Formation and Activity Enhancement of Surface Hydrides by the Metal–Oxide Interface

Abstract The observation of hydride species in reduced ceria has triggered recent interest because the formation of hydrides in solid catalysts is limited although hydrides are widely explored in homogeneous catalysis as active species for hydrogenation reactions. Here, a strategy is proposed to enhance the formation and activity of surface hydrides on oxide‐based catalysts via the construction of metal–oxide interface. Specifically, during the reaction with H 2 , Cu supported on CeO 2 nanorods (NRs) is found to enhance the formation of hydride species, with the capacity more than an order of magnitude higher than that of CeO 2 NRs. Moreover, sub‐nanometer clusters (sub‐NCs) of Cu supported on CeO 2 NRs can enhance the formation and activity of surface hydrides, much more superior to that of Cu nanoparticles on CeO 2 NRs. A combination of ambient‐pressure photoelectron spectroscopy techniques has enabled in situ measurements of hydrogen interaction and as such to directly correlate the electronic structures of solid catalysts with their activity. A strong metal–support interaction between undersaturated Cu clusters with CeO 2 is found to account for the enhanced stability and reactivity of surface hydrides at the (sub‐NCs) Cu–CeO 2 interface, which provides insight for the design of highly efficient catalysts for catalytic hydrogenation reactions.