Ethanol Oxidation on Rh/Pd(poly) in Alkaline Solution

Bimetallic electrodes prepared by Rh nanoislands spontaneously deposited on polycrystalline palladium, Pd(poly), at submonolayer coverage were explored for ethanol oxidation in alkaline media. Characterization of obtained Rh/Pd(poly) nanostructures was performed ex situ by AFM imaging and by X-ray photoelectron spectroscopy. In situ characterization of the obtained electrodes and subsequent ethanol oxidation measurements were performed by cyclic voltammetry in 0.1 M KOH. Palladium surface with 50% Rh coverage exhibited the highest catalytic activity for ethanol oxidation in alkaline media. The origin of the enhanced catalysis of Rh/Pd(poly) surfaces with respect to bare Pd was explained by the electronic effect. Possible reaction pathways for ethanol oxidation were discussed taking into account the activity of obtained bimetallic electrodes for the oxidation of CO and acetaldehyde, as the most probable reaction intermediates. (C) 2016 Elsevier Ltd. All rights reserved