Recent advance and perspectives on CO tolerant platinum-based alloys in PEMFC anodes

Global warming and energy consumption have spurred the research and development of proton exchange membrane fuel cells (PEMFCs), a high-energy-density and zero-emission energy conversion device. Currently, the predominant commercial catalyst employed for hydrogen oxidation reaction (HOR) in PEMFCs anode is Pt/C, and the efficiency of Pt-based catalysts is significantly undermined by the presence of CO mixed in the PEMFCs anode reactants. The incorporation of transition metals can modify the electronic structure of Pt-base catalysts and reduce the adsorption energy of CO on the platinum surface, thereby enhancing the CO tolerance. This timely review aims to present the crucial role of Pt-based alloy strategies for anti-CO poisoning of PEMFC anodes and performance optimization for HOR, and to offer a current overview of the research field. By following the demonstration on the CO poisoning mechanisms and the alloy design principles for anodic HOR in PEMFCs, recent progress on CO-resistant Pt-based alloy catalysts for high-efficiency PEMFCs is briefly presented. Finally, future challenges and directions for the commercialization of Pt-based alloy catalysts are reviewed. This review offers the significant insights into Pt-based alloys as a cutting-edge strategy for enhanced CO tolerance and favorable HOR for high performance PEMFCs.