Manipulating Valence‐Heterogeneous Pt Dual Sites via Metal‐Support Interactions for Highly Efficient Alkaline Hydrogen Evolution

ABSTRACT Alkaline water electrolysis is essential for sustainable green hydrogen production but is bottlenecked by sluggish water dissociation kinetics and catalyst degradation at high current densities. Herein, a low loading of Pt nanoclusters (4.2 wt.%) was anchored on multiwalled carbon nanotubes (Pt‐MWCNT) through a spontaneous reduction approach that triggers strong metal–support interaction (SMSI). A dual‐site coupled mechanism mediated by the valence‐heterogeneous Pt species was uncovered, where the electrophilic Pt 2+ sites accelerate H‐OH bond cleavage, while the adjacent Pt 4+ centers optimize the *H adsorption‐desorption strength for high‐efficiency H 2 evolution. More importantly, this synergy could be precisely tailored by leveraging the carbon support's work function as a regulatory dial for the Pt 2+ /Pt 4+ ratio. Through nitrogen doping, the resulting Pt‑N‑MWCNT electrocatalyst with an optimal Pt 2+ /Pt 4+ ratio of 1.04, achieved a kinetic equilibrium between water dissociation and hydrogen desorption, enabling a low overpotential of 28 mV at 10 mA cm −2 and a durability of over 500 h at 500 mA cm −2 . This work delivers critical insights into SMSI‐mediated electronic modulation, charting a pathway toward designing low‐loading noble metal catalysts for sustainable hydrogen technologies.