Platinum Alloy Catalysts for Oxygen Reduction Reaction: Advances, Challenges and Perspectives

One of the challenges in polymer electrolyte membrane fuel cells (PEMFCs) is developing cost‐effective, active and stable catalyst for oxygen reduction reaction (ORR). Platinum alloy‐based catalyst materials have drawn great attention and been intensively investigated for the excellent activity property, with some of them already exceeding 2020 DOE target for the ORR activity. In the meantime, the electrochemical stability of these Pt alloys remains a challenge to be overcome. This review first highlights important understandings of ORR pathways and mechanisms and then proceeds to summarize recent research progresses on development of Pt alloy catalyst materials. Current obstacles in Pt alloy catalyst research are discussed, with the stability issue being specifically emphasized and a theoretical model being developed for depicting the stability property. This review also provides perspectives of future research directions in this field. Platinum power: This minireview highlights current understanding of oxygen reduction reaction mechanisms and recent research progress in Pt alloy catalyst development, with specific emphasis on the stability issue of Pt alloy catalysts.