title: Highly selective plasma-activated copper catalysts for carbon dioxide reduction to ethylene.
abstract: There is an urgent need to develop technologies that use renewable energy to convert waste products such as carbon dioxide into hydrocarbon fuels. Carbon dioxide can be electrochemically reduced to hydrocarbons over copper catalysts, although higher efficiency is required. We have developed oxidized copper catalysts displaying lower overpotentials for carbon dioxide electroreduction and record selectivity towards ethylene (60%) through facile and tunable plasma treatments. Herein we provide insight into the improved performance of these catalysts by combining electrochemical measurements with microscopic and spectroscopic characterization techniques. Operando X-ray absorption spectroscopy and cross-sectional scanning transmission electron microscopy show that copper oxides are surprisingly resistant to reduction and copper(+) species remain on the surface during the reaction. Our results demonstrate that the roughness of oxide-derived copper catalysts plays only a partial role in determining the catalytic performance, while the presence of copper(+) is key for lowering the onset potential and enhancing ethylene selectivity.
authors.affiliation: Department of Physics, University of Central Florida, Orlando, Florida 32816, USA.|Department of Physics, Ruhr-University Bochum, 44780 Bochum, Germany.
authors.forename: Hemma
authors.identifier: 0000-0002-6065-3340
authors.initials: H
authors.lastname: Mistry
authors.affiliation: Department of Chemistry, Chemical Engineering Division, Technical University Berlin, 10623 Berlin, Germany.
authors.forename: Ana Sofia
authors.initials: AS
authors.lastname: Varela
authors.affiliation: Chemical and Petroleum Engineering and Physics, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, USA.
authors.forename: Cecile S
authors.initials: CS
authors.lastname: Bonifacio
authors.affiliation: Department of Physics, Ruhr-University Bochum, 44780 Bochum, Germany.
authors.forename: Ioannis
authors.initials: I
authors.lastname: Zegkinoglou
authors.affiliation: Department of Physics, Ruhr-University Bochum, 44780 Bochum, Germany.
authors.forename: Ilya
authors.initials: I
authors.lastname: Sinev
authors.affiliation: Department of Physics, Ruhr-University Bochum, 44780 Bochum, Germany.
authors.forename: Yong-Wook
authors.initials: YW
authors.lastname: Choi
authors.affiliation: Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, New York 11973, USA.
authors.forename: Kim
authors.initials: K
authors.lastname: Kisslinger
authors.affiliation: Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, New York 11973, USA.
authors.forename: Eric A
authors.identifier: 0000-0002-3366-2153
authors.initials: EA
authors.lastname: Stach
authors.affiliation: Chemical and Petroleum Engineering and Physics, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, USA.
authors.forename: Judith C
authors.initials: JC
authors.lastname: Yang
authors.affiliation: Department of Chemistry, Chemical Engineering Division, Technical University Berlin, 10623 Berlin, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Strasser
authors.affiliation: Department of Physics, Ruhr-University Bochum, 44780 Bochum, Germany.
authors.forename: Beatriz Roldan
authors.initials: BR
authors.lastname: Cuenya