CO₂-Promoted Electrocatalytic Reduction of Chlorinated Hydrocarbons
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1.
California Institute of Technology
Abstract
Electrochemical reactions and their catalysis are important for energy and environmental applications, such as carbon neutralization and water purification. However, the synergy in electrocatalysis between CO2 utilization and wastewater treatment has not been explored. In this study, we find that the electrochemical reduction of chlorinated organic compounds such as 1,2-dichloroethane, trichloroethylene, and tetrachloroethylene into ethylene in aqueous media, which is a category of challenging reactions due to the competition of H2 evolution, can be substantially enhanced by simultaneously carrying out the reduction of CO2 on an easily prepared and cost-effective Cu metal catalyst. In the case of 1,2-dichloroethane dechlorination, a 6-fold improvement in Faradaic efficiency and a 19-fold increase in partial current density are demonstrated. Through electrochemical kinetic studies, in situ Raman spectroscopy, and computational simulations, we further find that CO2 reduction reduces hydrogen coverage on the Cu catalyst, which not only exposes more active sites for the dechlorination reaction but also enhances the effective reductive potential on the catalyst surface and reduces the kinetic barrier of the rate-determining step.
Copyright and License
© 2024 American Chemical Society.
Acknowledgement
This work was supported by the U.S. National Science Foundation (grant CBET2028351). W.A.G. acknowledges support by the Liquid Sunlight Alliance, which is supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Fuels from Sunlight Hub under Award Number DE-SC0021266 (computational work). This work used the Extreme Science and Engineering Discovery Environment (XSEDE) for DFT calculations, which is supported by National Science Foundation grant number ACI-1548562. S.K. acknowledges the Resnick Sustainability Institute at Caltech for an individual fellowship (computational work).
Funding
U.S. National Science Foundation (grant CBET2028351)
Liquid Sunlight Alliance, supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Fuels from Sunlight Hub under Award Number DE-SC0021266
National Science Foundation grant number ACI-1548562
Resnick Sustainability Institute at Caltech
Data Availability
Experimental and computational details, and additional structural characterization, electrochemical reaction, in situ Raman spectroscopy, and DFT calculation results (PDF)
Additional details
- ISSN
- 1520-5126
- National Science Foundation
- CBET-2028351
- United States Department of Energy
- DE-SC0021266
- National Science Foundation
- ACI-1548562
- Resnick Sustainability Institute
- Caltech groups
- Liquid Sunlight Alliance, Resnick Sustainability Institute