A Kinetic Study of Oxalic Acid Electrochemical Oxidation on a Manganese Dioxide Rotating Cylinder Anode

This paper deals with the theory and kinetics of ox alic acid electrochemical oxidation, in an acidic solution containing sodium chloride, u sing a manganese dioxide rotating cylinder anode. Voltammetric and galvanostatic elec trolysis techniques were used. The voltametric study shows a higher anodic wave corres ponding to chlorine oxidation on the MnO2 electrode, prevailing oxalic acid indirect oxidati on. Galvanostatic electrolysis studies confirmed that the rate constant is affecte d by chloride concentration, current density, agitation and temperature. Electrochemical oxidation rate was found to be a pseudo-first order kinetic process. A strongly line ar relationship between the rate constant and chloride concentration was observed, w hile polynomial relations, with respect to current density and temperature, were fo und. The activation energy was found to be 14.541 kJ/mol, which suggests a diffusion con trol kinetic step in oxalic acid degradation. The findings of the present research v alidate that oxalic acid incineration can be successfully carried out on a MnO 2 anode, in NaCl presence.