A Novel Application of Fe3O4@MnO2/NC Bimetallic Oxide Catalyst with Core–Shell Structure toward Oxygen Reduction Reaction

Abstract

The energy crisis and environmental pollution have made the development of highly efficient oxygen reduction reaction (ORR) electrocatalysts a research priority to improve fuel cell performance. A simple one-pot hydrothermal method was successfully used to synthesize the Fe₃O₄@MnO₂/NC composite material, and the performance of catalyst was enhanced by adjusting the molar ratio of Fe–Mn and the addition of coconut shell carbon (CSC). The characterization results show that the Fe₃O₄@MnO₂/NC with core–shell structure has a high specific surface area (751 m² g^–1) and provides abundant active sites for ORR. The electrochemical test results show that Fe₃O₄@MnO₂/NC exhibits a superior ORR activity among the as-prepared catalysts due to strong interfacial coupling interaction. In addition, it also has a high specific capacitance, a small Tafel slope, and the lowest impedance in ORR. This not only verifies its excellent performance, but also provides a new approach and idea for developing non-precious metal ORR catalysts.