Enhanced hydrogen evolution of single-atom Ru sites via geometric and electronic engineering: N and S dual coordination

摘要

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 (Ru-SA) 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) of current density, 30 mV of Tafel slope and excellent durability of continuous 10,000 cyclic voltammetry cycles, outperforming the benchmark commercial Pt/C. The 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* - H-2), 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.