Molybdenum complex tethered to the surface of activated carbon as a new recoverable catalyst for the epoxidation of olefins

A new recoverable catalyst for the epoxidation of olefins was developed by covalent attachment of aminopropyl groups on the surface of oxidized activated carbon (AC) and next reaction with bis(acetylacetonato)dioxomolybdenum(VI). Characterization of the prepared catalyst was performed with different physicochemical methods such as Fourier transform infrared and atomic absorption spectroscopies, scanning electron microscopy, energy-dispersive X-ray and nitrogen sorption analyses. Nitrogen adsorption-desorption analysis revealed that the textural characteristics of the support were changed during the grafting experiments but the channels remained relatively accessible despite sequential reduction in surface area, pore volume and pore size. Elemental analysis showed the presence of 0.06 mmol g(-1) molybdenum in the catalyst. The prepared catalyst catalyzed the epoxidation of olefins and allyl alcohols with tert-butyl hydroperoxide (TBHP) and cumene hydroperoxide (CHP) quantitatively with excellent selectivity toward the corresponding epoxides under mild reaction conditions. The results indicated that the hydrophobicity of the AC support promoted the catalytic efficiency of the catalyst in the epoxidation of olefins. (C) 2014 Elsevier B.V. All rights reserved.