Pt doping and strong metal–support interaction as a strategy for NiMo-based electrocatalysts to boost the hydrogen evolution reaction in alkaline solution

Abstract

Although extensive research has been carried out on non-noble metal-based materials in the alkaline electrocatalytic hydrogen evolution reaction (HER), designing electrocatalysts that have excellent stability and intrinsic activity exceeding that of Pt/C is still an urgent challenge. Herein, we developed a novel strategy to resolve these two problems, which combines Pt doping and a strong metal–support interaction (SMSI). By a simple, quick (60 s) and solvent-free microwave reduction method, Pt–Ni₄Mo/CNT with small size (3–4 nm) was prepared and exhibits an extremely low overpotential of 18.6 mV at 10 mA cm⁻² in 1 M KOH. In addition, the catalyst has a large turnover frequency value at an overpotential of 100 mV, which is higher than that of Pt/C (4.31 s⁻¹). Benefiting from the SMSI, the catalytic activity of the catalyst can be maintained for 200 h at 100 mA cm⁻², indicating that the catalyst has excellent stability. Finally, in situ attenuated total reflection surface-enhanced infrared absorption spectroscopy (ATR-SEIRAS) and density functional theory (DFT) calculations demonstrated that the Ni₄Mo site mainly plays the role of dissociating water in the process of the HER to produce H* and OH*, then the strongly adsorbed H* intermediate is transferred to the Pt site, not only exposing the active center on Ni₄Mo but accelerating the H₂ desorption process. This original strategy will provide valuable inspiration for the design and synthesis of other catalysts in the future.