Composite Ionic Liquids Immobilized on MCM 22 as Efficient Catalysts for the Cycloaddition Reaction with CO2 and Propylene Oxide
Ionic liquids (ILs) have shown predominant catalytic activity in the field of catalytic conversion of CO2. Unfortunately, ILs catalysts can be only used in kettle catalysis as homogeneous systems, which suffered from the difficulty in product purification and catalysts recycling so affect their industrial application. In this work, a series of composite ILs were prepared by functionalized imidazolium ILs and lewis acid (ZnBr2) Then composite ILs immobilized on molecular sieve (MCM 22) with chemical bonding to obtain heterogeneous catalysts applied in the reaction of propylene oxide and carbon dioxide to synthesize propylene carbonate. The effects of catalytic temperature, pressure and cycle times on the conversion and yield were studied. The results showed that the optimal catalyst was MCM 22 [CeMIM]Cl/(ZnBr2)2, when the catalytic temperature is 120 degC, the pressure is 2.5 MPa and the dosage of catalyst is 2.0% the conversion rate is 100% and selectivity is 97.4%.Graphical Abstract
Catalysis Letters