锌铁氧化物催化剂的制备及在尿素与1,2-丙二醇合成碳酸丙烯酯反应中的催化性能  

PREPARATION OF ZINC-IRON OXIDE CATALYST AND ITS CATALYTIC PERFORMANCE IN REACTION FOR SYNTHESIS OF PROPYLENE CARBONATE FROM UREA AND 1,2-PROPYLENE GLYCOL

作　　者：贾志光[1] 赵新强[1] 王延吉[1] 

机构地区：[1]河北工业大学绿色化工研究所,天津300130

出　　处：《石油学报（石油加工）》2006年第1期77-83,共7页Acta Petrolei Sinica(Petroleum Processing Section)

基　　金：国家自然科学基金(20576025);河北省自然科学基金(2004000016)资助项目

摘　　要：采用共沉淀法制备了一系列锌铁氧化物催化剂,考察了沉淀剂种类和加入方式、沉淀pH值、焙烧温度等制备条件对催化剂性能的影响,得到的最佳制备条件为:以硝酸锌和硝酸铁为前驱体,Zn/Fe摩尔比为2,以氨水为沉淀剂(沉淀终点pH值8),采用正加法,焙烧温度450℃,焙烧时间4 h。考察了锌铁氧化物催化剂上尿素与1,2-丙二醇合成碳酸丙烯酯的反应性能,优化了反应条件。最佳反应条件为:反应温度170℃,反应时间2 h,催化剂质量分数1.4%,1,2-丙二醇/尿素摩尔比为4。在最佳反应条件下,碳酸丙烯酯收率最高为78.4%。应用XRD、CO2-TPD和XPS等技术对催化剂进行了表征,发现该复合氧化物含有ZnO和ZnFe2O4两种晶相,其中ZnO为主活性组分,ZnO和ZnFe2O4的共同作用促进催化活性的提高。A series of zinc-iron oxide catalysts was prepared by co-precipitation method. The effects of the kind of precipitator and it addition manner, precipitation end point pH, calcination temperature on the catalytic performance of the catalysts were investigated. The suitable preparation conditions were as follows： zinc nitrate and iron nitrate as the precursors, n（Zn）/n（Fe） of 2, ammonia as the precipitator, normal mixing manner for the precipitator, precipitation end-point pH of 8, and calcination temperature of 450℃. The catalytic activity of zinc-iron oxides for synthesis of propylene carbonate （PC） via urea and 1,2-propylene glycol （PG） was studied. The optimal reaction conditions were as follows, reaction temperature of 170℃, reaction time of 2 h, catalyst mass fraction of 1.4%, n（PG）/n（Urea） of 4. The highest yield of PC was 78.4% under the optimal conditions. XRD, CO2-TPD and XPS were employed for the catalyst characterization. It was found that there were two kinds of crystal phase, ZnO and ZnFe2O4 in the catalyst. ZnO acted as the main active component, and the synergistic effect of ZnO and ZnFe2O4 promotes the catalytic performance.

关 键 词：尿素 1 2-丙二醇 碳酸丙烯酯 锌铁氧化物催化剂 

分 类 号：TQ234.2[化学工程—有机化工]