interval 20 ? 800 ░? with the
heating rate 10 degrees/min. The sample weight
was 22.5 mg. The calcined alumina was used as a
sample of comparison.
The film-forming polymeric resins
were obtained by means of suberin sample
polycondensation in the rotating glass reactor
with the volume 500 ml in the temperature
range 110-220 ░? with the retention interval
at isothermal conditions for 15 min. Then the
thermally treated suberin was cooled till the
temperature 20 ░? and dissolved in styrene.
The conditional viscosity and solubility
of suberin samples were estimated [9].
Conditional viscosity of the suberin solution
was determined by the viscosimeter with a
nozzle diameter 4 mm. The suberin solubility
was characterized by the degree of light
? 356 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Irina G. Sudakova, Boris N. Kuznetsov,.. Functional and Thermal Analysis of Suberin Isolated from Birch Bark
transmission through the 10 mm cavity on the
spectrophotometer?Spekol-4?.
For the obtained lacquer compositions on
the base of polycondensed water-alkaline and
alcohol-alkaline suberin such characteristics, as
the film elasticity when bent and the drying up
time of coating at the temperature 20 ░? were
determined according to GOST 28196-89.
For the production of wood plate materials
there was used the pine-tree sawdust with
fractionsа < 2.5 mm and 3.8 % mass. humidity.
Suberin binding agent and wood filler were
carefully mixed in the ratio 30:70 at the
temperature 85 ░?. Then the produced staff was
pressed on the laboratory press under 10 MPa at
temperatures 130 ? 150 ░?.
The wood plate material quality was
characterized by density, water-resistance,
toughness when statically bent, which were
determined according to GOST 10632-89.
The Results and Discussion
The main characteristics of the birch bark
suberin samples under investigation are given in
Table 1.
The data of Table 1 show that the method of
suberin isolation considerably affects both surface
appearance and physico-chemical characteristics
of the suberin samples. So, atomic ratios ?/?
and ?/? are 1.12 and 0.24 for the water-alkaline
suberin, 1.58 and 0.27 for the alcohol-alkaline
suberin. The higher ratio H/C and lower melting
temperature, probably show lower condensation
degree of the alcohol-alkaline suberin in
comparison with the water-alkaline one.
IR-spectra of suberin samples, obtained by
water-alkaline and alcohol-alkaline hydrolysis
of the birch bark are given in Fig. 1. The
broad intensive absorption band in the field of
3400-3300 cm-1 indicates the presence of the
significant amount of hydroxyl groups linked by
intermolecular hydrogen bonds in the suberin
samples [10]. The absorption band at 1710 cm-1
relates to the vibrations C=O bonds in carboxyl
and carbonyl groups, the absorption band at 1266
cm-1 concerns stretching vibrations ?-? bonds in
carboxyl groups, bands in the field of 1180-1030
cm-1 correspond to the vibrations ?-? bond of
alcohol groups. The presence of indicated above
bands points to the fact that there are different
oxygen-containing functional groups in the
suberin samples.
IR-spectra of two suberin samples do not
have essential differences, except for the small
widening of the absorption band in the field
of 3400-3300 cm-1 of the suberin, isolated by
alcohol-alkaline hydrolysis of the birch bark, and
the emergence of the additional absorption band
at 1128 cm-1 related to the stretching vibrations
of the simple ether -?-?-?- bonds of the suberin
Table 1. Some characteristics of suberin samples
Characteristics
Water-alkaline suberin
Alcohol-alkaline suberin
Surface appearance
brown powder
brown viscous amorphous substance
Moisture, %
8.3
10.7
1.15
1.05
145
118
Density, kg/m
3
Melting temperature, ░C
Elemental composition, %
?
70.12
67.32
?
6.57
8.84
?
22.37
23.80
? 357 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Irina G. Sudakova, Boris N. Kuznetsov,.. Functional and Thermal Analysis of Suberin Isolated from Birch Bark
0,8
0,7
0,6
Absorbance
0,5
0,4
2
0,3
0,2
1
0,1
0
4000
3600
3200
2800
2400
2000
Wavenumber, cm-1
1600
1200
800
400
Fig. 1. IR-spectra of suberin samples, isolated from the birch bark by water-alkaline (1) and alcohol-alkaline (2)
hydrolysis
Mass loss, mg
25
20
15
10
1
5
2
0
20
120
220
320
?emperature,
420
520
░?
Fig. 2. Thermogravimetric curves of suberin samples, isolated from the birch bark by water-alkaline (1) and
alcohol-alkaline (2) hydrolysis
sample, obtained by water-alkaline hydrolysis.
Probably, water-alkaline hydrolysis of the birch
bark does not result in to the complete destruction
of bridge ether links in suberin, while the more
deep alcohol-alkaline hydrolysis gives the
mixture of suberinic acids. Suberinic acids can
undergo the condensation reactions and this fact
explains the differences in melting temperature
of the samples of water-alkaline (Tmelt= 145 ░?)
and alcohol-alkaline (Tmelt= 118 ░?) suberin.
The presence of a high amount of oxygencontaining functional groups in suberin, as
well as the low temperature of its softening
(65 ? 80а ░?) makes it worthwhile to use
the condensed suberin as a binder agent in
the wood plate material production and as
a film-forming agent in varnish-and-paint
compositions.
The methods of thermogravimetric (TGA)
and differential-thermal (DTA) analysis were
used in the study of thermal destruction of
suberin samples, isolated from the birch bark by
water-alkaline and alcohol-alkaline hydrolysis.
The curves of the loss of suberin samples
weight with temperature increasing are given
on Fig. 2. They show a difference in the thermal
behavior of water-alkaline and alcohol-alkaline
suberin samples.
As
it
follows
from
differential
thermogravimetric (DTG) curvers characterizing
a rate of mass loss (Fig. 3) the loss of suberin mass
goes through a few stages in the temperature
? 358 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Irina G. Sudakova, Boris N. Kuznetsov,.. Functional and Thermal Analysis of Suberin Isolated from Birch Bark
?emperature, ░?
0
100
200
300
400
500
600
0
DTG, r.u.
-0,5
-1
1
-1,5
-2
2
-2,5
-3
2
?
Fig. 3. Differental thermogravimetric curves of suberin samples, obtained from the birch bark by water-alkaline
(1) and alcohol-alkaline (2) hydrolysis
Fig. 4. DTA curves of suberin samples, obtained from outer birch bark by water-alkaline (1) and alcohol-alkaline
(2) hydrolysis
range 25-600 ░C. The loss of water-alkaline
suberin mass with the rise of temperature to 200
░C is only 3.2 %. At the temperature range 200400 ░C the main loss of the water-alkaline suberin
(64 % mass.) is observed. The few minimums
corresponding to the rate of destruction of
water-alkaline suberin are presented on the DTG
curve at this temperature range (Fig. 3, curve
1). The presence of low-temperature minimums
indicate that in thermodestruction process, at
first the rupture of weaker bonds (probably ether
and hydrogen bonds) takes place. At higher
temperatures the thermal-oxidative degradation
of suberin polymeric fragments is carried out.
In the case of alcohol-alkaline suberin the
first stage of mass loss (6 %) corresponds to the
temperature range 25-340 ░C (Fig. 3, curve 2). The
further increase of the temperature up to 440 ░C
is accompanied by the main mass loss of alcoholalkaline suberin (91 %). The higher temperatures
result in the complete combustion both of alcoholalkaline and water-alkaline samples of suberin.
The differences in the thermal behavior of
suberin samples obtained by water-alkaline and
alcohol-alkaline hydrolysis of outer birch-bark
were observed also by DTA method (Fig. 4).
DTA curve of water-alkaline suberin in
the temperature interval 40-260 ░C has small
endothermal minimum and few exothermal
maximums (Fig. 1, curve 1). The first exothermal
maximum at 360 ░C corresponds to the 45 %
mass loss of suberin relative to mass of the initial
? 359 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Irina G. Sudakova, Boris N. Kuznetsov,.. Functional and Thermal Analysis of Suberin Isolated from Birch Bark
100
Transmission degree, %
Conditional viscosity, s
120
1
100
2
80
60
40
20
110
130
150
80
60
40
2
20
1
0
170
110
Temperature,0?
130
150
170
Temperature,0?
Fig. 5. The temperature dependence of conditional
viscosity of thermally condensed water-alkaline (1)
and alcohol-alkaline (2) suberin solutions in styrene
(25 % mass.)
Fig. 6. The temperature dependence of the light
transmission degree of thermally condensed wateralkaline (1) and alcohol-alkaline (2) suberin solutions
in styrene (25 % mass.)
sample. On the DTA curve of alcohol-alkaline
suberin such exothermal maximum is absent.
The exothermal maximums at higher temperature
probably correspond to reactions of suberin
oxidative degradation.
For the alcohol-alkaline suberin the more
pronounced endothermal effect is observed in the
temperature range 40-360 ░C (Fig. 4, curve 2).
Obviously, at the lower temperatures of heating
(40-200 ░C) the desorption of water from suberin
samples takes place. The loss of mass of alcoholalkaline suberin at temperatures 200-360 ░C
can be explained by reactions of suberinic acids
polycondensation.
The results of the accomplished study show
that the suberin samples obtained by alcoholalkaline and water-alkaline hydrolysis of the
outer birch-bark possess different functional
composition that stipulates for the differences
in the processes of their thermochemical
conversions. The features of thermal behavior of
suberin obtained by different methods define the
possible areas of their application for instance in
the production of film-forming agent, for varnishand-paint compositions and of binder for wood
plate material.
Fig. 5 and 6 present the results of the
temperature influence on some characteristics
of suberin samples, obtained by alcohol-alkaline
and water-alkaline hydrolysis of the outer birchbark.
As it follows from Fig. 5, when the
temperature raises from 110 ░? to 150 ░? the
conditional viscosity of solutions of condensed
suberin samples increases from 40 and 32 to
103 and 93 s for water-alkaline and alcoholalkaline suberin accordingly. The sample of
condensed water-alkaline suberin, treated at
160 ░?, practically does not dissolve in styrene,
but it swells with the formation of colloidal
solution. The increase of condensation
temperature of alcohol-alkaline suberin to
180 ░? raises the conditional viscosity of
styrene solution to 110 s.
As it follows from Fig. 6, the degree
of light transmission of solutions of both
water-alkaline and alcolhol-alkaline suberin
samples condensed at temperatures 110-120 ░?
decreases insignificantly. The further increase
of condensation temperature of water-alkaline
suberin to 155а ░? leads to the sharp reduction
of its solubility. Increasing of the condensation
temperature of alcohol-alkaline suberin to 180
░? reduces the degree of light transmission of
its styrene solution to 51 %. The polymeric resin
sample, obtained by the condensation of alcohol-
? 360 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Irina G. Sudakova, Boris N. Kuznetsov,.. Functional and Thermal Analysis of Suberin Isolated from Birch Bark
Table 2. Main characteristics of varnish compositions, containing suberin rezin (25 % mass.) in styrene solution
Characteristics
Appearance
Water-alkaline suberin
Alcohol-alkaline suberin
Varnish PF 060
Buff, opalescent
Fallow, transparent
Transparent
103
93
90
0.7
1.2
1.0
46
18
24
Conditional viscosity, s
Elasticity when bent, mm
Drying time to Degree 3 at
200 ░C, h
Table 3. Influence of pressing temperature on physico-mechanical characteristics of wood plate material
Binding agent*
Water-alkaline
suberin
Alcohol-alkaline
suberin
Pressing
temperature, ░?
Density, kg/m3
Bending
strength, ?P?
Water
absorption for 2 hours, %
130
621
29
21
140
664
31
15
150
745
34
11
130
609
27
24
140
635
35
17
150
711
31
19
* 30 % relative to mass of press-composition
alkaline suberin at the temperature 215 ░? is
practically insoluble in styrene.
The water-alkaline and alcohol-alkaline
suberin samples, condensed at the temperature
150 ░?, were used as film-forming components
in varnish compositions, their characteristics are
presented in Table 2. For comparison the same
characteristics of commercial varnish PF-060 are
shown in this table.
The pressing temperature influence on
physico-mechanical characteristics of plate
material samples, produced in the conditions
when the content of suberin binding agent in the
press-compositions was 30% mass (Table 3).
The obtained data show that the increase
of pressing temperature from 130 ░? to
150 ░? at the pressure 10 MPa results in the
growth of plate materials density (from 609 to
new chemical bonds (most probably ester ones)
between suberin and wood filler and, hence, the
physico-mechanical characteristics of wood plate
materials are improved.
The use of suberin obtained by alcoholalkaline hydrolysis of the outer birch-bark as a
binding agent, the mechanical strength and water
resistance of plate composites have extreme
temperature dependence. The wood composite
materials, produced at the pressing temperature
140 ░?, possess maximum strength properties.
The further increase of pressing temperature
promotes condensation reactions between
suberinic acids; as a result, the part of binder
agent does not participate in the wood composite
formation. This results in deterioration of the
strength property of plate materials.
Based on the accomplished study, there
745 kg/m3), their bending strength and water
resistance. When pressing in high temperature,
obviously, there occurs the formation of gridtype structures due to the generation of the
may be given certain practical recommendations
on using water-alkaline and alcohol-alkaline
suberin. Due to its lower thermal stability, wateralkaline suberin should be used in thermoplastic
? 361 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Irina G. Sudakova, Boris N. Kuznetsov,.. Functional and Thermal Analysis of Suberin Isolated from Birch Bark
compositions produced and exploited in the
temperature range 40 ? 310 ░?. Alcohol-alkaline
suberin can be recommended for manufacturing
the more heat-resistant materials and coating.
Conclusion
The functional composition and the processes
of thermal-oxidative degradation of suberin
samples obtained by water-alkaline and alcoholalkaline hydrolysis of outer birch-bark were studied
by IR-spectroscopy, TGA and DTA methods. It
was shown that the partial hydrolysis of suberinic
polymer occurs in water-alkaline solution, while
the more complete alcohol-alkaline hydrolysis of
outer birch-bark yields the mixture of suberinic
acids. The alcohol-alkaline suberin destruction
occurs at higher temperatures than that of wateralkaline suberin. The basic weight loss of suberin
is observed at 340-400 ░? and 410-440 ░?. At these
temperatures the loss of weight is 64 % and 91 %
for samples of suberin, obtained by water-alkaline
and alcohol-alkaline hydrolysis of outer birchbark accordingly. It was shown that the method of
suberin isolation from birch-bark determines the
chemical composition of suberin samples and their
properties. The use of water-alkaline and alcoholalkaline suberins as film-forming materials and
binding agent was suggested.
References
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
Kuznetsov B.N., Kuznetsova S.A., Tarabanko V.E. The New methods of obtaining of chemical
products from Siberian tree biomass. Russian Chemical Journal. XLVIII (2004). N3. P.4.
(in Russian)
Kislitsyn A.N. Extractive substances of the birch bark: separation, composition, characteristic,
using. Wood Chemistry. 1994. N3. P.10. (in Russian)
Sudakova I.G., Kuznetsov B.N., Ivanov I.P, Ivanchenko N.M. The wood protection mixtures on
the base of birch bark suberin. Chemistry of Plant Raw Materials. 2005. N1. P.59. (in Russian)
Sudakova I.G., Kuznetsov B.N., Ivanov I.P, Ivanchenko N.M. Film-forming materials production
from birch bark suberin. Chemistry of Plant Raw Materials. 2004. N1. P.31. (in Russian)
Sudakova I.G., Kuznetsov B.N., Ivanov I.P., Ivanchenko N.M. The obtaining of wood fire-proof
compositions on the base of birch bark suberin. Vestnik Krasnoyarsk State University. 2006.
P. 101. (in Russian)
Sudakova I.G., Kuznetsov B.N. Pressed biofuels with improved characteristics. Proc. Siberian
International Forum on Biotechnology. Krasnoyarsk, November, 20 ? 23, 2007. P. 95. (in Russian)
Kuznetsov B.N., Levdanskiy V.A., Eskin A.P., Polezhaeva N.I. Betulin and suberin extraction
from the birch bark, activated by explosive autohydrolysis. Chemistry of Plant Raw Materials.
1998. N1. P.5. (in Russian)
Mironov V.A., Yankovskiy S.A. Spectroscopy in organic chemistry. M.: Chemistry. 1985. 159 p.
(in Russian)
Zhuchenko A.G., Cherkasova A.I. The motivation of the study direction on birch bark recovery.
The Collected Papers, SVERDNIIPDREV. M.: ?Timber industry?. 1969. Issue 4. P.80. (in
Russian)
Nikanisi K. Infrared spectra and structure of organic compounds. M.: Mir. 1965. 319p. (in
Russian)
Obolenskaya A.V., Schegolev V.P. Chemistry of Wood and Polymers. M.: Timber industry. 1980.
368p. (in Russian)
? 362 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Journal of Siberian Federal University. Chemistry 4 (2008 1) 363-368
~~~
??? 547.914
Study of Plant Growth Promoting Activity
and Chemical Composition of Pine Bark
after Various Storage Periods
Valeri E. Tarabankoa, Olga A. Ulyanovaa,b, Galina S. Kalachovac,
Valentina V. Chuprovab and Nikolai V. Tarabankoa*
a
Institute of Chemistry and Chemical Technology of SB RAS,
42 K.Marksa st., Krasnoyarsk, 660049 Russia
b
Krasnoyarsk State Agricultural University,
90 Mira, Krasnoyarsk, 660049 Russia
c
Institute of Biophysics of SB RAS,
Academgorodok, Krasnoyarsk, 660036 Russia 1
Received 24.11.2008, received in revised form 15.12.2008, accepted 22.12.2008
Composition and content of terpene compounds in pine bark (Pinus sylvestris) after various storage
periods were studied by GLC-MS. Resin acids were found to be the main diterpenoic compounds in
the bark. Content of dehydroabietic acid in initial bark is 0.6 g/kg and it decreases three-fold after one
year of storage. High activity of pine bark after various storage periods towards risogenesis of wheat
(Triticum aestivum) was discovered. Strong correlation (r = 0.89) between growth promoting activity
of pine bark and content of dehydroabietic acid in it was found.
Keywords: terpene compounds, pine bark, GLC-MS, diterpenoic compounds, dehydroabietic acid,
plant growth promoting activity.
Introduction
The use of plant growth stimulants is a
promising field in modern agrochemistry. They
attract even more interest if they are made of
cheap and easily available waste materials.
Tree bark can be such a material. Annual
accumulation of waste bark in Russia attains
20-30 million tons. Only 10 % of this amount
is processed into commodities and millions of
tons are kept in waste piles that last many years
[1, 2]. Thus the problem of waste bark disposal
is very important.
*
1
Chemical composition of fresh pine bark
is studied in detail in papers [3, 4]. However,
changes in pine bark composition in the process
of its storage is practically unresearched.
The present paper discusses the possibility
of obtaining plant growth stimulants by hot
water extraction from old pine bark after
various periods of its storage. Correlations
between the plant growth promoting activity
and changes in chemical composition of pine
bark after various storage periods are also
studied.
Corresponding author E-mail address: veta@icct.ru
й Siberian Federal University. All rights reserved
? 363 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Valeri E. Tarabanko, Olga. A. Ulyanova,.. Study of Plant Growth Promoting Activity and Chemical Composition?
Experimental
Bark of pine (Pinus sylvestris) sized to 3-5
mm (over 60 %) was used as the initial material
for studies. The bark was moistened to 60а %
humidity and was stored under aerobic conditions
at 18-21 0C without any additives for 3, 6, 9 and
12 months. Elemental analysis of bark samples
dried at 105 0C were accomplished by massspectrometry and atomic emission spectroscopy
methods.
To study the growth-promoting activity
water extracts of pine bark were prepared as
follows: the sample of bark sized down to 0.5-1
mm was immersed into boiling water (bark :
water ratio 1 : 20) and was let cool down for an
hour during which the mixture was occasionally
stirred. Then it was filtered through a paper filter.
The obtained water extracts were used to treat
the seeds of soft spring wheat ?Novosibirskaya
15? variety. These experiments were carried out
according to GOST 12038-84 [5] using rolls of
filter paper loaded with 100 seeds kept for 7 days
at 21-25 0C. Germinating ability and number of
roots formed were then determined. For control
experiment seeds treated with boiled tap water
were used.
To study the chemical composition of pine
bark after various storage periods and also
to isolate the diterpenoic compounds which
according to [6] have a growth-promoting
activity a sample of bark sized down to 0.5-1 mm
was extracted in a 250 ml flask by hexane (bark
: hexane ratio 1 : 20), the mixture was stirred
every hour during daytime. Total extraction
duration was 1.5 months. Then the extract was
filtered and evaporated under vacuum to 1 ml
residual volume. Determination of the chemical
composition of bark after various storage
periods was accomplished using the GLC-MS
spectrometer (GCD Plus, Hewlett Packard, USA.
