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The requirement of both water discharge and hydrogen adsorption free energy restricts the activity of most electrocatalysts for hydrogen evolution reaction (HER) in alkaline medium. Herein, the dual-descriptor-guided design without time-consuming transition-state calculations is proposed. Theory-driven precise surface reactivity tailoring of Ni 3 N is demonstrated toward the balance of hydrogen and hydroxyl species adsorption energetics. The results reveal that the rate-determining step of the Ni 3 N catalyst mainly originates from the strong hydrogen adsorption. By higher valance-state Mo, W, and V doping, the electronic structure of Ni 3 N is modulated, leading to lower surface reactivity and favorable hydrogen adsorption/desorption thermodynamics. Notably, Mo-doped Ni 3 N exhibits optimal hydroxyl adsorption energy and fast water discharge kinetics, while W doping leads to hydroxyl poisoning and sluggish kinetics of water discharge. The experimental investigations confirm the theoretical prediction, and Mo-Ni 3 N realizes about 12-fold, 9-fold, and 3-fold enhancement in alkaline HER activity compared to pure Ni 3 N, W-Ni 3 N, and V-Ni 3 N, respectively. This dual-descriptor-guided design opens up opportunities for developing superior alkaline HER electrocatalysts.
Zhang et al. (Thu,) studied this question.