Role of Adsorbate Coverage on the Oxygen Dissociation Rate on Sr-Doped LaMnO 3 Surfaces in the Presence of H 2 O and CO 2
Copyright © 2020 American Chemical Society. Sr-doped LaMnO3 (LSM) is a promising oxygen reduction reaction electrocatalyst in solid oxide fuel cells and other electrochemical devices. The presence of CO2 and H2O has been reported to promote the oxygen dissociation reaction on LSM surfaces. Here, we...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
American Chemical Society (ACS)
2021
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| Online Access: | https://hdl.handle.net/1721.1/132550 |
| _version_ | 1826194405058412544 |
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| author | Yang, Jing Polfus, Jonathan M Li, Zuoan Tuller, Harry L Yildiz, Bilge |
| author_facet | Yang, Jing Polfus, Jonathan M Li, Zuoan Tuller, Harry L Yildiz, Bilge |
| author_sort | Yang, Jing |
| collection | MIT |
| description | Copyright © 2020 American Chemical Society. Sr-doped LaMnO3 (LSM) is a promising oxygen reduction reaction electrocatalyst in solid oxide fuel cells and other electrochemical devices. The presence of CO2 and H2O has been reported to promote the oxygen dissociation reaction on LSM surfaces. Here, we investigate the coadsorption mechanism of O2 with H2O or CO2 by combining first-principles calculations of the (0 0 1) surface containing 25-100% Sr with thermodynamic adsorption models. The molecules were found to chemisorb by formation of charged oxygen, hydroxide, and carbonate species, and the adsorption energies were exothermic up to monolayer coverage. Low concentrations of H2O or CO2 do not compete with O2 for adsorption sites under relevant conditions. However, their presence contributes to the total amount of oxygen-containing species. The increased coverage of oxygen species provides a quantitative explanation for the reported enhancement in oxygen dissociation kinetics in the presence of H2O/CO2. This study thereby provides insights into oxygen exchange mechanisms on LSM surfaces. |
| first_indexed | 2024-09-23T09:55:36Z |
| format | Article |
| id | mit-1721.1/132550 |
| institution | Massachusetts Institute of Technology |
| language | English |
| last_indexed | 2024-09-23T09:55:36Z |
| publishDate | 2021 |
| publisher | American Chemical Society (ACS) |
| record_format | dspace |
| spelling | mit-1721.1/1325502021-09-21T03:54:12Z Role of Adsorbate Coverage on the Oxygen Dissociation Rate on Sr-Doped LaMnO 3 Surfaces in the Presence of H 2 O and CO 2 Yang, Jing Polfus, Jonathan M Li, Zuoan Tuller, Harry L Yildiz, Bilge Copyright © 2020 American Chemical Society. Sr-doped LaMnO3 (LSM) is a promising oxygen reduction reaction electrocatalyst in solid oxide fuel cells and other electrochemical devices. The presence of CO2 and H2O has been reported to promote the oxygen dissociation reaction on LSM surfaces. Here, we investigate the coadsorption mechanism of O2 with H2O or CO2 by combining first-principles calculations of the (0 0 1) surface containing 25-100% Sr with thermodynamic adsorption models. The molecules were found to chemisorb by formation of charged oxygen, hydroxide, and carbonate species, and the adsorption energies were exothermic up to monolayer coverage. Low concentrations of H2O or CO2 do not compete with O2 for adsorption sites under relevant conditions. However, their presence contributes to the total amount of oxygen-containing species. The increased coverage of oxygen species provides a quantitative explanation for the reported enhancement in oxygen dissociation kinetics in the presence of H2O/CO2. This study thereby provides insights into oxygen exchange mechanisms on LSM surfaces. 2021-09-20T18:22:59Z 2021-09-20T18:22:59Z 2020-11-16T14:02:18Z Article http://purl.org/eprint/type/JournalArticle https://hdl.handle.net/1721.1/132550 en 10.1021/ACS.CHEMMATER.9B05243 Chemistry of Materials Creative Commons Attribution 4.0 International license https://creativecommons.org/licenses/by/4.0/ application/pdf American Chemical Society (ACS) ACS |
| spellingShingle | Yang, Jing Polfus, Jonathan M Li, Zuoan Tuller, Harry L Yildiz, Bilge Role of Adsorbate Coverage on the Oxygen Dissociation Rate on Sr-Doped LaMnO 3 Surfaces in the Presence of H 2 O and CO 2 |
| title | Role of Adsorbate Coverage on the Oxygen Dissociation Rate on Sr-Doped LaMnO 3 Surfaces in the Presence of H 2 O and CO 2 |
| title_full | Role of Adsorbate Coverage on the Oxygen Dissociation Rate on Sr-Doped LaMnO 3 Surfaces in the Presence of H 2 O and CO 2 |
| title_fullStr | Role of Adsorbate Coverage on the Oxygen Dissociation Rate on Sr-Doped LaMnO 3 Surfaces in the Presence of H 2 O and CO 2 |
| title_full_unstemmed | Role of Adsorbate Coverage on the Oxygen Dissociation Rate on Sr-Doped LaMnO 3 Surfaces in the Presence of H 2 O and CO 2 |
| title_short | Role of Adsorbate Coverage on the Oxygen Dissociation Rate on Sr-Doped LaMnO 3 Surfaces in the Presence of H 2 O and CO 2 |
| title_sort | role of adsorbate coverage on the oxygen dissociation rate on sr doped lamno 3 surfaces in the presence of h 2 o and co 2 |
| url | https://hdl.handle.net/1721.1/132550 |
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