Oxygen adsorption on Ag(111): A density-functional theory investigation
- 16 January 2002
- journal article
- research article
- Published by American Physical Society (APS) in Physical Review B
- Vol. 65 (7), 075407
- https://doi.org/10.1103/physrevb.65.075407
Abstract
The oxygen/silver system exhibits unique catalytic behavior for several large-scale oxidation (and partial oxidation) industrial processes. In spite of its importance, very little is known on the microscopic level concerning the atomic geometry and chemical nature of the various O species that form. Using density-functional theory within the generalized gradient approximation, the interaction between atomic oxygen and the Ag(111) surface is investigated. We consider, for a wide range of coverages, on-surface adsorption as well as surface-substitutional adsorption. The on-surface fcc-hollow site is energetically preferred for the whole coverage range considered. A significant repulsive interaction between adatoms is identified, and on-surface adsorption becomes energetically unstable for coverages greater than about 0.5 monolayer (ML) with respect to gas-phase The notable repulsion even at these lower coverages causes O to adsorb in subsurface sites for coverages greater than about 0.25 ML. The O-Ag interaction results in the formation of bonding and antibonding states between Ag and O orbitals where the antibonding states are largely occupied, explaining the found relatively weak adsorption energy. Surface-substitutional adsorption initially exhibits a repulsive interaction between O atoms, but for higher coverages switches to attractive, towards a structure. Scanning tunneling microscopy simulations for this latter structure show good agreement with those obtained from experiment after high-temperature and high--gas-pressure treatments. We also discuss the effect of strain and the found marked dependence of the adsorption energy on it, which is different for different kinds of sites.
Keywords
This publication has 76 references indexed in Scilit:
- Oxygen adsorption on the Ag(111) surface: a quantum chemical study by the NDDO/MC methodJournal of Molecular Catalysis A: Chemical, 2000
- Structural and electronic properties of chemisorbed oxygen on Rh(111)Physical Review B, 1999
- High density adsorbed oxygen on Rh(111) and enhanced routes to metallic oxidation using atomic oxygenThe Journal of Chemical Physics, 1999
- Innovative computing and detailed properties of elementary reactions using time independent approachesComputer Physics Communications, 1999
- Density-functional theory calculations for poly-atomic systems: electronic structure, static and elastic properties and ab initio molecular dynamicsComputer Physics Communications, 1997
- Density functional study of atomic nitrogen and oxygen chemisorption on model clusters simulating the Cu and Ag (100) surfacesJournal of Molecular Catalysis A: Chemical, 1997
- Dipped adcluster model for chemisorption and catalytic reactionsProgress in Surface Science, 1997
- On the relation between catalytic performance and microstructure of polycrystalline silver in the partial oxidation of methanolCatalysis Letters, 1995
- Self-interaction correction to density-functional approximations for many-electron systemsPhysical Review B, 1981
- Electronegativity values from thermochemical dataJournal of Inorganic and Nuclear Chemistry, 1961