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dc.contributor.advisor Allam, Nageh Gameel, Kareem 2018-09-10T08:23:30Z 2018-12-09T22:00:21Z Summer 2018 en_US 2018-09-10
dc.description.abstract 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. en_US
dc.description.sponsorship This work would have never been presented before the reader without the support and funding I was given by the American University in Cairo, which provided the educational and research atmospheres required for excelling in the field of physics. I am grateful for the great professors who assisted in building the necessary theoretical knowledge that constitutes the foundation of a genuine scientist. On the research side, I am sincerely grateful for working with a top-quality professor like Prof. Nageh Allam, as my thesis advisor. From day one, he provided guidance with sincere care, while building strong work ethics and research skills. Dr. Nageh’s availability never ceased to stop 24 hours and throughout the whole week including weekends and holidays; indeed, he is a one pronounced example for dedication and devotion for science and research, and for building a powerful research generation of successful leaders who can survive and even excel in their fields at the most harsh and stressful environments. I would also like to acknowledge the generous support I received from Prof. Mohammad Shakre, who provided valuable and meticulous comments on my thesis work within a very short period of time. I would also like to acknowledge the support I got from my team-mates at the Energy Materials Laboratory (EML). I am particularly grateful for having the chance to collaborate with the theoretical sub-group of the EML in the learning and publishing processes. Moreover, I would like to express my sincere gratitude to my cheering wife (Nadine) for her loving support. Finally, I would like to express my gratefulness for my family, particularly my father, who implanted the love of science in me and to whom I appreciatively dedicate this work. en_US
dc.format.extent 127 p. en_US
dc.format.medium theses en_US
dc.language.iso en en_US
dc.rights Author retains all rights with regard to copyright. en
dc.subject Density Functional Theory en_US
dc.subject DFT en_US
dc.subject Adsorption en_US
dc.subject Surface Chemistry en_US
dc.subject Surface en_US
dc.subject Catalysis en_US
dc.subject Carbon Monoxide en_US
dc.subject Molecular Orbital Theory en_US
dc.subject Sensors en_US
dc.subject First Principles en_US
dc.subject Theoretical Chemistry en_US
dc.subject.lcsh Thesis (M.S.)--American University in Cairo en_US
dc.title First principles insights on CO adsorption on metal surfaces en_US
dc.type Text en_US
dc.subject.discipline Physics en_US
dc.rights.access This item is restricted for 3 months from the date issued en_US
dc.contributor.department American University in Cairo. Dept. of Physics en_US
dc.description.irb American University in Cairo Institutional Review Board approval is not necessary for this item, since the research is not concerned with living human beings or bodily tissue samples. en_US
dc.contributor.committeeMember Elshakre, Mohamed
dc.contributor.committeeMember Awad, Adel
dc.contributor.committeeMember Alfiky, Mohamed

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  • Theses and Dissertations [1702]
    This collection includes theses and dissertations authored by American University in Cairo graduate students.

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