大孔MgO/ZrO_2固体碱的制备及催化性能  

Preparation and Catalytic Property of Macroporous MgO/ZrO_2 Composite Catalyst

作　　者：尹锡俊[1] 龙能兵[1] 张祥洲[1] 侯琳熙[1] 

机构地区：[1]宁波大学材料科学与化学工程学院,宁波315211

出　　处：《无机化学学报》2013年第4期739-746,共8页Chinese Journal of Inorganic Chemistry

基　　金：浙江省教育厅2012年度科研计划项目(No.Y201223742);宁波大学王宽诚幸福基金资助项目

摘　　要：以多孔聚合物为整体型模板,利用锆酸四丁酯原位水解并结合高温烧结的方法制备出大孔ZrO2载体,通过Mg(NO3)2溶液浸渍、高温煅烧制备出大孔MgO/ZrO2复合材料。SEM、FTIR、XRD、TG-DSC表征发现ZrO2载体是由三维连续的纳米薄层构成的大孔材料,MgO以纳米颗粒形式沉积在ZrO2的三维超薄层上。进一步通过CO2-TPD手段发现该ZrO2表面具有弱碱性位,MgO的负载显著增加了复合物的碱性。以碳酸二甲酯和异辛醇酯交换合成碳酸二异辛酯为探针反应,考察焙烧温度及活性组分负载量等制备条件对大孔MgO/ZrO2固体碱催化活性的影响。结果表明,该催化剂对碳酸二异辛酯的合成具有较好的催化活性,当焙烧温度为600℃,MgO含量为50%时目标产物的产率可高达到65%。A macroporous ZrO2 support was prepared by using a three-dimensional （3D） skeletal polymer through an in situ hydrolysis of Zirconium butoxide and a subsequent calcination at high temperature. Macroprocous MgO/ ZrO2 composites were prepared by impregnation, calcination of magnesium nitrate solution. The composite materials were characterized by SEM, FTIR, XRD, TG-DSC. The results show that the macroporous zirconia supports have 3D ultrathin layer and the MgO nanoparticles cover on the 3D zirconia layer. The CO2-TPD curves indicate that the surface of zirconia supports has some weak alkaline sites and the sedimentation of MgO on the composite increases its alkalinity. The effect of preparation conditions on the catalytic activity was studied by using the transesterification of di-2-ethyl-hexyl carbonate from dimethyl carbonate and 2-ethyl-hexanol as the probe reaction. The results show that the macroporous MgO/ZrO2 solid base catalyst exhibits a better activity of transesterification. A better yield of the target product （65%） is obtained when the content of MgO is 50% and the calcination temperature is 600 ℃.

关 键 词：固体碱 二氧化锆载体 氧化镁 碳酸二异辛酯 大孔材料 

分 类 号：O643.3[理学—物理化学] O621.25[理学—化学]