Recent Advances in Non-Precious Metal Catalysts for Oxygen Reduction Reaction in Fuel Cells

The oxygen reduction reaction (ORR) is the key reaction at the cathode of proton exchange membrane fuel cells (PEMFCs), but its slow kinetics severely limit cell efficiency and commercialization. Currently, platinum-based catalysts serve as the benchmark for ORR, yet their high cost, scarcity, and susceptibility to poisoning restrict widespread application. Therefore, developing high-performance, low-cost non-precious metal catalysts (NPMCs) has become a core focus in fuel cell research. This review summarizes recent advances in NPMCs for ORR, highlighting transition metal-nitrogen-carbon (M-N-C, M=Fe, Co, Mn, etc.) materials, heteroatom-doped carbon materials, and transition metal oxides, sulfides, and nitrides. The article discusses synthesis strategies, structural features, active site identification, and performance evaluation of these catalysts. Furthermore, challenges related to activity, stability, and scalability are analyzed, and future research directions are proposed to accelerate the practical application of NPMCs in next-generation fuel cells.