The photo-assisted oxygen transfer to cyclohexene, cyclooctene and 1-octene was investigated using molecular O2 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.