Membrane‐electrode assembly design parameters for optimal CO2 reduction
Abstract Commercial‐scale generation of carbon‐containing chemicals and fuels by means of electrochemical CO2 reduction (CO2R) requires electrolyzers operating at high current densities and product selectivities. Membrane‐electrode assemblies (MEAs) have been shown to be suitable for this purpose. I...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Wiley-VCH
2023-02-01
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| Series: | Electrochemical Science Advances |
| Subjects: | |
| Online Access: | https://doi.org/10.1002/elsa.202100186 |
| _version_ | 1811165342105337856 |
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| author | Oyinkansola Romiluyi Nemanja Danilovic Alexis T. Bell Adam Z. Weber |
| author_facet | Oyinkansola Romiluyi Nemanja Danilovic Alexis T. Bell Adam Z. Weber |
| author_sort | Oyinkansola Romiluyi |
| collection | DOAJ |
| description | Abstract Commercial‐scale generation of carbon‐containing chemicals and fuels by means of electrochemical CO2 reduction (CO2R) requires electrolyzers operating at high current densities and product selectivities. Membrane‐electrode assemblies (MEAs) have been shown to be suitable for this purpose. In such devices, the cathode catalyst layer controls both the rate of CO2R and the distribution of products. In this study, we investigate how the ionomer‐to‐catalyst ratio (I:Cat), catalyst loading, and catalyst‐layer thickness influence the performance of a cathode catalyst layer containing Ag nanoparticles supported on carbon. In this paper, we explore how these parameters affect the cell performance and establish the role of the exchange solution (water vs. CsHCO3) behind the anode catalyst layer in cell performance. We show that a high total current density is best achieved using an I:Cat ratio of 3 at a Ag loading of 0.01–0.1 mgAg/cm2 and with a 1.0 M solution of CsHCO3 circulated behind the anode catalyst layer. For these conditions, the optimal CO partial current density depends on the voltage applied to the MEA. The work also reveals that the performance of the cathode catalyst layer is limited by a combination of the electrochemically active surface area and the degree to which mass transfer of CO2 to the surface of the Ag nanoparticles and the transport of OH− anions away from it limit the overall catalyst activity. Hydration of the ionomer in the cathode catalyst layer is found not to be an issue when using an exchange solution. The insights gained allowed for a Ag CO2R MEA that operates between 200 mA/cm2 and 1 A/cm2 with CO faradaic efficiencies of 78–91%, and the findings and understanding gained herein should be applicable to a broad range of CO2R MEA‐based devices. |
| first_indexed | 2024-04-10T15:36:45Z |
| format | Article |
| id | doaj.art-7e31065b8c20442eab184da4441899c1 |
| institution | Directory Open Access Journal |
| issn | 2698-5977 |
| language | English |
| last_indexed | 2024-04-10T15:36:45Z |
| publishDate | 2023-02-01 |
| publisher | Wiley-VCH |
| record_format | Article |
| series | Electrochemical Science Advances |
| spelling | doaj.art-7e31065b8c20442eab184da4441899c12023-02-13T05:14:13ZengWiley-VCHElectrochemical Science Advances2698-59772023-02-0131n/an/a10.1002/elsa.202100186Membrane‐electrode assembly design parameters for optimal CO2 reductionOyinkansola Romiluyi0Nemanja Danilovic1Alexis T. Bell2Adam Z. Weber3Department of Chemical and Biomolecular Engineering University of California Berkeley Berkeley California USAEnergy Storage and Distributed Resources Division Lawrence Berkeley National Laboratory Berkeley California USADepartment of Chemical and Biomolecular Engineering University of California Berkeley Berkeley California USAJoint Center for Artificial Photosynthesis Lawrence Berkeley National Laboratory Berkeley California USAAbstract Commercial‐scale generation of carbon‐containing chemicals and fuels by means of electrochemical CO2 reduction (CO2R) requires electrolyzers operating at high current densities and product selectivities. Membrane‐electrode assemblies (MEAs) have been shown to be suitable for this purpose. In such devices, the cathode catalyst layer controls both the rate of CO2R and the distribution of products. In this study, we investigate how the ionomer‐to‐catalyst ratio (I:Cat), catalyst loading, and catalyst‐layer thickness influence the performance of a cathode catalyst layer containing Ag nanoparticles supported on carbon. In this paper, we explore how these parameters affect the cell performance and establish the role of the exchange solution (water vs. CsHCO3) behind the anode catalyst layer in cell performance. We show that a high total current density is best achieved using an I:Cat ratio of 3 at a Ag loading of 0.01–0.1 mgAg/cm2 and with a 1.0 M solution of CsHCO3 circulated behind the anode catalyst layer. For these conditions, the optimal CO partial current density depends on the voltage applied to the MEA. The work also reveals that the performance of the cathode catalyst layer is limited by a combination of the electrochemically active surface area and the degree to which mass transfer of CO2 to the surface of the Ag nanoparticles and the transport of OH− anions away from it limit the overall catalyst activity. Hydration of the ionomer in the cathode catalyst layer is found not to be an issue when using an exchange solution. The insights gained allowed for a Ag CO2R MEA that operates between 200 mA/cm2 and 1 A/cm2 with CO faradaic efficiencies of 78–91%, and the findings and understanding gained herein should be applicable to a broad range of CO2R MEA‐based devices.https://doi.org/10.1002/elsa.202100186catalyst layerCO2 reductionelectrolyzerI:Cionomermembrane‐electrode assembly |
| spellingShingle | Oyinkansola Romiluyi Nemanja Danilovic Alexis T. Bell Adam Z. Weber Membrane‐electrode assembly design parameters for optimal CO2 reduction Electrochemical Science Advances catalyst layer CO2 reduction electrolyzer I:C ionomer membrane‐electrode assembly |
| title | Membrane‐electrode assembly design parameters for optimal CO2 reduction |
| title_full | Membrane‐electrode assembly design parameters for optimal CO2 reduction |
| title_fullStr | Membrane‐electrode assembly design parameters for optimal CO2 reduction |
| title_full_unstemmed | Membrane‐electrode assembly design parameters for optimal CO2 reduction |
| title_short | Membrane‐electrode assembly design parameters for optimal CO2 reduction |
| title_sort | membrane electrode assembly design parameters for optimal co2 reduction |
| topic | catalyst layer CO2 reduction electrolyzer I:C ionomer membrane‐electrode assembly |
| url | https://doi.org/10.1002/elsa.202100186 |
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