Electrochemical and surface studies of carbon dioxide reduction to methane and ethylene at copper electrodes in aqueous solutions

Journal Article · Thu Jun 01 00:00:00 EDT 1989 · Journal of the Electrochemical Society; (USA)

DOI:https://doi.org/10.1149/1.2096993· OSTI ID:5332229

DeWulf, D W; Jin, T; Bard, A J ^[1]

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1. Texas Univ., Austin, TX (USA). Dept. of Chemistry

The authors describe the electrochemical reduction of CO/sub 2/ to CH/sub 4/ and C/sub 2/H/sub 4/ in aqueous alkaline solutions at Cu electrodes. The current at the Cu electrodes and the rate of hydrocarbon formation were monitored as a function of time over a temperature range from 0 to 48%C. Solutions of formate, formaldehyde, and methanol, possible intermediates in the reduction process, were also electrolyzed. Surface analyses (XPS and AES) were also performed on the Cu electrodes following electrolysis to identify surface intermediates. In addition to hydrocarbon formation, a poisoning process occurred, causing a deposit of a black film on the surface of the Cu cathode. XPS and AES studies indicated that the black film was graphitic carbon, probably the result of a side reaction, the reduction of CO/sub 2/ through formate to graphite. A tentative reaction mechanism for CO/sub 2/ reduction, based upon the data here and those of previous investigators, involving the reaction path CO/sub 2/{yields}CO{yields} surface-bound formyl (Cu-HCO){yields} surface-bound methylene (Cu-CH/sub 2/){yields} hydrocarbon products, is proposed.

• OSTI ID: 5332229
• Journal Information: Journal of the Electrochemical Society; (USA), Vol. 136:6; ISSN 0013-4651
• Country of Publication: United States
• Language: English

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37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
30 DIRECT ENERGY CONVERSION
CARBON DIOXIDE
REDUCTION
ETHYLENE
SYNTHESIS
METHANE
AQUEOUS SOLUTIONS
CHEMICAL REACTION KINETICS
COPPER
ELECTROCHEMISTRY
ELECTRODES
FORMALDEHYDE
GRAPHITE
METHANOL
ALCOHOLS
ALDEHYDES
ALKANES
ALKENES
CARBON
CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
CHEMICAL REACTIONS
CHEMISTRY
DISPERSIONS
ELEMENTAL MINERALS
ELEMENTS
HYDROCARBONS
HYDROXY COMPOUNDS
KINETICS
METALS
MINERALS
MIXTURES
NONMETALS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
REACTION KINETICS
SOLUTIONS
TRANSITION ELEMENTS
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