Capillary column HP-5S, length 30 m, i.d. 0.25
mm. Carrier gas (helium) feed 1 ml/min. Sample
lead-in temperature 250 0C. Initial column
temperature 80 0C, final temperature 320 0C,
elevation rate 8 0C/min, 30 min isotermic mode.
Scanned mass range 45-450 m/z). Obtained massspectra were identified by comparing with data
of Finigan MAT NIST Library for GCQ/ICIS
database (Finigan DB). Mass spectra of identified
terpene compounds of pine bark are identical to
the database spectra (m/z values are listed, and
peak intensity is given in parentheses): ?- pinen
- 136 (11), 121а (15), 105 (8), 93 (100), 77а (21),
67(7), 53 (7), 41 (14); verbenol - 152 (7), 152 (7),
119 (29), 109 (100), 94 (71), 91 (50), 81 (57), 69
(71), 55 (43); 3- carene - 93 (100), 136 (14), 121
(17), 105 (13), 77 (36), 67 (10); camphene - 136
(11), 121 (57), 107 (29), 93 (100), 79 (46), 77 (29),
67 (31), 53 (13); longifolene - 204 (17), 189 (33),
161 (92), 147 (26), 135 (43), 121 (36), 119 (43), 94
(100); abietic acid - 302 (30), 285 (29), 239 (40),
213 (17), 197 (21), 121 (50), 105 (86), 91 (100);
kauren-18-carboxylic acid - 302 (21), 287 (36),
241 (21), 187 (21), 133 (50), 119 (54), 105 (91), 91
(100); dehydroabietic acid - 300 (23), 285 (73),
239 (100), 197 (48), 159 (15), 107 (85), 129 (38),
91 (37); ?-sitosterol - 414 (13), 255 (13), 163 (33),
145 (58), 121 (60), 107 (85), 81 (100), 67 (75);
stigmast-4-en-3-one - 412 (7), 370 (7), 289 (7),
229 (21), 149 (24), 124 (100), 95 (33), 55 (50).
Obtained experimental results were
processed by regression and correlation analysis
methods.
Results and Discussion
Pine bark contains all necessary elements
which can be available to plants after bark
mineralization. Element content decreases with
the order (element content mg/kg is given in
parentheses): Ca (5397) > K (913) > Al (681) > Mg
(524) > Fe (407) > ? (290) > Na (165) > Mn (116) >
Zn (17) > Cu (15) > B (4.40) > Ti (4.00) > Ni (1.00)
> As (1.00) > Cr (0.90) > Pb (0.90) > Li (0.85) >
V (0.75) > Cd (0.20) > Sr (0.14) > Ba (0.13) > Mo
? 364 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Valeri E. Tarabanko, Olga. A. Ulyanova,.. Study of Plant Growth Promoting Activity and Chemical Composition?
Monoterpenes
Diterpenes
Sesquiterpenes
Phytosterenes
14%
30%
a)
2%
54%
9%
b)
47%
0%
2%
c)
42%
45%
55%
0%
0%
d)
39%
34%
e)
61%
66%
Fig. 1. Changes in terpene compounds content in hexane extract of pine bark after various storage periods:
a) fresh bark, b) 3 months, c) 6 months, d) 9 months, e) 12 months
(0.08) > Cs (0.02) > Be (0.01). These results show
that content of toxic elements is low compared to
maximum permissible concentrations [7].
Total yield of hexane extract of initial pine
bark and bark stored for 3, 6, 9 and 12 months was
4.5, 2.5, 2.5, 2.3 and 4.2 % of air-dry bark sample
mass respectively. GLC-MS analysis data show
that diterpenoic compounds are predominant in
extracts of bark stored for 3-9 months (42-61 %
of total terpene compounds amount), and only
after a one year of storage its content decreases
to 34а% (Fig. 1).
The following compounds in hexane extracts
were identified by the GLC-MS method: bicyclic
monoterpenes ? ?-pinen, 3-carene, camphene,
verbenol; tricyclic sesquiterpene ? longifolene;
tricyclic diterpenes ? abietic acid, dehydroabietic
acid, kauren-18-carboxylic acid.
?-pinen can be noted as one of monoterpenoic
compounds prominent in the fresh bark extract
(10 %), but its content decreases by 3.4 times
after 3 months of storage. It can be result of its
volatilization during the bark was stored under
aerobic conditions as well some oxidation to
verbenol is possible. Insignificant amounts of
other monoterpenoic compounds (verbenol,
3-carene, camphene) were discovered. After 6
months of bark storage monoterpenes are not
found in extracts.
Diterpenes are predominant among the
identified terpenoic compounds. Abietic acid
which is found in fresh bark is unstable and
easily oxidized [8]. After 3 and more months
of bark storage it is not found in the extracts.
The predominant diterpene is dehydroabietic
acid which is not oxidized by oxygen and is
more stable. Its content in hexane extract can
make up 16 %. After 9 months of bark storage
the amount of dehydroabietic acid remains
high and only in extract of bark after one
year of storage its amount decreases by three
times. Depending on the bark storage duration
probability of dehydroabietic acid identification
in hexane extracts according to Finigan DB
spectra is 89 - 93 %.
It is known that abietic acid has growthpromoting activity [6]. Do other diterpenoic
compounds have this quality? Hereinafter
? 365 ?
85
WE of bark after 12 months storage
101
113
109
109
115
100
Number of roots formed, % of control
experiment
? 366 ?
0
0
6
9
12
0
0
0
1.05 (0.04)
0.88 (0.03)
sesquiterpenes
5.32 (0.20)
16.60 (0.61)
16.55 (0.61)
21.86 (0.81)
26.06 (0.97)
diterpenes
10.15 (0.38)
10.64 (0.39)
13.59 (0.50)
25.09 (0.93)
6.58 (0.24)
phytosterenes
0
0
0
0
2.71 (0.10)
abietic acid
5.32 (0.20)
16.60 (0.62)
12.89 (0.48)
18.75 (0.69)
16.19 (0.60)
dehydroabietic
acid
Compound content in extract, % and content in initial bark, g/kg (in parentheses)
0
0
3.66 (0.14)
3.11 (0.12)
7.16 (0.27)
kauren-18carboxylic acid
0.40
0.24
0.86
0.63
0.49
0.93
0.32
Monoterpenes
Sesquiterpenes
Diterpenes
Phytosterenes
Note: here and hereinafter r ? correlation coefficient, r2 ? determination coefficient.
0.10
r2
r
Compounds
Table 3. Correlations between a number of wheat roots formed during germination versus terpenoic compounds content in bark extracts
4.57 (0.17)
2.01 (0.07)
3
14.60 (0.54)
monoterpenes
Fresh bark
Bark storage
duration, months
Table 2. Content of terpenes in extracts of pine bark after various storage periods and number of wheat roots formed
89
90
WE of bark after 9 months storage
WE of bark after 3 months storage
WE of bark after 6 months storage
93
90
WE of fresh bark
84
Germinating ability,
%
Water ? control experiment
Seed treatment variant
Table 1. Influence of pine bark water extracts (WE) on germination of wheat seeds, лNovosibirskaya 15╗ variety
262
294
284
284
299
Number of wheat roots
per 100 seeds
260
(control experiment)
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Valeri E. Tarabanko, Olga. A. Ulyanova,.. Study of Plant Growth Promoting Activity and Chemical Composition?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Number of roots per 100 seeds
Valeri E. Tarabanko, Olga. A. Ulyanova,.. Study of Plant Growth Promoting Activity and Chemical Composition?
305
300
y = 1,9642x + 257,67
R2 = 0,8027
295
290
285
280
275
270
265
260
255
0
5
10
15
20
Dehydroabietic acid content in extract, %
Fig. 2. Dependence of number of wheat roots formed versus dehydroabietic acid content in extract
described results of correlation analysis indicate
that dehydroabietic acid also has this quality.
When treated by water extracts of pine bark
after various storage periods seeds germinating
ability increases by 6-11 %. Evidently, this
extract stimulates cell division which results
in 9 - 15 % increase of roots number during
germination of wheat seeds compared to control
experiment.
Table 2 presents data on terpenoic
compounds content in extract and number of
wheat roots formed versus bark storage duration.
These results demonstrate that with increase of
bark storage duration the content of monoterpenes
and diterpenes decreases gradually. The most
stable diterpenoid is dehydroabietic acid which is
present in bark throughout the time of research.
Table 3 presents correlation dependencies of
number of wheat roots formed during germination
versus terpenoic compounds content in bark
extracts.
Correlation dependencies of number of
roots formed versus content of monoterpenes,
sesquiterpenes and phytosterenes are defined
as weak and medium. Strong correlation
dependence (r = 0.93) is observed for number
of roots formed versus content of diterpenes.
Diterpenoic compounds are precursors of
gibberellins. Obtained results agree with data
of other researchers [9] which indicate that
diterpenes are intermediates in biosynthesis
of gibberellins. Metabolic path of gibberellins
synthesis, determined by use of 14C compounds
can be represented by the following schematic:
acetate ? melavonate ? numerous reformations
? kaurene (diterpene) ? gibberellin [9].
Among identified diterpenoic compounds
in extracts are: abietic acid, dehydroabietic acid
and kauren-18-carboxylic acid. Which of these
diterpenes has the stronger influence on the
growh-promoting effect? To answer this question
correlation dependencies of number of wheat roots
formed versus content of individual diterpenoids
in extracts were studied (Table 4).
The strongest correlation (r = 0.89) is
observed for dependence of number of roots
formed versus amount of dehydroabietic acid in
an extract (Fig. 2):
y=1.9642x + 257.67; r2 =0.8027,
where y ? total number of wheat roots formed, x ?
dehydroabietic acid content in extract, %.
? 367 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Valeri E. Tarabanko, Olga. A. Ulyanova,.. Study of Plant Growth Promoting Activity and Chemical Composition?
Correlation dependencies of number of roots
formed versus content of abietic acid or kauren18-carboxylic acid are weaker.
Thus the results of the present research
demonstrate that bulk waste material of wood
processing industry ? pine bark can be utilized
to obtain promising natural plant growth
stimulants, and that the most active component
that determines the growth-promoting activity is
dehydroabietic acid.
References
1.
2.
3.
4.
5.
6.
7.
8.
9
Varfolomeev L.A. Preparation of industrial composts based on solid waste from wood processingа/
VNIITEIAgroprom, Moscow, Russia. 1992. 52 p.
Sadovnikova L.K., Orlov D.S., Lozanovskaja I.N. Ecology and environment protection in case of
chemical contamination / Vysshaya shkola, Moscow, Russia. 2006. 334 p.
Dejneko I.P., Dejneko I.V., Belov L.P. Study of pine bark chemical composition // Russian journal
of chemistry of vegetative raw material. 2007, 1, pp. 19-24.
Permjakova G.V., Loskutov S.R., Semenovich A.V. Extraction of conifers bark by water with
monoethanolamine additive // Russian journal of chemistry of vegetative raw material. 2008, 1,
pp. 37-40.
GOST 12038-84. International standart: Seeds of agricultural crops. Germination ability
determination methods / Standarts. Moscow. Russia. 1985. 57 ?.
Pentegova V.A., Dubovenko Zh.V., Raldugin V.A., Schmidt E.N. Terpenoids of conifers / Nauka,
Novosibirsk, Russia. 1987. 96 p.
Toxic chemicals. Inorganic compounds of elements of I-IV groups. Reference book / Khimija,
Leningrad, SU. 1988. 512 p.
Grjaz'kin A.V., Evdokimov A.M., Egorenkov M.A. et al. Boxing and secondary forest use. College
textbook / Ecologija, Moscow, Russia, 1993. 304 p.
Glaston A., Davies P., Satter R. The Life of the green plant. Translation from English / Mir,
Moscow, SU. 1983. 552 p.
? 368 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Journal of Siberian Federal University. Chemistry 4 (2008 1) 369-375
~~~
??? 547, 597
??????? ????????????? ???????
?? ?????????? ??????????? ?????????? ? ????????,
??????????? ? ???????? ???????
???????? ?. ???????????,?, ????????? ?. ???????????,
????? ?. ?????????,?*
?
???????? ????? ? ?????????? ?????????? ?? ???,
??. ?. ??????, 42, ??????????, 660049 ??????,
?
????????? ??????????? ???????????,
??. ?????????, 79, ?. ??????????, 660041 ?????? 1
Received 24.11.2008, received in revised form 15.12.2008, accepted 22.12.2008
??????? ??????? ????????????? ??????? ?? ?????????? ??????????? ?????????? ? ????????
???????, ???????? ? ???????????. ???????????, ??? ? ??????????? ????????????? ???????
??????????? ?????????? ? ????? ???????? ??????? ?????????? ? ???????????? ?????????
??????????, ? ? ????? ???????? ? ??????????? ????????? ??????? ???????????? ??????????
? ???????????.
???????? ?????: ?????????, ????????????? ???????, ????????????, ????????????,
???????????, ???????? ??????????.
????????
?????????? ?? ???? ?????? ?????????,
? ????? ??? ?????????????? ??????????? ???????? ????????????? ????????????? ??????????? [1,2].
??????? ? ?????????? ?????????????
????? ? ??????? ????? ? ???????????????
?????? ????????? ???????????? ??? ????????????? ?????????? ???????????, ?
?????????, ????????? ???????? ??????????????? ? ??????????? (19?,28-???????????3-??) ? ?????????? ?? ???????? ????????.
??????? ???????????? ?????????? ? ??????????? ???????????? ? 1922 ?. ?????
????????? ?????????? ??????? 88 %-???
*
1
?????????? ???????? ? ???????????
????????? ????????????? ???????? ???????????? ??????????? ?????. ?? ?????
?? ????????????? ?????, ????? ????????
???????????, ???? ??????????? ???????????? ??? ????????? ?????????? ????????
???????? ? ??????????? ???????????????
???????????? [3].
???????????? ?????????? ? ???????????
????? ???? ???????????? ? ????? ???????
??? ?????????????????? ??????? [4]. ??????
? ???? ???????? ? ??????? ?? 20 % ?????????? ???????? ??????? ???????????? ? 20,28??????-19?H-?????-3?-??, ??? ???????????
??????? ????? ????????????.
Corresponding author E-mail address: bnk@icct.ru
й Siberian Federal University. All rights reserved
? 369 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
???????? ?. ??????????, ????????? ?. ??????????, ????? ?. ????????. ??????? ????????????? ????????
??????? ???????? ? ????????? ???????????? ? ???????? ????????????? ????????
??? ????????? ?????????? ? ???????????? ? ???????????? ??????? ??? ???????
???????, ??????????????? ?? ??????????
??? ?????? ???????? [5], ? ????? ??? ?????????? ?????????? ? ??????? 4-8 ????? ?
????????, ???????????, ????????, ???????
??? ?????? ? ??????????? ?????????????
??????? [6].
??????? ???????????? ?????????? ???????? ? ???????? ??????????? ??? ??????????????? ???????????? ?????? [7-9]. ???????? ?????????? ? ??????? ????? 90 % ?????
???? ??????? ?????????????????, ????? ????????? ?????????? ????????? ??????? ? ???????? ??????? ? ??????????? ????????????а?
?-??????????????????? [10].
? ?????? ?????? ? ????? ????????????????? ??????? ??????? ???????????? ? ????????? ?????????? ??????? ??????? ????????????? ??????? ?? ??????????? ??????????
? ????? ????????, ??????????? ? ???????? ???????.
????????????????? ?????
??-??????? ???????? ?? ????? ?????????????? Vector-22 ????? Bruker ?
????????? KBr, ??????? H1??? ????? ??
???????????? Bruker AM-400 (200 ???) ?
?????????????????. ? ???????? ???????????
????????? ??????????? ?????????? ??????
???????? ?????????? (?H=7,30 ?.?).
???????? ?? ????? ??????? ? ????????
?????????? ???????????? ??????? ??? ??
?????????? Silufol UV-254 ? ??????????????
??????? ????????????? ?????????-????????????????? ??????? (100:2:0,5), ??????????
????????? ???????????? ? ????? ????. ?????????? ?????? ???????? ?? ??????????
??????????? Flash E A??-1112 (Thermo Quest
Italia).
????????? ??????? ?? ??????? ??????
????????? ??????? [11]. ? ???????? ?????????? ??? ????????? ???????????? ???????????
? ???????? ??????????, ?????????? ????????? ???????? [6,12].
??? ????????? ???????????? ? ?????
??????? 250 ??, ?????????? ???????? ?????????????, ????????? 4,42 ? (0,01 ????)
??????????, ???????? 70 ?? ???????? ? ????????? 15-40 ? ????????????? ???????.
????? ???????? ?? ????????? ???? ? ??????? 15-20 ?. ?? ????????? ?????????? ?? ??????????? ????? ??? ???????? ?? ??????????? ?????????? ???????? ???????, ???????
?????????? 100 ?? ????. ???????? ???????
??????????????? ? ????????? ?? ???????
???????????????? ????? ?? ???????????
????????? ???. ?????? ?????????? ? ????????????????????? ?? ???????. ??????? ??????????? ???????????? ????????? ???????
??? ?? ?????????? Silufol. ?????? ??????????? ???????? ?????????? ??????? ??????????? ???????.
????????? ????????? ?????????? ???????????? ????????? ???????. ? ?????
??????? 250 ??, ?????????? ???????? ????????????? ????????? 4,42 ? (0,01 ????) ??????????, ???????? 50 ?? ??????? ????????
??????? ? ????????? 5-40 ? ?????????????
???????. ????? ???????? ?? ????????? ????
? ??????? 60-150 ???. ?? ????????? ?????????? ??????????? ????? ???????? ? ??????
??????? 1 ?, ? ??????? ????????? 200-250
?? ???????? ????. ???????? ??????? ??????????????? ? ????????? ?? ???????
???????????????? ????? ?? ???????????
????????? ???. ????? ?????? ?????????? ?
????????????????????? ?? ???????. ???????
??????????? ????????? ?????????? ????????? ??????? ??? ?? ?????????? Silufol. ?????? ??????????? ???????? ?????????? ??????? ??????????? ???????.
? 370 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
???????? ?. ??????????, ????????? ?. ??????????, ????? ?. ????????. ??????? ????????????? ????????
?????????? ? ??????????
???????????, ??? ? ??????????? ????????????? ??????? ??????? ????? ???????????? ??????????? ??? ?????????? ???????
???????????? ?????????? ? ????? ????????
??? ??????????? (????. 1). ????????????? ?????????? ????????????? ??????? ? ????????????????? ???????? ????????????. ?????????? ??????????? ??????? ????????????
?????????? (????. 1).
??? ??????? ?? ??????????? ? ????. 1
??????, ???????????? ????? ????????????
(?? 94 %) ??????????? ??? ????????? ?????????? ? ????????? ??? ???????????? ??????,
?????????? 42-46 % ????????????? ??????? ? ??????? 15-16 ?.
?????? ???????????? (C30H50O2), ??????????? ????????????? ?????????? ? ??????????? H3PO4, ??????????? ??????????
???????? (???????: ? (%) 81,40 ? 81,67, ? (%)
11,21а ? 11,48; ?????????: ? (%) 81,45, ? (%)
11,31). ??????????? ??? ????????? 275-277 ░?.
???????? ??????????? ???????????? ???????????? ??????? H1 ???-?????????????.
H1 ???-?????? ?????????? ????? ???????
???? ???????? ???????? ??????? ????? (4,71
? 4,59 ?.?.), ??????????? ??? ???? ??????????? ??????????, ??????? ??????????????? ??????. ? ?1 ???-??????? ????????????
(???. 1) ??????? ????????????? ???? ???????? ???????????, ??? ??????????????? ? ?????? ??????????? ?????????? ? ???????????.
??? ???????? ? ?????? [3], ??? ?????????
?????????? ? ???????? ??????? ? ???????????
?????? ??????? ?????????? ????????????
?????????? ? ??????????? ? ???????????? ?
???? ???? ?????????????? ?? ????????? ????????????? ?????? ? ???????????? ???????
????????????. ????? ???? ???????, ??? ?
??????????? ????????????? ??????? ??????????? ?????????? ? ????? ???????? ???????
????? ??????????? ?? ???? ?? ????, ??? ? ?
??????????? ?????? ??????? ? ????????????
??????? ????????????. ??????, ???? ????
???????????, ??? ??? ????????? ??????????
