Electrocatalytic oxidation of benzyl alcohol on a platinum electrode modified by underpotential-deposited heavy metal adatoms

Abstract

The oxidation of benzyl alcohol on platinum surfaces modified by foreign metal adatoms (Pb, Tl, Bi) deposited at an underpotential region was studied in both acid and alkaline media; it was found that Pb, Tl, and Bi submonolayers intensively catalyse the benzyl alcohol oxidation. The enhancement of the electrocatalytic activity of Pt for the benzyl alcohol oxidation in acid solutions has been explained through the mechanism of ăthird body" effect in electrocatalysis. On the other hand, the enhanced catalytic activity in alkaline media, which in the case of Bi adatoms yields current densities close to the diffusion-limited values, has been interpreted in terms of the bifunctional theory in electrocatalysis.