Electrocatalytic oxidation and reduction of H2O2 on Au single crystals

In this work, the reduction and oxidation of hydrogen peroxide on Au single crystals is studied in weakly adsorbing electrolytes. Results are discussed in terms of the potential of zero charge and the adsorption strength of different anions, which in turn depend on the crystallographic orientation of the electrode. Close to the reaction onset, both reactions follow the same activity trend with Au(100) and Au(111) being the most and the least active surface planes, respectively. At high potentials, gold oxides inhibit the oxidation of H2O2, which seems to be controlled by a surface process.