Electrocatalysis by ad-atoms: Part IX. A fast parallel path for formaldehyde oxidation on a platinum electrode by oxygen adsorbing ad-atoms

Abstract

The effect of various ad-atoms on formaldehyde oxidation was examined on a Pt electrode. Ad-atom species are found to be classified into two groups according to their way of affecting the electrode reaction: one consists of Cu, Ag, Tl, Hg, Pb, As, Bi, Te and Se, the other Ge, Sn and Sb. The enhancement effect of the former depends on the number of Pt sites occupied by an ad-atom of each species ( S M), which suggests to us that geometrical control of Pt site arrangement plays an important role in the enhancement. The latter group of ad-atoms adsorb oxygen atoms, and these oxygen atoms are considered to play an important role in this enhancement. The enhancement ratio by the latter group of ad-atoms is much greater than that by the former group. The enhancement by the latter group of ad-atoms is via a new rapid parallel path, which has not been found on a Pt electrode for formaldehyde oxidation.