Electrochemical reaction mechanism of aqueous polysulfide solution

Cyclic voltammetry and choronopotentiometry studies on aqueous polysulfide solution at graphite anode have been reported. The experiments show that the anode oxidation of the polysulfide, which consists of several parallel electrode reactions and following chemical reactions, is an irreversible process, and that the potential peak in timepotential curves for constant current steps indicates a self catalysis process in the electrochemical oxidation of the polysulfide solution. It is found from further analysis for the cyclic voltammetry and choronopotentiometry that the number of electrons transferred in rate determining process of the anode oxidation is close to 1, and that the reaction rate constant of self catalysis is large. These results indicate that interreactions of the polysulfide are quick processes. The potential peak in the potentialtime curve disappears with the increase of the current.