Structural effects in electrocatalysis: Oxidation of ethylene glycol on single crystal gold electrodes in alkaline solutions

Abstract

Ethylene glycol is a potential fuel of practical interest whose electrooxidation has not been studied in detail. This is a complex reaction whose mechanism is far from being understood. It is quite clear, however, that some kind of strongly bound intermediate is formed in the oxidation of ethylene glycol on platinum. This is indicated also by the effects of foreign metal adatoms covering a part of the Pt surface. Thus, pronounced catalytic effects of Pb, Tl and Bi have been observed in alkaline solutions and these are partly based on a suppression of formation and/or adsorption of strongly bound intermediates. In this work the oxidation of ethylene glycol on gold single crystals with the (100), (110) and (111) orientations has been studied with the aim of investigating whether there is structural sensitivity in this reaction. Structural sensitivity, as well as the role of AuOH species formed on surfaces, could be of interest for both electrocatalysis and catalysis.