Interplay between H₂O and CO₂ coadsorption and space-charge on Y-doped BaZrO₃ surfaces
The present work quantifies the equilibrium defect and adsorbate chemistry on oxide surfaces in the presence of multiple gas components at elevated temperatures and sub-surface space charge. The concentrations of chemisorbed H2O and CO2 as well as surface protons and oxygen vacancies were calculated...
| Main Authors: | , , |
|---|---|
| Other Authors: | |
| Format: | Article |
| Published: |
Royal Society of Chemistry (RSC)
2019
|
| Online Access: | http://hdl.handle.net/1721.1/120308 https://orcid.org/0000-0003-1855-0708 https://orcid.org/0000-0002-2688-5666 |
| _version_ | 1826206161131536384 |
|---|---|
| author | Yildiz, Bilge Polfus, Jonathan M Yang, Jing |
| author2 | Massachusetts Institute of Technology. Department of Materials Science and Engineering |
| author_facet | Massachusetts Institute of Technology. Department of Materials Science and Engineering Yildiz, Bilge Polfus, Jonathan M Yang, Jing |
| author_sort | Yildiz, Bilge |
| collection | MIT |
| description | The present work quantifies the equilibrium defect and adsorbate chemistry on oxide surfaces in the presence of multiple gas components at elevated temperatures and sub-surface space charge. The concentrations of chemisorbed H2O and CO2 as well as surface protons and oxygen vacancies were calculated for Y-doped BaZrO3 using a thermodynamic framework with input from first-principles calculations. The overall energy of the system was minimized based on contributions from gas adsorption, interactions between defects and adsorbates, segregation of point defects and space-charge formation, as well as configurational entropy. The coverage dependent adsorption energies were found as −1.44 + 0.34ΘH2O eV and −2.25 + 1.21ΘCO2 eV for chemisorption of H2O and CO2, respectively. The interaction between the adsorbates was found to follow 1.72ΘH2OΘCO2 eV. The coverage of surface protons was above 0.3 up to 1000 K under most considered conditions (0.01-1 bar H2O, 4 × 10−4-1 bar CO2) due to a favorable interaction with both surface hydroxide and CO2 adsorbates. Most importantly, the results show that the coadsorption, adsorbate interactions or space-charge formation each played a major role in the obtained defect concentrations and surface coverages. Thus, the approach in this work demonstrates the importance of considering quantitatively each of these aspects in obtaining accurately the surface equilibria on complex catalytic oxides. |
| first_indexed | 2024-09-23T13:25:03Z |
| format | Article |
| id | mit-1721.1/120308 |
| institution | Massachusetts Institute of Technology |
| last_indexed | 2024-09-23T13:25:03Z |
| publishDate | 2019 |
| publisher | Royal Society of Chemistry (RSC) |
| record_format | dspace |
| spelling | mit-1721.1/1203082022-10-01T15:09:11Z Interplay between H₂O and CO₂ coadsorption and space-charge on Y-doped BaZrO₃ surfaces Yildiz, Bilge Polfus, Jonathan M Yang, Jing Massachusetts Institute of Technology. Department of Materials Science and Engineering Massachusetts Institute of Technology. Department of Nuclear Science and Engineering Polfus, Jonathan M Yang, Jing Yildiz, Bilge The present work quantifies the equilibrium defect and adsorbate chemistry on oxide surfaces in the presence of multiple gas components at elevated temperatures and sub-surface space charge. The concentrations of chemisorbed H2O and CO2 as well as surface protons and oxygen vacancies were calculated for Y-doped BaZrO3 using a thermodynamic framework with input from first-principles calculations. The overall energy of the system was minimized based on contributions from gas adsorption, interactions between defects and adsorbates, segregation of point defects and space-charge formation, as well as configurational entropy. The coverage dependent adsorption energies were found as −1.44 + 0.34ΘH2O eV and −2.25 + 1.21ΘCO2 eV for chemisorption of H2O and CO2, respectively. The interaction between the adsorbates was found to follow 1.72ΘH2OΘCO2 eV. The coverage of surface protons was above 0.3 up to 1000 K under most considered conditions (0.01-1 bar H2O, 4 × 10−4-1 bar CO2) due to a favorable interaction with both surface hydroxide and CO2 adsorbates. Most importantly, the results show that the coadsorption, adsorbate interactions or space-charge formation each played a major role in the obtained defect concentrations and surface coverages. Thus, the approach in this work demonstrates the importance of considering quantitatively each of these aspects in obtaining accurately the surface equilibria on complex catalytic oxides. Norwegian Research Council (through the FOXCET project (Nano2021, 228355) Norwegian CCS Research Centre (NCCS, 257579) Norwegian Research Council. National infrastructure for high-performance computing (project nn9259k) United States. Department of Energy. Consortium for Advanced Simulation of Light Water Reactors (U.S. Department of Energy Contract No. DE-AC05-00OR22725) 2019-02-11T13:40:16Z 2019-02-11T13:40:16Z 2018-11 2018-10 2019-01-16T17:59:51Z Article http://purl.org/eprint/type/JournalArticle 2050-7488 2050-7496 http://hdl.handle.net/1721.1/120308 Polfus, Jonathan M., Jing Yang, and Bilge Yildiz. “Interplay Between H2O and CO2 Coadsorption and Space-Charge on Y-Doped BaZrO3 Surfaces.” Journal of Materials Chemistry A 6, no. 48 (2018): 24823–24830. https://orcid.org/0000-0003-1855-0708 https://orcid.org/0000-0002-2688-5666 http://dx.doi.org/10.1039/c8ta09491h Journal of Materials Chemistry A Creative Commons Attribution 4.0 International license https://creativecommons.org/licenses/by/4.0/ application/pdf Royal Society of Chemistry (RSC) Royal Society of Chemistry (RSC) |
| spellingShingle | Yildiz, Bilge Polfus, Jonathan M Yang, Jing Interplay between H₂O and CO₂ coadsorption and space-charge on Y-doped BaZrO₃ surfaces |
| title | Interplay between H₂O and CO₂ coadsorption and space-charge on Y-doped BaZrO₃ surfaces |
| title_full | Interplay between H₂O and CO₂ coadsorption and space-charge on Y-doped BaZrO₃ surfaces |
| title_fullStr | Interplay between H₂O and CO₂ coadsorption and space-charge on Y-doped BaZrO₃ surfaces |
| title_full_unstemmed | Interplay between H₂O and CO₂ coadsorption and space-charge on Y-doped BaZrO₃ surfaces |
| title_short | Interplay between H₂O and CO₂ coadsorption and space-charge on Y-doped BaZrO₃ surfaces |
| title_sort | interplay between h₂o and co₂ coadsorption and space charge on y doped bazro₃ surfaces |
| url | http://hdl.handle.net/1721.1/120308 https://orcid.org/0000-0003-1855-0708 https://orcid.org/0000-0002-2688-5666 |
| work_keys_str_mv | AT yildizbilge interplaybetweenh2oandco2coadsorptionandspacechargeonydopedbazro3surfaces AT polfusjonathanm interplaybetweenh2oandco2coadsorptionandspacechargeonydopedbazro3surfaces AT yangjing interplaybetweenh2oandco2coadsorptionandspacechargeonydopedbazro3surfaces |