Boosting hydrogen evolution reaction activity of Ru anchored binary oxyhydroxide by F-doping in alkaline seawater

Seawater electrolysis still faces harsh challenges especially at elevated current densities, which has to be ensured by highly-efficient and stable electrocatalyst. Recently, strategy involving hydrogen spillover between metal clusters and carriers has emerged as a means to enhance the hydrogen evolution reaction (HER) efficiency. In this study, we present a heterogeneous Ru/F-FeCoOOH catalyst to dissect the mechanism of hydrogen spillover between these two constituents. The DFT calculations and in-situ Raman analysis confirm the spillover of hydrogen species (H*) from Ru to F-FeCoOOH carrier. Furthermore, the introduction of F-doping narrows the work function disparity between the Ru metal and the F-FeCoOOH carrier, fostering a milieu that curtails interface H* capture and augments the potential for interface hydrogen spillover. Moreover, in-situ electrochemical impedance spectroscopy (EIS) and kinetic isotope effects (KIEs) corroborate that Ru/F-FeCoOOH exhibits extensive H* adsorption coverage and hydrogen transfer influences reaction rates. Leveraging the hydrogen spillover mechanism, the resultant Ru/F-FeCoOOH heterogeneous catalyst manifests a low overpotential of 260 mV at 2 A cm−2 and with long-term stability at least for 400 h in alkaline seawater.