We have demonstrated that a heterogeneous catalyst system of $WO_3/MCM-48$ can act as an efficient catalyst for the epoxidation of olefins, the Baeyer-Villiger oxidation of cyclic ketones, and the selective oxidation of sulfides with the use of $H_2O_2$ or peracetic acid as an oxidant under mild conditions. We have observed that support materials have significant effects on the efficiency of the immobilized tungsten nanoparticles. The catalyst can be recovered easily and reused for the oxidations examined, and the process is readily scaled up to gram scales without giving any practical difficulties. In addition, the selectivity for the formation of epoxides, lactones, and sulfoxides over diols or other over oxidized adducts was significantly high.