Dual‐Site Ru Single‐Atoms and RuP Nanoclusters on N, P, and B Co‐Doped Porous Carbon for Efficient Alkaline HER and AEM Water Electrolysis

ABSTRACT Optimizing intermediate adsorption energetics across coupled elementary steps remains challenging for the alkaline hydrogen evolution reaction. Porous boronate polymer nanospheres (BPNSs), formed by condensation between boronic acid and catechol monomers, are used as a precursor scaffold to construct a dual‐site catalyst comprising Ru single atoms (Ru SAs) and RuP nanoclusters (NCs) anchored on N, P, and B co‐doped porous carbon nanospheres (Ru SA ‐RuP@NPB‐CNSs). During in situ pyrolysis/phosphidation, the BPNS precursor simultaneously i) supplies P to form RuP NCs, ii) transforms into highly porous N, P, and B co‐doped carbon nanospheres via a coordination‐driven Kirkendall effect, and iii) establishes strong metal‐support interactions and spatial confinement that stabilize both Ru SAs and RuP NCs while tuning their electronic structures. Density functional theory and operando spectroscopy identify complementary roles: RuP NCs facilitate water dissociation, whereas Ru SAs accelerate recombination of H * and H 2 desorption. Ru SA ‐RuP@NPB‐CNSs delivers an overpotential of 19 mV at 10 mA cm −2 , an eightfold higher mass activity than commercial Pt/C in 1.0 M KOH, and stable operation at 100 mA cm −2 for over 800 h. In anion‐exchange membrane water electrolysis, a low Ru loading of 50 µg Ru cm −2 achieves 1.0 A cm −2 at 1.80 V and sustains 500 h at 1.0 A cm −2 .