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First principles insights on CO adsorption on metal surfaces
Density functional theory (DFT) has been regularly exploited for meticulous studying of complex surface interactions at a molecular orbital scale. However, DFT calculations usually yield inaccurate thermodynamics results that contradict experimental findings. A clear example is the CO adsorption puz...
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2019
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| _version_ | 1867613410663858176 |
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| access_status_str | Open Access |
| author | Gameel, Kareem |
| author_browse | Gameel, Kareem |
| author_facet | Gameel, Kareem |
| author_sort | Gameel, Kareem |
| collection | Thesis |
| dc_rights_str_mv | The author retains all rights with regard to copyright. The author certifies that written permission from the owner(s) of third-party copyrighted matter included in the thesis, dissertation, paper, or record of study has been obtained. The author further certifies that IRB approval has been obtained for this thesis, or that IRB approval is not necessary for this thesis. Insofar as this thesis, dissertation, paper, or record of study is an educational record as defined in the Family Educational Rights and Privacy Act (FERPA) (20 USC 1232g), the author has granted consent to disclosure of it to anyone who requests a copy. |
| description | Density functional theory (DFT) has been regularly exploited for meticulous studying of complex surface interactions at a molecular orbital scale. However, DFT calculations usually yield inaccurate thermodynamics results that contradict experimental findings. A clear example is the CO adsorption puzzle caused by the wrong estimation of adsorption sites, especially for the (111) transition metal surfaces. The puzzle is still not fully resolved and a complete adsorption picture is yet to be reported. Herein, we demonstrate the reliability of DFT calculations for the study of local bond properties, despite the wrong energetics predictions. We also highlight the importance of considering a comprehensive analysis of all the possible adsorption sites over distinctive surface facets. Each surface facet, with its unique arrangement of atoms, results in a varying adsorbate behavior, although the same adsorption site is studied. Investigating these variations gives insights about the influence of surface atomic arrangement on the orbitals' interactions. Within the investigation, it is found that the varying density of orbitals, with the matching symmetry for interaction at different adsorption sites, affects the magnitude of orbital interaction, and thus, acts as an additional factor for determining the site preference. Based on the frontier (5σ and 2π*) orbital energy description, calculated using RPBE functional, new perceptions to the understanding of the adsorption puzzle have been exposed. In addition, we emphasize the significance of considering a holistic analysis of adsorbate orbitals, not only limited to the main CO frontier orbitals. This approach leads to a better understanding of the surface bonding and CO final structure. This investigation can help in providing guidelines for innovating design principles for materials, based on the required adsorbate behavior and charge transport phenomena, to be used for catalysis and sensors applications. |
| format | Thesis |
| id | oai:fount.aucegypt.edu:etds-1537 |
| institution | American University in Cairo (Egypt) |
| last_indexed | 2026-06-10T12:35:42.290Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from AUC Knowledge Fountain — bepress |
| publishDate | 2019 |
| publishDateRange | 2019 |
| publishDateSort | 2019 |
| publisher | AUC Knowledge Fountain |
| publisherStr | AUC Knowledge Fountain |
| record_format | dspace |
| source_str | AUC Knowledge Fountain — bepress |
| spelling | oai:fount.aucegypt.edu:etds-1537 First principles insights on CO adsorption on metal surfaces Gameel, Kareem Density functional theory (DFT) has been regularly exploited for meticulous studying of complex surface interactions at a molecular orbital scale. However, DFT calculations usually yield inaccurate thermodynamics results that contradict experimental findings. A clear example is the CO adsorption puzzle caused by the wrong estimation of adsorption sites, especially for the (111) transition metal surfaces. The puzzle is still not fully resolved and a complete adsorption picture is yet to be reported. Herein, we demonstrate the reliability of DFT calculations for the study of local bond properties, despite the wrong energetics predictions. We also highlight the importance of considering a comprehensive analysis of all the possible adsorption sites over distinctive surface facets. Each surface facet, with its unique arrangement of atoms, results in a varying adsorbate behavior, although the same adsorption site is studied. Investigating these variations gives insights about the influence of surface atomic arrangement on the orbitals' interactions. Within the investigation, it is found that the varying density of orbitals, with the matching symmetry for interaction at different adsorption sites, affects the magnitude of orbital interaction, and thus, acts as an additional factor for determining the site preference. Based on the frontier (5σ and 2π*) orbital energy description, calculated using RPBE functional, new perceptions to the understanding of the adsorption puzzle have been exposed. In addition, we emphasize the significance of considering a holistic analysis of adsorbate orbitals, not only limited to the main CO frontier orbitals. This approach leads to a better understanding of the surface bonding and CO final structure. This investigation can help in providing guidelines for innovating design principles for materials, based on the required adsorbate behavior and charge transport phenomena, to be used for catalysis and sensors applications. 2019-02-01T08:00:00Z thesis application/pdf https://fount.aucegypt.edu/etds/538 https://fount.aucegypt.edu/context/etds/article/1537/viewcontent/THESIS.pdf The author retains all rights with regard to copyright. The author certifies that written permission from the owner(s) of third-party copyrighted matter included in the thesis, dissertation, paper, or record of study has been obtained. The author further certifies that IRB approval has been obtained for this thesis, or that IRB approval is not necessary for this thesis. Insofar as this thesis, dissertation, paper, or record of study is an educational record as defined in the Family Educational Rights and Privacy Act (FERPA) (20 USC 1232g), the author has granted consent to disclosure of it to anyone who requests a copy. Theses and Dissertations AUC Knowledge Fountain Density Functional Theory DFT |
| spellingShingle | Density Functional Theory DFT Gameel, Kareem First principles insights on CO adsorption on metal surfaces |
| title | First principles insights on CO adsorption on metal surfaces |
| title_full | First principles insights on CO adsorption on metal surfaces |
| title_fullStr | First principles insights on CO adsorption on metal surfaces |
| title_full_unstemmed | First principles insights on CO adsorption on metal surfaces |
| title_short | First principles insights on CO adsorption on metal surfaces |
| title_sort | first principles insights on co adsorption on metal surfaces |
| topic | Density Functional Theory DFT |
| url | https://fount.aucegypt.edu/etds/538 https://fount.aucegypt.edu/context/etds/article/1537/viewcontent/THESIS.pdf |
| work_keys_str_mv | AT gameelkareem firstprinciplesinsightsoncoadsorptiononmetalsurfaces |