Tuning Binding Strength of Multiple Intermediates towards Efficient pH‐universal Electrocatalytic Hydrogen Evolution by Mo8O26‐NbNxOy Heterocatalysts

Abstract Developing efficient and robust hydrogen evolution reaction (HER) catalysts for scalable and sustainable hydrogen production through electrochemical water splitting is strategic and challenging. Herein, heterogeneous Mo 8 O 26 ‐NbN x O y supported on N‐doped graphene (defined as Mo 8 O 26 ‐NbN x O y /NG) is synthesized by controllable hydrothermal reaction and nitridation process. The O‐exposed Mo 8 O 26 clusters covalently confined on NbN x O y nanodomains provide a distinctive interface configuration and appropriate electronic structure, where fully exposed multiple active sites give excellent HER performance beyond commercial Pt/C catalyst in pH‐universal electrolytes. Theoretical studies reveal that the Mo 8 O 26 ‐NbN x O y interface with electronic reconstruction affords near‐optimal hydrogen adsorption energy and enhanced initial H 2 O adsorption. Furthermore, the terminal O atoms in Mo 8 O 26 clusters cooperate with Nb atoms to promote the initial H 2 O adsorption, and subsequently reduce the H 2 O dissociation energy, accelerating the entire HER kinetics.