Boosting Electron/Mass Transport via Interfacial Coupling in a Dual-Supported Catalyst toward Ampere-Level Hydrogen Evolution

Developing hydrogen evolution reaction (HER) electrocatalysts with high activity and long-term durability at industrial current densities remains challenging because catalytic kinetics, electron transport, and mass transport must be optimized simultaneously. Here, we report a one-pot method to anchor Pt-single-atom-modified NiCoP onto MXene with a high surface coverage of ∼97%. The Pt-NiCoP@MXene catalyst requires overpotentials of only 13.8 and 175 mV in 1 M KOH to deliver 10 and 1000 mA cm–2, respectively, and exhibits an ultralow decay rate of 7.1 μV h–1 over 1000 h at 1000 mA cm–2 in a three-electrode system. In an anion-exchange membrane electrolyzer, it achieves 1 A cm–2 at 1.74 V in a 4 cm2 cell with 98% voltage retention after 1000 h and maintains 97% retention over 500 h with a scaled 25 cm2 cell. Experiments and DFT calculations demonstrate the interface strong coupling via Ni/Co–O–Ti bonding bridges NiCoP and MXene effectively and accelerates the electron transport of catalytic layer, while the uniform dispersion of NiCoP on MXene improves surface wettability and facilitates bubble release and electrolyte replenishment. Additionally, Pt–P coordination increases the metallicity of Pt atoms and optimizes hydrogen adsorption/desorption. This work provides a facile strategy for synthesizing high-quality dual-supported catalysts and validates their industrial application potential.