Catalytic performance of zinc containing ionic liquids immobilized on silica for the synthesis of cyclic carbonates

• Published in: Journal of industrial and engineering chemistry (Seoul, Korea) Vol. 20; no. 5; pp. 3102 - 3107
• Main Authors: Kim, Moon-Il, Choi, Soo-Jin, Kim, Dong-Woo, Park, Dae-Won
• Format: Journal Article
• Language: English
• Published: 한국공업화학회 25.09.2014
• Subjects: Bromides; Carbon dioxide; Carbonates; Catalysis; Catalysts; Halides; Ionic liquids; Zinc; 화학공학
• ISSN: 1226-086X; 1876-794X
• DOI: 10.1016/j.jiec.2013.11.051

Cycloaddition of carbon dioxide and epoxides was investigated using zinc halide based Lewis acidic ionic liquids (ILs) as catalysts. ILs such as 1-butyl-3-methylimidazolium bromide (BMImBr), 1-butylpyridinium bromide (BPyBr), tetra-n-butylammonium bromide (TBABr) were mixed with zinc halide and supported on silica gel to produce heterogeneous catalysts. Catalytic reaction tests demonstrated that the incorporation of zinc ions can significantly enhance the catalytic activity of the silica-supported ILs for the cycloaddition of CO sub(2) to epoxides in solvent-free conditions. BPyBr-ZnCl sub(2)/SiO sub(2) showed the highest propylene carbonate yield of 98% when the reaction was carried out with 0.5 g of catalyst at 120 degree C at 1.89 MPa of CO sub(2) pressure for 4 h. The immobilized zinc containing IL catalyst could be reused for at least four cycles without any considerable loss of its activity.