Multiscale Synergistic Design of High-Performance Electrocatalysts for Alkaline Hydrogen Evolution

Hydrogen, with its high energy density and positive environmental impact, offers an ideal solution for energy storage via water electrolysis. Anion exchange membrane water electrolysis (AEMWE) has gained significant attention due to its high current density and low-cost advantages, but the slow kinetics of the hydrogen evolution reaction (HER) remain a bottleneck. Here, a multiscale-engineered catalyst is developed by growing CuRu single-atom alloy nanosheets on Ni-wrapped Cu nanowires (CuRu₁-1/Ni). Electronic structure optimization alleviates the strong hydrogen adsorption on Ru sites, while the tip effect of nanosheets promotes alkali metal cation accumulation and rapid adsorbed hydroxyl (OH_ad) desorption. The CuRu₁-1/Ni catalyst achieves optimized hydrogen adsorption through synergistic electronic interactions between CuRu single-atom alloys and the Ni substrate. In situ Raman spectroscopy, CO stripping, alkali metal ion probe experiments, and finite element simulations confirm that the tip effect accelerates OH_ad desorption and OH^- transport. The CuRu₁-1/Ni catalyst demonstrates excellent alkaline HER performance with the overpotential at 10 mA cm^-2 of 30 mV, a Tafel slope of 30.2 mV dec^-1, and a mass activity of 0.347 A mg_Ru ^-1 at 50 mV overpotential, surpassing Pt/C by 12-fold. The catalyst also exhibits favorable stability, achieving a high current density of 1 A cm^-2 in AEMWE.