复合氧化物LaMgAlO催化剂催化酯交换合成碳酸二丙酯

摘要

采用共沉淀法制备了复合氧化物LaMgAlO催化剂,采用XRD和DTA手段对催化剂进行了表征,并考察了LaMgA1O催化剂对丙醇与碳酸二甲酯(DMC)酯交换合成碳酸二丙酯(DPC)反应的性能.实验结果表明,当复合氧化物为n(La)∶n(Mg)∶n(Al) =0.7:3:1(即0.7 LaMgAlO催化剂具有水滑石结构)时,在650℃下焙烧5h制备的0.7 LaMgAlO催化剂对合成DPC的酯交换反应的活性最高；最佳的工艺条件为:反应温度90℃、n(丙醇)∶n(DMC)=3、催化剂用量3.0％(w)、反应时间6h,在此条件下,DMC的转化率达到97A％,DPC的选择性达到95.4％.%Composite oxides LaMgAlO with different La amount were prepared by co-precipitation and were characterized by means of XRD and DTA. The performances of the catalysts for synthesis of dipropyl carbonate(DPC) through transesterification of dimethyl carbonate(DMC) with n-propanol were investigated. The results indicated that when the molar ratio of La : Mg : Al was 0.7 : 3 : 1, the catalyst exhibited the highest catalytic activity. Under the optimum reaction conditions: 90 ℃, 6 h, n(n-propanol) : n(DMC) 3 and amount of the catalyst in the reactants 3.0%(w), the conversion of DMC and the selectivity to DPC reached 97.4% and 95.4%, respectively.