The electrochemical oxidation of sulphur dioxide at porous catalysed carbon electrodes in sulphuric acid

The electrochemical oxidation of sulphur dioxide has been studied in sulphuric acid solution at porous carbon electrodes coated with catalysts consisting of aluminum-vanadium mixed oxides with traces of platinum.Catalyst activity and stability in acid electrolytes are determined by the preparation conditions and the V₂O₅: Al₂O₃ ratio.Potentiodynamic measurements were made for investigating the mechanism of the anodic oxidation of sulphur dioxide. When catalysts are present, sulphur dioxide is anodically oxidized at the porous carbon electrodes. Direct electron transfer from the sulphur dioxide to the anode takes place at low potentials, whereas at more positive potentials reaction takes place between the sulphur dioxide and the electrolytically produced surface oxides on the platinum.