Dual-site Synergistic Catalysis Between Single Atomic Ru and Tungsten Compound Heterojunction for Enhanced Alkaline Hydrogen Evolution

Abstract

It is important to develop efficient, low-cost alkaline electrolytic water catalysts to replace commercial Pt/C in order to promote the hydrogen economy. This work presents a dual-site synergistic catalyst (Ru-W₂N/WO₂) designed using a single-atom modified heterojunction strategy. This strategy simultaneously optimizes the kinetics of hydrolysis dissociation and hydrogen adsorption, achieving catalytic activity and stability that surpass those of Pt/C. When applied as a cathode in a membrane electrode assembly device, the modified catalyst Ru-W₂N/WO₂ exhibits significantly enhanced performance compared to the original one, and it operates stably at a high current density of 100 mA cm^-2 for 270 hours.Through a combination of experimental characterization and theoretical calculations, the synergistic mechanism of the catalyst is revealed: the W site efficiently adsorbs OH^- by virtue of its abundant outermost hollow orbitals. This accelerates hydrolysis dissociation and provides protonation and hydrogen adsorption, which in turn accelerates hydrolysis dissociation and provides protons. Meanwhile, the Ru site optimizes the adsorption and recombination of *H and promotes H₂ generation. This study elucidates the dual-site synergistic mechanism of the W heterojunction substrate and Ru single atoms, providing a deeper understanding of the rational design of efficient alkaline water electrolysis catalysts.