? ???????? ??????? ? ??????????? ????????????? ??????? ?????????? ???????? ?????????? (???. 2), ?.?. ???????? ??????????????
????????? ???????? ???????????? ?????????? ? ?????? ????????.
???? ??????? ??????????? ?????????? ? ????? ???????? ??????? ? ???????????
??????? 1. ?????? ?? ???????????? ?????????? ? ??????????? ? ??????????? ????????????? ???????
? ?????
????????????
2
3
4
5
???????
1
?????????? ?3??4, ?
(% ???)
????????????????? ???????, ?
????? ????????????
(% ???)
15 (23,8)
18
85
20 (29,4)
18
88
25 (34,3)
18
90
30 (38,5)
17
92
35 (42,2)
16
94
40 (45,5)
15
93
7
15 (23,8)
20
87
20 (29,4)
20
88
25 (34,3)
20
89
8
9
10
11
12
??????????
6
30 (38,5)
18
91
35 (42,2)
15
94
40 (45,5)
15
94
? 371 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
???????? ?. ??????????, ????????? ?. ??????????, ????? ?. ????????. ??????? ????????????? ????????
???. 1. H1 ???-?????? ????????????
???????? ??????????
???. 2. ????? ??????????? ?????????? ? ??????????? ????????????? ??????? ? ????????? ??????
? 372 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
???????? ?. ??????????, ????????? ?. ??????????, ????? ?. ????????. ??????? ????????????? ????????
??????? 2. ??????? ???????????? H3PO4 ? ????????????????? ???????? ?? ????? ????????? ??????????
? ????? ???????? ???????
? ?????
?????????? ?3??4, ?
(% ???.)
????????????????? ???????,
???
????? ????????? ??????????,
% ???.
1
5 (9,1)
150
81
2
10 (16,7)
150
83
3
15 (23,0)
120
87
4
20 (28,6)
100
89
5
25 (33,3)
90
95
6
30 (37,5)
60
95
7
40 (44,4)
60
94
???. 3. H1 ???-?????? ????????? ??????????
????????????? ??????? ????????? ????????????.
??? ??????? ?? ??????????? ? ????. 2
??????, ??????? ????? ????????? ?????????? (????? 80 % ???.) ??????????? ??? ??? ???????????? ????????????? ??????? ??????
9 % ???. ? ????????????????? ??????? 150
???. ???????????? ????? ????????? ?????????? (95 % ???.) ??????? ? ????? ????????
??????? ??? ????????????? ?????????????
??????? 30-35 % ???. ? ?????????????????
??????? 60-90 ???.
?????? ????????? ?????????? (C34H54O4),
??????????? ??????????????? ??????????
???????? ???????? ? ??????????? ????????????? ???????, ??????????? ??????????
???????? (???????: ? (%) 77,63 ? 77,68, ? (%)
10,01 ? 10,43; ?????????: ? (%) 77,57, ? (%)
10,27). ??????????? ??? ????????? 222а ░?).
???????? ?????????? ???????? ???????????? ???????? ??- ? H1 ???-?????????????.
???, ??? H1 ???-?????? (???.а 3) ?????????
????????? ??????? ????????? ??????????, ??????????? ????????? ??????? [12].
? 373 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
???????? ?. ??????????, ????????? ?. ??????????, ????? ?. ????????. ??????? ????????????? ????????
??????
???????? ???????????? ??????? ??????? ???????????? ?? ?????? ???????????? ??????????? ??????????: ? ???????????
????????????? ??????? ? ????? ????????
??? ??????????? ????????? ???????????? ?????????? ? ???????????, ? ? ????? ????????
??????? ? ??? ?????????????? ? ???????? ??????????.
??????????? ?????? ??????? ?????????? ??????? ?????????????? ? ???????????? ??????????, ?????????????? ?????????
????????? ?????????? ? ??????? 95 % ???. ?
???????????? ? ??????? 94 % ???.
?????? ????????? ??? ?????????? ????????? ????????????? ???????? ????? ?????
(????? 18G102).
?????? ??????????
1.
2.
3.
4.
5.
6.
7.
8.
9.
?????????? ?.?., ??????? ?.?., ????? ?.?., ??????? ?.?., ????????? ?.?. ??????? ? ???
???????????. ????? ? ????????????? ?????????? // ????? ? ????????? ???????????
????????. 2003. ?13. ?. 1-30.
??????? ?.?., ????????? ?.?., ?????????? ?.?., ??????? ?.?., ????? ?.?., ??????? ?.?,
????????? ?.?. ?????? ? ????????????????? ?????????? ?????? ????????, ???????????
??????? ? ???????????? // ??????-???????????????? ??????. 2005. ?.39. ?8. ?. 9-12.
Barton D.H.R., Holness N.J. Triterpenoids. Part V. Some Relative Configuration in rings C.D. and
E. of the ?-Amyrin and the Lupeol Group of Triterpenoids // J. Chem. Soc. 1952. P. 78-92.
Errington S.G., Chisalberti E.L., Jefferies P.R. The Chemistry of the Euphorbiaceae. XXIV. Lup20(29)-ene-3?,16?,28-triol from Beyeria brevifolia var. brevifolia // Austr. J. Chem. 1976. 29. N 8.
P. 1809-1814.
Lavoie Serge, Pichette Andre, Garneau Francois-Xavier, Girard Michel, Gaudet Daniel. Synthesis of
betulin derivatives with solid supported reagents // Synth. Commun. 2001. 31. ? 10. ?. 1565-1571.
???. 2174126 ??. ?????? ????????? ????????????. ???????? ?.?., ???????? ?.?. ?????.
27.09.2001.
??????? ?.?., ?????????? ?.?., ???????? ?.?., ???????????? ?.?., ??????? ?.?., ???????
?.?., ???????? ?.?., ???????? ?.?., ??????? ?.?., ????? ?.?., ????????? ?.?. ?????? ??????
?????????????? ?????? ?????? ? ?? ?????????????????? ?????????? // ???????????????
?????. 2000. ?.26. ?3. ?. 215-223.
??????? ?.?., ?????????? ?.?., ???????????? ?.?., ??????????? ?.?., ??????? ?.?.,
??????? ?.?., ????? ?.?., ???????? ?.?., ????????? ?.?., ????????? ?.?., ??????????
?.?. ?????? ? ????????????????? ?????????? ???????????? ???????? // ???????????????
?????. 2002. ?.28. ?6. ?. 543-550.
??????? ?.?., ????????? ?.?., ?????????? ?.?., ??????? ?.?., ????? ?.?., ??????? ?.?.,
????????? ?.?. ?????? ? ????????????????? ?????????? ?????? ????????, ???????????
??????? ? ???????????? // ??????-???????????????? ??????. 2005. ?.39. ?8. ?. 9-12.
10. ???. 2150473 ??. ?????? ????????? ????????? ??????????. ???????? ?.?., ????????
?.?., ???????? ?.?., ??????? ?.?. ?????. 10.06.2000.
11. ???. 2074867 ??. ?????? ????????? ????????. ???????? ?.?., ?????????? ?.?., ???????
?.?., ????? ?.?. ?????. 10.03.1997.
? 374 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
???????? ?. ??????????, ????????? ?. ??????????, ????? ?. ????????. ??????? ????????????? ????????
12. ???. 2150473 ??. ?????? ????????? ????????? ??????????. ???????? ?.?., ????????
?.?., ???????? ?.?., ??????? ?.?. ?????. 10.06.2000.
Influence of Orthophosphoric Acid on Chemical Transformations
of Betulinol in Butanol, Isobutanol, and an Acetic Acid
Vladimir A. Levdanskya,b, Alexander V. Levdanskya
and Boris N. Kuznetsova,b
a
Institute of Chemistry and Chemical Technology SB RAS,
42 K. Marx st., Krasnoyarsk, 660049 Russia
b
Siberian Federal University,
79 Svobodny, Krasnoyarsk, 660041 Russia
Influence of orthophosphoric acid on chemical transformations of betulinol in an acetic acid, butanol,
and isobutanol was investigated. It was established that in the presence of orthophosphoric acid
the transformation of betulinol in acetic acid medium occurs with formation of betulinol diacetate;
in butanol and isobutanol medium the reaction of isomerization of betulinol into allobetulin takes
place.
Keywords: betulinol, orthophosphoric acid, acylation, isomerization, allobetulin, betulinol diacetate.
? 375 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Journal of Siberian Federal University. Chemistry 4 (2008 1) 376-388
~~~
??? 541.45/.459:541.182.8/.84:544.774:548.313
????????? ???????????? ????????
?????????????????????? ??????????? ????????? ???-41
? ?????????? ????????????????? ?????????
???????? ?. ????????*, ???????? ?. ?????????,
??????? ?. ?????????, ?????? ?. ??????,?
?
???????? ????? ? ?????????? ?????????? ?? ???,
??. ?. ??????, 42, ??????????, 660049 ??????
?
???????????? ??????? ????? ?? ???,
?????????????, 50, ??????????, 660036 ??????
?
????????? ??????????? ???????????,
??. ?????????, 79, ??????????, 660041 ?????? 1
Received 24.11.2008, received in revised form 15.12.2008, accepted 22.12.2008
??????? ??????? ????????? ????? ?????????????????? ??????????? (????????????, ?????????
??????????? ? ???????????, ?????? ? ???????? ?????? ?????? ??? 100 ??, ?? ???????????????
???????) ?? ????????? ???????????? ???????? ??????????? ??????????????????????
????????????? ??????????? ????????? ???-41. ?????????????? ??????????? ????????? ?
??????? ??????????????, ??-?????????????, ???????????? ??????? ? ??????? ?????????
?????. ????????? ??????????? ???????? ? ?????????? ???????????? ??????????? ?????.
??????????, ??? ??? ???-41 ??-?? ???????????? ???????? ??????? ?????????? ????????????,
?????????? ??????? ???????? ? ?????????? ?????????. ??? ?????? ????????? ??? 100 ??
???????? ?????????? ???????????? ?????????? 3-4 ??/??2. ???????? ?? ?????????? ????????
?????????????? ????????? (?????????? ???????????, ?????, ???????? ???????) ????????
???????????. ????? ???????, ??????? ??????????? ?? ????????? ???????????. ?????? ?????
?????? ?? ???????? ??????? ?????????, ?? ?? ?????? ?? ????????? ???????????? ????????.
???????? ?????: SiO2, ???????????? ????????????????????? ???????, MCM?41, ???????????
?????, ??????????? ??????, ??????????????????? ??????, ??-?????????????.
????????
????????? ???????????????? ?????????? (???) ???????? ?????? ????????????? ???????????? ??????????, ???????????? ??????????????, ??????????????
???????????????? ? ?.?. [1, 2]. ???????????
??????????? ?????????? ? ??????????? ??*
1
????????????? ???????????? ???????????
????????? ????? ??????????? ????? SiOH (?????????????, ??????????? ? ??????????? ??????) (???. 1), ?? ?????????????
????????????? (??????????? ?????), ??????????? ???????????? ? ??????????? ?????????????.
Corresponding author E-mail address: sakozlova@gmail.com
й Siberian Federal University. All rights reserved
? 376 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
???????? ?. ???????, ???????? ?. ????????,.. ????????? ???????????? ???????? ???????????????????????
???. 1. ???? ??????????? ????? ?? ???????????
?????????? ?????????? [20]
??????? ? ?????????? ?????????????
????? ?? ?????????? ??????????? ?????
???? ????????????? ????? ?????????? ?
??????-?????????? ???????: ???????????
?????????? ?????????????? [3-5], ?????????????? [6], ??-?????????????? [7-14], ????????????????? [15-17], ?????????????????
[17-22], ??? ???????????????? ??????????? ????????????? [23, 24], ? ??????????
???????.
?????????? ?????? ???????? ?? ??????? ????????????? ??-????? ? ??????????
??????????? ??????????? (???????????????? [3], ????????? [4], ??????? ????????
[25], ???????????????-?-????????? [26] ?
??.). ? ?????????????? ?????????? ??????
???? ???????? ??????????? ????? ??? ????????? ????? ???????????, ??????????? ?
???????? 2,90-4,08 ??-?????/??2 [4]. ????
? ?????????? [27] ?????????? ??? ????????
????????? ??????????? ????????? ?? 3,63 ??
5,78 ??/??2, ??? ???????? ? 2,00-2,21 ??/??2.
????? [28] ????????, ??? ? ???????? ??????????, ?????????? ??? 170 ░?, ????? ?????????? ???? ?????????? 8 ??/??2, ?? ??? ?????
5,7 ??/??2 ???? ?????????????? ???????????? ????????. ? ??????? [25, 29] ????????,
??? ?? 1 ??2 ?????????? 4,6 ????? ??. ?? ???
? ??. [30] ?????????, ??? ???????????? ???-
????????? ????????? ???????? ????????????
????? ?????????? ????? 4,55 ??-?????/??2.
??????
??????????
?
????????????? ??????? ??????? ???? ?????
????????????????. ????? ????????????
?????? ?????????? (?.?.) ??? 3749 ???1 ????????? ??????????? ????? ??????????? ?
??????? ???? ??????????? ????? ?????????
? ??????? ??? ??????? ???????????? (????
600 ░?). ???????????? ????????? ???????
??????????????? ??????? ???? ????????
?.?. ?????????????? ????????? ???????
? 2O (1640 ??-1). ????????????? ??????, ????????? ???????? ?????????? ??????, ????? ??????? ?.?. ? ??????? 3600-3400 ??-1.
?????????????? ??????, ?????????? ??
??-?????????????, ?????????? ??????. ???????? [31] ????? ??????????? ????????????
??????????? ????? ????? ??? ?? 100 ????????? ???????? ?????????? ??????? ????????????? ? ????-?????????????????? ????????
?????? ? ??????????, ??? ??????????? ????? ????????? ??????????????????? ?????????? ????????? ? ???????? 4,2-5,7 ??/?? 2.
???????? [32], ????????? 1H-???, ?????, ???
???????????? ??????????? ????? ?? ?????????? ?????????? 4,2 ??-?????/?? 2.
??????? ? ?????????? [33] ????????????
?????? ?????????? ?? ?????????? ?????????????????????? ??????? ??? ??????????? ????? ????????????? ??-????? ?? ???????????,
??????? ? ????????? ????? ??????? ???????
?????????? [18, 20]. ????? [34] ?????????,
??? ??????? ??? ???? ??????????????? ????,
???? ?? ??????? ????????????? ??? ???????? ??????? ? ????????? 25-105 ░?, ?????? ? ?
????????? 105-180 ░?. ????? [8] ????????,
??? ??????? ???????????? ??????????????????? ??????????? ???????? ??? ??????: ??
?????? ?????? (500-600 ░?) ?????????? ??????????? ????????? ?????????? ?????? ????????????? ??????????? ?????. ?? ??????
? 377 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
???????? ?. ???????, ???????? ?. ????????,.. ????????? ???????????? ???????? ???????????????????????
?????? (600-1200 ░?) ???? ????? ???????? ????????????? ???????? ???????????. ??????
???????????? ???????? ??????????, ??? ?????? ?????????? ???????? ??? ???? ???????
? ?????? ?????? ???? ????? ???? ??-???????, ?
?????????? ???????? ???????????? ????? ??????????? ? ?????????? ??????? ?????????
[4, 6, 8-10, 15, 24, 25-29, 32, 35].
??????????? ? ????????? ?????? ???????????? ????????????????????? ???????
???-41 [36] ?????????? ??????? ????????????????? ???????????????? ??? ??????????? ?????????????? ?????????? (????????)
? ??????????? ???????????????????? ??????
? ????????????-????????? ???????? (???).
????????? ?????????? ????????? ???????????? ????? ?????? ? ????? ???????? ???. ??????? ??? - ????? 35 ┼, ??????? ?????? ?????
?????? - 8 ┼. ???????? ???????? ????????
???????????? ????? 1000 ?2/?.
???????? ?? ?????? ?????????? ??????
? ??????????????? ??????? ???????????,
????????????????????? ???????? ? ????
????? ??????????? ???????????? [37-41] ????????? ????????????? ????????. ????? ????
????????? ?????????????? ????????? ????????? ???????????? ???????? ??????????
???? ???-41 ? ??????? ??-?????????????
[10, 15, 35], ??????????? ??????? ??/???
[15, 17, 35, 42] ? ???????? ???????? ?????????? ????????? [35]: 1H ??? [17] ? 29Si ??? [15].
? ????????? ?????????????? ????????????
??? 550 ░? ??????????? ????????? ????41
???? ??????????? [17], ??? ?????????? ????????? ????????????? ???? ?? ??? ??????????? ?????????? ????? 1 ???????? ?? 1 ??2,
?????????? ?????????? ??????????? ?????
??? 550 ░? ?????????? 0,82-0,84 ??/??2, ???
1000 ░? ??-?????? ??????????? ???????????. ?? ?????? ?????? [35], ??????????????? ??????? ???-41 ???????? 0,27-0,30 OH????? ?? 1 ???? Si, ??? 4,43 ?????/?. ??? ?
?????????? [15] ?????????? ??? ???????????? ???-41 2,5 ??/??2 ? ??? л?????????????????╗ ??????? ? 3,0 ??/??2. ????? ??????
???????????? (2,5-3,0 ??/??2) ?? ?????????
? ??????? ???????????? (5-8 ??/??2) ??????
????????? ???, ??? ???-41 ????? ??????????, ?????? ?????? ?????????? ?, ??? ?????????, ?????? ???????????????? ???????????
???????? ??????? ????? SiOH-?????.
???????????? ?? ??????? ????????????? ????????? ?? ??????????? ?????????
??????????? ? ?????????? ? ???????? ???
??????????? (???????????) [43-46] ? ??????????? ??????????? ??? ????????????????????? ??????????. ? ????????? ??????
?????????????? ????????? ?????? ????????????????? ???????????, ???????????????? ?? ??????? ?? ?????????? Si-OH ?????.
???????????? ???? ?????? ?????? ???????? ?
?????? ???????????? ?????? ?????????????
??????????? ??????????? ????????? ???-41
????? ?????????? ???????????????? ???
?????????? ???????? ???????????????????
?????????.
????????????????? ?????
?????????? ????????. ?????? ???-41
????????? ?? ????????, ???????????? ? [47].
???????????? ????????: ????????????????
(TEOS): Si(C2H5O)4, ?.?.?., T? 6-09-3687-74;
???????????????????? ?????? (???Br):
C16H33(CH3O)3NBr, Aldrich (Cat.:85.582-0); ?????? ??????? ??????? 13,4 ?, ?=0,905?/??3,
?.?.?.; ?????? (EtOH), 96 % ????. ??????? ??????????? ?????????: 1 TEOS : 0,2 CTABr :
22 NH3 : 52 EtOH : 475 H2O.
3,98 ? ???Br ?????????? ? ?????????????? ???????? (400 ?? H2O ? 168 ??
EtOH) ??? ????????? ??????????? ??? ???????? ?????????????. ?? ?????????? ??????????? ????????? 89 ?? ??????? (?? 12,5).
????? ???????? ????????? 11,5 ? TEOS ?
? 378 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
???????? ?. ???????, ???????? ?. ????????,.. ????????? ???????????? ???????? ???????????????????????
??????? 1. ??????? ?????????? ????????? ??????????? ???-41
?
??????????? ???????
??????? ??? ?????????
??
?, ???
?, ░?
1
S0-ext
??????????????? ???
?
24╫4
20
2
S1-3h
????? ???
?
3
550
3
S1-20h
????? ???
?
20
550
4
S1-HCl-1?
1? HCl
?
1
100
5
S1-HCl-pH2
HCl
2
1
100
6
S1-H2O
H2O
6-7
1
100
7
S1-NH3
NH3aq
10
1
100
8
S1-HF
0,17M HF
?
╜
20
???????????? ??????? ? ??????? ???? ?????.
????? ??? ??????????? 120 ░? ? ??????? ????
????? ????????? ??????????????? ?????????. ?????????? ?????? ???????????, ????????? ????? ? ?????? ?? ??????? ??? ????????? ???????????.
? ?????? ???? ????????? ??? ??????? ?????????? ???????????? ??????????
(????????????-????????? ???????? ? ???)
?? ??????????? ????????????????? ?????????: ??????????????? (??????? S0-ext)
? ????? (S1-3h ? S1-20h). ????? ?????????? ??? 550 ░? ? ????????? ????? ? ???????
3 ? (??????? S1-3h) ? 20 ? (??????? S1-20h).
??????????????? ??? ????????? ?????????????? ???????????? ?? ??????? ???????????? ????? 1? HCl ? ????????? ?????? ?
??????????? ?? 24 ?. ?????????? ??? ???????????????? ??????? ??-?????????????.
