COMPETITIVE OXIDATION OF FORMALDEHYDE AND FORMATE ON AMORPHOUS COPPER-PALLADIUM-ZIRCONIUM ALLOY ELECTRODES IN ALKALINE MEDIA

Raney-type Cu-Pd alloy electrodes were prepared from amorphous Cu-Pd-Zr ternary alloys by treatment with aq. HF, and competitive anodic oxidation reactions of HCHO and HCOO** minus were studied on these electrodes in alkaline media. The initial HCHO oxidation product was HCOO** minus even on Pd or Pd-rich alloy electrodes which should be more active to the HCOO** minus oxidation than to HCHO. The product HCOO** minus was oxidized only after a large decrease of the HCHO concentration in the electrolyte. The oxidation rate of HCOO** minus was considerably lowered by the existence of even a small amount of HCHO, as well as by the introduction of CO. These results suggest that the HCHO electro-oxidation is accompanied by production of a surface contaminant such as adsorbed CO.