title: Adsorbate-mediated strong metal-support interactions in oxide-supported Rh catalysts.
abstract: The optimization of supported metal catalysts predominantly focuses on engineering the metal site, for which physical insights based on extensive theoretical and experimental contributions have enabled the rational design of active sites. Although it is well known that supports can influence the catalytic properties of metals, insights into how metal-support interactions can be exploited to optimize metal active-site properties are lacking. Here we utilize in situ spectroscopy and microscopy to identify and characterize a support effect in oxide-supported heterogeneous Rh catalysts. This effect is characterized by strongly bound adsorbates (HCOx) on reducible oxide supports (TiO2and Nb2O5) that induce oxygen-vacancy formation in the support and cause HCOx-functionalized encapsulation of Rh nanoparticles by the support. The encapsulation layer is permeable to reactants, stable under the reaction conditions and strongly influences the catalytic properties of Rh, which enables rational and dynamic tuning of CO2-reduction selectivity.
authors.affiliation: Department of Chemical and Environmental Engineering, University of California, Riverside, California 92521, USA.
authors.forename: John C
authors.initials: JC
authors.lastname: Matsubu
authors.affiliation: Department of Chemical Engineering and Materials Science, University of California, Irvine, Irvine, California 92697, USA.|Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA.
authors.forename: Shuyi
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Department of Chemical and Environmental Engineering, University of California, Riverside, California 92521, USA.
authors.forename: Leo
authors.initials: L
authors.lastname: DeRita
authors.affiliation: Department of Chemical Engineering, Columbia University, New York 10027, USA.
authors.forename: Nebojsa S
authors.initials: NS
authors.lastname: Marinkovic
authors.affiliation: Department of Chemical Engineering, Columbia University, New York 10027, USA.|Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973, USA.
authors.forename: Jingguang G
authors.initials: JG
authors.lastname: Chen
authors.affiliation: Department of Chemical Engineering and Materials Science, University of California, Irvine, Irvine, California 92697, USA.|Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA.
authors.forename: George W
authors.initials: GW
authors.lastname: Graham
authors.affiliation: Department of Chemical Engineering and Materials Science, University of California, Irvine, Irvine, California 92697, USA.|Department of Physics and Astronomy, University of California, Irvine, Irvine, California 92697, USA.
authors.forename: Xiaoqing
authors.initials: X
authors.lastname: Pan
authors.affiliation: Department of Chemical and Environmental Engineering, University of California, Riverside, California 92521, USA.|Program in Materials Science, University of California, Riverside, Riverside, California 92521, USA.|UCR Center for Catalysis, University of California, Riverside, Riverside, California 92521, USA.
authors.forename: Phillip
authors.initials: P
authors.lastname: Christopher