Progress of Biomass/Coal-Based Carbon Materials as Electrocatalysts for Oxygen Reduction Reaction
The oxygen reduction reaction (ORR) is a critical cathode reaction in fuel cells and metal-air batteries, yet its sluggish kinetics and high overpotential severely limit device performance. Conventional platinum-based catalysts suffer from prohibitive cost (accounting for up to 40% of total fuel cell system cost), scarce reserves, and poor tolerance to methanol and carbon monoxide, impeding large-scale commercialization. This review systematically summarizes recent advances in biomass/coal-based carbon materials as ORR electrocatalysts, focusing on raw material characteristics, preparation methods, structural regulation, and performance evaluation. Biomass and coal precursors offer advantages of low cost, abundant availability, and natural heteroatom doping (N, P, S), enabling the design of high-performance, metal-free catalysts. Key challenges include ensuring raw material homogeneity, precise control of active sites, and scalable synthesis. Future research directions emphasize optimizing pore structure and surface chemistry to enhance four-electron selectivity and stability. The review provides theoretical guidance for developing cost-effective ORR catalysts to replace platinum, thereby accelerating the deployment of clean energy technologies.