Carbon Monoxide Tolerant Pt-Based Electrocatalysts for H₂-PEMFC Applications: Current Progress and Challenges

• Main Authors: Costas Molochas, Panagiotis Tsiakaras
• Format: Article
• Language: English
• Published: MDPI AG 2021-09-01
• Series: Catalysts
• Subjects: H₂-PEMFCs degradation; CO-tolerant electrocatalysts; H₂-PEMFCs anodes; Pt-based electrocatalysis
• Online Access: https://www.mdpi.com/2073-4344/11/9/1127

The activity degradation of hydrogen-fed proton exchange membrane fuel cells (H₂-PEMFCs) in the presence of even trace amounts of carbon monoxide (CO) in the H₂ fuel is among the major drawbacks currently hindering their commercialization. Although significant progress has been made, the development of a practical anode electrocatalyst with both high CO tolerance and stability has still not occurred. Currently, efforts are being devoted to Pt-based electrocatalysts, including (i) alloys developed via novel synthesis methods, (ii) Pt combinations with metal oxides, (iii) core–shell structures, and (iv) surface-modified Pt/C catalysts. Additionally, the prospect of substituting the conventional carbon black support with advanced carbonaceous materials or metal oxides and carbides has been widely explored. In the present review, we provide a brief introduction to the fundamental aspects of CO tolerance, followed by a comprehensive presentation and thorough discussion of the recent strategies applied to enhance the CO tolerance and stability of anode electrocatalysts. The aim is to determine the progress made so far, highlight the most promising state-of-the-art CO-tolerant electrocatalysts, and identify the contributions of the novel strategies and the future challenges.