Electrooxidation of methanol on polycrystalline and single crystal gold electrodes

Oxidation of methanol has been investigated on polycrystalline and single crystal gold electrodes: Au(poly), Au(1 11) and Au(2 1 0), in acidic, neutral and alkaline solutions. As expected, catalytic activity of gold towards methanol oxidation increases with increasing pH of the solution. It has been found that in all studied solutions methanol is oxidised in two potential regions, prior to gold surface oxide monolayer formation and in more positive potentials, on gold surface oxide after so called turn over. Surface structure of the electrode has little influence on the oxidation current, however potentials at which oxidation is observed depends on the crystallographic orientation. The mechanism of electro-oxidation of methanol on gold is discussed. (C) 2003 Elsevier Ltd. All rights reserved.