title: The Central Role of Bicarbonate in the Electrochemical Reduction of Carbon Dioxide on Gold.
abstract: Much effort has been devoted in the development of efficient catalysts for electrochemical reduction of CO2. Molecular level understanding of electrode-mediated process, particularly the role of bicarbonate in increasing CO2reduction rates, is still lacking due to the difficulty of directly probing the electrochemical interface. We developed a protocol to observe normally invisible reaction intermediates with a surface enhanced spectroscopy by applying square-wave potential profiles. Further, we demonstrate that bicarbonate, through equilibrium exchange with dissolved CO2, rather than the supplied CO2, is the primary source of carbon in the CO formed at the Au electrode by a combination of in situ spectroscopic, isotopic labeling, and mass spectroscopic investigations. We propose that bicarbonate enhances the rate of CO production on Au by increasing the effective concentration of dissolved CO2near the electrode surface through rapid equilibrium between bicarbonate and dissolved CO2.
authors.affiliation: Center for Catalytic Science and Technology, Department of Chemical and Biomolecular Engineering, University of Delaware , Newark, Delaware 19716, United States.
authors.forename: Marco
authors.initials: M
authors.lastname: Dunwell
authors.affiliation: Center for Catalytic Science and Technology, Department of Chemical and Biomolecular Engineering, University of Delaware , Newark, Delaware 19716, United States.|Department of Chemical Engineering, Columbia University , New York, New York 10027, United States.
authors.forename: Qi
authors.initials: Q
authors.lastname: Lu
authors.affiliation: Center for Catalytic Science and Technology, Department of Chemical and Biomolecular Engineering, University of Delaware , Newark, Delaware 19716, United States.
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Heyes
authors.affiliation: Center for Catalytic Science and Technology, Department of Chemical and Biomolecular Engineering, University of Delaware , Newark, Delaware 19716, United States.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Rosen
authors.affiliation: Department of Chemical Engineering, Columbia University , New York, New York 10027, United States.
authors.forename: Jingguang G
authors.initials: JG
authors.lastname: Chen
authors.affiliation: Center for Catalytic Science and Technology, Department of Chemical and Biomolecular Engineering, University of Delaware , Newark, Delaware 19716, United States.
authors.forename: Yushan
authors.initials: Y
authors.lastname: Yan
authors.affiliation: Center for Catalytic Science and Technology, Department of Chemical and Biomolecular Engineering, University of Delaware , Newark, Delaware 19716, United States.
authors.forename: Feng
authors.identifier: 0000-0002-3335-3203
authors.initials: F
authors.lastname: Jiao
authors.affiliation: Center for Catalytic Science and Technology, Department of Chemical and Biomolecular Engineering, University of Delaware , Newark, Delaware 19716, United States.
authors.forename: Bingjun
authors.identifier: 0000-0002-2303-257X
authors.initials: B
authors.lastname: Xu