Study of the Kinetics of Vanadium Redox Reaction by Rotating Disk Electrode

摘要

This work studied the kinetics of electrochemical reaction of vanadyl ion (VO~(+2)) oxidation (from VO~(+2) to VO_2~+) and reduction (from VO~(+2) to V~(+3)) in aqueous solution containing different vanadium concentrations and pH values. The rotating disk electrode was used to study the reaction kinetics. The potential of the water electrolysis reaction could be shifted by changing the solution of pH. Nineteen different solutions were tested in our study. The rate constants of VO~(+2) oxidation and reduction reactions were calculated, as well as the diffusion coefficient of VO~(+2) in different electrolytes. We found that the oxidation reaction was much faster than the reduction reaction. The diffusion coefficient of VO~(+2) varied as the electrolyte pH changed.