BISMUTH(III) AND COPPER(II) OXIDES AS CATALYSTS FOR THE ELECTROOXIDATION OF ORGANIC-COMPOUNDS

It was shown that copper(II) oxide bound to the anode with polystyrene containing a cationic surfactant acted as a catalyst for the oxidatio n of organic compounds in aqueous systems in a manner similar to powde red copper oxide suspended in aqueous systems containing the organic c ompounds and the cationic surfactant. Voltammetric measurements made w ith these electrodes were reproducible over an extended period of time , and it was possible to reproducibly use the polystyrene bound copper oxide as a catalyst for anodic destruction of several organic compoun ds. On the other hand, while bismuth(III) oxide (Bi2O3) bound to plati num with polystyrene was a catalyst for the oxidation of organic compo unds in cationic surfactant suspensions, the results were not reproduc ible. The rate of renewal of the reactant adsorbed on the anode after oxidation was extremely slow. In addition, the Bi2O3 gradually changed during the catalytic reaction to BiO(OH). Both of the bismuth compoun ds acted as catalysts for the oxidation reaction, but the potential fb r oxidation of Bi2O3 was less anodic than the potential for BiO(OH). P revious coulometric experiments have indicated clearly that the cataly tic intermediate for the copper oxidations is copper(III); however, th e coulometric oxidations of bismuth indicate that the intermediate has a bismuth oxidation state slightly over 4. Most probably the intermed iate is bismuth (V) and some of the bismuth had agglomerated so that n ot all of it has been oxidized.