Lattice-Matched Epitaxial Growth between Ru and Titanium Carbide for Efficient Hydrogen Oxidation Reaction in Alkaline Media

The development of stable and efficient alkaline hydrogen oxidation reaction (HOR) electrocatalysts is critical for advancing alkaline exchange membrane fuel cells. Ruthenium (Ru) shows promise as a HOR catalyst with cost advantages over platinum (Pt) but suffers from low intrinsic activity and oxidation vulnerability. Herein, we combine lattice-matched epitaxial growth with active metal carrier interaction (RMSI). For the first time, a simple impregnation-annealing method was employed to achieve lattice-matched epitaxial growth between Ru nanoparticles and titanium carbide (TiC) during deposition on the TiC surface, providing an efficient and stable interfacial structure for the RMSI. RMSI promotes electron transfer from TiC to Ru, modulates Ru’s electronic structure, and optimizes its hydrogen adsorption Gibbs free energy (△ G H* ). Experimental data and density functional theory (DFT) calculations confirm that the synergy between the epitaxial structure and RMSI significantly enhances the alkaline HOR activity. Consequently, the Ru/TiC-200 catalyst exhibits a higher kinetic current density than Pt/C, with a performance 5.31 times that of Ru/C.