Superiority of Activated Carbon versus MCM-41 for the Immobilization of Molybdenum Dithiocarbamate Complex as Heterogeneous Epoxidation Catalyst

Two heterogeneous catalysts were developed by covalent anchoring of molybdenum-dithiocarbamate complex onto the mesoporous silica (MCM-41) and activated carbon (AC). Characterization of the functionalized materials by various physicochemical techniques indicated that the molybdenum complex is grafted successfully on the surface of supports. Textural properties of the prepared catalysts proved that the surface properties of supports have been changed after grafting of molybdenum-dithiocarbamate complex. These heterogeneous catalysts were utilized for the epoxidation of olefins with tertbutyl hydroperoxide (TBHP) as oxidant, presenting high efficiency and facile recovery. These catalysts can be reused five times without apparent loss of their catalytic performance. Also, the effect of the nature of MCM-41 and AC supports on the catalytic activity has been discussed based on their hydrophobic and hydrophilic character.