Abbreviated Journal Title
J. Chem. Phys.
Keywords
ELECTRONIC-STRUCTURE; MOLECULAR-DYNAMICS; CEO2; H2O; PRINCIPLES; CEO2(111); CHEMISTRY; DIOXIDE; SOLIDS; CO; Physics, Atomic, Molecular & Chemical
Abstract
We study the structure and energetics of water molecules adsorbed at ceria (111) surfaces for 0.5 and 1.0 ML coverages using density functional theory. The results of this study provide a theoretical framework for interpreting recent experimental results on the redox properties of water at ceria (111) surfaces. In particular, we have computed the structure and energetics of various absorption geometries at the stoichiometric ceria (111) surface. We find that single hydrogen bonds between the water and the oxide surface are favored in all cases. At stoichiometric surfaces, the water adsorption energy depends rather weakly on coverage. We predict that the observed coverage dependence of the water adsorption energy at stoichiometric surfaces is likely the result of dipole-dipole interactions between adsorbed water molecules. When oxygen vacancies are introduced in various surface layers, water molecules are attracted more strongly to the surface. We find that it is very slightly energetically favorable for adsorbed water to oxidized the reduced (111) surface with the evolution of H-2. In the event that water does not oxidize the surface, we predict that the effective attractive water-vacancy interaction will result in a significant enhancement of the vacancy concentration at the surface in agreement with experimental observations. Finally, we present our results in the context of recent experimental and theoretical studies of vacancy clustering at the (111) ceria surface.
Journal Title
Journal of Chemical Physics
Volume
125
Issue/Number
20
Publication Date
1-1-2006
Document Type
Article
DOI Link
Language
English
First Page
8
WOS Identifier
ISSN
0021-9606
Recommended Citation
Kumar, Santosh and Schelling, Patrick K., "Density functional theory study of water adsorption at reduced and stoichiometric ceria (111) surfaces" (2006). Faculty Bibliography 2000s. 6321.
https://stars.library.ucf.edu/facultybib2000/6321
Comments
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