Interfacial Ir-V Direct Metal Bonding Enhanced Hydrogen Evolution Activity in Vanadium Oxides Supported Catalysts

Tuning the interfacial structure of metal oxide substrates is an essential strategy to induce electronic structure reconstruction of supported catalysts, which is of great importance in optimizing their catalytic activities. Herein, vanadium oxides-supported Ir catalysts (Ir-V₂O₃, Ir-VO₂, and Ir-V₂O₅) with different interfacial bonding environments (Ir-V, Ir-O_bri, and Ir-O, respectively) were investigated for hydrogen evolution reaction (HER). The regulating mechanism of the influence of different interfacial bonding environments on HER activity was investigated by both experimental results and computational evidence. Benefiting from the unique advantages of interfacial Ir-V direct metal bonds in Ir-V₂O₃, including enhanced electron transfer and electron donation ability, an optimized HER performance can be obtained with lowest overpotentials of 16 and 26 mV at 10 mA cm^-2, high mass activities of 11.24 and 6.66 A mg^-1, and turnover frequency values of 11.20 and 6.63 s^-1, in acidic and alkaline conditions respectively. Furthermore, the assembled Ir-V₂O₃||RuO₂ anion exchange membrane (AEM) electrolyzer requires only 1.92 V to achieve a high current density of 500 mA cm^-2 and realizes long-term stability. This study provides essential insights into the regulating mechanism of interfacial chemical bonding in electrocatalysts and offers a new pathway to design noble metal catalysts for different applications.