Understanding the Atomic and Defective Interface Effect on Ruthenium Clusters for the Hydrogen Evolution Reaction

Water electrolysis powered by renewable electric energy is a promising technology for green hydrogen production without carbon emissions, while highly efficient and cost-effective electrocatalysts with long durability are urgently needed. Here, we demonstrate oxygen-coordinated single-atom iron sites (Fe-O-4) decorated carbon nanotubes with abundant vacancies as the substrate for stabilizing Ru clusters (CNT-V-Fe-Ru). The catalyst shows high performance for the hydrogen evolution reaction (HER) in both acidic and alkaline media, respectively. The HER kinetics analysis demonstrates that the defective substrate with single-atomic sites could significantly improve the intrinsic activity of Ru species. Theoretical calculations also support the superior HER behavior of CNT-V-Fe-Ru with fundamental insights into metal-substrate interactions. The present study highlights a unique feature of single-atom catalysts for serving as advanced supporting materials, which offers tremendous opportunities to adequately regulate electronic structures of metal-substrate interfaces at the atomic level.