Anodic sulphite oxidation on lead electrode in a neutral environment

Abstract

The purpose of the research, anodic oxidation of the sulphite ions on the lead electrode in neutral solution, is both to establish the mechanism of sulphite electrooxidation on lead electrode and to determine the optimal parameters for the anodic process. The work started from the premise that the electrodes used in the anodic electrode processes that are carried out in aqueous solutions must have catalytic properties for the oxygen evolution release reaction. Among the metals tested as possible anodes to equip the electrochemical reactors used to obtain oxygen electrochemically from alkaline and acid electrolyte solutions, platinum exhibits the highest catalytic activity. Due to both the high price and the existence of a limited quantity of this metal, researches have been focused on identifying other metals and metal alloys that have catalytic properties for anodic processes [1].The electrochemical behaviour of the sulphite ions in the test solutions was studied by cyclic and linear voltammetry. The Tafel plot method was applied for a complete characterization of the process studied at the lead electrode / neutral electrolyte interface and for the determination of kinetic parameters (current density io and anode transfer coefficient α) [2]. The chrono-electrochemical methods (chronoamperometry, chronocoulometry) were chosen to determine the optimal parameters of the studied oxidation process (current density, optimal range of specific oxidation potential for sulphite electrooxidation and degree of transformation of sulphite ions in test solutions) [3].The presented studies regarding the electrochemical behaviour of sulphite ions in neutral medium on lead electrodes, are the initial point for the development of a Na2SO3 / O2 fuel cell [3].