??????? S1-20h ??????????? ????????? ????? ??????????? ????????? (????. 1): ????????? ? ???? (??????????? ?????), ? ????????? ???????? (???????? ?????) ? ? ?????????
?????? HF ? HCl.
?????? ?????????????? ????????.
?????? ????????????? ????????? ?? ????????????? X'Pert PRO ? ?????????? PIXcel
(PANalytical), ????????????? ??????????
??????????????, ??? ????????????? ?u K??????????. ??????? ??????: ???????? ?? 2?
? 0,70-10,00░, ??? ? 0,026║, ?t ? 90 ?.
????????????? ????????? ??????????? ????????? ?? ??????? ASAP 2420
(Micromeritics) ??? T=98? ? ????????? ????????????? ???????? (?/??) 0,06-0,99 ? ?????
0,015. ???????? ??????? ??????????? ???????????? ?? ?????? BET [48] ? ?????????
(p/p?) 0,06-0,25, ??????????? ???????? ? ??????? лt?plot╗ [49], ?????????? ????? ? ??
?????? лsingle point BET╗ [50, ?.30], ? ????????????? ??? ?? ???????? ???????? ?? ????????? ???????? BJH [51].
??-??????? ?????????????? ?? ???????????? Specord 75IR ? ????????? 400-4000а??-1
? ?????????????? ???????? ??????????????
??????? ? KBr.
??????????? ?????? ???????? ????????? ? ?????????? ?????? ?? ???????????
??????????? STA449-QMS403c (Netzsch). ???
???????? ? 5 ??, ???????? ?????? 40-1250 ░?,
???????? ??????? ? 10 ░?/???. ??????????
??????????? ? ?????? ?????? (30 ??/???) ?
????-?????????????????? ???????? ????????? ?????.
?????????? ???????????
??????????????????? ??????. ?? ???. 2
???????????? ?????????????? ????????????? ????????. ?? ??????????????? ????? ?????????? ?? 4-?????, ??????????? ??? ?????????? ?????????????? ????????? ????41.
????? ????????????? ??????????, ??? ???-
? 379 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
?????????????
???????? ?. ???????, ???????? ?. ????????,.. ????????? ???????????? ???????? ???????????????????????
30000
(100)
(110)
3000
2500
25000
(200)
2000
1500
20000
1000
15000
500
0
3,5
10000
4,0
4,5
5,0
(110) (200)
5000
5,5
6,0
6,5
7,0
7,5
S1-HF
S1-NH3
S1-H2O
S1-HCl-pH2
S1-HCl-1?
S1-20h
0
1,0 1,5 2,0 2,5 3,0 3,5 4,0 4,5 5,0 5,5 6,0 6,5 7,0
24, ????.
???. 2. ?????????????? ???????? (????. 2). ?? ??????? ???????????? ??????? 2? 3.5-7.5 ????. ???????????
????????? (100)/(110): ??? S1-20h, S1-HCl-1?, S1-HCl-pH2, S1-H2O, S1-NH3, S1-HF ?????????? 7.1; 5.4; 5.3;
3.5; 4.1 ? 3.1, ??????????????. ?????????? ????????? ??????? ????? ? ????????? (44.1▒0.02)
????????? ????????? ??????????????????? ?? ??????????. ????????? ????????????
????????? ??????? ??? ????????? ????????????. ????????? ?????????? ?????????
??????????? ??? ???????? ?? S1-3h ? S1-20h.
????????, ??? ?? ?????????? ?????????? ???????????? ??????? ??????????? ????????.
??????? ?????????? ?????? ??? ????????
?3-8 (???. 2) ???????????? ? ???????? ????? 1 %, ??? ?????? ????????? ????????????
????????? ?????? ? ????? ?????. ?? ??????????????? ????? ???????? ????????? ????????????????? ????????????? (??????????
????????????? ??????? ? ???????? ????? ??
????????? ? ???????), ??????? ??????? ??????????? ??? ??????????? ??????? ???????.
????? ???????, ??????????? ???? ????????? ??????????? ???????? ? ????????? ?????????? (???????????) ?????? ?????????, ?
????? ?? ????? ???????? ?????????????.
??-?????????????. ???????????? ?????????????????? ??-???????? ???????????? ?? ???. 3 ????????? ???????? S1-20h,
S1-3h ? S1-HCl-1?. ??????? S1?HCl?pH2;
S1-H 2O; S1-NH 3; S1-HF; S0?ext ?????????? ??-??????? S1-HCl-1?. ?? ????????
????????? ???????? ?????????? ????????
?????????. ??????? S1-3h, ? ????? ? ?????
??????? ?????????????? ??????? S1-20h
????? ????? ?.?. ? ?????? 3745-3750 ??-1,
??????? ???????????????? ??? ?????????
????????? (O-H) ????????????? ??????????? ????? [24, ?. 882]. ????? ??????????
?????? ???? ????????? ??????????? ?.?.
??? 3750 ??-1 ???????? ??? ???????? ????????? ? ??????? ?.?. ? ?????????? 34403480 ???1, ?????????? ???????????? ???????????? ????????. ????? ?????????
??????? ?????? ????? ??????????? ?????
?? ??????????? ? ?????????????? ?????????? ?????? ????? ????. ???????????
??????? ????? ???????? ?????? ? ??????????? 1600-1640 ???1, 2344-2368 ?? -1 [19].
??????? 250-1200 ??-1 ???????? ??? ??????, ?????????? ?????????? Si-O-Si ??????
? ????????? SiO 4.
? 380 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
???????? ?. ???????, ???????? ?. ????????,.. ????????? ???????????? ???????? ???????????????????????
80
S1-HCl-1?
S1-20h
60
40
20
00
S1-3h
80
60
2930
40
20
2360
1635
3750
810
1100
0
4000
3500
3000
2500
2000
1500
1000
470
500
-1
Q, ??
3
?????????? ??????????????, ?? /? STP
???. 3. ??-??????? ???????? (????. 1). ?.?. ??? 3750 ??-1 ????? ?????? ?? ??????????? ??????????????
???????? S1-20h ? S1-3h. ??????? S1-3h ??? ???????????? ????????, ?????????? ???? ?? ??? ???????
??????????? ?.?. ??? 2930 ??-1. ? ??????? S1-20h ?????????? ??????????? ???????? ?? ???????
???????????? ????? ????????????? ????? ????????? ????????? ? ????? ??????????? ??????? (???????
?.?. ??? 3750 ??-1 ????????????? ? ???????? 3400-3500 ??-1)
600
1
525
2
3
4
5
6
7
8
450
375
1- S1-3h
2- S1-20h
3- S1-HCl-1?
4- S1-HCl-pH2
5- S1-H2O
6- S1-NH3
7- S1-HF
8- S0-ext
300
225
150
0,0
0,1
0,2
0,3
0,4
0,5
0,6
0,7
0,8
0,9
????????????? ????????, ?/?0
???. 4. ???????? ?????????-????????? ????? ??? ??????????? ????????
? 381 ?
1,0
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
???????? ?. ???????, ???????? ?. ????????,.. ????????? ???????????? ???????? ???????????????????????
??????? 2. ????????????? ?????????????? ????????
???????????
???????
???????? ??????????? (BET),
S?? (?2/?)
????? ????? ???
(Single point BET),
V??? (??3/?)
??????? ??? (BJH),
d??? (┼)
S0-ext
831
0,58
28,9
S1-3h
1048
0,86
32,7
S1-20h
844
0,67
29,7
S1-HCl-1?
836
0,67
30,6
S1-HCl-pH2
801
0,64
28,6
S1-H2O
789
0,63
31,1
S1-NH3
749
0,61
29,1
S1-HF
748
0,60
30,0
????????????? ?????????. ?? ???.а 4
????????????
????????
?????????????????? ????? ???????????? ?????????.
?? ????????? ?????? ?? ????????? ???????????? ???????? ??? ????????? ??? ??????? (????. 2). ???????? ???????? ???,
??????????? ??????? BJH [47], ????? ??????????? ????????. ? ?????? ?????????
MCM-41, ??? ?????????? ??????? ???, ???????????? ?? ????????????? ??????, ?????????? ???????? (35▒1) ┼, ? ???? ???????,
л?????????????╗ ??????? ????? ????????
??????????? ? ????? ?? ????????? ? ???????? ??????.
???????? ?? ??????? ???????? ??????,
??????? ? ??????? S0-ext ??????????? ???????????? ?????????? ????????? ???????
???????? ??????????? ? ??????? ?????????? ????? ?? ????????? ? S1-3h. ???????????? ? ??????? 3 ? (??????? S1-3h) ?????????????? ????? ?????? ????????????? ??? ?
??????????? ???????????. ?????????? ???????????? ???????? ???????????? ??????????? ??????????, ?????????? ? ??????
??????? (??????? S1-20h).
?? ?????????? ??????????? ?? ?????????
????? (????. 2) ?????, ??? ????????? ???-41
? ????????? ????????? ??????????? ????????
? ?????????????? ?????????? ? ????????
?????????. ? ?????, ??? ??????????? ? ???????????????????? ? ??-???????????????????
???????, ?????????? ????. ?? ?????????????? ? ????. 2 ?????? ????? ?????????
?????????? ??????? ??????????? ? ?????????? ?????? ??? ???????? ????????????
????????? (S1-20h). ???????? ?????????
?????????? ??? ???????????? ???????????
????????, ???? ?? ????? ? ?????? ?????? ? HF.
????? ????????? ???-41 ????????? ? ????????????? ??????? [45-46] ?? ???????????
??????????? ???? ?? ??????????, ? ???????????? ? ???????? ? ?????????? ???????????
? ???????? ?????????? ????? ???????????
?????????? ??????? ???????????. ??????
??????????? ?????????? ??????? ??? ? ??????????? ??????????? ??? ???????? ???-41.
??????? ????? ????? ???? ??????? ? ???????????? ??????????? ??????????????????
???????? ???-41 [37-41]. ????????? ???????? ??????????? ?????? ??? ????41, ?????? ?
???????? ???????? ????? ??????????? ??????
? ???????????. ?? ????????, ?????????? ??????????? ?????????, ?????????????? ???????? ???????? ???????? ?? ???. 5. ????????
???????? ??????????? ?????? ? ???????????
??? ???? ?????????? ?????????????.
?????????? ????? ??? ???????????
??? ???????? S1-HF ? S1-NH3, ??? ????? ????
? 382 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
???????? ?. ???????, ???????? ?. ????????,.. ????????? ???????????? ???????? ???????????????????????
O
-
OH
OH
OH
Si
Si
Si
O
Si
O
O
Si
O
OH
Si
O
O
Si
O
O
O
-
+ HO-
O
OH
Si
Si
O
Si
O
O
O
Si
OH
O
Si
Si
-
Si
-
OH H - HO
O
OH
OH
Si
Si
O
O
Si
Si
O
O
O
-
+ H2O
Si
OH
Si
O
HO
OH
OH
O
Si
Si
Si
O
-
+
Si(OH) 5
-
???. 5. ???????? ??????????? ?????????? ? ???? ? ??????????? ????? ??- ?? ?????? [28]. ??????????
????? ?????????? ??????????? ??????? ??? (?????????-????)
????????? ??????????? ??? ???????????
??????? ?????????.
??/???-??????. ??????????? ?????????? ????????????? ???? ? ???????????
????? ?? ??????????? ??? ??????? ??????? ???? ????????? ??????????? ????????.
?????????? ????????? ????????????? ????
???????????? ??? ?????? ????? ?? 200 ░?. ????? ?????????? ??????????? ????? ?????????????? ?? ?????? ????? ?? 200 ?? 1250 ░?.
? ????. 3 ????????? ????????? ??????????
???????, ?????????? ? ????????? ????????
??? ???????? ?????????.
?? ?????????? ????, ????????????? ??
???????????, ??????? ????? ???? ?????????
?? ??? ??????. ?????????? ???????? ?????????? ??????? S0-ext, ??? ???????? ?????????
???????????, ????????? ????? ????????? ????????? ? ???????? ???????????????? ?????????, ? ??????? ??????????? ???????????
?????. ???????? ????? ??????? ????????
?????????? ??????? S1-3h, S1-HCl-1?, S1H2O. ? ??????? ?????? ????? ??????? ???????, ??????? ????? ???????? ?????????????
???? ?? ???????? ?????? ??????. ??????? S1HF, ????????, ????? ?????????? ??????????
????????????? ???? ????? ???? ?????????????? ????????. ??? ??????????? ? ??????????
????????? ????????? ???????? ???????????? ??????? ?????, ?, ??? ?????????, ????? ????????? ???????????? ??????????? ???? ??
???????????.
?? ?????????? ????????????? ?????
?? ??????????? ?????????? ??????? S0-ext
? S1-20h. ??????? S0-ext ????? ????????????
????????, ???, ??? ??????????, ???????? ?????????? ???????? ??????????? ??????????.
?????? ? ??? ?????????? ???????? ?????? ?
????????? ?????? ??????? ?? ???????????
???? (4,48 ??????/??2) ? ????????????? ????????????? ???????????? ?????????? ???????? ???????????? ????? 4,55 ??-?????/??2
[30]. ????????, ??? ??????? ???????? ?????
??????????? ????? ????????? ?????????
??????????????????? ??????? ?????????.
???, ??????? S0?ext ???????? ???????? ????? ?????????????. ?? ?? ??????????? ?????????? ????????? ? ???????? ??? ???????.
???????, ??? ?? ?????? ??? ???????????
?????? ?????????? ???????? ???? ???????? ??????????? ????, ?? ???? ???????? ????
??????? ? ???????????? ?????????? ?????
?-???????. ??????? S1-20h ???????? ???????? ????? ?????????????, ??? ???? ?????????
?????????? ???????? ???????????? ?????.
????? ???? ?????? ????????? ???? ???????
? 383 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
WH 2O
???????? ?. ???????, ???????? ?. ????????,..
????????? ???????????? ???????? ???????????????????????
nH
O
2
??????? 3. ?????????? ???????????? ???????
????????*
??????????
?????????
N H 2O
?????????????
????
WH 2O
W H 2O , W
n H 2O ,
N H 2O ,
OH
%
?????/?
?????/??2
n
?
???.
???????????
???????
1
S0-ext
2
S1-3h
2,48
3
S1-20h**
0,07
4
S1-HCl-1?
1,78
5
S1-HCl-pH2
1,30
6
S1-H2O
2,90
7
S1-NH3
1,03
8
S1-HF
0,37
5,54
H 2O
nOH
N OH
WOH,
%
nOH,
?????/?
NOH,
?????/??2
3,1
2,2
6,32
7,0
5,1
1,4
NH
0,9
5,16
5,7
3,6
0,0
2O
WOH
0,9
nOH
?????????? ????????????? ?????
0,7
2n H 2O
nOH
1,6
0,6
WT0 WT fin
N
0,2
OH
0,0
1,66
1,8
1,3
0,7
3,95
4,4
3,2
2(WT0 W0,5
T fin )
100 Ш M H1,2
2O
3,67
4,1
3,1
4,54
5,0
3,9
0,5
4,94
5,1
4,4
0,2
4,02
4,5
3,6
T0 T fin
2(WT0 WT fin )
?????? [17] nH2O ? nOH ?????????? ?? ???????: nOH 2n H 2O
, ??? W T0а?аW Tfin ? ?????? ????? (???.а%) ?
100 Ш M H 2O
M H 2O
????????????? ????????? T0а?аTfin , MH2O ? ???????????? ????? ????. ????? ??????? ???? ? ??-????? (N) ?? 1 ?? 2
W W
n Ш N A TШ010 18T fin
???????????? ???????? ????????? (2): N
, (2), ??? n ? ????? ????? ???? ??? ??-?????, ?????/?; NA ?
S ??
T
T
0
fin
????? ????????, S?? ? ???????? ??????? ???????????
???????, ? 2/?.
**
??????????? ?????? ??????? S1-20h ??? ?????????? ????? ????? ????????????, ?.?. ?????????? ????????????
M H 2O
??????? ? ????????.
*
n Ш N A Ш10 18
N
????? ??-??????. ????????? ???????
??- S ?? ??????? ??????????? ????? (3,1 ??/??2) ???
?????? ??????? ??????????? ?????????? ? ??????? S1-HCl-pH2.
????????? ???????? 3-4 ??-?????/??2. ???
????? ???????, ??????? ?????????,
???????? ????????????? ????, ??? ? ??????- ??????????? ? ??????? ????????? ???????????? 65-85 % ?????? ???? ??????? ????? ????? ??????????? ????????? ???-41, ????-??????. ???????? ???????? ??????????? ???????? ?? ???? ???????? ? ?????? ??????
????????? ???????? ????? ????????? ????? ????????? ?? ????????? ?????. ???????????????, ??-????????, ??????????????? ? ????? ???????????? ??????????? ???????
???, ??? ?????????? ?????? ?????????, ???? ?????, ???????, ? ???????? ?????, ?? ??????
???????? ?????????? ?????? ???????????? ? ?????? ????????? ??????????????, ?? ??????????? ???-41 ? ???????? ??????????? ????????? ???? ? ????? ? ?????? ???????
?? ???????. ????? ???????, ??? ??????????? S1?HF. ??????????? ???????? ????????? ????????????? ???????, ??????? ?????????? ?????????? ?????? (Si-O-Si), ???????????
????????????? ????????. ????? ??????????- ?????? ?????????, ? ??????????? ?? ????????? ?????? ??????????? ? ?????????????? ????? ????? ??????????? ????? (Si-OH).
???????, ???????????? ?? ?????????? ??- ???????????? ??????????? ????? ?? ???????? ? ? ?????????????? ???????, ?????- ????????? ??? ????????? ? ?????? ????????????? ???????? ?????????? ?????????? ??? ??? 100 ░? ????? ? ????????? 3-4 ??/?? 2.
??????????????.
??????? ???????????, ??? ??? ????????????
??? ?? 2 (???????????????? ?????) ??? ??????????? ????, ???????????, ??????
??????????? ??????????? ??????????? ???- ? ???? ????? ??????? ?????? (????? 8 ┼)
????????, ??? ????? ???? ????????? ????- ?????????? ???? ????????? ?????? ? ??-
? 384 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
???????? ?. ???????, ???????? ?. ????????,.. ????????? ???????????? ???????? ???????????????????????
????????? ??????? ????????? ? ????????,
??????????? ???????? ????????, ? ?????
?????? ?????????? ??????, ?????????????? ???????? ?????????. ? ?????????? ???
????????? ????????????? ???? ? ?????????? ????????????? ??????????? ?????
?????????? ? ???????? ??????????????
(???????? ???????, ???????? ???????????
? ????????? ??????????? ?????) ???????????. ????????, ??? ???????? ??????????
??????? ? ????????? ?????? ??????.
? ????? ?????? ?????????????? ?????
?????????? ?????? ?????????? ? ?????????? ????????? ???????????, ??????? ???????? ? ????, ????? ? ??????????? ???????
????????? ???????? ? ???????? ???????????? ??????????? ?????????. ? ??????????
??????????? ???????????? ???? ????????,
??? ???????? ?????????? ????? ?????????
????? ??????? ????????????????? ????????? ?????????????????????? ?????????
???-41 ? ??????????????? ???????.
?????? ????????? ??? ????????? ???????: ????-???? 070796805, ???? 18G161,
?78 ??????????????? ???????? ?????????? ???????? ?? ???.
?????? ??????????
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
???????????????? ?????????? ? ???????, ???????? ? ?????????????/ ??? ???. ?.?.
?????????. ? ?.: ?????, 1986. ? 248 ?.
?????? ?.?., ???????? ?.?. ?????????? ??????? ? ???????? ??????????? ??????????. ?
????: ??????? ?????, 1991. ? 261 ?.
A.M. Varvarin and L.A. Belyakova. Method for determining the concentration of isolated silanol
groups on silica surface with dimethilchlorosilane // Russian Journal of Applied Chemistry. 2003.
Vol. 76. ?2. P. 203-206.
S.C. Antakli, J. Serpinet. Determination of the concentration of silanol groups by a chemical
reaction with methyllithium and GC measurements of evolned methane // Chromatographia.
1987. Vol. 23. ? 10. P. 767-769.
A.V. Karyakin, G.A. Muradova and G.V. Maisuradze. IR spectroscopic study of water with silanol
groups // Journal of Applied Spectroscopy. 1970. Vol. 12. ?5. P. 675-677.
S. Wallace and L.L. Hench. Structural analysis of water adsorbed in silica gel // J. Sol-Gel Science
and Technology. 1994. ?1. P. 153-168.
