Elucidating the active phases of CoO x films on Au(111) in the CO oxidation reaction.

Autor: Chen H; Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA., Falling LJ; Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.; Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA., Kersell H; Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.; School of Chemical, Biological, and Environmental Engineering, Oregon State University, Corvallis, OR, 97331, USA., Yan G; Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, Los Angeles, CA, 90095, USA., Zhao X; Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.; Department of Materials Science and Engineering, University of California, Berkeley, CA, 94720, USA., Oliver-Meseguer J; Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA., Jaugstetter M; Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA., Nemsak S; Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.; Department of Physics and Astronomy, University of California, Davis, CA, 95616, USA., Hunt A; National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, NY, 11973, USA., Waluyo I; National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, NY, 11973, USA., Ogasawara H; SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA., Bell AT; Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.; Department of Chemical and Biomolecular Engineering, University of California, Berkeley, CA, 94720, USA., Sautet P; Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, Los Angeles, CA, 90095, USA.; Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA, 90095, USA., Salmeron M; Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA. mbsalmeron@lbl.gov.; Department of Materials Science and Engineering, University of California, Berkeley, CA, 94720, USA. mbsalmeron@lbl.gov.
Jazyk: angličtina
Zdroj: Nature communications [Nat Commun] 2023 Oct 28; Vol. 14 (1), pp. 6889. Date of Electronic Publication: 2023 Oct 28.
DOI: 10.1038/s41467-023-42301-7
Abstrakt: Noble metals supported on reducible oxides, like CoO x and TiO x , exhibit superior activity in many chemical reactions, but the origin of the increased activity is not well understood. To answer this question we studied thin films of CoO x supported on an Au(111) single crystal surface as a model for the CO oxidation reaction. We show that three reaction regimes exist in response to chemical and topographic restructuring of the CoO x catalyst as a function of reactant gas phase CO/O 2 stoichiometry and temperature. Under oxygen-lean conditions and moderate temperatures (≤150 °C), partially oxidized films (CoO x<1 ) containing Co 0 were found to be efficient catalysts. In contrast, stoichiometric CoO films containing only Co 2+ form carbonates in the presence of CO that poison the reaction below 300 °C. Under oxygen-rich conditions a more oxidized catalyst phase (CoO x>1 ) forms containing Co 3+ species that are effective in a wide temperature range. Resonant photoemission spectroscopy (ResPES) revealed the unique role of Co 3+ sites in catalyzing the CO oxidation. Density function theory (DFT) calculations provided deeper insights into the pathway and free energy barriers for the reactions on these oxide phases. These findings in this work highlight the versatility of catalysts and their evolution to form different active phases, both topological and chemically, in response to reaction conditions exposing a new paradigm in the catalyst structure during operation.
(© 2023. The Author(s).)
Databáze: MEDLINE
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