K_2O-MgO/Al_2O_3的制备及其在丙酮缩合中的应用  

Preparation and Application of K_2O-MgO/Al_2O_3 in Acetone Condensation

作　　者：苑丽质[1] 

机构地区：[1]唐山学院环境与化学工程系,河北唐山063000

出　　处：《化学世界》2016年第5期280-283,292,共5页Chemical World

基　　金：唐山市科学技术局项目(15130201a)

摘　　要：以Al_2O_3和MgO粉体为原料,KOH为改性剂,采用机混法制备了酸碱双功能催化剂,并以丙酮气相合成异佛尔酮为研究对象,优化了催化剂制备条件,并通过透射电子显微镜(SEM)和程序升温脱附法(TPD)对催化剂结构和性质进行了分析。结果表明,n(Mg)∶n(Al)催化剂适宜的制备条件是:压片焙烧温度为500℃,KOH浸渍时间为6h,KOH改性后焙烧温度为300℃,丙酮转化率和异佛尔酮选择性分别为9.6%和68.4%。由表征结果可知,压片焙烧温度过高易使催化剂表面发生烧结,产生较强的酸中心和较小的酸碱量,导致催化剂活性下降。The acid-base bifunctional catalysts were prepared by mechanical mixing method with A1203 and MgO as raw materials and KOH as modifier. The preparation conditions of catalysts were optimized for gas phase synthesis of isophorone from acetone, and the structure of the catalysts was analyzed by scan- ning electron microscope （SEM） and temperature programmed desorption （TPD）. The results showed that the optimum preparation conditions were as follows, the calcinating temperature of tablet was 500℃, the KOH impregnation time was 6 h, and the calcinating temperature of KOH modified catalysts was 300℃. The conversion of acetone and the selectivity of isophorone were 9.6% and 68.4%, respectively. The characterization results showed that the catalyst surface was sintered and produced strong acid center and the amount of total acid and alkali sites was decreased at high calcinating temperature, so the catalyst activity was declined.

关 键 词：K2O-MgO/Al2O3 酸碱催化剂 异佛尔酮 机混法 

分 类 号：TQ224.22[化学工程—有机化工] O643.36[理学—物理化学]