Oxygen adsorption and stability of surface oxides on: A first-principles investigation
- 28 April 2006
- journal article
- research article
- Published by American Physical Society (APS) in Physical Review B
- Vol. 73 (16), 165424
- https://doi.org/10.1103/physrevb.73.165424
Abstract
As a first step towards gaining microscopic understanding of copper-based catalysts, e.g., for the low-temperature water-gas shift reaction and methanol oxidation reactions, we present density-functional theory calculations investigating the chemisorption of oxygen, and the stability of surface oxides on . We report atomic geometries, binding energies, and electronic properties for a wide range of oxygen coverages, in addition to the properties of bulk copper oxide. Through calculation of the Gibbs free energy, taking into account the temperature and pressure via the oxygen chemical potential, we obtain the phase diagram of . Our results show that for the conditions typical of technical catalysis the bulk oxide is thermodynamically most stable. If, however, formation of this fully oxidized surface is prevented due to a kinetic hindering, a thin surface-oxide structure is found to be energetically preferred compared to chemisorbed oxygen on the surface, even at very low coverage. Similarly to the late transition metals (Ru, Rh, Pd, Ag), sub-surface oxygen is found to be energetically unfavorable.
Keywords
This publication has 54 references indexed in Scilit:
- Surface processes and phase transitions from ab initio atomistic thermodynamics and statistical mechanicsCatalysis Today, 2005
- Fundamentals of Methanol Synthesis and DecompositionTopics in Catalysis, 2003
- Catalysis and corrosion: the theoretical surface-science contextSurface Science, 2002
- Adsorption and dissociation of O2 on Cu(Surface Science, 2001
- Adsorption of oxygen on (100), (110) and (111) surfaces of Ag, Cu and Ni: An electron spectroscopic studySurface Science, 1990
- Reconstruction and relaxation of the oxygen-covered Cu(111) surface: A sexafs studySurface Science, 1988
- The interaction of oxygen with Cu(111): Adsorption, incorporation and reconstructionSurface Science, 1986
- Surface reconstruction of Cu (111) upon oxygen adsorptionSurface Science, 1983
- The adsorption of oxygen on copper surfaces: II. Cu(111)Surface Science, 1982
- Untersuchung von oberflächenreaktionen mittels beugung langsamer elektronen (LEED): I. Wechselwirkung von O2 und N2O mit (110)-, (111)- und (100)-Kupfer-OberflächenSurface Science, 1967