Proton Provision-Conversion-Spillover Cascade Programming on Dual Supported Pt Atoms for Robust Hydrogen Production

Rational proton engineering offers a powerful strategy for enhancing the hydrogen evolution reaction (HER) performance of single-atom catalysts (SACs). Notably, achieving concerted proton management across multiple reaction steps presents a highly efficient approach, yet it remains more challenging to implement than single-step regulation. Here, we propose a domino-type proton provision-conversion-spillover programming for Pt SACs in acidic HER, enabled by ultrathin porous nitrogen-doped carbon (main 1-2 atomic layers, sub-1 nm) encapsulated TiN nanowires with tips as dual-support tip-platform (Pt-NC₁@TiN NWs). Experimental and theoretical results demonstrate that this platform triggers tip-distance-spillover domino effects to drive a proton cascade throughout HER. Specifically, NC₁@TiN nanotips induce tip-enhanced effect that promotes interfacial proton accessibility. Concurrently, the short-distance Pt/TiN vertical coupling optimizes electronic modulation of unsaturated Pt-N₂ sites to enhance their intrinsic activity. Exposed TiN sites function as hydrogen spillover centers to facilitate H₂ desorption. Consequently, Pt-NC₁@TiN NWs achieve a superior Pt mass activity of 153.5 A/mg_Pt@-100 mV, surpassing Pt/C by two orders of magnitude. Notably, it reaches 2 A/cm² at low cell voltage of 1.75 V and sustains stable operation at 1 A/cm² for 1200 h in proton exchange membrane water electrolyzer (PEMWE). This work indicates the potential of harnessing multi-step domino processes for advanced catalyst design.