??????? ?.?., ????? ?.?., ??????? ?.?. ???????????? ?????????? ???????
???????????????????? ? ???????????????????? ??????????? ?????????? ???????
???????????? ????????????? // ???. 1986. ?. 60. ?7. ?. 1701-1706.
????? ?.?. ???????????? ??????? ??-????????????? ????????? ????????? ???????????
??????????? ??? ??????????? ??????????????????? ? ??????????????????? ? ?????
???? // ????. ???. ???. 2001. ?. 71. ???. 9. ?. 1448-1451.
S. Lфufer. Infrarot-spektralphotometrische Bestimmung der ?freien? Silanolgruppen in pyrogenen
Kieselsфuren // Z. Anal. Chem. 1980. Bd. 301. S. 10-13.
Jentys, K. Kleestorfer, H. Vinek. Concentration of surface hydroxyl group on MCM?41 //
Microporous and Mesoporous Materials. 1999. Vol. 27. P. 321-328.
T.N. Lambert, S. Chittamuru, H.K. Jacobs et. al. Near infrared and ab initio study of the vibrational
modes of isolated silanol on silica // Phys. Chem Chem. Phys. 2000. ?2. P. 3217-3226.
? 385 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
???????? ?. ???????, ???????? ?. ????????,.. ????????? ???????????? ???????? ???????????????????????
12. A.A. Christy and P.K. Egeberg. Quantitative determination of surface silanol groups in silicagel
by deuterium exchange combined with infrared spectroscopy and chemometrics // Analyst. 2005.
Vol. 130. P. 738-744.
13. B.A. Morrow, I.A. Cody, L.S.M. Lee. Infrared studies of reactions on oxide surfaces. 7. Mechanism
of the adsorption of water and ammonia on dehydroxylated silica // J. Phys. Chem. 1976. Vol. 80.
?25. P. 2761-2767.
14. Burneau Andre and Cedric Carteret. Near infrared and ab initio study of the vibrational modes of
isolated silanol on silica // Phys. Chem. Chem. Phys. 2000. ?2. P. 3217-3226.
15. X.S. Zhao, G.Q. Lu, A.K. Whittaker et.al. Comprehensive study of surface chemistry of MCM41 using 29Si CP/MAS NMR, FTIR, Pyridine-TPD, and TGA // J. Phys. Chem. B. 1997. Vol. 101.
P. 6525-6531.
16. J. Casanovas, F. Illas, G. Pacchioni. Ab initio calculations of 29Si solid state NMR chemical
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
shifts of silane and silanol groups in silica // Chemical Physics Letters. 2000. Vol. 326.
P. 523-529.
S. Ek, A. Root, M. Peussa et al. Determination of the hydroxyl group content in silica by
thermogravimetry and a comparison with 1H MAS NMR results // Thermochimica Acta. 2001.
Vol. 379. P. 201-212.
A.N. Murashkevich, P.P. Mardilovich et. al. Structural arrangement of silanol groups of some
silica-fillers according to spectroscopic and gravimetric data // Journal of Applied Spectroscopy.
1993. Vol. 57. ?3-4. P. 709-713.
A.V. Karyakin, G.A. Muradova and G.V. Maisuradze. IR spectroscopic study of water with silanol
groups // Journal of Applied Spectroscopy. 1970. Vol. 12. ?5. P. 675-677.
V.V. Potapov and L.T. Zhuravlev. Temperature dependence of the concentration of silanol groups
in silica precipitated from a hydrothermal solution // Glass Physics and Chemistry. 2005. Vol. 31.
?5. P. 661-670.
B. Lumely, T.M. Khong, D. Perrett. The characterization of chemically bonded chromatographic
stationary phases by thermogravimetry // Chromatographia. 2004. Vol. 60. ?1/2. P. 59-62.
R.F. de Farias, C. Airoldi. Thermogravimetry as a reliable tool to estimate the density of silanols
on a silica gel surface // J. Thermal Anal. 1998. Vol. 53. P. 751-756.
C.A. Fung Kee Fung, M.F. Burke. Investigation of the behaviour of water on the surface of modified
silica using differential scanning calorimetry // J. Chromatogr. A. 1996. Vol. 752. P. 41?57.
S. Wallace and L.L. Hench. Structural analysis of water adsorbed in silica gel // J. Sol-Gel Science
and Technology. 1994. ?1. P. 153-168.
J.J. Fripiat, J. Uytterhoeven et al. Hydroxyl content in silica gel ?Aerosil? // J. Phys. Chem. 1962.
Vol. 66. P. 800-805.
G.E. Kellum and K.L. Uglum. Lithium aluminum dibutylamide as a direct acidbase titrant for
determination of silanols // Anal. Chem. 1967. Vol. 39. ? 341. P. 1623-1627.
W. Noll, K. Damm, R. Fauss // Kolloid-Z. 1960. Vol. 169. P. 18.
????? ?. ????? ??????????. ? ?.: ???, 1982. ?. 1,2. ? 1127 ?.
?. Morimoto, H. Naono. Water content on metal oxides. I. Water content on silica gel,
magnesium oxide, zinc oxide and titanium dioxide // Bull. Chem. Soc. Jap. 1973. Vol. 46.
P. 2000-2003.
? 386 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
???????? ?. ???????, ???????? ?. ????????,.. ????????? ???????????? ???????? ???????????????????????
30. J.H. de Boer. Untersuchungen №ber mikroporЎse Salz- und Oxyd-Systeme // Angew. Chem. 1958.
Vol. 70. ?13. P. 383-389.
31. L.T. Zhuravlev. Concentration of hydroxyl groups on the surface of amorphous silicas// Langmuir.
1987. Vol. 3. P. 316-318.
32. V.M. Bermudez. Infrared study of boron trichloride chemisorbed on silica gel// J. Phys. Chem.
1971. Vol. 75. P. 3249.
33. ??????? ?.?., ?????????? ?.?. ? ???????? ?.?. ??????? ??????????? ????????? ??
?????????????? ?????????? ?????????? // ???. 1950. ?. 24. ?. 1416-1419.
34. K.R. Lange. The characterization of molecular water on silica surfaces// J. Colloid. Sci. 1965. Vol.
20. P. 231.
35. H. Landmesser, H. Kosslick., W. Storek et al. Interior surface hydroxyl groups in ordered
mesoporous silicates // Solid State Ionics. 1997. Vol. 101-103. P. 271-277.
36. J.S. Beck, J.C. Vartuli, W.J. Roth et al. A New Family of Mesoporous Molecular
Sieves Prepared with Liquid Crystal Templates // J. Am. Chem. Soc. 1992. Vol. 114.
P. 10834-10843.
37. L.A. Solovyov, S.D. Kirik, A.N. Shmakov and V.N. Romannikov. X-ray structural modelling of
silicate mesoporous mesophase materials// Microporous and Mesoporous Materials. 2001. Vol.
44-45. P. 17-23.
38. ???????? ?.?., ????? ?.?. ??????? ??????????? ????? ?? ??????????????? ????????????
?????????????????????? ??????????? ????????? ???-41 // ????? ? ?????????
??????????? ????????. 2003. ?11. ?. 787-793.
39. L.A. Solovyov, O.V. Belousov, R.E. Dinnebier et al. X-ray Diffraction Structure Analysis of
MCM-48 Mesoporous Silica// J. Phys. Chem. B. 2005. Vol. 109. P. 3233-3237.
40. S.D. Kirik, O.V. Belousov, V.A. Parfenov, and M.A. Vershinina. System approach to analysis of
the role of the synthesis components and stability of MCM-41 mesostructured silicate material//
Glass Physics and Chemistry. 2005. Vol. 31. ?4. P. 439?451.
41. ???????? ?.?., ????? ?.?. ????????? ???????????? ????????? ???????
?????????????????????? ??????????? ????????? ???-41 ?? ???????? ??????? ???
???????????? ??????? ????????????? ?????????// ???????????. ?????????????,
????????????? ? ?????????? ????????????. 2006. ?2. ?. 6-11.
42. S.A. Araujo, M. Ionashiro, V.J. Fernandes ?t al. Thermogravimetric investigations during the
synthesis of silica-based MCM-41 // Journal of Thermal Analysis and Calorimetry. 2001. Vol. 64.
P. 801-805.
43. ??????? ?.?., ???????? ?.?. ??????????, ??? ?????????, ???????? ? ??????????. ? ????:
??????? ?????, 1973. ? 200 c.
44. ?????? ?.?. ????????????? ???????????? ????????? ???????? ?????? ??????????????
???????? ? ??? ??????????? ??????????? // ????. ?? ????. 1952. ?. 82. ?. 281-284.
45. ???????? ?.?. ??????????????? ???????? ????????? // ????. ?? ????. 1967. ?. 174. ?3.
?. 631-633.
46. ??????? ?.?., ??????? ?.?., ????? ?.?. ? ??????? ?????????? ????????? ?? ????????? ?
????????????? ???????? ??????????? ????????? ????? // ????? ? ?????????? ?????? ?
?????. 1964. ?. 8. ?. 21-26.
? 387 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
???????? ?. ???????, ???????? ?. ????????,.. ????????? ???????????? ???????? ???????????????????????
47. ???????? ?.?., ???????? ?.?., ???????? ?.?., ????? ?.?. ?????? ??????????? ?????????
???????????? ????????????????????? ?????????? ?????????? ???? ????41. ???. ??
?2287485 // 2005.
48. S. Brunauer, P.H. Emmet, E. Teller. Adsorption of gases in multimolecular layers // J. Am. Chem.
Soc. 1938. Vol. 60. P. 309.
49. G.J. Halsey. Physical Adsorption on Non-Uniform Surfaces // J. Chem. Phys. 1948. Vol. 16. ?10.
P. 931-937.
50. S. Lowell, J.E. Shields. Powder Surface Area and Porosity. ? Chapman, 1984. ? 247 p.
51. E.P. Barrett, L.G. Joyner, P.H. Halenda. The determination of pore volume and area distributions
in pure substances // J. Am. Soc. 1951. Vol. 73. P. 373.
The State of Silanol Coverage of the Mesostructured Silicate
Material MCM-41 as a Result of Postsynthetic Activation
Svetlana A. Kozlovaa, Vladimir A. Parfenova,
Ludmila S. Tarasovab and Sergey D. Kirika,c
a
Institute of Chemistry and Chemical Technology SB RAS,
42 K. Marx st., Krasnoyarsk, 660049 Russia
b
Krasnoyarsk scientific center SB RAS,
50 Akademgorodok, Krasnoyarsk, 660036 Russia
c
Siberian Federal University,
79 Svobodny, Krasnoyarsk, 660041 Russia
The influence of various types of postsynthetic activations (calcination, treatment in neutral, acid
and alkaline water mediums at 100░?, in hydrofluoric acid) on the state of silanol coverage of
mesostructured silicated material MCM-41 surface was studied. The surface was characterized by
XRD, IR-spectroscopy, thermogravimetric analysis and nitrogen adsorption. Activation of surface
resulted in increasing silanol groups concentration. There was found the limit of the silanol number
for ???-41, beyond which the material destruction caused because of structure features. The value of
critical silanol number is 3-4 OH/nm2 for water solutions at 100░?. In spite of a destruction the specific
characteristics of a material (the internal surface, volume, parameter of a lattice) remain invariable.
Thus, there are limits on activation of a surface. The composition of reaction solution influences the
rate of material collapse, but does not influence density of silanol coverage.
Keywords: SiO2, mesostructured mesoporous silicate, MCM?41, silanol number, thermogravimetric
analysis, XRD, IR-spectroscopy.
? 388 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Journal of Siberian Federal University. Chemistry 4 (2008 1) 389-398
~~~
??? 541.11
??????? ?????????????? ??????? ?? ???????????? ??????
????????? ?????? ? ??????????????? ?????
???????? ?. ?????????*, ????????? ?. ???????,
????? ?. ???????????, ??????? ?. ?????????,?, ????? ?. ?????????
?
???????? ????? ? ?????????? ?????????? ?? ???,
??. ?.??????, 42, ??????????, 660049 ??????
?
????????? ??????????? ???????????,
??. ?????????, 79, ??????????, 660041 ?????? 1
Received 24.11.2008, received in revised form 15.12.2008, accepted 22.12.2008
???????? ??????????? ?????????, ??????????? ? ???????? ????????????? ? ????????????
?????????? ?????????? ?? ?????? ????????? ?????? ? ???????????????? ???? (??). ????????, ???
??????? ?? ? ?????? ?????? ???????? ????? ??????????? ????????? ? ???????? ????????????.
???????????, ??? ?????????? ???????? ???????????? (????? 1500 ?2?? ?1) ???????? ???????
????? ?????????? ?????????, ?????????? ????????????? ??????????, ????????????????
??? ? ???-ZnCl2, ??? 800а░?. ??????????????? ????????? ????????? ???????? ????????
? ????????? ????? ???????? ???????????? ??????????? ????????? ? ???????? ????????????
?? 500 ?2?? ?1. ???????????, ??? ??????????????????? ????????? ???????? ????????????
???????? ???????? ????????? ?????????? ?????????.
???????? ?????: ???????? ?????????? ?????????, ?????????, ??????????????? ???,
????????????, ?????????, ????????.
???????? ????? ????? ???????? ?????????? ?????????? (???) ?? ???????? ?????????? ????? ???????? ?????????? ???????,
???????? ????????? ???????????? ??????
????????????? ??? ? ??????????????? ????????? ? ? ?????? ?????????? ?????. ???????? ?????????? ????????? ???????? ??
????????? ????? ?????????? ?????: ?????????? ?????, ?????????, ?????, ?????????? ?
??., ? ????? ?? ????????? ? ??????? ?? ??????????? [1-6]. ?????? ???? ???????????? ????????? ????? ????????????? ? ????????????
?????????????, ???? ??? ?????????????*
1
???? ?????? ????????? ?????????????????
?????????? ???????? ?????????? ????????
?????????????? [4,5].
?????? ??????? ? ???????? ???????????????? ?????????? ?????????? ? ???? ?????
???????????? ??????????, ???? ?? ??????????? ??????? ???????????? ?????????
?????? ???????? ??? ????????????. ???, ??????????? ??????????? ?????????? ??????
????? ?? ?????????????? ?????????? ??????????????? ???????? ? ?????????? ??????
??????????? ???????? [4], ????????, ? ?????????? ???????????? ????????????????????
Corresponding author E-mail address: light@icct.ru
й Siberian Federal University. All rights reserved
? 389 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
???????? ?. ????????, ????????? ?. ??????,.. ??????? ?????????????? ??????? ?? ???????????? ???????
????????????? ??????????, ???????????? ?
??????.
? ????????? ????? ??? ????????? ?????????? ????????? ?????? ????????? ?????????
????????????? ????? ??????????? ??????????
[7-10]. ???, ? ??????? [6,7] ???? ???? ??????????? ??????? ??????? ????? ?? ???????????
????????? ?????? ?????? ? ???????? ???????????? ? ????????, ??? ZnCl2 ??????????? ??????? ????????????? ? ??????????? ???????????? ????? ?????????, ??? ? ????? ???????? ?
????????? ????????? ??????????? ???????? ?
???????? ???????????? ?? 670 ?2??-1.
???? ????????? ?????? ??????????? ?
???????? ????????? ??????????????? ???????? ??????????? ?????, ????????? ???????, ??????? ????? ? ???????? ?????????
???????? ?????????? ?????????? ?? ??????
?????? ?????? ? ???????????????? ????.
????????????????? ?????
?????????????? ???????? (??) ???
??????????? ?? ?????? ????????-????? ????????? ?????? (??????? ????? 0,5 ??) ? ???????????????????? ???????????????? ????,
????????????? ?? ??????? 0,5 ??, ????? ???
???????????? ??? ??????-??????? (?????????????? ???????????????? ????????) ?????
????????????? ????????. ??????????? ???????????????? ???? ? ????????? ? ?? ?????????? 1:4. ?????????? ?????? ?????????
? ????, ??????????? ? ????. 1, ??????????????? ? ????????? л?????????????? ??????????????╗ ???? ? ?????????: ??????? ?????????? ???????? ? ???? ????? ???????? ?????
??????????? ????????, ? ??????? ??????????
????????? ? ????????? ??? ????????????
???????? ????? ?????????????? ?????????
??????????? ???????? ? ???????? ???????????? ?????????.
?????????????? ???????? ?????????????? ????? ?????????. ???? ?? ??? ???????? ???????? ?????? ????????? ??? ???
?3??4 ? ??????? ??????????? ????????????
? ????????? 1:1 (??-??? ??? ??-?3??4).
?????????? ???????????????? ????? ????????? ???????????? ? ????????? ?? ???????????? ?????? ? ???? ???????? ?????????
15 ?? ? ??????? 5 ??, ??????? ??????????
?? ?????????? ?????.
?????? ?????? ??????? ?? ???????? ?????? ?????? ?????? ????????? ??????? ????? ? ??????????? ?????? ??? ???????????
110а░? ?? ??????????? ????. ?????????? ZnCl2
? ???????????????? ???????? ?????????? 10
???.%. ???????????????? ????????? ?????
????????? ? ??????????????? ????? ? ??????????? 4:1 (??-ZnCl2) ? ????? ???????????
?????? ????????? ?????? ????? ((??-ZnCl2)???). ??????????? (??-ZnCl2):??? ?????????? 1:1.
?????????? ????????, ? ??????????? ??
???? ????????????, ??????????? ?????????
???????. ??? ????????? ? ? ???????? ???????
????? ?????????? ?????????? ??????-???????
????. ??? ?????????? ?????? ??????????
??????????-????? ??????? ? ???????????
?????? ???????? ???????? ?? 10 % ????? ?????. ??? ???????? ??????? ???????? ??????????? ?????? ???????
??????? 1. ?????????? ?????? ????????? ?????? ? ???????????????? ????
???????? ???????
?????????? ??????, ???. %
?
?
?
?/?
?/?
????????? ??????
50,3
6,1
44,5
0,7
1,5
??????????????? ???
91,8
4,4
1,1
1,8
116,6
? 390 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
???????? ?. ????????, ????????? ?. ??????,.. ??????? ?????????????? ??????? ?? ???????????? ???????
?????????? ??????? ?????????? ???????????? ? ????????????? ???????? ????????? 150 ??, ?????? 900 ?? ??? ????????????????? ???????? ??????? 10а ░??????1 ?
???? ??????, ??????????? ?? ????????? 130
??3?????1. ??? ?????????? ???????? ??????????? (200-800 ??) ??????? ??????????? ?
???? ?????? ? ??????? 30 ?????. ? ???? ??????? ???????, ??????????????? ??? 800 ░?,
?????????? ???????????????? ?????????
???????? ??? ???? ?? ???????????. ? ???????? ???????????? ??????????? ??????????
???????? ?? ????????? ? ? ???????? ??? ??????????. ???????, ???????????????? ????????? ???????? ? ???????? ?????, ????????? ???? ???????? ?????, ???? ?????????? ?
???????? ???????? ?? 20-25 %. ??????????
??????? ?????????? ???????? (??) ???????? ???????????????? ????? ??? ???????????
60 ░?.
???????? ??????????? ?????????? ?????????? ???????? ??????? ???????? ????????? ????? ?? ??????? ????????-1. ??????????? ??-???????? ??????????? ???????? ?
??????? 4000-400 ???1 ???????????? ?? ??????? ???????????? Tensor-27 (????? Bruker),
????? ?????? ? 50, ?????????? 2 ???1. ????????? ???????????? ?????????? ????????? ?
?????????????? ?????? ???????? OPUS 5.0.
??????? ??? ?????? ??-???????? ??????????
? ??????? ?????????? ????? ??? ????????????? ???????? ???????? ? ???????.
?????????? ? ??????????
??? ????????? ?????????, ???????????? ? ???????? ????????????? ?????????????? ??????????, ???? ????????????
?????????? ???????? ??????????? ???????????? ????????? ? ???????????????? ????????. ?? ???. 1 ???????????? ??-???????
???????? ??????????? ?????????. ??????????? ??????? ?????? ?????????? ? ??-
????? 3800-3050 ???1 (???????? ???????? ?
3422 ???1) ????????? ? ????????? ??????????
????????????? ?????, ????????? ??????????? ???????, ? ?????? ??? 1653 ? 665 ???1
? ? ?????????????? ?????????? ????????
[11]. ?????????? ? ???????? 3000-2800 ???1 ?
1450-1370 ???1 ???????????, ??????????????,
?????????? ? ??????????????? ??????????? ????????????? ??3? ? ??2?????? [11], ?
?????? ? ?????????? ??? 1742 ???1 ????????????? ????????? ????????? ????????????
