Nitrogen-Doped Mesoporous Graphene as a Synergistic Electrocatalyst Matrix for High-Performance Oxygen Reduction Reaction

Abstract

To balance the anchoring sites and conductivity of the catalyst supports is a dilemma in electrocatalytic oxygen reduction reaction (ORR). Nitrogen-doped mesoporous graphene (N-MG) with large surface area, high porosity, and superior intrinsic conductivity has been developed to address this issue. Using N-MG as the backbone, a hybrid catalyst of Co₃O₄ nanocrystals embedded on N-MG (Co₃O₄/N-MG) was prepared for the electrocatalytic ORR in alkaline media. The Co₃O₄/N-MG showed high catalytic activity for the four-electron ORR, giving a more positive onset potential (0.93 V vs RHE) and a higher current density. The unique property of N-MG and the synergetic effect of Co₃O₄ and N-MG are prominent for ORR. With improved electrocatalytic activity and durability, the Co₃O₄/N-MG can be an efficient nonprecious metal catalyst and potentially used to substitute the platinum-based cathode catalysts in fuel cells and metal–air batteries