ZnO-Fe2O3 catalysts were prepared by thermal decomposition of layered double hydroxides containing zinc and iron within the brucite-like layers and carbonate as the interlayer anion, then the hydrotalcite precursor and mixed oxides were characterized by ICP, XRD and N2 adsorption/desorption techniques. XRD patterns showed that both ZnO and ZnFe2O4 phases appeared for the mixed oxides and their proportion and crystalline degrees depended on the heat treatment temperature. Furthermore, these mixed oxides were tested for the diethyl carbonate (DEC) synthesis from ethyl carbamate and ethanol. More important, the DEC yield could reach to about 32.3% in the bacth reactor under the optimal reactions.

An ionic liquid 1- (triethoxysilyl) propyl-3-methylimidazolium hydroxide ([Smim]OH) was grafted on three kinds of mesoporous hydrophobic silica gel by means of post-grafting under mild conditions. The catalysts were [Smim]OH/SiO2-MTES (methyltriethoxysilane), [Smim]OH/SiO2-TMCS (trimethylchlorosilane), [Smim]OH/SiO2-CPTEO (triethoxysilyl propyl chloride). Such grafted ionic liquids (GILs), which were characterized by means of FTIR and N2 adsorption-desorption could be used as effective heterogeneous catalysts toward propylene carbonate synthesis through cycloaddition of carbon dioxide with propylene oxide under solventless and mild conditions.

An ionic liquid 1-butyl-3-methylimidazolium hydroxide ([Bmim]OH) was grafted on silica gel by post-grafting method. Such grafted ionic liquids (GILs) which were verified by means of FTIR, element analysis N2adsorption-desorption and TG could be used as highly effective heterogeneous catalysts toward propylene carbonate synthesis through cycloaddition of carbon dioxide with propylene oxide under solventless and mild conditions.