?????.
? ??????? ???? ???????????? ?????? ??????????, ??????????????? ????????? ?
?????????????? ?????????? ?????? ? ????????????? ???????????. ?????????? ? ???????
1640-1450 ???1 ????? ??????? ? ?????????
?????????? ?=? ?????, ????????? ? ????????????? ?????. ??????????? ?????????? ? ??????? ???? 900 ???1, ????????, ??????????? ??????????????? ??????????? ????? ??? [11].
????????????? ??????????? ?????????????????? ? ???????????????? ?????????? (???. 2) ??????????????? ? ?????????????? ??????? ??????? ????? ?? ?? ?????????.
?????????? ??? ? ??????? ??????????? ?????? ???????????? ???????. ??????????? ?
??????? ??????????? ????? ?????????? ?
??????????? ??? 1600, 1376 ? 1062 ???1 ????? ????????????????? ? ??????? ? ???????
??????? ???????? ????? ?????????? ??????.
??????????? ?????? ?????????? ???????
????????????? ??????? ? ? ??????? ???????
(??-ZnCl2) -???.
??? ??????? ??-?3??4 ?????????? ??????????? ?????? ?????????? ? ???????
1050-980 ???1, ????????????????? ? ???????
?????????????????? ?????????? ? ????????
P?O?????? ? P?O?P, ? ??????? ?????? ?????????? ???????? ? ??????? 2700-2560 ???1,
??????????? ??? ????????? ??????????, ?????????? ?????? ???? [12].
? 391 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
???????? ?. ????????, ????????? ?. ??????,.. ??????? ?????????????? ??????? ?? ???????????? ???????
3
2
1
4000
3500
3000
2500
2000
1500
???????? ?????, ??
1000
500
-1
???. 1. ??-??????? ??????????? ??????????????? ?????????: ????????? ?????? (1), ????????? ?????? ?
10 ???.% ZnCl2 (2) ? ???????????????? ???? (3)
5
4
3
2
1
4000
3500
3000
2500
2000
1500
???????? ?????, ??
1000
500
-1
???. 2. ??-??????? ????????? (1) ? ???????????????? ZnCl2 (2), ZnCl2-??? (3), ??? (4) ? ?3??4 (5)
??????????
? 392 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
???????? ?. ????????, ????????? ?. ??????,.. ??????? ?????????????? ??????? ?? ???????????? ???????
??????? 2. ????? ??????? ?????????, ?????????? ????????????? ????????? ?????? (??) ? ????????
???????????????? ? ?????????????????? ??????????
???????
?????, ???. %
500 ░?
600 ░?
700 ░?
800 ░?
??
22,3
21,9
19,8
18,9
??
36,6
35,4
34,1
32,4
??-ZnCl2
43,9
40,3
35,2
32,8
??-?3??4
54,9
52,3
51,3
45,7
??-???
57,5
56,6
55,4
47,8
(??-ZnCl2)-???
77,6
76,1
74,7
73,6
????? ???????, ??? ????????? ??????
?????????? ???????? ????????? ?????????
????????? ? ???????????? ???????? ?????
?????????? ??????. ?????????????? ????????? ??????? ? ??????????? ?????????? ?????????????? ???????????? ?????????????????? ??????????, ????? ??? ????????? ?
????????????? ????? [8, 13].
? ????. 2 ????????? ?????? ? ??????
?????????? ??????????, ?????????? ???
????????? ???????????? ???????????? ???????????????? ? ??????????????????
??????????. ???????????, ??? ?????????? ?
????????? ??????? ???????????????? ????
???????? ????? ?? ?? 14 ???.%. ??????????????? ????? ????????? ZnCl2 ?????????????
?????? ?? ????? ?? ??? 800 ░?. ??????????
????????? ??????? ??? ??????????? ?????
? ???????? ???????? ? ????????? ????? ?????? ??: ??? 500 ░? ? ???????? ?? 20 %, ???
800 ░? ? ?? 14 % ?? ????????? ? ??? ???????
?? ??????????????????? ??. ??????????
????? ??????????? ????????? ???????????
??? ???????????? ??????? (??-ZnCl2)-???,
??????? ? ??? ???? ????????? ????? ?? ??
??????????????????? ?????????.
???????? ???????? ??????????? ?? ??
???????????????? ???????? ??????? ??????
? ????????? ?????????? ???????????? 700800 ░? (???. 3). ???????? ??????? ????????
??????????? ??????????? ??? ??, ???????-
???? ????????????? ??????? ??-?3??4, ? ?????????? ????? 300 ?2?? ?1 ??? ??????????? ????????? 800 ║C.
???????? ????????? ???????? ??????????? ?? ??????????? ????? ?? ???????? ????? ??? 60 ░? ? ????? ???????? ??????????????? ?????????????? ??????????.
???????? ??????????? ????????? ??????????? ?????????, ??????????? ??? ????????????
??-?3??4 ? ????????? ?????????? 500-800
░?, ?????????? ?? 310 ?? 500 ?2?? ?1 (???. 4).
??? ??????? ?? ?????????? ??????, ????? ???????? ?????????? ??????????, ?????????? ????????????? ??-??? ? (??ZnCl2)-???, ???????? ???????? ???????????
?????????? ??????????? ?? ??? ??????? ???
???????????? ???????????? 700 ? 800 ░?.
?????? ????? ?? ??? ???? ???????????, ?
?????????? ???????? ??????????????? ??????????? ? ?????????? 10-15 ???. %. ???????????? ???????? ??????????? (1535 ?2?? ?1)
??????????? ??? ???????? ??, ???????????
????????????? (??-ZnCl2)-??? ??? 800 ░?.
?????? ??????????????????????? ???????
??????????, ??? ? ??????? ???????, ?????????? ????????????? ??-??? ??? 800 ░?, ?????????? ????? ?????????? 60 %, ? ????? ???
??????? ? ????? 3 %. ?????????????, ??????????????? ?????????? ? ???? ??????????
????????? ???????????????, ? ?? ????????
?????????? ???????? ????????? ??. ??-
? 393 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
???????? ?. ????????, ????????? ?. ??????,.. ??????? ?????????????? ??????? ?? ???????????? ???????
350
5
2
???????? ???????????, ? /?
300
250
200
150
4
100
3
50
2
1
0
500
550
600
650
700
750
800
850
?
???????????, ?
???. 3. ??????? ??????????? ?? ???????? ???????? ??????????? ?????????? ??????????, ??????????
????????????? ?? (1), (??-ZnCl2)-??? (2), ??-ZnCl2 (3), ??-??? (4) ? ??-?3??4 (5)
1600
5
2
???????? ???????????, ? /?
1400
1200
4
1000
800
600
3
400
2
1
200
0
500
550
600
650
700
750
800
850
?
???????????, ?
???. 4. ??????? ??????????? ?? ???????? ???????? ??????????? ??????????????? ? ??????? ?????
?????????? ??????????: ?? (1), ??-ZnCl2 (2), ??-?3??4 (3), ??-??? (4) ? (??-ZnCl2)-??? (5)
? 394 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
???????? ?. ????????, ????????? ?. ??????,.. ??????? ?????????????? ??????? ?? ???????????? ???????
2
???????? ???????????, ? /?
1600
1
o
1
1400
2
o
2
1200
1000
800
600
400
200
0
??
?? -? 3 ?? 4
?? -?? ? ( ?? -ZnC l 2 ) -?? ?
???. 5. ????????????? ???????? ??????????? ?????????? ??????????, ?????????? ?????????????
?????????? ??? 800 ░? ? ??????????? ???????????????? ????????? ? ????? ?????? (1, 2) ? ??
??????? (1░, 2░)
??????? ????? ??????????????? ????????
??-H3PO4 ??????????? ?? ?????? ?? ????? ?
???????? ??????????? ??????????? ?????????.
????? ???????, ??????????????? ????????? ????????? ???????? ????????? ???????? ??????????? ??????? ? ??????? ??????? ? ???????? ???????????? 500 ?2?? ?1.
??????????????? ????????? ??????? ?
???????? ????? ???????? ? ??????? ????????? ???????? ???????? ??????????? (??
1535 ?2?? ?1) ????? ?????? ??????? ??????????? ?????????.
?????????? ?????? ??????????, ???
???????????? ???????????? ????????? ??????? ????????? ? ???????? ?????????? ?
???????? ?????????????, ??? ???????????? ?
??????? ????? ??. ??? ????????? ????????? ??????? ?????????????? ????? ????????? ??????? ??????????, ?????????? ??????
???????. ???, ????????, ??????????? ??????????? ??????????????????? ???????????
?????????, ? ????????? ????????????. ???-
???????? ?????????, ?????????????? ????????? ????????, ????? ???????? ? ??????????? ????????? ? ????????????? ??????.
???????????? ???????? ????????? ?? ???
???????????? ???? 500 ░?, ??-????????, ??????? ????????? ?????????????????? ?????
??? ???? ???????????? [8].
?? ?????? ????? ? ?????????? [14],
????????? ??????????? ????????? ??? ????????? ??? ?????????????? ? ???????????
??????? ???????????, ??? ??????? ???????
?????????? ?? ?? ? ??2, ??? ????????????
???????? ???????? ?????????, ? ? 2??3 ?????????? ??? ???????? ???????. ??????????
?????, ??? ??? ???????????? 550-900 ░? ???????? ??????????? ?????????????? ?????,
?????????????????? ????? ???????????
?????? ? ?????????? ?????????????? ? 2?
?????????. ???, ?? ?????? ???????, ????? ?
?????????? ??????????? ?????? ??????????
?????????. ??-????????, ?????????? ???????????? ??????? ??-??? ?? ???????????????? ????????? ? ???????? ????????????
? 395 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
???????? ?. ????????, ????????? ?. ??????,.. ??????? ?????????????? ??????? ?? ???????????? ???????
? ???????????? ???????? ????????? ?????
??????? ?????, ? ????????, ??????? ? ???????????? ???????? ?????, ??????? ?? ???????????? ?????? ????????????? ?????????? ?
???????? ???????????? ? ????? ??????????
?????, ????????? ??? ???????? ?????????.
????????? ? ???????? ??????? ???????
????? ????? ??????????? ?????????? ????????? ???????, ?????????? ??????? ???????????? ? ??????????? ???????????? ??????????
?????????, ? ????? ??????? ??????????????? ???????????? ? ???????.
??? ????????, ?????????? ????????? ??
?????? ??????????, ??? ?2, ??2, ?2?, ???????????? ???????? ??? ???????? ?????????
[15]. ? ????? ????????? ???????? ??????????? ?????????? ??????????, ??????????
????????????? ???????? ? ????????? ???????????????? ??????????, ???????????? ??
????????????? ????????? ????????. ???????? ??????? ??????????????????? ????????? ?? ? ????????? ? ???????? ?????? ?? ??
???????? ??????????? ?????????????? ???.
5. ??????????, ??? ???????????????? ???????? ?????????? ?? ??? 800 ░? ?? ???-
???? ??????? ???????? ?? ???????? ???????????.
??????
?????????? ???????? ??????????????? ???????? ??????????? ?????, ?????????
??????? ? ??????? ????? ? ???????? ????????? ???????? ?????????? ?????????? ??
?????? ?????? ?????? ? ????????????????
????. ????????, ??? ??????? ???? ? ????????? ?????? ???????? ????? ???????????
?????????. ??????????????? ?????????
?????????-??? ????????? ???????? ???????? ? ????????? ???????????? ?????????
? ??????? 46 ???.% ? ???????? ???????????? ?? 500 ? 2?? ?1. ??????? ???????????
????? ? ??????? ????? ? ???????? ??????? ????????? ????????? ??? ????????????, ??????? ???????????? ????????? ???
???????? ??????????? (????? 1500 ? 2?? ?1)
????? ?????? ??????? ????? ??? ??????????? 60 ░?. ????????????? ????????? ??
?????????? ??????? ??? 800 ? ? ???????????? ??????????? ???????? ??? ???????? ?????????.
?????? ??????????
1.
???????? ?.?. ?????????? ???????? ?? ?????????? ????????????? ????? ? ???????????
???????????? ?? ?? ??????. ???????? ? ???????. 2007. ?.48. ?4. ?.а612-620.
2. Simonova V.V., Shendrik T.G., Kucherenko V.A., Chesnokov N.V., Kuznetsov B.N. Study of
Thermochemical Transformations of Hydrolytic Lignin and the Properties of the Produced Active
Carbon. J. Siberian Federal Univ.: Chemistry. 2008, N 2, P. 107-117.
3. Kuznetsov B.N., Chesnokov N.V., Mikova N.M., Shendrik T.G. Palladium Catalysts on Carbon
Supports prepared from a Natural Graphite and Anthracite. J. Siberian Federal Univ.: Chemistry.
2008, N 1, P. ?. 3-14.
4. ??????? ?.?., ???????????? ?.?., ???????? ?.?. ??????????? ?????????
?????????? ????????? ?? ?????? ?????????? ????????? ??????? ? ?????????????
????????? ???????????????. ????? ? ????????? ??????????? ????????. 2005. ?.13.
?1. ?.103?110.
5. ??????? ?.?., ??????? ?.?., ???????? ?.?., ??????? ?.?., ????????? ?.?., ???????? ?.?.
?????????? ?? ??????? ? ????????? ???????? ???????. ????? ???????? ???????. 2007.
?2. ?.62-67.
? 396 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
???????? ?. ????????, ????????? ?. ??????,.. ??????? ?????????????? ??????? ?? ???????????? ???????
6. ???????? ?.?., ????????? ?.?., ?????????? ?.?., ???????? ?.?., ???????? ?.?. ?????????
???????? ?????????? ?????????? ?? ???????????????? ZnCl2 ?????? ??????. ??????
?????????? ?????. 2007. ?.80. ? 6. ?. 943-945.
7. ???????? ?.?., ???????? ?.?., ????????? ?.?., ???????? ?. ?., ??????? ?. ?., ????????
?.?. ????????? ? ???????? ???????? ?????????? ????????? ?? ????????????????
????????? ??????. ??. ??????? ?????? л25 ??? ????????? ????? ? ?????????? ??????????
?? ???: ????? ? ???????????╗. ??????????. 2006. ?. 95-104.
8. Solum M.S., Pugmire R.J., Jagtoyen M., Derbyshire F. Evolution of carbon structure in chemically
activated wood. Carbon. 1995. V.33, N 9. P. 1247-1254.
9. Benaddi H., Bandosz T.J., Jagiello J., Schwarz J.A., Rouzaud J.N., Legras D., Beguin F. Surface
Functionality and Porosity of Activated Carbons Obtained from Chemical Activation of Wood.
Carbon. 2000. V. 38. P. 669-674.
10. Yang T., Chong Lua A. Characteristics of activated carbon prepared from pistachio-nut
shells by potassium hydroxide activation. Microporous and Mesoporous Materials. 2003.
V. 63. P. 113-124.
11. ?????? ?. ???????????? ????????????? ??????? ???????. ?.: ???????????? ???????????
??????????, 1963. 590 ?.
12. ?????? ?, ???? ?., ?????? ?., ?????? ?. ???????????? ????????????? ?????????. ?.:
?????, 1976. 471 ?.
13. Nakagawa Y., Molina-Sabio M. and Rodrэguez-Reinoso F. Modification of the porous structure
along the preparation of activated carbon monoliths with H 3PO 4 and ZnCl 2. Microporous and
Mesoporous Materials, V. 103. 2007. P. 29-34.
14. Marsh H., Yan D.S., O?Grady T.M. Wenneerberg A. Formation of active carbons from cokes using
potassium hydroxide. Carbon. 1984. V.22. N6. P. 603-611.
15. ????????? ?.?. ???????? ? ?????????? ????? ???????????? ?????????????????
????????? ??????????? ? ?????????????. ???????????: ???-?? ?? ???, 2002. 414 ?.
? 397 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
???????? ?. ????????, ????????? ?. ??????,.. ??????? ?????????????? ??????? ?? ???????????? ???????
Influence of Modified Agents on Carbonization Birchwood Sawdust
and Coal-tar Pitch Mixtures
Svetlana I. Tsyganovaa, Alexandr N. Shvezova, Irina V. Korol?kovaa,
Nikolai V. Chesnokova,b and Boris N. Kuznetzova,b
a
Institute of Chemistry and Chemical Technology SB RAS,
42 ?. ??rx st., Krasnoyarsk, 660049 Russia
b
Siberian Federal University,
79 Svobodny, Krasnoyarsk, 660041 Russia
Structural changes during preparing and carbonization of carbonic materials from birch sawdust
and coal-tar pitch mixtures have been presented. It has been shown that adding of coal-tar pitch in
birch sawdust increase a yield of carbonic material during carbonization. It has been established that
maximum of specific surface area (more than 1500 m2?g-1) have washed away by water the carbonic
materials obtained for carbonization of composites modified with KOH and KOH-ZnCl2.at 800░C.
Modification of composite with phosphoric acid reduces to production more strong shaped carbonic
material with specific surface area up to 500 m2?g-1. It has been established that high-temperature air
processing of all samples promotes developing of a void structure of carbonic products.
Keywords: porous carbon materials, birchwood, coal-tar pitch, carbonization, activation,
properties.
? 398 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
Journal of Siberian Federal University. Chemistry 4 (2008 1) 399-404
~~~
??? 630.86.075.8
?????? ???????????? ???? ????? ?????????
???????? ?. ??????????, ??????? ?. ??????????*
????????? ??????????????? ??????????????? ???????????
??. ????, 82, ??????????, 660049 ?????? 1
Received 24.11.2008, received in revised form 15.12.2008, accepted 22.12.2008
?????? ?????? ???????????? ???? ????? ????????? ? ????????? ??????? ????????
?????. ??????????? ???????? ?????????????? ?????????? ? ?????????????????
?????????????????????? ? ???? ????? ????????? ? ???? ??????????.
???????? ?????: ??????????? ???? ????? ?????????, ??????, ?????????? ? ?????????????.
????????
? ????????? ????? ?????????????
??????? ??????? ???????? ???????? ????????? ???????? ??????????? ?????
????????? ??????? ????????. ????? ???
?????? ????? ???????? ???????????. ?????? ?? ???????? ??????? ????????????
????? ??????????? ? ????? XIX ?., ?? ????
? ????????? ???????????, ????????? ????????????? ??????? ??????-???????????
? ??????????????? ????????, ??????????
???????????? ?????? ? ??????? ???????????? ?? ?????????. ??????????? ???????????? ? ????????, ???????????, ???????,
??????????-?????????????, ???????????,
??????????, ?????????? ??????????????.
?????? ??????? ? ????????? ????? ?????
?????? ??????? ? ???????????? ???????????? ????????? ?????? ??????? ????????,
?????????? ????????????? ?????? ??? ??
?????????. ???????? ??????? ???????????? ?????? ??????? ???????? ????? ? ?????? ?????? ??????, ????????? ? ?????????*
1
???? ?????????? ??????????? ??????? ?
???? ?????????? ????????.
????? ???? ??????? ???????????????? ???? ????? ????????? [1]. ? ??????????? ???? ???????????? ? ????????? ??????
??????? ????????? ?????? ????????????
???? ????? ????????? ? ???? ???????? ?????, ??????????????, ??????????-??????? ?
??????????-??????? ??????? ?????????????????????? [1].
????????????????? ?????
????? ???? ???? ????? ????????? ????????? ?? ??????????????? ???????? ? ??????? 2003-2005 ??. ?? ?????? ?????? ???????
??????. ??????????, ??????????? ? ??????,а?
??????? ?? ?????????? ?????? ????????????. ????????? ??????? ????????? ? ??????
?????????????????? ???? ? ????????????
?????????? ? ????????????? ??????? ????????????? ????. ????? ???????? ???????
????????? ?? ???? ?? ?????? ????? ? ??????
?????? ????????????? ?????????: ????????-
Corresponding author E-mail address: sibstu@sibstu.kts.ru
й Siberian Federal University. All rights reserved
? 399 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
???????? ?. ??????????, ??????? ?. ??????????. ?????? ???????????? ???? ????? ?????????
????? ????? ? ??????????? 1а:а2 ?? ??????.
??????? ??????? ?? ?????????? ????????
????????? ????-??????????? ?? ?????????,
?????????? ? [2-5].
????????? ???????????? ?? ????????? ??????? ??????? ????????? ???????
????????????? ?????????? ?????????????. ?????????? ???????? ????????????
???????????? ??? ??????????? ??? ?????????? ??????? ??????? ?????????????????
?????н? ???????. ?????????? ?????????
????????? ????? ???????????? ???????????? ??? ??????????? ???????. ??????
