A simple modeling study of the Ce(IV) regeneration in sulfuric acid solutions

► The simple model of electrochemical regeneration of Ce(IV) in sulfuric acid solutions at PbO 2 anode has been developed. ► The study showed that Ce ( SO 4 ) 2 − is the kinetically active species and the decomposition of surface complex of Ce(IV) at the anode surface is the rate determining step. ► There is no relation between current density and concentrations of ions participating in the anodic reaction. The electrochemical regeneration of Ce(IV) for mediated electrochemical oxidation in sulfuric acid media was investigated in an electrolytic membrane reactor. A simple kinetic model was developed to analyze and simulate the regeneration of Ce(IV) in the electrolysis process. The model was based on the Faraday's law and the mass balance of components in the reactor. The key operating conditions of the initial electrolyte concentration and the regeneration time were analyzed. It was found that the simulating model agreed well with the experimental data for regeneration of Ce(IV). Experimental results showed that Ce ( SO 4 ) 2 − is the active species. The decomposition of surface complex of Ce(IV) at the anode surface is the rate determining step. Constant-current electrolysis shows that the high proton and Ce(III) concentrations are electrochemically favorable for the regeneration of Ce(IV). The current efficiency for regeneration of Ce(IV) decrease obviously with the increase of SO 4 2− concentration from 0.8 to 2.4 mol/L.