New Electrodes Based on Pt-Co Alloys Used as Anodic Materials for Sulphite Oxidation in Alkaline Fuel Cells
In this paper, electrooxidation of sulphite ions on Cu/Pt-Co electrodes in alkaline media (1 mol L-1 NaOH) has been investigated in order to establish the mechanism and to determine optimal parameters of the anodic process. Electrochemical behavior of sulphite ions on Cu/Pt-Co electrodes in alkaline solutions has been studied by voltammetric techniques (cyclic and linear), and kinetic parameters (current density io and anodic transfer coefficient α) have been determined by Tafel plots method. Furthermore, electrochemical impedance spectroscopy was carried out to confirm the sulphite oxidation mechanism on this type of electrode. Chrono-electrochemical techniques have been applied in order to determine the optimum characteristic parameters: current density, oxidation potential for sulphite electrooxidation and transformation degree of SO3 2- ions in the anodic process at different electrolysis times.