Controlling the Valence‐Electron Arrangement of Nickel Active Centers for Efficient Hydrogen Oxidation Electrocatalysis

Abstract The valence‐electron arrangement of heterogeneous catalysts can significantly affect the binding behavior of absorbates. However, it remains a challenge to understand the role of the valence‐electron arrangement in electrocatalysis, which limits its utilization as a tool to design efficient electrocatalysts. Here, we describe experiments in which the valence‐electron arrangement of Ni active centers for hydrogen oxidation is controlled precisely by using Ni‐vacancy‐enriched Ni 3 N as a platform. These Ni vacancies can promote the valence‐electron delocalization of OH‐adsorption centers to enhance the Ni ds –O 2 p valence‐electron‐orbital interaction with elevated OH adsorption. Meanwhile, the deficit of valence‐electrons of H‐adsorption centers at Ni vacancies can lower Ni ds –H 1 s interaction with weakened H binding. Relative to Ni 3 N poor in vacancies, the Ni‐vacancy‐enriched Ni 3 N showed a mass activity enhanced by 15‐fold. This strategy paves a rational way to design efficient catalysts by finely tuning the valence‐electron arrangement.