title: Acetaldehyde as an Intermediate in the Electroreduction of Carbon Monoxide to Ethanol on Oxide-Derived Copper.
abstract: Oxide-derived copper (OD-Cu) electrodes exhibit unprecedented CO reduction performance towards liquid fuels, producing ethanol and acetate with >50% Faradaic efficiency at -0.3 V (vs. RHE). By using static headspace-gas chromatography for liquid phase analysis, we identify acetaldehyde as a minor product and key intermediate in the electroreduction of CO to ethanol on OD-Cu electrodes. Acetaldehyde is produced with a Faradaic efficiency of ≈5% at -0.33 V (vs. RHE). We show that acetaldehyde forms at low steady-state concentrations, and that free acetaldehyde is difficult to detect in alkaline solutions using NMR spectroscopy, requiring alternative methods for detection and quantification. Our results represent an important step towards understanding the CO reduction mechanism on OD-Cu electrodes.
authors.affiliation: Department of Physics, Technical University of Denmark, 2800 Kgs., Lyngby, Denmark.
authors.forename: Erlend
authors.identifier: http://orcid.org/0000-0002-6482-8937
authors.initials: E
authors.lastname: Bertheussen
authors.affiliation: Department of Physics, Technical University of Denmark, 2800 Kgs., Lyngby, Denmark.
authors.forename: Arnau
authors.initials: A
authors.lastname: Verdaguer-Casadevall
authors.affiliation: Carlsberg Laboratory, Gamle Carlsberg vej 4, 1799, København V, Denmark.
authors.forename: Davide
authors.initials: D
authors.lastname: Ravasio
authors.affiliation: SUNCAT Center for Catalysis and Interface Science, Department of Chemical Engineering, Stanford University, 443 Via Ortega, Stanford, CA, 94305, USA.
authors.forename: Joseph H
authors.initials: JH
authors.lastname: Montoya
authors.affiliation: Department of Physics, Technical University of Denmark, 2800 Kgs., Lyngby, Denmark.
authors.forename: Daniel B
authors.initials: DB
authors.lastname: Trimarco
authors.affiliation: Department of Physics, Technical University of Denmark, 2800 Kgs., Lyngby, Denmark.
authors.forename: Claudie
authors.initials: C
authors.lastname: Roy
authors.affiliation: Department of Chemistry, Technical University of Denmark, 2800 Kongens, Lyngby, Denmark.
authors.forename: Sebastian
authors.identifier: http://orcid.org/0000-0003-3761-3217
authors.initials: S
authors.lastname: Meier
authors.affiliation: Carlsberg Laboratory, Gamle Carlsberg vej 4, 1799, København V, Denmark.
authors.forename: Jürgen
authors.identifier: http://orcid.org/0000-0001-8350-253X
authors.initials: J
authors.lastname: Wendland
authors.affiliation: SUNCAT Center for Catalysis and Interface Science, SLAC National Accelerator Laboratory, 2675 Sand Hill Road, Menlo Park, CA, 94025, USA.
authors.forename: Jens K
authors.initials: JK
authors.lastname: Nørskov
authors.affiliation: Department of Physics, Technical University of Denmark, 2800 Kgs., Lyngby, Denmark. ifan@fysik.dtu.dk.|Department of Mechanical Engineering, Massachusetts Institute of Technology (MIT), 77 Massachusetts Avenue, Cambridge, MA, 02319, USA. ifan@fysik.dtu.dk.
authors.forename: Ifan E L
authors.identifier: http://orcid.org/0000-0003-2157-492X
authors.initials: IE
authors.lastname: Stephens
authors.affiliation: Department of Physics, Technical University of Denmark, 2800 Kgs., Lyngby, Denmark. ibchork@fysik.dtu.dk.
authors.forename: Ib
authors.identifier: http://orcid.org/0000-0003-2738-0325
authors.initials: I
authors.lastname: Chorkendorff
keywords: analytical chemistry; catalysis; electrochemistry; energy conversion; materials science