Direct Oxidative Carboxylation of Styrene to Styrene Carbonate over Cobalt-containing Mesoporous Molecular Sieves（Co-MCM-41） and Tetrabutylammonium Bromide Co-catalysts

Abstract

Synthesis of cyclic carbonate from styrene and CO2gives a simple route that avoids the preliminary synthesis and isolation of epoxides. This direct synthesis route for cyclic carbonate from olefin is not only energy saving but also simple and economical. Herein,we synthesized various metal-dopped MCM-41 such as M-MCM-41( M = Co,Fe,Ni,Cu,Ti),and Co-MCM-41 catalyst showed the highest selectivity and yield to styrene epoxide among the various catalysts in the epoxidation of styrene. Then Co-MCM-41 was chosen to combine with tetrabutylammonium bromide( TBAB) to catalyze the direct oxidative carboxylation in one-pot. It was found that the Co-MCM-41 / TBAB catalysts efficiently catalyzed the direct oxidative carboxylation of styrene to styrene carbonate. An improved styrene carbonate yield of 46. 1% was obtained under mild reaction conditions of 80 ℃,7 h,and 4 MPa CO2pressure. It was found that Co-MCM-41 catalyzed the first epoxidation reaction and TBAB catalyzed the second cycloaddition reaction of CO2.