Tuning charge distribution of Ru nanoparticles via coupling ammonium tungsten bronze as Pt-Like electrocatalyst for hydrogen evolution reaction

Reasonable structure design and fine electronic modulation are the keys to achieving the platinum-like hydrogen evolution reaction (HER) performance on Ru-based catalyst, but also challenges. Here, the integration of uniformly dispersed ultra-fine Ru nanoparticles with beta-hexagonal ammonium tungsten bronze (beta-HATB) nanowires is reported as an efficient acidic electrocatalyst. Due to the strong metal-support interaction, the surface charge state of Ru is effectively regulated, forming a mixed valence state composed of zero valence and offset state. The prepared Ru@beta-HATB/CC exhibits a Pt-like catalytic activity with a small overpotential of 25 mV and a very low Tafel slope of 27.6 mV dec(-1). In-situ Raman spectroscopy and electrochemical analysis reveal that beta-HATB does not directly participate in HER reaction and hydrogen spillover effect (H-ads from beta-HATB to Ru NPs) is not the main reason for the hydrogen evolution activity, but beta-HATB can optimize the kinetics of hydrogen adsorption/desorption behavior on Ru surface and provide a stable and fast charge transfer channel, thus improving HER activity.