Unravelling the Role of Oxygen Groups in Fe─N─C Fuel Cell Catalyst Degradation

ABSTRACT The insufficient stability of transition metal nitrogen‐doped carbon (TM‐N‐C) catalysts has hindered the widespread adoption of non‐precious‐metal proton‐exchange‐membrane fuel cells (PEMFCs). Herein, using Fe‐doped MET(Zn)‐derived materials as a versatile platform, we unravel the role of oxygen groups in Fe‐N‐C catalyst degradation while achieving substantially enhanced fuel cell performance. DFT results indicate that carbonyl (C═O) and epoxy (C─O─C) groups lower the energy barrier of the rate‐determining step in the carbon oxidation reaction (COR), strengthen intermediate *OOH adsorption, and thereby accelerate carbon support corrosion. Based on this, a hydrogen‐thermal reduction strategy was developed to construct the Fe SA /NC‐H catalyst with low surface oxygen content. Experimental results demonstrate the outstanding activity and stability of the Fe SA /NC‐H catalyst. In H 2 ‐O 2 PEMFCs, the catalyst achieves a peak power density ( P max ) of 1.32 W cm −2 , which is 1.26 times that of the reference catalyst (1.05 W cm −2 ). After 30 000 accelerated stress tests, Fe SA /NC‐H retains 77.3% of its initial P max , 1.56 times that of Fe SA /NC (49.5%). It also shows only 7.5% voltage decay during a 100 h open‐circuit voltage durability test.