Mansheng Liao, Yong Zhang, qianyi lin, Kaiming Liang, Yayun Hong, Lei Zhang
ABSTRACT 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‐NC 1 @TiN NWs). Experimental and theoretical results demonstrate that this platform triggers tip‐distance‐spillover domino effects to drive a proton cascade throughout HER. Specifically, NC 1 @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‐N 2 sites to enhance their intrinsic activity. Exposed TiN sites function as hydrogen spillover centers to facilitate H 2 desorption. Consequently, Pt‐NC 1 @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/cm 2 at low cell voltage of 1.75 V and sustains stable operation at 1 A/cm 2 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.