Probing the Catalytically Active Region in a Nanoporous Gold Gas Diffusion Electrode for Highly Selective Carbon Dioxide Reduction
Abstract
We report the use of a nanoporous gold (np-Au) catalyst for CO₂ reduction in a gas diffusion electrode (GDE) and characterize the role of wetting in electrochemical performance. The np-Au catalyst has pores on the order of 20 nm and is cross-sectionally isotropic, enabling Faradaic efficiencies for CO of greater than 95% across a wide range of potentials and a maximum partial current density for CO of 168 mA/cm². Secondary ion mass spectroscopy and in situ copper underpotential deposition were employed to provide insights into catalyst wetting. At a typical CO₂ flow rate of 50 SCCM, approximately half of the catalyst is in contact with the electrolyte during operation, and the dry region exists in the bottom half of the nanoporous catalyst. We discuss implications of the nanoporous GDE wetting characteristics for catalyst performance and the design of improved GDE architectures that can maximize the catalytically active area.
Additional Information
© 2022 American Chemical Society. Received 17 October 2021. Accepted 30 December 2021. Published online 27 January 2022. This work was performed within 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. A.J.W. acknowledges support from the Resnick Sustainability Institute at Caltech for fellowship support and from the National Science Foundation (NSF) Graduate Research Fellowship Program under Base Award No. 174530. Author Contributions. A.Q.F. and A.J.W. contributed equally to this work. Any opinions, findings, and conclusions expressed in this material are those of the authors and do not necessarily reflect those of DOE or NSF. The authors declare no competing financial interest.Attached Files
Supplemental Material - nz1c02267_si_001.pdf
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Additional details
- Eprint ID
- 113232
- Resolver ID
- CaltechAUTHORS:20220202-544247000
- Department of Energy (DOE)
- DE-SC0021266
- Resnick Sustainability Institute
- NSF Graduate Research Fellowship
- DGE-174530
- Created
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2022-02-02Created from EPrint's datestamp field
- Updated
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2022-05-10Created from EPrint's last_modified field
- Caltech groups
- Liquid Sunlight Alliance, Resnick Sustainability Institute