pH Effect on Oxidation of Hydrogen Peroxide on Au(111) Electrode in Alkaline Solutions

The hydrogen peroxide oxidation reaction (HPOOR) on Au(111) electrode in alkaline solutions with pH values ranging from 10 to 13 was examined systematically. HPOOR activity increased and the slope of the $i$ - $E$ curve decreased with increasing pH. HO $_2$ $^-$ is suggested to be the main reactive intermediate for HPOOR in alkaline media. The fast kinetics for HPOOR in alkaline solution is facilitated by the electrostatic interaction between the positively charged electrode and the reactive anions ( i.e ., HO $_2$ $^-$ and OH $^-$ ), which increases the concentration of these reactants and the thermodynamic driving force for HO $_2$ $^-$ oxidation at the reaction plane.