Structure-Stability Engineering of Pt-Based and Fe-N-C Catalysts Toward Oxygen Reduction Reaction

Achieving long-term durability of oxygen reduction reaction (ORR) catalysts is a critical requirement for the practical deployment of electrochemical energy technologies, such as fuel cells and metal-air batteries. Platinum-based (Pt-based) catalysts remain the benchmark for ORR activity. However, their high cost, limited availability, and performance degradation caused by carbon corrosion, nanoparticle agglomeration, and Pt dissolution present significant barriers for sustained performance. In parallel, iron-nitrogen-carbon (Fe-N-C) catalysts have emerged as promising alternatives, delivering near-Pt activity through atomically dispersed Fe-N_x active sites. Yet, their insufficient stability, primarily due to Fe leaching and protonation-induced deactivation, continues to hinder their practical applications. This review comprehensively summarizes recent advances in improving the stability and durability of Pt-based and Fe-N-C catalysts. For Pt-based systems, strategies include electronic structure regulation, entropy-driven alloying, and support-interface engineering. For Fe-N-C catalysts, progress has been made in graphitization enhancement, heteroatom doping, defect engineering, and dual-metal site incorporation, all aiming to suppress degradation pathways. Furthermore, structure-stability correlations revealed by experimental and computational studies provide mechanistic insights into degradation processes and stability-limiting factors. Special attention is given to the interactions among catalyst structure, electronic configuration, and electrochemical microenvironment, offering guidance for robust catalyst design. Finally, we discuss ongoing challenges and future opportunities for developing highly stable ORR catalysts, providing a roadmap toward next-generation cost-effective and durable ORR catalysts, and accelerating the industrial realization of sustainable energy conversion technologies.