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Ionic liquids (ILs) immobilized onto a structurally modified Merrifield peptide resin (MPR) were prepared through the reaction of imidazole with alkoxylated MPR. Elemental analysis and scanning electron microscopy (SEM) observations showed that the immobilized IL groups were effectively incorporated on the support. The MPR-supported ILs (MPR-ILs) proved to be effective heterogeneous catalysts for the synthesis of glycerol carbonate (GC) from glycerol and urea. MPR-ILs with longer alkyl chain linkers and fewer sterically hindered counteranions resulted in higher conversion of glycerol. High temperature, high degree of vacuum and the presence of zinc oxide co-catalyst were favorable for glycerol conversion. The MPR-ILs could be reused in up to three consecutive runs without significant loss of their catalytic activity.

A variety of imidazolium-based ionic liquids (ILs) have been widely developed to effectively catalyze the cycloaddition reactions of CO 2 and epoxides. To further improve the catalytic performance of those IL catalysts, we incorporated various metal chlorides (CoCl 2 , NiCl 2 , CuCl 2 , ZnCl 2 , and MnCl 2 ) into silica-grafted 1-methyl-3-[(triethoxysilyl)propyl] imidazolium chloride to produce a series of heterogeneous catalysts. Catalytic reaction tests demonstrated that the incorporation of such metal ions can significantly enhance the catalytic reactivity of the silica-grafted ILs towards cycloaddition reactions of CO 2 and epoxides that produce cyclic carbonates in solvent-free conditions. In addition, the effects on the catalytic reactivity of reaction parameters including reaction time, reaction temperature and CO 2 pressure were investigated.

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