Features of Sulfite Oxidation on Gold Anode

Electrochemical oxidation of sulfite ions on gold was studied by means of voltammetry with the electrode renewed by cutting off a thin layer. It was demonstrated that two different kinds of voltammograms can be recorded on gold, depending on experimental conditions. Voltammograms of the first kind, with current maximum at 0.8 V, is typical for the fresh gold surface. The second one, with current maximum at 0.6 V, is observed on gold surface modified during sulfite oxidation. Modification of gold surface is likely to be due to the formation of “sulfur adlayer” in the reduction of adsorbed products of sulfite oxidation. Attention is attracted to the fact that the characteristics of the oxidation of sulfite and sulfur dioxide on gold have many common features.