Methods—A Potential–Dependent Thiele Modulus to Quantify the Effectiveness of Porous Electrocatalysts
<jats:p>Electrochemical reactors often employ high surface area electrocatalysts to accelerate volumetric reaction rates and increase productivity. While electrocatalysts can alleviate kinetic overpotentials, diffusional resistances at the pore-scale often prevent full catalyst utilization. Th...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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The Electrochemical Society
2022
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| Online Access: | https://hdl.handle.net/1721.1/142494 |
| _version_ | 1811069758556078080 |
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| author | Wan, Charles Tai-Chieh Greco, Katharine V Alazmi, Amira Darling, Robert M Chiang, Yet-Ming Brushett, Fikile R |
| author2 | Massachusetts Institute of Technology. Department of Chemical Engineering |
| author_facet | Massachusetts Institute of Technology. Department of Chemical Engineering Wan, Charles Tai-Chieh Greco, Katharine V Alazmi, Amira Darling, Robert M Chiang, Yet-Ming Brushett, Fikile R |
| author_sort | Wan, Charles Tai-Chieh |
| collection | MIT |
| description | <jats:p>Electrochemical reactors often employ high surface area electrocatalysts to accelerate volumetric reaction rates and increase productivity. While electrocatalysts can alleviate kinetic overpotentials, diffusional resistances at the pore-scale often prevent full catalyst utilization. The effect of intraparticle diffusion on the overall reaction rate can be quantified through an effectiveness factor expression governed by the Thiele modulus parameter. This analytical approach is integral to the development of catalytic structures for thermochemical processes and has previously been extended to electrochemical processes by accounting for the relationship between reaction kinetics and electrode overpotential. In this paper, we illustrate the method by deriving the expression for the potential-dependent Thiele modulus and using it to quantify the effectiveness factor for porous electrocatalytic structures. Specifically, we demonstrate the application of this mathematical framework to spherical microparticles as a function of applied overpotential across catalyst properties and reactant characteristics. The relative effects of kinetics and mass transport are related to overall reaction rates, revealing markedly lower catalyst utilization at increasing overpotential. Subsequently, we generalize the analysis to different catalyst shapes and provide guidance on the design of porous catalytic materials for use in electrochemical reactors.</jats:p> |
| first_indexed | 2024-09-23T08:15:34Z |
| format | Article |
| id | mit-1721.1/142494 |
| institution | Massachusetts Institute of Technology |
| language | English |
| last_indexed | 2024-09-23T08:15:34Z |
| publishDate | 2022 |
| publisher | The Electrochemical Society |
| record_format | dspace |
| spelling | mit-1721.1/1424942023-02-01T16:38:52Z Methods—A Potential–Dependent Thiele Modulus to Quantify the Effectiveness of Porous Electrocatalysts Wan, Charles Tai-Chieh Greco, Katharine V Alazmi, Amira Darling, Robert M Chiang, Yet-Ming Brushett, Fikile R Massachusetts Institute of Technology. Department of Chemical Engineering Massachusetts Institute of Technology. Department of Materials Science and Engineering <jats:p>Electrochemical reactors often employ high surface area electrocatalysts to accelerate volumetric reaction rates and increase productivity. While electrocatalysts can alleviate kinetic overpotentials, diffusional resistances at the pore-scale often prevent full catalyst utilization. The effect of intraparticle diffusion on the overall reaction rate can be quantified through an effectiveness factor expression governed by the Thiele modulus parameter. This analytical approach is integral to the development of catalytic structures for thermochemical processes and has previously been extended to electrochemical processes by accounting for the relationship between reaction kinetics and electrode overpotential. In this paper, we illustrate the method by deriving the expression for the potential-dependent Thiele modulus and using it to quantify the effectiveness factor for porous electrocatalytic structures. Specifically, we demonstrate the application of this mathematical framework to spherical microparticles as a function of applied overpotential across catalyst properties and reactant characteristics. The relative effects of kinetics and mass transport are related to overall reaction rates, revealing markedly lower catalyst utilization at increasing overpotential. Subsequently, we generalize the analysis to different catalyst shapes and provide guidance on the design of porous catalytic materials for use in electrochemical reactors.</jats:p> 2022-05-11T18:30:08Z 2022-05-11T18:30:08Z 2021 2022-05-11T18:26:53Z Article http://purl.org/eprint/type/JournalArticle https://hdl.handle.net/1721.1/142494 Wan, Charles Tai-Chieh, Greco, Katharine V, Alazmi, Amira, Darling, Robert M, Chiang, Yet-Ming et al. 2021. "Methods—A Potential–Dependent Thiele Modulus to Quantify the Effectiveness of Porous Electrocatalysts." Journal of The Electrochemical Society, 168 (12). en 10.1149/1945-7111/AC34CE Journal of The Electrochemical Society Attribution-NonCommercial-ShareAlike 4.0 International https://creativecommons.org/licenses/by-nc-sa/4.0/ application/pdf The Electrochemical Society ChemRxiv |
| spellingShingle | Wan, Charles Tai-Chieh Greco, Katharine V Alazmi, Amira Darling, Robert M Chiang, Yet-Ming Brushett, Fikile R Methods—A Potential–Dependent Thiele Modulus to Quantify the Effectiveness of Porous Electrocatalysts |
| title | Methods—A Potential–Dependent Thiele Modulus to Quantify the Effectiveness of Porous Electrocatalysts |
| title_full | Methods—A Potential–Dependent Thiele Modulus to Quantify the Effectiveness of Porous Electrocatalysts |
| title_fullStr | Methods—A Potential–Dependent Thiele Modulus to Quantify the Effectiveness of Porous Electrocatalysts |
| title_full_unstemmed | Methods—A Potential–Dependent Thiele Modulus to Quantify the Effectiveness of Porous Electrocatalysts |
| title_short | Methods—A Potential–Dependent Thiele Modulus to Quantify the Effectiveness of Porous Electrocatalysts |
| title_sort | methods a potential dependent thiele modulus to quantify the effectiveness of porous electrocatalysts |
| url | https://hdl.handle.net/1721.1/142494 |
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