Preparation and Performance of SAPO Molecular Sieve Solid-loaded Ionic Liquid Catalysts

The ionic liquids [BMIM]Br/(ZnBr2)2 and [HeMIM]Cl/(ZnBr2)2 were prepared by N-methylimidazole, haloalkanes and zinc bromide in a one-step method with stirring at 80℃ for 24 h. Then the ionic liquids were solidified onto the SAPO molecular sieve to prepare the solidified ionic liquid catalysts SAPO-[BMIM]Br/(ZnBr2)2and SAPO-[HeMIM]Cl/(ZnBr2)2. The structure of the solidified ionic liquid catalysts was investigated. The solidified ionic liquid catalysts were used to catalyze the synthesis of propylene carbonate with CO2 and propylene oxide. Meanwhile, the result show that synergistic catalytic effect between hydroxyl group of [HeMIM]Cl/(ZnBr2)2 and the SAPO molecular sieve was more favorable for the reaction and increased the conversion, product selectivity and yield of propylene oxide.