Formation and Activity Enhancement of Surface Hydrides by the Metal-Oxide Interface
The observation of hydride species in reduced ceria has triggered recent interest, because the formation of hydrides in solid catalysts has been limited although hydrides are widely explored in homogeneous catalysis as active species for hydrogenation reactions. Here, we proposed a strategy 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 H2, Cu supported on CeO2 nano-rods (NRs) were found to enhance the formation of hydride species, with the capacity more than an order of magnitude higher than that of CeO2 NRs. Moreover, sub-nanometer clusters (sub-NCs) of Cu supported on CeO2 NRs could enhance the formation and activity of surface hydrides, much more superior than that of Cu nanoparticles (NPs) on CeO2 NRs. A combination of ambient pressure photoelectron spectroscopy (AP-PES) techniques has enabled in-situ measurements of hydrogen interaction and as such, to correlate directly the electronic structures of solid catalysts with their activity. A strong metal-support interaction between under-saturated Cu clusters with CeO2 was found to account for the enhanced stability and reactivity of surface hydrides at the (sub-NCs) Cu-CeO2 interface, which provides insight for the design of highly efficient catalysts for catalytic hydrogenation reactions.
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Scheme 1. H- distribution for CeO2, 2CuCe and 5CuCe.
Graphical Abstract and Supporting Information.
Posted 12 Jan, 2021
Formation and Activity Enhancement of Surface Hydrides by the Metal-Oxide Interface
Posted 12 Jan, 2021
The observation of hydride species in reduced ceria has triggered recent interest, because the formation of hydrides in solid catalysts has been limited although hydrides are widely explored in homogeneous catalysis as active species for hydrogenation reactions. Here, we proposed a strategy 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 H2, Cu supported on CeO2 nano-rods (NRs) were found to enhance the formation of hydride species, with the capacity more than an order of magnitude higher than that of CeO2 NRs. Moreover, sub-nanometer clusters (sub-NCs) of Cu supported on CeO2 NRs could enhance the formation and activity of surface hydrides, much more superior than that of Cu nanoparticles (NPs) on CeO2 NRs. A combination of ambient pressure photoelectron spectroscopy (AP-PES) techniques has enabled in-situ measurements of hydrogen interaction and as such, to correlate directly the electronic structures of solid catalysts with their activity. A strong metal-support interaction between under-saturated Cu clusters with CeO2 was found to account for the enhanced stability and reactivity of surface hydrides at the (sub-NCs) Cu-CeO2 interface, which provides insight for the design of highly efficient catalysts for catalytic hydrogenation reactions.
Figure 1
Figure 2
Figure 3
Figure 4