Reconstructing Oxygen-Deficient Zirconia with Ruthenium Catalyst on Atomic-Scale Interfaces toward Hydrogen Production

Downsizing a catalyst nanoparticle (NP) to a single atom (SA) has proven to be highly effective in increasing catalytic activity and decreasing the amount of catalyst required for various electrochemical reactions. However, insufficient stability of the single-atom site catalysts (SACs) is still a significant challenge for their practical application. Here, SACs firmly bound to stable metal oxide NPs are proposed to dramatically increase the electrochemical activity and stability of SA-based catalysts for hydrogen evolution reaction (HER). Starting from a Ru-infiltrated, Zr-based metal-organic framework (MOF), the tetragonal zirconium oxide (ZrO2-x) NPs-embedded carbon matrix is fabricated as support through facile pyrolysis. Simultaneously, Ru SAs as active sites are well dispersed on the surface of ZrO2-x NPs due to the generation of oxygen vacancies in the tetragonal ZrO2-x. The Ru-ZrO2-x SAC exhibits a 4-5 times higher mass activity than commercial Pt and Ru catalysts and superior durability due to strong metal-support interaction (SMSI) between Ru atoms and ZrO2-x substrate.