A reversed gas diffusion electrode enables collection of high purity gas products from CO₂ electroreduction
Creators
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1.
National University of Singapore
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2.
Institute of Materials Research and Engineering
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3.
California Institute of Technology
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4.
Agency for Science, Technology and Research
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5.
Institute of Chemical Technology
Abstract
Electrochemical CO2 reduction (CO2R) in conventional systems typically generates highly diluted product output streams. This necessitates energy intensive and costly product separation, which potentially decreases the feasibility and economic viability of the process. Here, we describe the design and fabrication of a reversed gas diffusion electrode, which makes use of electrolyte pressure to channel products toward a collection chamber. Importantly, this strategy successfully excludes CO2 and permits gas products to be siphoned off at high purity. We further show that the electrolyte pressure and gas diffusion layer pore size are the key factors which govern the product collection efficiency. Using a nanoporous Au catalyst, we showcase the continuous production of high purity syngas over an extended 76 h period, operating at a full-cell energy efficiency of 37%. Importantly, we also demonstrate that this system is oxygen-tolerant, with no parasitic loss of current towards the oxygen reduction reaction even with a 95% CO2 + 5% O2 gas feed. Taken together, our results introduce a new design approach for CO2R electrolyzer systems.
Acknowledgement
Y. L. acknowledges support and funding from the A*STAR (Agency for Science, Technology, and Research) under its LCERFI program (Award No. U2102d2002). Y. L. acknowledges support and funding from the NRF Fellowship (Award No. NRF-NRFF14-2022-0003). We acknowledge use of the XAFCA beamline of the Singapore Synchrotron Light Source (SSLS) for collection of the XAS data used in this work. We thank professor Shamsuzzaman Farooq for help and guidance on the pressure gap and gas transport calculations.
Copyright and License
© 2025 The Author(s).
This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence.
Supplemental Material
Data Availability
The authors declare that the data supporting the findings of this study are available within the paper and its ESI.† Should any raw data files be needed in another format they are available from the corresponding author upon reasonable request.
Contributions
Y. L. supervised the project. Y. L. and B. W. conceived the idea and designed the experiments. B. W. carried out all the experimental work. J. Z. carried out all the gas product GCMS analysis. A. Q. F. and H. A. A. performed and supervised the catalyst synthesis respectively. B. W., C. W. and S. X. carried out the XAS experiments. B. W., N. N., and M. W. carried out the bubble growth video capture. Y. J. and S. Z. carried out and supervised the gas flux experiments respectively. B. W., Z. M., Z. A., W. W. T., and M. Z. performed the catalyst characterization and analysis. L. D. V. carried out calculations of pressure gap, permeance and pore flooding. C. S. M. and I. A. K. supervised the calculations. Y. L. and B. W. co-wrote the manuscript. All authors discussed the results and assisted during the manuscript preparation.
Conflict of Interest
The authors declare no competing interests.
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Additional details
Funding
- Agency for Science, Technology and Research
- LCERFI U2102d2002
- National Research Foundation
- NRF Fellowship NRF-NRFF14-2022-0003
Dates
- Accepted
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2024-12-16Accepted
- Available
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2025-01-14Published online