Flower-like CeO2-supported small-sized Ru nanoparticle hybrids for highly efficient alkaline hydrogen evolution: Roles of interfacial effects

Ruthenium (Ru) is perceived as a promising electrocatalyst for alkaline hydrogen evolution reaction (HER) due to its fast water dissociation ability, but its performance is mainly limited by the intense hydrogen bond strength. Herein, the unique three-dimensional Ru/CeO2 hybrids with interfacial effects were proposed to significantly enhance the alkaline HER performance of Ru. The combination of structural characterizations, electrochemical analyses and theoretical calculations demonstrates that Ru/CeO2 interfaces as real active sites play a crucial role. The strong surface interaction bewteen small-sized Ru nanoparticles and nanosheet-based flower-like CeO2 suppotrs not only greatly increases the actives sites but also optimizes the hydrogen binding and water absorption/dissociation energies. Subsequently, the optimal hybrid catalyst with low Ru loadings of only 3 wt% exhibits a relatively small overpotential of 28.9 mV at 10 mA cm−2, a low Tafel slope of 53.2 mV dec-1 as well as an excellent long-term durability in 1 M KOH.