Recent Progress on Durable Metal‐N‐C Catalysts for Proton Exchange Membrane Fuel Cells.

It is essential for the widespread application of proton exchange membrane fuel cells (PEMFCs) to investigate low‐cost, extremely active, and long‐lasting oxygen reduction catalysts. Initial performance of PGM‐free metal‐nitrogen‐carbon (M−N−C) catalysts for oxygen reduction reaction (ORR) has advanced significantly, particularly for Fe−N−C‐based catalysts. However, the insufficient stability of M−N−C catalysts still impedes their use in practical fuel cells. In this review, we focus on the understanding of the structure‐stability relationship of M−N−C ORR catalysts and summarize valuable guidance for the rational design of durable M−N−C catalysts. In the first section of this review, we discuss the inherent degrading mechanisms of M−N−C catalysts, such as carbon corrosion, demetallation, H2O2 attack, etc. As we gain a thorough comprehension of these deterioration mechanisms, we shift our attention to the investigation of strategies that can mitigate catalyst deterioration and increase its stability. These strategies include enhancing the anti‐oxidation of carbon, fortifying M−N bonds, and maximizing the effectiveness of free radical scavengers. This review offers a prospective view on the enhancement of the stability of non‐noble metal catalysts. [ABSTRACT FROM AUTHOR]