Surface oxides of the oxygen–copper system: Precursors to the bulk oxide phase?

摘要: To gain an initial understanding of the copper-based catalysts in commercially important chemical reactions such as oxygenassisted water–gas shift reaction, we performed density-functional theory calculations, investigating interaction oxygen and copper, focusing on relative stability surface oxides oxide surfaces O/Cu system. By employing technique ‘‘ab initio atomistic thermodynamics’’, show that are only metastable at relevant pressures temperatures technical catalysis, with no stable chemisorption phase observed even very low coverage. Although exhibiting metastability, these resemble bulk material both geometrically electronically, may serve a precursor before onset phase. Having identified most under realistic catalytic conditions, Cu2O(1 1 1) Cu vacancies has lower free energy than stoichiometric for considered range potential could be catalytically relevant. � 2007 Elsevier B.V. All rights reserved.