Density functional theory characterization of the formation of copper clusters on F-s and F-s(+) centers on a MgO surface

摘要

Electronic structure and chemical reactivity of Cu-n clusters (n = 1-4) supported on a regular site (O-5c) and on an oxygen vacancy (F-s and F-s(+)) of the MgO (100) surface were investigated using density functional theory. It was found that neutral oxygen vacancies, F-s centers, are good trapping sites for Cu atoms and nucleation centers while F-s(+) centers are not. Both, first ionization potential and the chemical reactivity present odd-even oscillations in the free and supported clusters, these oscillations are related to the electronic nature of the layer open/closed for clusters with odd and even n, respectively, this behavior is similar for supported clusters on an F. center compared with free clusters. It is also found that the ionization potential and the chemical reactivity are modified when the clusters are supported on the MgO vacancies. (c) 2006 Elsevier B.V. All rights reserved.