Enhanced Hydrogen Evolution of Single-Atom Ru Sites via Geometric and Electronic Engineering: N and S Dual Coordination

Abstract Single-atom catalysts (SACs) have attracted wide attention, however a challenge in both the synthesis and determination of such active sites still occurs. Here a simply one-pot hydrothermal method has been reported to prepare SACs based on strong dual-coordinated interactions. The comprehensive structure analysis uncloses the highly dispersed single-atom Ru (RuSA) sites and formation of Ru-N and Ru-S bonds, suggesting the strong Ru-support interactions. The achieved catalyst Ru/N,S-Go shows robust hydrogen evolution reaction (HER) performances with a low overpotential 26 mV at a typical 10 mA cm-2 current density, Tafel slope 30 mV dec-1 and excellent durability of continuous 10000 cyclic voltammetry cycles, outperforming the benchmark commercial Pt/C. Density functional theory (DFT) calculations uncover that the strong coordination of Ru-N and Ru-S bonds could be not only efficient to water splitting, but then promote the formation of adsorbed hydrogen to hydrogen molecules (H* → H2), implying ultrahigh inherent HER activity. We believe that this work could provide a new idea for preparation of other SACs applied in different electrochemical fields.