The photo-assisted oxygen transfer to cyclohexene, cyclooctene and 1-octene was investigated using molecular O-2 as a primary oxidant with a dichloro-dioxo-(4,4'-dicarboxylato-2,2'-bipyridine) molybdenum((VI)) complex grafted on the surface of mesoporous TiO2 supports exhibiting different textural properties. Such mesoporous titania samples were prepared following a hydrothermal treatment (HT) and through an original procedure under supercritical CO2 (SC) conditions. Non porous TiO2 Degussa P-25 was also used for comparison purposes. The porosity of the titania supports, as well as the amount and dispersion of the covalently anchored dioxo Mo-(VI) complex were shown to strongly influence the resulting photo-catalytic properties. A particular attention was also devoted to the stability of the grafted catalysts by performing long-term epoxidation experiments. The new hybrid Mo-(VI)-derivatized mesoporous SC TiO2 catalyst proved to be the most efficient in the photo-assisted oxygen transfer to various alkenes. Additionally, the high stability of such catalyst was ascertained by recycling studies. (C) 2016 Elsevier B.V. All rights reserved.