Pb/SiO_2催化剂上尿素与1,2-丙二醇合成碳酸丙烯酯  

Synthesis of Propylene Carbonate from Urea and 1,2-Propylene Glycol over Silica-Supported Lead Catalyst

作　　者：贾志光[1] 赵新强[1] 安华良[1] 邬长城[1] 王延吉[1] 

机构地区：[1]河北工业大学绿色化工与高效节能河北省重点实验室,天津300130

出　　处：《石油化工》2006年第10期927-931,共5页Petrochemical Technology

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

摘　　要：采用等体积浸渍法制备了一系列负载型Pb催化剂,考察了它们对尿素与1,2-丙二醇合成碳酸丙烯酯反应的催化性能。研究了载体种类、Pb负载量及还原气氛和还原温度对负载型Pb催化剂性能的影响。确定了负载型Pb催化剂的适宜制备条件:SiO2为载体,Pb负载量(质量分数)为10%,纯H2气氛还原,还原温度500℃。利用X射线衍射技术对Pb/SiO2催化剂的结构进行了表征,表征结果显示,Pb/SiO2催化剂中含有Pb和PbO两种晶相。在反应温度180℃、反应时间2h、Pb/SiO2催化剂质量分数0.9%、尿素与1,2-丙二醇摩尔比1∶4的条件下,碳酸丙烯酯的收率为86.9%。A series of supported lead catalysts were prepared by impregnation and their catalytic activities in synthesis of propylene carbonate （PC）from urea and 1,2-propylene glycol （PG）were investigated. The effects of different supports, loading of lead, reducing atmosphere and reduction temperature on activity of catalysts were studied. The optimal preparation conditions for the catalyst are as follows： silica as support, loading of lead 10% （mass fraction）, hydrogen as reducing agent and reduction temperature at 500 ℃. The catalysts were characterized by means of XRD. PbO and Pb were detected. Under optimal reaction conditions： reaction temperature 180 ℃, reaction time 2 h, Pb/SiO2 catalyst mass fraction 0.9% and mole ratio of urea to PG 1 ： 4,yield of PC can reach 86.9%.

关 键 词：尿素 1 2-丙二醇 碳酸丙烯酯 负载型铅催化剂 氧化硅 

分 类 号：TQ203.2[化学工程—有机化工]