Enhanced Tri‐Atom Ru‐Based Catalyst for Hydrogen Evolution Reaction via Rapid Pyrolysis of Precursor

Abstract Atomically precise supported nanocluster catalysts (APSNCs), with well‐defined metal active sites, unique geometrical and electronic structures and metal–metal bonds, demonstrate excellent catalytic performance. However, the synthesis of APSNCs with well‐defined active centers and stable structures remains a huge challenge due to uncontrollable aggregation during synthesis and catalytic reactions. Herein, the Ru 3 nanocluster catalysts uniformly dispersed on oxidized carbon nanotubes (Ru 3 /OCNT) is successfully synthesized by using a rapid pyrolysis of precursor strategy. The obtained Ru 3 /OCNT exhibits excellent catalytic performance for alkaline hydrogen evolution reaction (HER). The catalyst achieves an overpotential of 19 mV at a current density of 10 mA cm −2 in 1 m KOH solution, outperforming commercial 20 wt.% Pt/C and 5 wt.% Ru/C. Moreover, the mass activity of Ru 3 /OCNT is 23.47 and 11.83 times higher than that of commercial Pt/C and Ru/C. Density functional theory (DFT) calculations reveal that the metal–metal interaction and metal–support interaction in Ru 3 /OCNT effectively modulate the electronic structure of Ru atoms, lower the hydrogen adsorption energy of the catalytic site, and promote the H* desorption. This work offers a new perspective on the design and synthesis of APSNCs with excellent alkaline hydrogen evolution performance.