Evolution of Grain Boundaries Promoted Hydrogen Production for Industrial‐Grade Current Density

Abstract The development of efficient and durable high‐current‐density hydrogen production electrocatalysts is crucial for the large‐scale production of green hydrogen and the early realization of hydrogen economic blueprint. Herein, the evolution of grain boundaries through Cu‐mediated NiMo bimetallic oxides (MCu‐BNiMo), which leading to the high efficiency of electrocatalyst for hydrogen evolution process (HER) in industrial‐grade current density, is successfully driven. The optimal MCu_0.10‐BNiMo demonstrates ultrahigh current density (>2 A cm⁻²) at a smaller overpotential in 1 m KOH (572 mV), than that of BNiMo, which does not have lattice strain. Experimental and theoretical calculations reveal that MCu_0.10‐BNiMo with optimal lattice strain generated more electrophilic Mo sites with partial oxidation owing to accelerated charge transfer from Cu to Mo, which lowers the energy barriers for H* adsorption. These synergistic effects lead to the enhanced HER performance of MCu_0.10‐BNiMo. More importantly, industrial application of MCu_0.10‐BNiMo operated in alkaline electrolytic cell is also determined, with its current density reached 0.5 A cm⁻² at 2.12 V and 0.1 A cm⁻² at 1.79 V, which is nearly five‐fold that of the state‐of‐the‐art HER electrocatalyst Pt/C. The strategy provides valuable insights for achieving industrial‐scale hydrogen production through a highly efficient HER electrocatalyst.