Parameter Evaluation of ORR at a RRDE

摘要

The humps and plateaus in the ring polarization curves for oxygen reduction reaction at a rotating ring disk (smooth platinum) electrode in 0.5 M sulfuric acid solution and 0.5 M perchloric acid solution were analyzed. The oxygen reduction is assumed to take a 4-electron transfer pathway in majority, and two different 2-electron transfer pathways leading to peroxide generation in minority. The exchange current densities and transfer coefficients of the above three reactions were evaluated by the Gauss-Newton nonlinear parameter estimation technique with experimental data. The oxygen concentrations in the electrolytes were also evaluated as variables since tend to cause errors in the experiments. The fits between experimental results and regression results are with fair quality and support the proposed reaction mechanism.