Ionic liquid immobilized on mesocellular silica foam as an efficient heterogeneous catalyst for the synthesis of dimethyl carbonate via transesterification

Abstract

Functionalized basic ionic liquid, 1-(triethoxysilyl) propyl-3-methylimidazolium hydroxide ([SmIm]OH) was immobilized on the mesocellular silica foams (MCF) material and then applied in the catalytic synthesis of dimethyl carbonate (DMC) via transesterification of ethylene carbonate (EC) with methanol (MeOH). Combined characterization results of FT-IR, 29Si NMR, N2 adsorption–desorption, and TEM suggest that [SmIm]OH has been successfully grafted on the MCF material, and the three-dimensional mesoporosity with large pore size (∼34nm) of MCF has been well retained during the immobilization procedure. The influences of reaction temperature, time, and the molar ratio of MeOH/EC have also been investigated in detail. The catalytic tests demonstrated that MCF-[SmIm]OH could catalyze the transesterification of EC and MeOH with high efficiency, allowing a stable and high DMC yield as much as 83% under mild reaction conditions, superior to those results of the heterogeneous catalysts reported previously.