Manipulating the Water Dissociation Electrocatalytic Sites of Bimetallic Nickel‐Based Alloys for Highly Efficient Alkaline Hydrogen Evolution

Abstract Transition‐metal alloys are currently drawing increasing attention as promising electrocatalysts for the alkaline hydrogen evolution reaction (HER). However, traditional density‐functional‐theory‐derived d ‐band theory fails to describe the hydrogen adsorption energy (Δ G H ) on hollow sites. Herein, by studying the Δ G H for a series of Ni−M (M=Ti, V, Cr, Mn, Fe, Co, Cu, Zn, Mo, W) bimetallic alloys, an improved d ‐band center was provided and a potential NiCu electrocatalyst with a near‐optimal Δ G H was discovered. Moreover, oxygen atoms were introduced into Ni−M (O−NiM) to balance the adsorption/desorption of hydroxyl species. The tailored electrocatalytic sites for water dissociation can synergistically accelerate the multi‐step alkaline HER. The prepared O−NiCu shows the optimum HER activity with a low overpotential of 23 mV at 10 mA cm −2 . This work not only broadens the applicability of d ‐band theory, but also provides crucial understanding for designing efficient HER electrocatalysts.