Lattice-Confined Ru Electrocatalysts with OptimalLocalized Interfacial Electrons for Efficient Alkaline Hydrogen Oxidation

The interfacial electronic structure has a significant influence on the electrocatalytic activity and durability of metal oxide-supported ruthenium (Ru) electrocatalysts for the alkaline hydrogen oxidation reaction (HOR). Herein, we optimize the interfacial electronic structure by tuning the Ru–O bonds within MnO lattice-confined Ru electrocatalysts, creating efficient and stable sites for alkaline HOR. The formed Ru–O bonds generate localized interfacial electrons and a downshifted d-band center of interfacial Ru atoms, which results in optimal adsorption ability of H* and OH* together with the reduced energy barrier of H₂O formation. The mass activity achieves 1.26 mA μg_Ru^–1 in 0.1 M KOH, which is 13.0-fold and 8.0-fold higher than that of the contrast Ru/C (0.097 mA μg_Ru^–1) and commercial Pt/C (0.158 mA μg_Pt^–1), respectively, while also exhibiting favorable durability and CO tolerance. This work highlights the rational design of Ru–O bonds in optimizing the interfacial electronic structure to enhance the alkaline HOR activity.