Synergistic effect of dual active sites over Ru/α-MoC for accelerating alkaline hydrogen evolution reaction.

Developing alkaline hydrogen evolution reaction catalysts with ultra-low overpotential remains a significant challenge. In this paper, a three-dimensional porous Ru/α-MoC has been developed, which features the dual active sites of α-MoC and Ru. The coexistence of ultrafine Ru nanoparticles and Ru single atoms in Ru/α-MoC system is demonstrated by multiple structural characterizations. The fabricated Ru/α-MoC exhibits excellent alkaline HER activity with a low overpotential 25 mV at 10 mA cm−2, outperforming commercial 20% Pt/C (45 mV), and robust electrocatalytic stability at an industrial-scale current density of 400 mA cm−2. Particularly, the turnover frequency value reaches 39.2 s−1 at the overpotential of 100 mV. Experiments and theory investigations demonstrate the electron redistribution at the interface of α-MoC and Ru. The synergistic effect of dual active sites enables the easy cleavage of H-OH bond and the optimal H adsorption energy simultaneously. This work opens up a feasible way to rationally design high-efficient electrocatalysts with dual active sites for typical multistep reactions. The three-dimensional porous Ru/α-MoC with dual active sites as HER electrocatalyst achieves ultralow overpotential at alkaline media. The excellent activity origin is the synergistic effect of dual active sites that facilitate water dissociation and weaken the H adsorption free energy, resulting in an accelerated reaction kinetics for alkaline hydrogen generation. [Display omitted] • High dispersed Ru species are anchored on α-MoC to construct Ru/α-MoC nanocomposites with dual active sites. • Ru/α-MoC interfaces afford remarkably promoted alkaline HER performance. • The synergistic effect of dual active sites at the interfaces enables the easy cleavage of H-OH bond and the optimal H adsorption energy simultaneously. [ABSTRACT FROM AUTHOR]