title: Subsurface Oxygen in Oxide-Derived Copper Electrocatalysts for Carbon Dioxide Reduction.
abstract: Copper electrocatalysts derived from an oxide have shown extraordinary electrochemical properties for the carbon dioxide reduction reaction (CO2RR). Using in situ ambient pressure X-ray photoelectron spectroscopy and quasi in situ electron energy-loss spectroscopy in a transmission electron microscope, we show that there is a substantial amount of residual oxygen in nanostructured, oxide-derived copper electrocatalysts but no residual copper oxide. On the basis of these findings in combination with density functional theory simulations, we propose that residual subsurface oxygen changes the electronic structure of the catalyst and creates sites with higher carbon monoxide binding energy. If such sites are stable under the strongly reducing conditions found in CO2RR, these findings would explain the high efficiencies of oxide-derived copper in reducing carbon dioxide to multicarbon compounds such as ethylene.
authors.affiliation: SLAC National Accelerator Laboratory , 2575 Sand Hill Road, Menlo Park, California 94025, United States.|SUNCAT Center for Interface Science and Catalysis, Department of Chemical Engineering, Stanford University , 443 Via Ortega, Stanford, California 95305, United States.|Department of Physics, AlbaNova University Center, Stockholm University , S-10691 Stockholm, Sweden.
authors.forename: André
authors.initials: A
authors.lastname: Eilert
authors.affiliation: SLAC National Accelerator Laboratory , 2575 Sand Hill Road, Menlo Park, California 94025, United States.|SUNCAT Center for Interface Science and Catalysis, Department of Chemical Engineering, Stanford University , 443 Via Ortega, Stanford, California 95305, United States.|Department of Physics, AlbaNova University Center, Stockholm University , S-10691 Stockholm, Sweden.
authors.forename: Filippo
authors.initials: F
authors.lastname: Cavalca
authors.affiliation: SLAC National Accelerator Laboratory , 2575 Sand Hill Road, Menlo Park, California 94025, United States.|SUNCAT Center for Interface Science and Catalysis, Department of Chemical Engineering, Stanford University , 443 Via Ortega, Stanford, California 95305, United States.|Department of Physics, AlbaNova University Center, Stockholm University , S-10691 Stockholm, Sweden.
authors.forename: F Sloan
authors.identifier: http://orcid.org/0000-0002-9794-0941
authors.initials: FS
authors.lastname: Roberts
authors.affiliation: Department of Physics, University of Zürich , Winterthurerstrasse 190, 8057 Zürich, Switzerland.
authors.forename: Jürg
authors.initials: J
authors.lastname: Osterwalder
authors.affiliation: Department of Physics, AlbaNova University Center, Stockholm University , S-10691 Stockholm, Sweden.
authors.forename: Chang
authors.initials: C
authors.lastname: Liu
authors.affiliation: Advanced Light Source, Lawrence Berkeley National Laboratory , 6 Cyclotron Road, Berkeley, California 94720, United States.|Joint Center for Artificial Photosynthesis, Lawrence Berkeley National Laboratory , 1 Cyclotron Road, Berkeley, California 94720, United States.|Chemical Sciences Division, Lawrence Berkeley National Laboratory , 1 Cyclotron Road, Berkeley, California 94720, United States.
authors.forename: Marco
authors.initials: M
authors.lastname: Favaro
authors.affiliation: Advanced Light Source, Lawrence Berkeley National Laboratory , 6 Cyclotron Road, Berkeley, California 94720, United States.
authors.forename: Ethan J
authors.initials: EJ
authors.lastname: Crumlin
authors.affiliation: SLAC National Accelerator Laboratory , 2575 Sand Hill Road, Menlo Park, California 94025, United States.
authors.forename: Hirohito
authors.initials: H
authors.lastname: Ogasawara
authors.affiliation: SLAC National Accelerator Laboratory , 2575 Sand Hill Road, Menlo Park, California 94025, United States.
authors.forename: Daniel
authors.initials: D
authors.lastname: Friebel
authors.affiliation: Department of Physics, AlbaNova University Center, Stockholm University , S-10691 Stockholm, Sweden.
authors.forename: Lars G M
authors.initials: LG
authors.lastname: Pettersson
authors.affiliation: SLAC National Accelerator Laboratory , 2575 Sand Hill Road, Menlo Park, California 94025, United States.|SUNCAT Center for Interface Science and Catalysis, Department of Chemical Engineering, Stanford University , 443 Via Ortega, Stanford, California 95305, United States.|Department of Physics, AlbaNova University Center, Stockholm University , S-10691 Stockholm, Sweden.
authors.forename: Anders
authors.identifier: http://orcid.org/0000-0003-1968-8696
authors.initials: A
authors.lastname: Nilsson