Reduction of SO2 on platinum with surface catalyst formation

Electroreduction of adsorbed SO2 layers on platinum is studied. The adsorption takes place at open circuit condition. The reaction product is a sulphide that behaves as a catalyst or as an inhibitor for the electrochemical SO2 oxidation reaction. Depending on the surface properties, the SO2 sulfur atom initialy adsorbed can be linked to either one or two sites. In case is linked to two sites, the first layer is capable of adsorbing multilayers and the reduction product offers excelent catalyst properties for the SO2 electrooxidation reaction.