Mo-Dopant Mediated Intra-lattice Ultrashort-range Hydrogen Spillover for Ampere-Level Alkaline Hydrogen Evolution

Abstract Hydrogen spillover is an effective strategy to improve the efficiency of the hydrogen evolution reaction (HER), but the challenges remain in creating efficient spillover channels. Herein, an intra-lattice ultrashort-range hydrogen spillover strategy is proposed, which was achieved by doping molybdenum (Mo) into Ni(OH)2 forming a Ni–Mo site cooperation mediated efficient H spillover channel in the alkaline HER. Studies reveal that Mo doping modulates the electronic structure of Ni sites, accelerating water dissociation and weakening H* adsorption. This triggers H* spillover from Ni sites to adjacent Mo sites for efficient H* desorption via ultrashort channels across the Ni–O–Mo interface. This intra-lattice ultrashort-range hydrogen spillover design promotes the spatial decoupling of water dissociation and the H* spillover at the atomic scale, thus significantly improving the kinetic performance of the alkaline HER. As a result, the electrode achieves 10 mA cm–2 at an ultralow overpotential of 13 mV, superior to many reported HER electrocatalysts. The alkaline electrolyzer using the as-developed electrode delivers a 1.0 A cm–2 at 1.82 V and stable operation for 800 h. This work presents a promising approach for designing high-performance alkaline HER catalysts by regulating hydrogen spillover channels on the catalyst lattice.