Fluorine-Mediated Electronic Modulation Optimizes Ru─H Bond Desorption Enabling Stable Hydrogen Evolution at Industrial-Level Current Densities

Abstract

Rapid performance degradation in alkaline hydrogen evolution catalysts, attributed to low intrinsic activity and bubble-shielding effects under high current densities, poses a significant obstacle to achieving industrial hydrogen production. In response, a novel phosphorus-doped activated carbon-loaded ruthenium cobalt fluoride-based heterostructured catalyst (Ru-CoF2@PAC) is developed. Acting as an “electron trader”, this catalyst leverages the exceptional electron-donating capability of fluoride anions bound to cobalt, effectively bringing the d-band center of the Ru site close to the Fermi level. This optimizes the adsorption energy of the H intermediate (Ru-H) in the Vomer step, subsequently facilitating rapid H conversion (H→H*). Moreover, the incorporated fluorine enhances catalyst hydrophilicity, significantly improving bubble diffusion kinetics at the catalyst surface and catalytic stability when operated under high current density. Remarkably, the Ru-CoF2@PAC catalyst loaded with 1.1 wt.% Ru requires only 27 mV to achieve the 10 mA cm−2 current density needed to split water under alkaline conditions. Furthermore, the catalyst exhibits exceptional stability during at least 140 h of operation at 1200 mA cm−2 with negligible degradation. This study provides valuable insights for guiding the development of durable catalysts suitable for large-scale industrial hydrogen production.