Spatially Extended Interfacial Optimization via Holey-Defect Architectures for Hydrogen Evolution Reaction.

Supported metal catalysts provide a highly effective route to achieving high-performance water electrolysis with minimized noble-metal usage, where precise engineering of the catalyst-support interface is crucial to unlock outstanding activity. Herein, we present a strategy to engineer catalyst interfaces by introducing holey defects for highly efficient hydrogen evolution reaction. The holey defects promote uniform dispersion of Pt nanoclusters across the basal planes, rather than the edge-confined deposition observed on pristine ReS2 (Pt-hReS2). Beyond geometric templating, the holey architecture enriches local electron density, stabilizes Pt-S interfacial bridge motifs, tunes the adsorption energy toward near-thermoneutral values, and lowers the water-dissociation barrier. These synergistic effects shift the catalytic regime, moving the rate-determining step from dissociation to desorption, which is revealed in characterizations and density functional theory calculations. Consequently, Pt-hReS2 requires only 12 mV overpotential at 10 mA cm-2, which outperforms commercial Pt/C while using substantially less Pt. In an anion-exchange membrane water electrolyzer, a Pt-hReS2 cathode achieves 1.77 V at 0.5 A cm-2 and 1.99 V at 1.0 A cm-2, with stable operation exceeding 100 h. This work establishes holey-defect engineering as a powerful approach for interface optimization, opening new avenues for rational catalyst design in energy-conversion applications.