To obtain insight into the structure and surface stoichiometry of copper-based catalysts in commercially important chemical reactions such as the oxygen-assisted water-gas shift reaction, we perform density-functional theory calculations to investigate the relative stability of low-index copper oxide surfaces. By employing the technique of "ab initio atomistic thermodynamics," we identify low-energy surface structures that are most stable under realistic catalytic conditions are found to exhibit a metallic character. Three surfaces are shown to have notably lower surface free energies compared to the others considered and could be catalytically relevant; in particular, under oxygen-rich conditions, they are the Cu2 O (110): CuO surface, which is terminated with both Cu and O surface atoms, and the Cu2 O (111) - CuCUS surface, which contains a surface (coordinatively unsaturated) Cu vacancy, while for the oxygen-lean conditions, the Cu2 O (111) surface with a surface interstitial Cu atom is found to be energetically most favorable, highlighting the importance of defects at the surface.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - 2007 Mar 21|
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics