K. Otsuka et I. Yamanaka, Oxygenation of alkanes and aromatics by reductively activated oxygen during H-2-O-2 cell reactions, CATAL TODAY, 57(1-2), 2000, pp. 71-86
Direct oxygenation of aromatics to phenols, C6 alkanes and light alkanes to
alcohols and aldehydes are realized at the cathode during H-2-O-2 fuel cel
l reactions at room temperature. The advantages of these H-2-O-2 fuel cell
systems compared with the common catalytic oxidation systems are demonstrat
ed and the electrocatalysis of the cathodes and the reaction mechanisms for
the oxygenations are discussed in detail. The topics are the omega-oxidati
on of n-hexane with (FeCl3 + alpha-cyclodextrin)/graphite cathode, the syne
rgism of Pd-black and iron compounds for the formation of phenol on (Pd-bla
ck + Fe3O4)/carbon-whisker (CW) cathode, cogeneration of phenol and electri
city by using CuSO4/CW cathode, the synergism of different carbon materials
in the cathode for the product selectivity in the oxidation of toluene on
(CW + Active Carbon) cathodes, and the oxidation of propane over (Pd-black
+ VO(acac)(2))/carbon-fiber cathodes in the gas phase. Reductive activation
of oxygen on the cathode is essential for these oxygenations. For most of
the electrocatalytic systems used in this work, the oxygenations of alkanes
and aromatics can be explained on the basis of Fenton Chemistry assuming H
O. as the active oxygen species, except for the SmCl3/graphite cathode. (C)
2000 Elsevier Science B.V. All rights reserved.