磁性氧化石墨烯负载离子液体催化碳酸二甲酯的合成

Synthesis of dimethyl carbonate catalyzed by magnetic graphene oxide supported ionic liquid

通过共价键接枝法制备以磁性氧化石墨烯为载体、咪唑盐型碱性离子液体为活性中心的负载型催化剂Fe3O4/GO-[bSIm]OH。通过FT-IR、TGA、XRD等手段对样品进行表征,考察了催化剂质量、原料摩尔比、反应时间、反应温度等条件对甲醇和碳酸乙烯酯合成碳酸二甲酯的酯交换反应的影响。实验结果表明,催化剂质量为0. 1 g、反应温度为90℃、n(Me OH)∶n(EC)=10∶1、反应时间为3 h时,DMC的收率达到95%,选择性达到99%。通过外部磁场将催化剂从反应体系中分离,重复使用5次后,催化剂仍能保持良好的催化活性。

Graphene oxide immobilized imidazolium-type basic ionic liquid(Fe3 O4/GO-[b SIm]OH)is prepared through covalent binding method.The properties of the catalyst are verified by means of FT-IR,TGA and XRD.It is evaluated in the transesterification of ethylene carbonate with methanol to generate dimethyl carbonate(DMC).Reaction conditions including reaction time,reaction temperature,molar ratio of MeOH∶EC and catalyst dosage are investigated.Under optimum reaction conditions,i.e.,5 h,90℃,molar ratio of MeOH to EC at 10∶1 and 0.1 g catalyst,the yield and selectivity to DMC reaches 95%and 99%,respectively.Furthermore,this catalyst can be simply separated from the system by an external magnet,and remains stable catalytic activity after recycled at least for 5 runs.