Enhanced alkaline hydrogen evolution performance through Ru-Incorporated electronic structure Modification: Transitioning from Mo3P to Mo2RuP

In accordance with the Sabatier principle, Mo-based catalysts typically exhibit lower catalytic activity in the hydrogen evolution reaction (HER) due to strong interactions between Mo and hydrogen within their structures. To overcome this limitation, here, we introduce a novel approach by incorporating Ru into Mo3P to modify its electronic structure, resulting in a novel water splitting cathode material of I̅42m structured Mo2RuP. Notably, Mo2RuP demonstrates as an efficient catalyst for alkaline HER, exhibiting outstanding performance with extremely low overpotentials of 29 mV and 62 mV at current densities of 10 mA cm−2 and 100 mA cm−2, respectively. It also displays a small Tafel slope (30 mV dec-1) and long-term durability in hydrogen production even at a current density of 100 mA cm−2 in a 1 mol/L KOH solution. First-principles density functional theory (DFT) calculations elucidate that Ru-substitution significantly reduces the hydrogen adsorption Gibbs free energy on various crystal facets of Mo2RuP. This alteration facilitates the transformation of the material to the kinetically favorable Volmer-Heyrovsky pathway during the HER. Furthermore, a comprehensive characterization and investigation into the electronic structure of this innovative material validate the efficacy of Ru modulation within the Mo3P structure. The strategy of Ru-substitution to adjust the electronic structure of Mo-based catalysts offers a viable approach for the development of novel, stable, and high-performance catalysts for the HER.