The properties of molybdena-alumina, molybdena-silica-alumina and molybdena-silica systems prepared by thermal spreading of MoO2(acac)(2) Complex were investigated with XRD and XPS. The activity of the catalysts in propene metathesis was measured for a wide range of Mo loadings. For the low Mo content, the specific activity of the molybdena-silica-alumina catalyst is much higher than for both other systems, while for the high Mo loadings, the molybdena-alumina catalyst exhibits the highest efficiency. (C) 2006 Elsevier B.V. All rights reserved.