Dual active site and metal–substrate interface effect endow platinum–ruthenium/molybdenum carbide efficient pH-universal hydrogen evolution reaction

Exploring suitable dual active site and metal–substrate interface effect is essential for designing efficient and robust electrocatalysts across a wide pH range for the hydrogen evolution reaction (HER). Herein, alloyed platinum–ruthenium clusters supported on nanosheet-assembled molybdenum carbide microflowers (PtRu/Mo 2 C) are reported as efficient pH-universal electrocatalysts for HER. Due to dual active site and metal–substrate interface effect, the optimized Pt 0.83 Ru 0.17 /Mo 2 C electrocatalyst exhibits extremely low overpotentials (η 10 ) of 9, 19, and 33 mV to deliver 10 mA cm −2 in 0.5 M H 2 SO 4 , 1.0 M KOH, and 1.0 M phosphate buffered electrolytes (PBS), outperforming the benchmark Pt electrocatalyst. In addition, Pt 0.83 Ru 0.17 /Mo 2 C achieves excellent stability of 200 h at a big current density of 500 mA cm −2 in the anionic exchange membrane water electrolyzer. Density functional theory (DFT) calculations and in situ Raman spectra reveal that the interaction of PtRu clusters with Mo 2 C substrate, while Ru modulates the electron cloud density of Pt, thus accelerating H 2 O dissociation and H* desorption on the surface of Pt 0.83 Ru 0.17 /Mo 2 C and thus synergistically enhancing the HER kinetics. The research opens up an efficient strategy to exploit cost-effective, high-performance, and pH–universal HER electrocatalyst while facilitating green hydrogen energy development.