Strong electronic metal-support interaction of Ni4Mo/N-SrMoO4 promotes alkaline hydrogen electrocatalysis

Ni4Mo electrocatalyst stands out as the promising candidate for hydrogen evolution/oxidation reaction (HER/ HOR), yet the intensive hydrogen adsorption leads to sluggish kinetics, decreasing hydrogen catalysis efficiency. Herein, the structure of Ni4Mo nanoparticles anchored on wafer-biscuit-like N-SrMoO4 nanorods (Ni4Mo/N- SrMoO4) is developed to accelerate reaction kinetics by modulating electronic structure. The designed N-SrMoO4 support enables strong electronic metal-support interaction with Ni4Mo, resulting in a downward shift of d-band center and achieving thermally neutral hydrogen adsorption. Ni4Mo/N-SrMoO4 exhibits HER performance with an ultralow overpotential of 15 mV at 10 mA cm(-2), superior to Pt/C (eta(10)=18 mV). The outstanding exchange current density of 10.2 mA cm(-2) for HOR is three times higher than that of Pt/C (3.5 mA cm(-2)). Ni4Mo/N- SrMoO4 is further assembled in anion exchange membrane water electrolyzer (AEMWE), resulting in a current density of 100 mA cm(-2) at voltage of 1.71 V and the excellent stability of 300 hours. Theoretical calculations and in-situ spectroscopy indicate that the introduction of Sr in N-SrMoO4 effectively enhances electronic metal- support interaction, facilitates the enrichment of adsorbed hydroxyl (OHads) ads ) on active sites and weakens hydrogen adsorption on Ni4Mo, thereby accelerating reaction kinetics of hydrogen electrocatalysis.