High-density ultrafine RuP2 with strong catalyst-support interaction driven by dual-ligand and tungsten-oxygen sites for hydrogen evolution at 1 A cm−2

Ultrafine and high-density RuP2 based on coordination chemistry and catalyst-support correlation shows potential for hydrogen evolution reaction (HER). Herein, the uniform and high-density W-doped ultra-small RuP2 (W0.05-RuP2@C3N4-NC) are synthesized by incorporating oxygen-bridged [WO4] tetrahedron into tetraacetic acid (EDTA)-melamino-formaldehyde (MF) ligands. EDTA-MF shows strong metal-support interaction, dedicating to the optimal dispersion, highest Ru yields, and HER activity. W atoms regulate local electron structure and coordination environment, leading to faster proton supply and hydrogen release, thus achieving 10 mA cm−2 at low overpotential of 27 mV (alkaline) and 66 mV (acidic). Notably, W0.05-RuP2@C3N4-NC maintains stability with staged 500–1000 mA cm−2 for 1000 h in alkaline, and 1000 mA cm−2 for ~300 h in acid, ascribing to the immobilized ultra-stable RuP2 nanoclusters via EDTA-MF and metal-oxygen sites. The excellent activity and stability hold promise for industrial hydrogen production, which provides deeper insights into catalyst-support interaction and reasonable design of high Ru-loading electrocatalysts.