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Developments of Fuel Cells.

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vapor pressure isotope effect whereas they are fully excited a t
room temperature and thus d o not contribute.
Lecture at Heidelberg (Germany) on February 28th, 1967 [VB 74 IE]
German version: Angew. Chem. 79,728 (1967)
ment of the equilibrium are suppressed by internal hydrogen
bridges. For instance, the 2-methoxycarbonyl compound ( I )
is a true nitrosophenol both in the solid state and in benzene
or dioxane.
[*I Prof. Dr. H.Wolff and Dr. A. Hopfner
Physikalisch-Chemisches Institut der Universitait
Tiergartenstr.
69 Heidelberg (Germany)
Developments of Fuel Cells
By W. Vielstich [*I
General Motors recently exhibited a bus (Electrovan) driven
by a 32 kW H2/02 battery (Union Carbide Inc.) operating
an alternating current motor. Disadvantages of this experimental model are the tanks containing liquid hydrogen and liquid oxygen (danger of explosion) and the high
cost of the noble metals in the hydrogen electrode. A 200 kW
battery constructed by Firma ASEA, Sweden, for propulsion of a submarine, utilizes ammonia and liquid air;
the ammonia is first cracked in a reformer and the hydrogen
obtained is fed to skeleton nickel electrodes.
The triangular potential scan method is useful for study of
the fundamental principles. In the region between initial
H2- and 02-evolution, the electrode potential varies linearly
with time in a periodic manner. In this way, the experimental
electrode is reproducibly reactivated during measurement.
The nature of the intermediate product in the oxidation of
formic acid is of particular interest. By comparing the
charge needed for oxidation of the adsorbed intermediate
with the amount of carbonate formed (determined by
titration) it was shown that one electron is consumed per
carbon atom. This result suggests that COOH radicals are
the intermediates, rather than CO.
The composition and structure o f the catalyst have a great
effect o n the dehydrogenation of methanol and formate in
alkaline electrolytes. At the same electrode potential the
anodic current densities for methanol (uncharged particles)
and formate (charged particles) on various catalysts (e.g. Pt,
Pd, and Pt/Pd alloys) differ by more than one order of
magnitude.
Fuel cell batteries based on methanol/air and formate/air
and incorporating these catalysts have already been tested as
energy sources in signal installations and TV relay stations.
Fuel monocells are superior to the usual dry batteries
in respect of greater capacity, constant discharge potential,
ease of recharging, and better storage life. Monocells are
constructed o n the following principles: The lid of the
monocell is fitted with a cylindrical carbon diffusion electrode
with an air inlet and a metal terminal. The cell also contains
a cylindrical fuel electrode and fuel electrolyte (20 ml 4 M
C H 3 0 H + 9 N KOH). After discharge (e.g. 50 mA, 0.6 v,
240 h, 12 Ah), the element can be regenerated simply by
renewal o f the electrolyte.
Lecture at Gottingen (Germany) on February 23rd, 1967 [VB 75 IEI
German version: Angew. Chem. 79, 726 (1967)
On the other hand, in the solid state the 3-methoxycarbonyl
compound (2) is a quinone oxime with intermolecular
hydrogen bridges. The oxime group is in the anti-position to
the methoxycarbonyl group, as it is also in other quinone
4-oximes having a substituent on C-3 [21.
5-Methoxy-2-nitrosophenol exists in a brownish-green and
in a n orange form. Burawoy 131 concluded from the electronic
spectra of this compound in various solvents that an equilibrium exists between the nitrosophenol with a n internal
bridge and a quinone oxime with a n internal bridge. Bartindale[4] proved that the orange form in the solid state is a
quinone oxime with intramolecular bridges and anti-relation
of the oxime group to the quinone oxygen atom, which is in
agreement with the behavior of 1,4-quinone oximes [21. By
means of IR and electron band spectra of the two solid forms
and in various solvents, aided by the dependence of the
spectra on the hydrogen ion concentration and on temperature, it has been found that, in carbon tetrachloride, there is
a n o-nitrosophenol with an internal bridge but that in polar
solvents there is a n equilibrium between the nitrosophenol
with an internal bridge, the mesomeric ion, and the quinone
oxime with intermolecular bridges (cf., however 9.
A 1,2-quinone oxime with internal bridge is to be expected
if a substituent in the second neighboring position to the
oxime group prevents the movement of that group from the
syn-position to the quinone oxygen, even though this type of
substitution favors the quinone oxime structure. Such a case
exists in 1,2-naphthoquinone I-oxime; here also polar solvents lead to partial fission of the internal hydrogen bridge,
so that the naphthoquinone with internal bridge is in equilibrium with the mesomeric ion and 1-nitroso-2-naphthol.
Lecture at Hanover (Germany) on February 23rd 1967
[VB 71 IEJ
German version: Angew. Chem. 79, 692 (1967)
[*] Dr. H. Uffmann
Institut fur Organische Chemie der Technischen Hochschule
Callinstr. 46
3 Hannover (Germany)
[l] E. Havinga and A . Schors, Rec. Trav. chim. Pays-Bas 69, 457
(1950); H . Uffmann,Tetrahedron Letters 1966, 4631.
Z. Naturforsch., in press.
[2] H . U’mann,
[3] A . Burawoy et al., J. chem. SOC.(London) 1955, 3727.
141 G. W. R. Bartindale et ai., Acta crystallogr. 12, 111 (1959)
[ 5 ] C. Romers, Acta crystallogr. 17, 1287 (1964).
Investigation of Unstable Molecules and Free
Radicals by Rotational Spectroscopy
[*I Prof. Dr. W.Vielstich
Institut fur physikalische Chemie der Universitlt
Wegelerstr. 12
53 Bonn (Germany)
IntramolecularHydrogen Bridges in Nitrosophenols
By H. U#mann~*I
Tautomeric equilibria of the type p-nitrosophenol 2 1,4benzoquinone 4-monoxime are established via a n intermediate mesomeric ion which can itself play a considerable
part in the equilibrium[ll. Formation of the ion and achieve-
714
By M . Winnewisser[*l
The millimeter and submillimeter region of the electromagnetic spectrum is a field of molecular spectroscopy that
is rich but almost undeveloped. Because of their short
wavelength [lo mm (30000 MHz) to 1 mm (300000 MHz)
these waves can be collimated and focused by a combination
of waveguides, horns, and Teflon lenses, which permits
the use of large glass or quartz absorption cells for spectroscopy of unstable molecules and gaseous radicals [I].
The gases to be studied a-e contained in a cylindrical glass
cell (diameter 10 cm, length 100 cm), which is placed in the
path of the millimeter radiation. A system of gas discharge
Angew. Chem. internat. Edit.
1 Vol. 6 (1967)
No. 8
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