摘要
分别采用物理研磨、浸渍和共沉淀3种方法制备了负载型固体碱MgO/ZrO2催化剂,并将其用于催化碳酸二甲酯与异辛醇的酯交换反应合成碳酸二异辛酯。结果表明,催化剂的活性在焙烧温度为973 K时达到最佳,合成产物的收率分别为67.00%,51.00%,59.93%。催化剂的X射线衍射、CO2程序升温脱附、FTIR表征表明,催化剂的活性及稳定性取决于MgO/ZrO2的结构。四方氧化锆晶相对催化活性有积极的影响,当单斜氧化锆晶相明显时,催化活性显著下降。用物理研磨法制备的催化剂,由于MgO均匀分散于载体表面而使其显示高催化活性。用共沉淀法制备的催化剂,由于Mg2+进入Zr4+的晶格形成MgO/ZrO2固溶体结构,使其显示了高的稳定性和活性。
MgO/ZrO2 catalysts,developed for the synthesis of 2-ethyl-hexanol carbonate from dimethyl carbonate and 2-ethyl-hexanol were prepared by physical mixing, impregnation and coprecipitation methods. It was found that the performance of the reaction was greatly dependent on the calcination temperature. The activity of catalysts all reached to a peak value when the calcination temperature was 973K and the conversion reached 67.00% ,51.00% and 59. 93% respectively. XRD,CO2-TPD and FTIR measurements of the catalysts revealed that both catalytic stability and activity were strongly influenced by the structure of MgO/ZrO2. Tetragonal zirconia phase has a favorable effect on catalytic activity. The activity of reaction decrease when the monoclinic zirconia phase is predominant. High catalytic activity of MgO/ZrO2 catalyst prepared by physical mixing method is due to the fact that MgO is evenly dispersed on the surface of the carrier. Mg2＋ ion substitute for Zr4 ＋ ion in the host lattice to form homogeneous MgO/ZrO2 solid solution, which leads to the strong interaction between MgO and ZrO2 resulting to high stability and activity.
出处
《精细化工》
EI
CAS
CSCD
北大核心
2009年第2期166-169,共4页
Fine Chemicals
关键词
制备方法
MgO/ZrO2
酯交换
碳酸二异辛酯
preparation method
MgO／ZrO2
dimcthyl carbonate
transesterification
di-2-ethylhexyl carbonate