?????? ?????? ??????????????????????
?????????????, ????????? ?????? ??? ?
???. ??????????? ????????????? ?????? ?????? ? ??????????? ????? ???????
?????????????????????? ?????????????
??????? ??????????????? ????????? [5].
?? ??????????? ??????? ?????? ??????
???? ???????? ??????????-??????? ?
??????????-??????? ??????? ?????????????????????? [5].
?????????? ? ?? ??????????
???????? ???????? ?????????? ???????????? ? ???? ? ???? ???????? ????? ? ??
????????? ?????? ???????????? ?? ???. 1.
? ???? ????? ????????? ??????????
???????????? ? ???? ???????? ????? ?????????? ? ???????? 0,58а ? 1,36а % ? ?????????? ? ???????а? ?????? (1,36а%) ? ????????? ? ?????? (0,58а %). ? ?????????
??????? ???????????? ???? ??????????
???????????????? (??), ????????????????????? (??), ???????????????? (??),
????????????????? (??). ??? ?????? ??
????????? ????? ???????????? ?????????? ???? ???????? ???????? ??????????.
??? ?? ? ?? ???? ???????? ??????? ????
?????????? ? ?????? ? ?????? ??????.
? ?? ?? ????? ?? ???????????? ? ???? ?
???????????? ?????????? ???? ?????, ?
????????? ?????????? ? ???? ?? ? ???????
???? ?????????????.
?????? ?????? ?????? ?? ???? ???????? ? ????. 1. ?????????? ??????????
0,8
? % ? ?.?.?. ????
0,7
0,6
0,5
0,4
0,3
0,2
0,1
0
1
2
3
4
?????
5
6
7
8
9
10
11
12
????????????????
?????????????????????
????????????????
?????????????????
???. 1. ????????? ?????? ???????????? ???? ????? ?????????
? 400 ?
? 401 ?
0,20
0,70
0,50
0,40
0,60
0,40
0,20
Sn-2
Sn-1
Sn-2
Sn-1
Sn-2
0,70
Sn-1
Sn-1
1,00
Sn-2
Sn-2
0,60
Sn-1
0,50
0,80
Sn-2
0,60
0,60
Sn-1
Sn-1
0,40
Sn-2
Sn-2
0,30
0,60
Sn-1
0,50
Sn-1
Sn-2
0,40
0,20
0,30
Sn-1
0,50
Sn-1
Sn-2
Sn-2
0,80
0,24
Sn-1
Sn-2
?10:0
?????????*
0,10
0,50
0,60
1,20
0,40
0,60
0,30
0,70
0,60
0,80
0,90
0,70
0,50
0,70
0,30
0,50
0,80
0,60
0,40
0,80
0,40
0,80
0,35
0,65
?12:0
0,20
0,40
0,35
0,85
0,30
0,50
0,30
0,70
0,50
0,70
0,60
0,80
0,40
0,80
0,20
0,60
0,10
0,70
0,20
0,40
0,10
0,30
0,35
0,45
?14:0
6,70
18,70
4,70
15,60
6,20
17,60
6,00
20,00
12,10
15,90
10,00
18,80
10,60
19,00
4,54
21,46
4,40
22,00
6,85
20,85
5,10
16,90
6,40
18,90
?16:0
5,40
4,60
6,70
3,10
6,40
5,60
6,75
3,45
5,80
4,20
4,70
3,90
4,00
3,60
5,08
3,12
5,30
3,00
5,40
2,20
4,50
3,80
6,10
4,20
1,75
8,65
1,20
6,40
2,20
7,80
6,35
9,65
6,90
9,60
6,20
11,10
7,40
10,20
4,73
12,87
4,12
12,12
3,44
17,86
1,00
18,60
0,44
14,66
?18:0
42,80
37,60
43,15
36,15
45,15
34,45
41,30
35,50
36,60
38,40
37,20
35,80
37,85
35,55
45,00
30,80
43,38
32,34
46,50
30,00
48,10
35,70
47,81
34,85
?18:1
25,35
14,85
25,20
20,40
22,35
18,85
22,60
16,80
19,80
18,00
21,60
17,90
21,55
17,25
22,30
17,70
23,46
16,82
22,14
15,86
25,20
12,10
23,66
12,74
?18:2
??????????,а% ? ????? ??????а
?16:1
* Sn-1 ? Sn-2: 1-? ? 2-? ????????? ? ??????????? ????? ??????? ??????????????????????.
???????
??????
???????
????????
??????
????
????
???
??????
????
???????
??????
??????
??????? 1. ?????? ?????? ?????? ?????????????????????? ???? ????? ?????????
17,00
12,80
16,40
13,80
15,20
12,80
15,00
11,00
13,60
10,00
14,80
9,00
14,30
9,70
15,75
9,65
15,54
9,80
13,57
10,63
13,30
8,90
13,35
10,45
?18:3
0,10
0,70
0,60
1,20
0,60
0,40
0,50
0,70
1,70
1,00
1,30
0,90
0,90
1,50
0,40
1,20
0,90
0,82
0,70
0,50
1,10
0,90
0,40
0,80
?20:0
0,20
0,40
0,20
0,40
0,30
0,40
0,20
0,60
0,90
0,40
0,90
0,30
1,00
0,60
0,40
0,80
0,80
0,60
0,50
0,30
0,30
0,50
0,60
0,70
?20:4
0,20
0,40
0,30
0,50
0,40
0,30
0,50
0,30
1,00
0,30
0,80
0,20
0,70
0,50
0,90
0,70
0,90
0,70
0,10
0,20
0,60
1,00
0,30
0,80
?22:0
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
???????? ?. ??????????, ??????? ?. ??????????. ?????? ???????????? ???? ????? ?????????
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
???????? ?. ??????????, ??????? ?. ??????????. ?????? ???????????? ???? ????? ?????????
??????? 2. ???????? ???????????? ????? ?????????????????????? ???? ????? ?????????
??????
??????
???????
????
??????
???
????
????
??????
????????
???????
??????
???????
????????????
?????
?18:1 / ?18:1
?18:1 / ?18:2
?18:1 / ?18:3
?18:2 / ?18:1
?18:1 / ?18:1
?18:1 / ?18:2
?18:1 / ?18:3
?18:2 / ?18:1
?18:1 / ?18:1
?18:1 / ?18:2
?18:1 / ?18:3
?18:2 / ?18:1
?18:1 / ?18:1
?18:1 / ?18:2
?18:1 / ?18:3
?18:2 / ?18:1
?18:1 / ?18:1
?18:1 / ?18:2
?18:1 / ?18:3
?18:2 / ?18:1
?18:1 / ?18:1
?18:1 / ?18:2
?18:1 / ?18:3
?18:2 / ?18:1
?18:1 / ?18:1
?18:1 / ?18:2
?18:1 / ?18:3
?18:2 / ?18:1
?18:1 / ?18:1
?18:1 / ?18:2
?18:1 / ?18:3
?18:2 / ?18:1
?18:1 / ?18:1
?18:1 / ?18:2
?18:1 / ?18:3
?18:2 / ?18:1
?18:1 / ?18:1
?18:1 / ?18:2
?18:1 / ?18:3
?18:2 / ?18:1
?18:1 / ?18:1
?18:1 / ?18:2
?18:1 / ?18:3
?18:2 / ?18:1
?18:1 / ?18:1
?18:1 / ?18:2
?18:1 / ?18:3
?18:2 / ?18:1
??????????,
а% ? ????? ??
16,66
8,24
4,65
6,10
17,17
9,00
4,75
5,82
13,95
6,64
4,07
7,37
14,00
7,60
5,00
7,30
13,86
6,90
4,85
8,00
13,45
7,66
5,10
6,53
13,32
7,73
5,30
6,66
????????????
?????
?18:3 / ?18:1
?16:0 / ?18:1
?18:0 / ?18:1
?18:0 / ?18:2
?18:3 / ?18:1
?16:0/ ?18:1
?18:0 / ?18:1
?18:0 / ?18:2
?18:3 / ?18:1
?16:0/ ?18:1
?16:0/ ?18:2
?18:0 / ?18:1
?16:0/ ?18:1
?16:0/ ?18:2
?18:0 / ?18:1
?18:2 / ?18:2
?18:2 / ?18:2
?16:0/ ?18:2
?16:0/ ?18:1
?16:0/ ?18:3
?18:2 / ?18:2
?16:0/ ?18:1
?16:0/ ?18:2
?18:0 / ?18:1
??????????,
а% ? ????? ??
5,00
9,00
7,00
3,47
4,28
7,37
9,70
4,61
5,00
9,70
4,61
8,30
9,54
5,16
5,26
3,95
4,00
4,80
9,66
3,40
3,72
7,20
4,10
3,86
?18:2 / ?18:2
?16:0/ ?18:1
?16:0/ ?18:2
?18:0 / ?18:1
3,86
7,00
4,10
4,13
14,10
7,60
5,22
6,60
14,66
8,02
5,32
6,94
15,55
7,70
5,23
8,51
15,60
9,11
5,93
8,80
16,10
9,53
6,39
6,36
?18:2 / ?18:2
?16:0/ ?18:1
?16:0/ ?18:2
?18:0 / ?18:1
?18:2 / ?18:2
?16:0/ ?18:1
?16:0/ ?18:2
?18:0 / ?18:1
?18:2 / ?18:2
?16:0/ ?18:1
?16:0/ ?18:2
?18:0 / ?18:1
?18:2 / ?18:2
?16:0/ ?18:1
?16:0/ ?18:2
?18:0 / ?18:1
?18:2 / ?18:2
?16:0/ ?18:1
?16:0/ ?18:2
?18:0 / ?18:1
3,56
5,82
3,15
3,51
3,80
8,26
4,52
4,00
4,21
7,95
3,93
3,52
5,14
6,73
3,93
2,76
3,76
8,00
4,74
3,70
? 402 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
???????? ?. ??????????, ??????? ?. ??????????. ?????? ???????????? ???? ????? ?????????
??????? 3. ??????????-??????? ?????? ?????????????????????? ???? ????? ?????????
??????
??????????,а% ? ????? ??
U/S*
U/U
S/U
S/S
??????
5,34
57,60
33,92
3,14
???????
5,25
55,75
35,65
3,35
????
7,01
51,98
36,14
4,87
??????
7,21
55,35
33,13
4,31
???
7,10
54,95
33,60
4,35
????
14,20
52,50
26,20
7,10
????
13,92
53,00
26,20
6,88
??????
16,54
54,46
22,24
6,76
????????
9,53
57,82
28,03
4,62
???????
7,64
64,46
24,94
2,96
??????
6,20
67,70
24,00
2,10
???????
6,50
63,75
27,00
2,75
* Uа? ????? ???????????? ??????, ??????????? Sn-1а? ????????? ??????????? ????? ??????? ??.
Sа? ????? ?????????? ??????, ??????????? Sn-2а? ????????? ??????????? ????? ??????? ??.
???????????????, ??? ? ??????? ?? ???????????? ??????? ?12а ? ? 22. ?????н???????
??????? ???????????? ????????? (C18:1),
????????? (C18:2), ??????????? (C18:3),
???????????????? (C16:1). ??????? ????????, ??? ??????? C18:1 ????????????? ??????????? ????? ?????н??????? ?????? ??.
????? ?????????? ?????? ?????????????
?????????? ????????????? (?16:0) ? ??????????? (?18:0). ???? ????????? (?10:0), ?????????? (?12:0), ???????????? (?14:0), ??????????
(?20:0), ????????? (?22:0) ?????? ?? ?????????
? ?????????? ????????? ????????. ? ????
???????? ????? ?????????????? ?????????????? ????????? ??????? ?????? ??????
??: ????????? ???? ???????????? ??????
? ??????-?????? ?????? ? ???????? ?? ?????????? ? ?????? ??????. ? ?????????
?? ?????? ??????? ???????????? ?????
Sn-1 ? Sn-2а ? ??????????? ????????????.
? ??????????-??????? ??????? ?????????
????????????? ??????? ???????? ??????????, ? ????????? ??????? Sn-1 ????????? ??????????? ?????????????, ?????????, ?????????, ??????????? ?????????,
? Sn-2 ?????????а ? ????????????? ?????????: ?????????, ?????????, ???????????.
????? ??? ? ??????? ???????? ????? ????????????? ??????????? ???????????? ????? ?18:1а /а ?18:1 (????. 2, 3). ? ????????????????? ??????? ?? ???????? ?????
?????????? ?????????? Uа/аU ? Sа/аU ?????
(Sа ? ????? ?????????? ??????, Uа ? ?????
???????????? ??????). ?? ????????? ?????????? ? ??????? ???????? ????? ??????????
?? 76а% ?? 90а% ?? ????? ??. ??????????
??, ??????? ??????????-??????? ??????? Uа/аS ? Sа/аS ?????, ?? ????????? 23а%. ?
?????? ????? ?????????? ?????????? ?? ?
??????????-??????? ???????? Uа/аU (?????
50а% ?? ????? ??).
????? ???????, ?? ????????? ?????????? ???????????? ???????????:
- ??????????? ???? ????? ?????????
???????????? ??????????????????, ???????????????????????, ??????????????????,
???????????????????;
- ???????? ???????? ?????????? ???????????? ? ???? ????? ????????? ????? ???????????? ????????; ??? ???? ????? ?????-
? 403 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
???????? ?. ??????????, ??????? ?. ??????????. ?????? ???????????? ???? ????? ?????????
??????? ?????????? ?? ?????????? ? ??????
??????;
- ? ??????-?????? ?????? ? ???? ?????
????????? ?????????? ?????????? ??????????????????????, ? ????????? ???????
Sn-2а? ????????? ??????????? ????????????? ?????????;
- ? ??????? ???????? ????? ? ???????
?????????????????????? ?????????????
?????????? ????? ??????????, ? ????????? ??????? Sn-1 ? Sn-2а ? ?????????
??????????? ????????? ????????, ?.?.
??????? ??????????-??????? ??????
?18:1а/а?18:1.
?????? ??????????
1.
?????????? ?.?., ?????????? ?.?. ??????????? ???? ????? ?????????. ??????? ??????
?? ?????????? ????????????? ??????-???????????? ??????????? л?????? ? ??????????
?????????а? ???????? ? ???????╗. ??????????, 2006. ?. 1. ?. 157а? 159.
2. ????? ?. ??????? ???????????. ?.: ???, 1975. 322 ?.
3. ?????????? X. ?., ???????? ?., ?????????? ?. ?. ??????? ????? ???????????? ?????
??????????? ? ?????? ?? ???????? ????????????? ???????. ????? ????????? ??????????.
1988. N 6. ?. 785-789.
4. ???????? ?. ?., ????? ?. ?. ????? ????????? ? ????????????? ?? ??????? ???????
??????? ? ???????????? ????????. ?????????? ? ???????? ?????????? ????????. 1971.
?. 3, N 6. ?. 651-656.
5. ?????????? ?.?., ??????????? ?.?., ???????????? ?.?., ???????? ?.?., ???????? ?.?.,
????????? ?. ?. ????????????? ???????? ???????. ?.: ?????, 1982. 256 ?.
6. ???????? ?.?. ???????? ?????? ????????? ?????? ??????????? ?????????: ???. ?????.
???. ????. ??????????, 1992. 165 ?.
Phospholipid Composition of Pinus Sibirica Needles
Svetlana A. Bistriakova and Ludmila P. Rubtchevskaya
Siberian State Technological University,
82 Mira, Krasnoyarsk, 660049 Russia
Annual variation in the phospholipid composition of Pinus sibirica needle was studied. Basic
regularities of phosphatidilethanolamins accumulation and redistribution in needles of Pinus sibirica
during ontogenesis were established.
Keywords: phospholipids of needles of Pinus sibirica, composition, accumulation, redistribusion.
? 404 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
??????? ????????????? ??????
??? ??????????
1. ????? ???????? ?? ?????? ????????? 30 ?. ??? ???????? ????????????? ? ????????????? ?????? ? 15 ?. ??? ?????? ??????????, ??????? ???????, ???????????, ?????? ??????????, ????????? ? ??????? WinWord, ??????? ?????????, 12 ?????. ????? ? ??? ??????????????
????????? ?????????????? ? ???????? ?????? ? ??????????? ????.
2. ???? ?????????? ??????? ??? ?????????? (?????????? ? ???????????????). ????????
?? ???????????? ??????? ????????????? ??????, ??? ???? ??????? ??????? ??????????? ?? ?????????? ????? ??????, ????????, ???????? ?????, ????? ?????? ? ???????, ??????????????
??????? ????? ? ???????(?) ??????(??).
3. ???????? ?????? ?????? ??????, ?? ??????????? ????? ???????? ?????????? ????????. ?????? ? ?????? ???????? ?????? ? ????????? ?????? ???????????? ???????? ????????
???????? ????? ?????? ? ??????.
4. ?????. ?????? ???????? ???????? ??????????? ?????? ?????????: ???????? ??????, ?????? ??? ? ???????(?) ??????(??), ????? ?????? ??????? ? ????????? ??????, ??????. ???????? ????? ??????, ???? ????????? ?????, ????? ?????????? ?? ???? ?? ????????. ????? ??????
??????? ????? ????????? ?? ???????, ?? ??????????? ??????? ???????? ? ??????????????
?????????. ??? ????? ???????????? ??? ?????, ??? ???? ??????????? ??????????? ?????????
????? ???? ??????????. ???????? ???????????? ???????????? ???????? ?????? ?? ???????
????????, ????????? ? ??????, ??????????, ?????????? ???????????, ?????????? (??????), ?? ???????? ? ???? ????????? ?????????????? ????????? ?????????? ?????? ??? ??????? ????????????? ?????? ? ??????? ?????????? ????????. ? ?????? ????????? ?????? ??????????? ??????????, ????????? ??????? ?????????????? ??? ?????? ??????????. ????????
?????? ???????? ?? ?????? ????????? ?????? ? ??????????? ????????, ?? ???????? ???????
??????????? ??????? ? ??????????? ???? ?????? ??????; ????????, ??????? ????? ????? ????
??????? ? ??????? ???????.
5. ??????????? ??????????. ?????? ?? ???????????? ? ?????????? ?????????? ??????????? ?? ???? ? 7.0.5 ? 2008.
6. ??????? ??????????? ?? ????????? ????????? ????? ?????? ???????????? ??????????, ??? ?????? ???? ???????? ???????? ? ??????? ??????? ? ??? ? ???????? ??????. ???
??????? ?????? ????? ?????? ????????. ????????? ????? ?????? ?????????? ????? 2 ?????????, ??? ?????????????? ?????????????? ?????, ?? ??????????? ?????, ?????????? ????????
??????? ?? ?????????? ????????? ??????. ??? ??????? ??????? ?????? ????? ???????? ???????? (??? ???????? ????? ????????? ??????????, ??????????? ??????? ?????? ???? ????????? ? ??????????? ? ???????). ?????? ?????? ?? ?????? ??????????? ???????? ?????.
7. ??? ???????????, ???? ?? ??????????? ???????, ??????? ??? ??????????, ?????????
л?????????╗ ? ????? ???????? ?????????? ?????????????? ??????????? ?? ? ???????? ??????.
??????????? ???????, ???????, ?????????? ?????? ???? ????????????, ???????? ?? ?????
??????? A4, ? ????????? ?????? ??????? TIFF, GIF, JPEG, EPS, PPT, ???? ???????????? ???
????????? Word. ?? ????????? ????? ? ?????? ??????? ???????? ?????? ???????? ? ????????, ?????????? ?????? ???????? ???? ???????? ???????????, ???????? ????????, ?????? ?????????.
? 405 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
??????? ????????????? ?????? ??? ??????????
8. ??????. ????????? ? ????????? ??????, ???????, ??? ??? ???????? ????? ?????????
??? ?????????? ? ????? ??????? ??????????? ?????????? ?? ???????? ? ??????. ??????? ?????????? ? ?????? ??? ? ??????????? ?????? ? ????????????? ??????. ???????, ??? ??????а?
??? ?? ?????????. ????? ?????? ?????? ???? ??????????? ????????????? ? ????????, ?????? ?????, ???????? ?????????? ?????? ?, ?? ???? ???????????, ??????? ?? ?????????. ????
???????? ??????????? ?????? ???????? ???????????? ?????????????? ?????????? ??? ?? ?????????????? ???????, ???????????? ???????? ?? ? ????? ?????? ? ????????? ???????? ????
????????? ???????. ??????????? ????? ??????а? ?? 1/3 ?? 2/3а????????.
9. ??????????????. ??? ????????????? ??????????? ????????????? ??????????????
