Ordered Mesoporous Carbon CMK-3 Immobilized with Ionic Liquids as Efficient Catalysts for the Synthesis of Cyclic Carbonates from CO2 and Epoxides

Abstract

CMK-3-IL heterogeneous catalysts were synthesized using ordered mesoporous carbons CMK-3 as the support to immobilize imidazoles ionic liquids and applied to the synthesis of cyclic carbonate. The catalyst samples were characterized by X-ray powder diffraction( XRD),nitrogen adsorption-desorption,transmission electron microscopy( TEM),thermogravimetric analysis( TGA) and elemental analysis. The results show that the ionic liquids are grafted on the surface of the CMK-3 and the resultant hybrid materials retains mesoporous structure after immobilization. The nitrogen adsorption results indicate that pore volume,pore diameter and surface area of CMK-3-IL are slightly reduced. CMK-3-IL shows much higher catalytic activity. A 64% conversion of propylene oxide and a 99% selectivity of propylene carbonate can be achieved when the catalytic reaction is carried out at 120 ℃ under 2 MPa for 6 h.