Electrochemical Reduction of Ozone in Acidic Media

The stoichiometry of the electrochemical reduction of ozone at a platinum electrode in 1M sulfuric and 0.1M perchloric acid media was studied by classical chemical and electrochemical methods at a rotating gold ring-platinum disk electrode. The reaction was established to be O₃ + 2H+ + 2e → O₂ + H₂O. The diffusion coefficient was calculated from the Levich equation to be 1.53 ± 0.12 × 10⁻⁵ sq cm per second in 1M sulfuric acid and 1.39 ± 0.05 × 10⁻⁵ sq cm per second in 0.1M perchloric acid. These values were verified using chronopotentiometry and linear scan voltammetry. From a wave analysis of a current-potential curve obtained for a potential scan from + to −, αn_a = 0.32, while for a potential scan from − to +, αn_a = 0.57. In 0.1M perchloric acid, the corresponding values were 0.38 and 0.59.