Scale Differentiation Tuning of Electronic Metal–Support Interactions to Construct a Robust Ruthenium‐Based Catalyst for Efficient Hydrogen Evolution

Abstract Low‐cost, efficient hydrogen evolution reaction (HER) catalysts are crucial for the industrialization of water electrolysis. While Ru‐based catalysts offer promise as Pt alternatives, conventional Ru‐based catalysts are limited by their poor activity and low utilization rate. To overcome this, a differently scaled Ru single‐atom/nanocluster (Ru SA/NC ) structure on 3D ordered hierarchical porous N‐doped carbon (3DOM‐NC) is designed, which optimizes electronic metal‐support interaction through scale differentiation of the active sites. This dual‐site catalyst leverages high atomic utilization efficiency and superior water dissociation capability to deliver exceptional intrinsic HER activity, achieving a turnover frequency (TOF) value at 100 mV overpotential 7.7 times greater than commercial Pt/C. Investigations reveal that N‐anchored Ru single atoms modulate the electronic structure of adjacent nanoclusters, downshifting the Ru d‐band center. This optimization of reaction intermediate adsorption energy, combined with synergistic site interactions, significantly lowers the HER energy barrier. Critically, the catalyst demonstrated robust stability for over 130 h at 100 mA cm −2 during overall water splitting in an anion exchange membrane electrolyzer. This work presents a novel strategy for designing highly active and stable electrolytic catalysts for hydrogen production.