ABSTRACT Integrating water electrolyzers with intermittent renewable energy poses critical durability challenges from dynamic load fluctuations inducing catalyst degradation. We report a zinc‐mediated sacrificial protection strategy enhancing NiMo catalyst stability through in situ dendritic passivation. Zinc‐decorated NiMo on nickel felt (Zn‐NiMo/NF) exhibits considerable hydrogen evolution activity (94.6 mV overpotential at 50 mA cm −2 ) comparable to Pt/C. Under stringent load fluctuation cycling protocols (−500/50 mA cm −2 ), the zinc overlayer spontaneously reconstructs into laterally oriented, NiMo‐enriched dendrites providing dual protection: physical barriers suppressing dissolution (order‐of‐magnitude reductions in metal leaching) and sacrificial buffering wherein zinc preferentially oxidizes to zincate, shielding nickel from irreversible hydroxide formation. Zn‐NiMo/NF maintains stable performance while pristine NiMo/NF degrades substantially. Anion exchange membrane electrolyzer validation confirms minimal voltage escalation over 100 h cycling (1.645– 1.667 V), outperforming Pt/C (1.7028–1.857 V). This establishes sacrificial interface engineering as an effective paradigm for robust earth‐abundant electrocatalysts in renewable energy‐integrated hydrogen production.
Jeong et al. (2026) studied this question.