Revealing the Role of Ru‐O‐Ce Interface Coupling in CeO2‐Ru Aerogel for Boosting Hydrogen Evolution Kinetics

Abstract Designing heterogeneous interface to enhance the kinetics for electrocatalysts is a highly efficient but challenging pathway toward hydrogen evolution reaction (HER) in water electrolysis. Herein, the heterogeneous coupling of CeO 2 quantum dots onto porous Ru aerogel through interfacial Ru‐O‐Ce bridge is proposed to construct CeO 2 ‐Ru aerogel as the superior HER electrocatalyst with ultra‐low overpotentials. In situ characterizations and theoretical calculations reveal the electron distribution at the heterogeneous Ru‐O‐Ce bridge to boost hydrogen bonding at Ru sites, and the faster water adsorption and dissociation at the CeO 2 sites to enhance the HER kinetics. Furthermore, CeO 2 ‐Ru aerogel is employed as excellent cathodes for both acidic and alkaline water electrolyzers with ampere‐level current density and stably operated over 500 hours. Thus, the synergistic effect for CeO 2 ‐Ru aerogel through the Ru‐O‐Ce bridge tunes the HER catalytic mechanism and reinforces the activity, realizing highly efficient hydrogen generation in water electrolysis.