Advances in CO-tolerant anode catalysts for proton exchange membrane fuel cells

Pt-based catalysts are often used in a proton exchange membrane fuel cell due to their high activities to oxygen reduction and hydrogen oxidation reaction. However, these catalysts are easily poisoned by CO, resulting in a significant reduction of fuel cell performance. The use of CO-tolerant catalysts can effectively solve this problem. The CO poisoning mechanism and anti-poisoning strategies were briefly discussed in this article. It mainly focused on the research progress on CO-tolerant catalysts in three aspects: Pt alloy catalysts, metal oxide composite catalysts, and blocking layer covered catalysts. The advantages and limitations of various catalysts in recent years were also discussed. Creating a porous blocking layer covered on the surface of the catalyst can effectively enhance the CO-tolerance of the catalysts which could be a promising approach for developing anti-poison catalysts other than CO-tolerance. Finally, the prospects for future development of CO-tolerant fuel cell catalysts were described.