Electrocatalytic Activities of Perovskite toward Oxygen Reduction Reaction in Concentrated Alkaline Electrolytes

Abstract

Perovskite La0.6Ca0.4CoO3 powder was prepared through a sol-gel method and characterized by XRD and BET. The electrocatalytic properties of La0.6Ca0.4CoO3 (LCCO) and La0.6Ca0.4CoO3-Carbon composite (LCCO-C) based electrode layers towards oxygen reduction reaction (ORR) were studied using rotating ring-disk electrode technique (RRDE) in 1, 4, and 6 M KOH electrolytes. Koutechy-Levich theory and RRDE measurement were applied to acquire the overall electron transfer number and kinetic parameters, such as the kinetic currents and rate constants. The overall electron transfer number was measured to be almost 4 for both pure LCCO and composite LCCO-C. A synergetic effect toward the ORR was observed in the LCCO electrode layer in the presence of carbon. This synergetic effect might be one of the reasons for the improved ORR performance on the composite LCCO-C electrode.