Electrocatalytic reduction of oxygen to water at Au nanoclusters vacuum-evaporated on boron-doped diamond in acidic solution

Electrocatalytic reduction of oxygen at a boron (B)-doped diamond (BDD) electrode on which Au nanoclusters (GNCs) were deposited by vacuum-evaporation was investigated in 50 mM H2SO4 solution. Oxygen reduction current started to flow at a more positive potential at the GNCs/BDD electrode than at a polycrystalline gold electrode. Formation of water through a 4-electron reduction pathway at the GNCs/BDD electrode was confirmed, although oxygen reduction at gold electrodes in acidic solutions generally proceeds via a 2-electron pathway generating H2O2. (C) 2004 Published by Elsevier B.V.