?????????????? ? ?????????? ???????? ??????(??) ??????? ????????? ?????? ???? ???????????? ? ?????????? ??????? ????????????? ? ?????? ??????? ????? ???? ?? ??????? ??????????. ?????????? ??????? ????? ?? ??????????? ????? ? ????? ????? ?????? (?? ??????????? ? ???????, ????), ? ????? ???-??? ?????????? ?? ??????????????? ???????? ? ????????,
???????? ? ???? Web of Sciences ISI, ?.?. ??????? ??????-?????? ISI.
10. ????? ???????? ?????? ? ?????????? ?????? ?????? ????? ??????????? ? ????????
???? ?????????? ? ???????????? ??????????.
11. ????? ? ?????????. ?????????????? ?????????? ????? ???????? ? ??????????????
????????? ???????? ????????????? ????? ????????? ?? ???????? (391) 244-82-31.
E-mail: rio@lan.krasu.ru
??????? ???????? ?????: ???????? ????? ?????????? ? ?????????, ?????? ??????????
????. ??????? (391) 249-48-94.
E-mail: bnk@icct.ru
? 406 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
? ? ? ? ? ? ? ? ? 2009
?? ?????? - ????
?? ????????????? ???????? л?????? ??????╗
?? ????? ? ???????? 2008 ?. ?????????? ????????? ???????? ??
? л?????? ?????????? ???????????? ????????????. ????????╗
? л?????? ?????????? ???????????? ????????????. ???????????? ?????╗
? л?????? ?????????? ???????????? ????????????. ?????????? ? ??????╗
? л?????? ?????????? ???????????? ????????????. ??????? ? ??????????╗
? л?????? ?????????? ???????????? ????????????. ?????╗
?? ????????????? ???????? ?????? ?????? л????????-2009, ??????
?????????╗ ?? ???????? 42325, 42326, 42327, 42328, 42329.
??????? ?????????? ???????? (?????????, ???????, ?????????) ?? ???????
? I ???? ????????, ?? ?????????, ????????? ? ???????????? ? ??????????
??????????.
???????? ???????????? ??????? ?? ?????!
?????????? ????? ???????? ??????????? ?? ??????????????? ????????
(391)244-82-31
?? ??????????? ??????? ???????????? ?????????
?????? ???????? ??? ????????????. ???, ??????????? ??????????? ?????????? ??????
????? ?? ?????????????? ?????????? ??????????????? ???????? ? ?????????? ??????
??????????? ???????? [4], ????????, ? ?????????? ???????????? ????????????????????
Corresponding author E-mail address: light@icct.ru
й Siberian Federal University. All rights reserved
? 389 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
???????? ?. ????????, ????????? ?. ??????,.. ??????? ?????????????? ??????? ?? ???????????? ???????
????????????? ??????????, ???????????? ?
??????.
? ????????? ????? ??? ????????? ?????????? ????????? ?????? ????????? ?????????
????????????? ????? ??????????? ??????????
[7-10]. ???, ? ??????? [6,7] ???? ???? ??????????? ??????? ??????? ????? ?? ???????????
????????? ?????? ?????? ? ???????? ???????????? ? ????????, ??? ZnCl2 ??????????? ??????? ????????????? ? ??????????? ???????????? ????? ?????????, ??? ? ????? ???????? ?
????????? ????????? ??????????? ???????? ?
???????? ???????????? ?? 670 ?2??-1.
???? ????????? ?????? ??????????? ?
???????? ????????? ??????????????? ???????? ??????????? ?????, ????????? ???????, ??????? ????? ? ???????? ?????????
???????? ?????????? ?????????? ?? ??????
?????? ?????? ? ???????????????? ????.
????????????????? ?????
?????????????? ???????? (??) ???
??????????? ?? ?????? ????????-????? ????????? ?????? (??????? ????? 0,5 ??) ? ???????????????????? ???????????????? ????,
????????????? ?? ??????? 0,5 ??, ????? ???
???????????? ??? ??????-??????? (?????????????? ???????????????? ????????) ?????
????????????? ????????. ??????????? ???????????????? ???? ? ????????? ? ?? ?????????? 1:4. ?????????? ?????? ?????????
? ????, ??????????? ? ????. 1, ??????????????? ? ????????? л?????????????? ??????????????╗ ???? ? ?????????: ??????? ?????????? ???????? ? ???? ????? ???????? ?????
??????????? ????????, ? ??????? ??????????
????????? ? ????????? ??? ????????????
???????? ????? ?????????????? ?????????
??????????? ???????? ? ???????? ???????????? ?????????.
?????????????? ???????? ?????????????? ????? ?????????. ???? ?? ??? ???????? ???????? ?????? ????????? ??? ???
?3??4 ? ??????? ??????????? ????????????
? ????????? 1:1 (??-??? ??? ??-?3??4).
?????????? ???????????????? ????? ????????? ???????????? ? ????????? ?? ???????????? ?????? ? ???? ???????? ?????????
15 ?? ? ??????? 5 ??, ??????? ??????????
?? ?????????? ?????.
?????? ?????? ??????? ?? ???????? ?????? ?????? ?????? ????????? ??????? ????? ? ??????????? ?????? ??? ???????????
110а░? ?? ??????????? ????. ?????????? ZnCl2
? ???????????????? ???????? ?????????? 10
???.%. ???????????????? ????????? ?????
????????? ? ??????????????? ????? ? ??????????? 4:1 (??-ZnCl2) ? ????? ???????????
?????? ????????? ?????? ????? ((??-ZnCl2)???). ??????????? (??-ZnCl2):??? ?????????? 1:1.
?????????? ????????, ? ??????????? ??
???? ????????????, ??????????? ?????????
???????. ??? ????????? ? ? ???????? ???????
????? ?????????? ?????????? ??????-???????
????. ??? ?????????? ?????? ??????????
??????????-????? ??????? ? ???????????
?????? ???????? ???????? ?? 10 % ????? ?????. ??? ???????? ??????? ???????? ??????????? ?????? ???????
??????? 1. ?????????? ?????? ????????? ?????? ? ???????????????? ????
???????? ???????
?????????? ??????, ???. %
?
?
?
?/?
?/?
????????? ??????
50,3
6,1
44,5
0,7
1,5
??????????????? ???
91,8
4,4
1,1
1,8
116,6
? 390 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
???????? ?. ????????, ????????? ?. ??????,.. ??????? ?????????????? ??????? ?? ???????????? ???????
?????????? ??????? ?????????? ???????????? ? ????????????? ???????? ????????? 150 ??, ?????? 900 ?? ??? ????????????????? ???????? ??????? 10а ░??????1 ?
???? ??????, ??????????? ?? ????????? 130
??3?????1. ??? ?????????? ???????? ??????????? (200-800 ??) ??????? ??????????? ?
???? ?????? ? ??????? 30 ?????. ? ???? ??????? ???????, ??????????????? ??? 800 ░?,
?????????? ???????????????? ?????????
???????? ??? ???? ?? ???????????. ? ???????? ???????????? ??????????? ??????????
???????? ?? ????????? ? ? ???????? ??? ??????????. ???????, ???????????????? ????????? ???????? ? ???????? ?????, ????????? ???? ???????? ?????, ???? ?????????? ?
???????? ???????? ?? 20-25 %. ??????????
??????? ?????????? ???????? (??) ???????? ???????????????? ????? ??? ???????????
60 ░?.
???????? ??????????? ?????????? ?????????? ???????? ??????? ???????? ????????? ????? ?? ??????? ????????-1. ??????????? ??-???????? ??????????? ???????? ?
??????? 4000-400 ???1 ???????????? ?? ??????? ???????????? Tensor-27 (????? Bruker),
????? ?????? ? 50, ?????????? 2 ???1. ????????? ???????????? ?????????? ????????? ?
?????????????? ?????? ???????? OPUS 5.0.
??????? ??? ?????? ??-???????? ??????????
? ??????? ?????????? ????? ??? ????????????? ???????? ???????? ? ???????.
?????????? ? ??????????
??? ????????? ?????????, ???????????? ? ???????? ????????????? ?????????????? ??????????, ???? ????????????
?????????? ???????? ??????????? ???????????? ????????? ? ???????????????? ????????. ?? ???. 1 ???????????? ??-???????
???????? ??????????? ?????????. ??????????? ??????? ?????? ?????????? ? ??-
????? 3800-3050 ???1 (???????? ???????? ?
3422 ???1) ????????? ? ????????? ??????????
????????????? ?????, ????????? ??????????? ???????, ? ?????? ??? 1653 ? 665 ???1
? ? ?????????????? ?????????? ????????
[11]. ?????????? ? ???????? 3000-2800 ???1 ?
1450-1370 ???1 ???????????, ??????????????,
?????????? ? ??????????????? ??????????? ????????????? ??3? ? ??2?????? [11], ?
?????? ? ?????????? ??? 1742 ???1 ????????????? ????????? ????????? ????????????
?????.
? ??????? ???? ???????????? ?????? ??????????, ??????????????? ????????? ?
?????????????? ?????????? ?????? ? ????????????? ???????????. ?????????? ? ???????
1640-1450 ???1 ????? ??????? ? ?????????
?????????? ?=? ?????, ????????? ? ????????????? ?????. ??????????? ?????????? ? ??????? ???? 900 ???1, ????????, ??????????? ??????????????? ??????????? ????? ??? [11].
????????????? ??????????? ?????????????????? ? ???????????????? ?????????? (???. 2) ??????????????? ? ?????????????? ??????? ??????? ????? ?? ?? ?????????.
?????????? ??? ? ??????? ??????????? ?????? ???????????? ???????. ??????????? ?
??????? ??????????? ????? ?????????? ?
??????????? ??? 1600, 1376 ? 1062 ???1 ????? ????????????????? ? ??????? ? ???????
??????? ???????? ????? ?????????? ??????.
??????????? ?????? ?????????? ???????
????????????? ??????? ? ? ??????? ???????
(??-ZnCl2) -???.
??? ??????? ??-?3??4 ?????????? ??????????? ?????? ?????????? ? ???????
1050-980 ???1, ????????????????? ? ???????
?????????????????? ?????????? ? ????????
P?O?????? ? P?O?P, ? ??????? ?????? ?????????? ???????? ? ??????? 2700-2560 ???1,
??????????? ??? ????????? ??????????, ?????????? ?????? ???? [12].
? 391 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
???????? ?. ????????, ????????? ?. ??????,.. ??????? ?????????????? ??????? ?? ???????????? ???????
3
2
1
4000
3500
3000
2500
2000
1500
???????? ?????, ??
1000
500
-1
???. 1. ??-??????? ??????????? ??????????????? ?????????: ????????? ?????? (1), ????????? ?????? ?
10 ???.% ZnCl2 (2) ? ???????????????? ???? (3)
5
4
3
2
1
4000
3500
3000
2500
2000
1500
???????? ?????, ??
1000
500
-1
???. 2. ??-??????? ????????? (1) ? ???????????????? ZnCl2 (2), ZnCl2-??? (3), ??? (4) ? ?3??4 (5)
??????????
? 392 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
???????? ?. ????????, ????????? ?. ??????,.. ??????? ?????????????? ??????? ?? ???????????? ???????
??????? 2. ????? ??????? ?????????, ?????????? ????????????? ????????? ?????? (??) ? ????????
???????????????? ? ?????????????????? ??????????
???????
?????, ???. %
500 ░?
600 ░?
700 ░?
800 ░?
??
22,3
21,9
19,8
18,9
??
36,6
35,4
34,1
32,4
??-ZnCl2
43,9
40,3
35,2
32,8
??-?3??4
54,9
52,3
51,3
45,7
??-???
57,5
56,6
55,4
47,8
(??-ZnCl2)-???
77,6
76,1
74,7
73,6
????? ???????, ??? ????????? ??????
?????????? ???????? ????????? ?????????
????????? ? ???????????? ???????? ?????
?????????? ??????. ?????????????? ????????? ??????? ? ??????????? ?????????? ?????????????? ???????????? ?????????????????? ??????????, ????? ??? ????????? ?
????????????? ????? [8, 13].
? ????. 2 ????????? ?????? ? ??????
?????????? ??????????, ?????????? ???
????????? ???????????? ???????????? ???????????????? ? ??????????????????
??????????. ???????????, ??? ?????????? ?
????????? ??????? ???????????????? ????
???????? ????? ?? ?? 14 ???.%. ??????????????? ????? ????????? ZnCl2 ?????????????
?????? ?? ????? ?? ??? 800 ░?. ??????????
????????? ??????? ??? ??????????? ?????
? ???????? ???????? ? ????????? ????? ?????? ??: ??? 500 ░? ? ???????? ?? 20 %, ???
800 ░? ? ?? 14 % ?? ????????? ? ??? ???????
?? ??????????????????? ??. ??????????
????? ??????????? ????????? ???????????
??? ???????????? ??????? (??-ZnCl2)-???,
??????? ? ??? ???? ????????? ????? ?? ??
??????????????????? ?????????.
???????? ???????? ??????????? ?? ??
???????????????? ???????? ??????? ??????
? ????????? ?????????? ???????????? 700800 ░? (???. 3). ???????? ??????? ????????
??????????? ??????????? ??? ??, ???????-
???? ????????????? ??????? ??-?3??4, ? ?????????? ????? 300 ?2?? ?1 ??? ??????????? ????????? 800 ║C.
???????? ????????? ???????? ??????????? ?? ??????????? ????? ?? ???????? ????? ??? 60 ░? ? ????? ???????? ??????????????? ?????????????? ??????????.
???????? ??????????? ????????? ??????????? ?????????, ??????????? ??? ????????????
??-?3??4 ? ????????? ?????????? 500-800
░?, ?????????? ?? 310 ?? 500 ?2?? ?1 (???. 4).
??? ??????? ?? ?????????? ??????, ????? ???????? ?????????? ??????????, ?????????? ????????????? ??-??? ? (??ZnCl2)-???, ???????? ???????? ???????????
?????????? ??????????? ?? ??? ??????? ???
???????????? ???????????? 700 ? 800 ░?.
?????? ????? ?? ??? ???? ???????????, ?
?????????? ???????? ??????????????? ??????????? ? ?????????? 10-15 ???. %. ???????????? ???????? ??????????? (1535 ?2?? ?1)
??????????? ??? ???????? ??, ???????????
????????????? (??-ZnCl2)-??? ??? 800 ░?.
?????? ??????????????????????? ???????
??????????, ??? ? ??????? ???????, ?????????? ????????????? ??-??? ??? 800 ░?, ?????????? ????? ?????????? 60 %, ? ????? ???
??????? ? ????? 3 %. ?????????????, ??????????????? ?????????? ? ???? ??????????
????????? ???????????????, ? ?? ????????
?????????? ???????? ????????? ??. ??-
? 393 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
???????? ?. ????????, ????????? ?. ??????,.. ??????? ?????????????? ??????? ?? ???????????? ???????
350
5
2
???????? ???????????, ? /?
300
250
200
150
4
100
3
50
2
1
0
500
550
600
650
700
750
800
850
?
???????????, ?
???. 3. ??????? ??????????? ?? ???????? ???????? ??????????? ?????????? ??????????, ??????????
????????????? ?? (1), (??-ZnCl2)-??? (2), ??-ZnCl2 (3), ??-??? (4) ? ??-?3??4 (5)
1600
5
2
???????? ???????????, ? /?
1400
1200
4
1000
800
600
3
400
2
1
200
0
500
550
600
650
700
750
800
850
?
???????????, ?
???. 4. ??????? ??????????? ?? ???????? ???????? ??????????? ??????????????? ? ??????? ?????
?????????? ??????????: ?? (1), ??-ZnCl2 (2), ??-?3??4 (3), ??-??? (4) ? (??-ZnCl2)-??? (5)
? 394 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
???????? ?. ????????, ????????? ?. ??????,.. ??????? ?????????????? ??????? ?? ???????????? ???????
2
???????? ???????????, ? /?
1600
1
o
1
1400
2
o
2
1200
1000
800
600
400
200
0
??
?? -? 3 ?? 4
?? -?? ? ( ?? -ZnC l 2 ) -?? ?
???. 5. ????????????? ???????? ??????????? ?????????? ??????????, ?????????? ?????????????
?????????? ??? 800 ░? ? ??????????? ???????????????? ????????? ? ????? ?????? (1, 2) ? ??
??????? (1░, 2░)
??????? ????? ??????????????? ????????
??-H3PO4 ??????????? ?? ?????? ?? ????? ?
???????? ??????????? ??????????? ?????????.
????? ???????, ??????????????? ????????? ????????? ???????? ????????? ???????? ??????????? ??????? ? ??????? ??????? ? ???????? ???????????? 500 ?2?? ?1.
??????????????? ????????? ??????? ?
???????? ????? ???????? ? ??????? ????????? ???????? ???????? ??????????? (??
1535 ?2?? ?1) ????? ?????? ??????? ??????????? ?????????.
?????????? ?????? ??????????, ???
???????????? ???????????? ????????? ??????? ????????? ? ???????? ?????????? ?
???????? ?????????????, ??? ???????????? ?
??????? ????? ??. ??? ????????? ????????? ??????? ?????????????? ????? ????????? ??????? ??????????, ?????????? ??????
???????. ???, ????????, ??????????? ??????????? ??????????????????? ???????????
?????????, ? ????????? ????????????. ???-
???????? ?????????, ?????????????? ????????? ????????, ????? ???????? ? ??????????? ????????? ? ????????????? ??????.
???????????? ???????? ????????? ?? ???
???????????? ???? 500 ░?, ??-????????, ??????? ????????? ?????????????????? ?????
??? ???? ???????????? [8].
?? ?????? ????? ? ?????????? [14],
????????? ??????????? ????????? ??? ????????? ??? ?????????????? ? ???????????
??????? ???????????, ??? ??????? ???????
?????????? ?? ?? ? ??2, ??? ????????????
???????? ???????? ?????????, ? ? 2??3 ?????????? ??? ???????? ???????. ??????????
?????, ??? ??? ???????????? 550-900 ░? ???????? ??????????? ?????????????? ?????,
?????????????????? ????? ???????????
?????? ? ?????????? ?????????????? ? 2?
?????????. ???, ?? ?????? ???????, ????? ?
?????????? ??????????? ?????? ??????????
?????????. ??-????????, ?????????? ???????????? ??????? ??-??? ?? ???????????????? ????????? ? ???????? ????????????
? 395 ?
Copyright ??? л??? л??????╗ & ??? лA???????? K????-C?????╗
???????? ?. ????????, ????????? ?. ??????,.. ??????? ?????????????? ??????? ?? ???????????? ???????
? ???????????? ???????? ????????? ?????
??????? ?????, ? ????????, ??????? ? ???????????? ???????? ?????, ??????? ?? ???????????? ?????? ????????????? ?????????? ?
???????? ???????????? ? ????? ??????????
?????, ????????? ??? ???????? ?????????.
????????? ? ???????? ??????? ???????
????? ????? ??????????? ?????????? ????????? ???????, ?????????? ??????? ???????????? ? ??????????? ???????????? ??????????
?????????, ? ????? ??????? ??????????????? ???????????? ? ???????.
??? ????????, ?????????? ????????? ??
?????? ??????????, ??? ?2, ??2, ?2?, ???????????? ???????? ??? ???????? ?????????
[15]. ? ????? ????????? ???????? ??????????? ?????????? ??????????, ??????????
????????????? ???????? ? ????????? ???????????????? ??????????, ???????????? ??
????????????? ????????? ????????. ???????? ??????? ??????????????????? ????????? ?? ? ????????? ? ???????? ?????? ?? ??
???????? ??????????? ?????????????? ???.
5. ??????????, ??? ???????????????? ???????? ?????????? ?? ??? 800 ░? ?? ???-
???? ??????? ???????? ?? ???????? ???????????.
??????
?????????? ???????? ??????????????? ???????? ??????????? ?????, ?????????
??????? ? ??????? ????? ? ???????? ????????? ???????? ?????????? ?????????? ??
?????? ?????? ?????? ? ????????????????
????. ????????, ??? ??????? ???? ? ????????? ?????? ???????? ????? ???????????
?????????. ??????????????? ?????????
?????????-??? ????????? ???????? ???????? ? ????????? ???????????? ?????????
? ??????? 46 ???.% ? ???????? ???????????? ?? 500 ? 2?? ?1. ??????? ???????????
????? ? ??????? ????? ? ???????? ??????? ????????? ????????? ??? ????????????, ?????
Документ
Категория
Фундаментальная
Просмотров
49
Размер файла
3 403 Кб
Теги
2008, журнал, университета, 183, сер, сибирской, химия, федеральное
1/--страниц
Пожаловаться на содержимое документа