Understanding the Influence of Carbon on the Oxygen Reduction and Evolution Activities of BSCF/Carbon Composite Electrodes in Alkaline Electrolyte

Abstract

The influence of carbon on the oxygen reduction and evolution reactions (ORR and OER) on Ba0.5Sr0.5Co0.8Fe0.2O3-δ (BSCF) perovskite oxide has been studied in alkaline electrolyte. A lowering of the ORR overpotential by 100 mV for the BSCF/Carbon composite electrode compared to BSCF without carbon was observed, while for the OER the overpotential was reduced by some 65 mV. The results of this work suggest that the carbon present in the composite electrodes acts as more than a simple conductivity-improving agent and enhances the electrocatalytic activity of the oxide significantly.