Engineering Platinum-Based Alloy Catalysts for Oxygen Reduction Reaction in Hydrogen Fuel Cells: A Mini-Review

Proton exchange membrane fuel cells are clean power sources for heavy industry and hard-to-abate sectors such as large electric vehicles and long-haul transportation, yet the high cost of platinum catalysts and their performance challenges hinder their broader adoption. This review summarizes recent progress in developing platinum-based alloy catalysts as cost-effective alternatives for the oxygen reduction reaction in hydrogen fuel cells. We begin by clarifying the definitions and classifications of alloy catalysts, followed by a discussion of key factors that determine their catalytic performance. State-of-the-art oxygen reduction reaction catalysts are then comprehensively examined, highlighting the evolution from disordered alloys to ordered intermetallic compounds. Particular attention is given to strategies for mitigating nanoparticle aggregation during the synthesis of ordered catalysts, which is critical for maintaining high activity and durability. We also discuss the role of platinum-group metal-free support in stabilizing platinum-based catalysts and reducing precious metal usage. Finally, we summarize the challenges and opportunities for platinum-based alloy catalysts for hydrogen fuel cells. Overall, this review offers valuable insights into the rational design of platinum-based oxygen reduction reaction catalysts with superior activity and long-term stability, paving the way for the development of next-generation low-platinum hydrogen fuel cells.