Competitive adsorption: Inhibiting the hydroxyl poisoning effect on lattice-confined Ru atoms in metal carbides nanoislands for boosting hydrogen production

Ruthenium (Ru)-based electrocatalysts are regarded as promising for applications in hydrogen evolution reactions (HER) due to their suitable metal-hydrogen (M-H) bonding energy. However, the strong affinity for adsorbed hydroxyl groups (OHad) leads to the inactivation of Ru active sites, leading to unsatisfactory performance in practical HER applications. Herein, a competitive adsorption strategy for the design of crystalline lattice-confined atomic Ru in Tungsten Carbide Nanoislands is reported. Benefiting from the unique "island-multi-atoms" structural features, Ru/WCx exhibits ultra-high mass activity (6000 mA mg-1) and excellent turnover frequency (3.89 H2- 1) at - 100 mV vs. RHE, which is 9.5 and 51.2 times higher than commercial 20% Pt/C, respectively. In-depth mechanistic analysis demonstrates that the strength of Ru-OHad is regulated by the oxophilicity of W atoms and the stronger W-OHad bond to alleviate Ru site inactivation, thus enhancing the HER activity. This strategy provides a novel concept for designing advanced catalysts.