Cluster model study on the surface interactions of γ-alumina-supported metal oxides

Cluster models embodying the periodicity and symmetry of atomic arrangement on the surface of gamma-Al2O3, as a support, have been applied to discuss the dispersion state of metal oxide (i.e., MoO3, NiO, or CuO) on the basis of the incorporation model from the theoretical chemistry's point of view. The preference occupation of the tetrahedral or octahedral vacant sites available on the surface of gamma-Al2O3 by the dispersed metal cations is related to the intrinsic properties and the amount of the dispersed metal oxide as well as the calcination temperature used for sample preparation. The results are in good agreement with the experimental facts. (C) 1999 Elsevier Science B.V. All rights reserved.