Engineering Robust PEMFC Catalysts via a Dual-Pronged Stability Enhancement Strategy

The durability of proton exchange membrane fuel cells under start-up/shutdown (SUSD) and dynamic load cycling is constrained by a trade-off between carbon support corrosion and Pt ripening. Herein, we report a nitrogen-modified graphitized carbon (N-GC) support mitigating both degradation pathways simultaneously. Graphitization of Ketjenblack EC-300J (EC300) yields graphitized carbon (GC) with a highly ordered framework, while ultralow nitrogen incorporation introduces electron modulation at the metal–support interface. This strengthens metal–support interactions, suppressing Pt nanoparticle migration and coarsening during dynamic load cycling and maintaining corrosion resistance under SUSD. Pt/N-GC exhibits exceptional robustness following U.S. Department of Energy (DOE)-specified accelerated stress tests (ASTs). During carbon support-focused AST, Pt/N-GC limits voltage loss to 27 mV at 1.5 A cm^–2 and retains 61.88% of its initial electrochemical surface area (ECSA), outperforming Pt/EC300 (>140 mV, 23.98%) and meeting DOE targets. Under catalyst-focused AST, Pt/N-GC limits voltage loss to 42 mV at 0.8 A cm^–2 and shows superior ECSA retention of 53.22% compared to Pt/GC (60 mV, 36.21%). In a 100 W air-cooled stack under simulated two-wheeler cycles, Pt/N-GC delivers a 237.2 h lifetime, exceeding both Pt/GC (226.2 h) and Pt/EC300 (143.9 h). This work establishes a support-design strategy that reconciles carbon corrosion and Pt ripening, validating durability from single-cell to engineered stacks.