Curvature-engineered interfacial hydrogen-bond networks driving proton-coupled electron transfer boosts hydrogen...

Precise manipulation of interfacial microenvironments within the electrical double layer remains a fundamental challenge, primarily due to dynamic structural rearrangements and competitive adsorption processes during reactions. Here, we employ nanoscale curvature engineering to construct three RuIr-based electrocatalysts with precisely controlled surface curvatures, establishing a direct correlation between geometric effects and hydrogen oxidation reaction efficiency. Finite-element simulations coupled with electrochemical analysis reveal that concave nanocage (CNC) morphology enhances localized electric field, simultaneously weakening adsorbed hydrogen (H_ads) binding and promoting its subsequent cooperative oxidation with more OH_ads. Operando spectroscopy and ab initio molecular dynamics simulations demonstrate that high-curvature RuIr CNC drives ordered O-down H₂O alignment at the electrode-electrolyte interface, strengthening hydrogen-bond networks and accelerating proton-coupled electron transfer kinetics. The optimized RuIr CNCs achieve a mass activity of 7.51 mA μg^-1 (three-electrode system) and enable a peak power density of 1.52 W cm^-2 (H₂/O₂ anion-exchange membrane fuel cell), with stability over 150 hours.