Carbon corrosion mechanism and mitigation strategies in a proton exchange membrane fuel cell (PEMFC): A review

This paper presents an overview of the causes and consequences of the carbon corrosion mechanism and summarizes the corresponding mitigation strategies for various operating conditions. The high potential at the cathode caused by the anode hydrogen-oxygen interface leads to the occurrence of carbon corrosion reactions during the startup and shutdown process. System strategies, including gas purge and auxiliary load, have been developed to alleviate the performance decay during startup and shutdown processes. Improper water management will cause local flooding to accelerate the carbon corrosion. Many novel flow fields have been proposed to solve water management problems, such as an optimized 3D flow field, baffle flow field and porous media flow field. The carbon corrosion under normal operation is not as serious as that under start-up and flooding, but it is serious enough to affect the later performance of the PEMFC after long-term operation. Varieties of new supports, such as mesoporous carbon, graphitized carbon, carbon nanotubes (CNTs), carbon nanofibers (CNF), and metal oxides, have been developed to improve the durability of the catalyst support. This review aims to provide a clear understanding of the carbon corrosion mechanisms, thereby helping researchers to prolong the lifetime of PEMFCs.