硅胶担载离子液体催化剂的制备及其在由胺制二取代脲反应中的应用  

Preparation of SiO_2-Gel Supported Ionic Liquid Catalyst and Its Application in Synthesis of N,N′-Disubstituted Ureas from Amines

作　　者：张庆华[1] 石峰[1] 邓友全[1] 

机构地区：[1]中国科学院兰州化学物理研究所绿色化学与催化研究中心,甘肃兰州730000

出　　处：《催化学报》2004年第8期607-610,共4页

基　　金：国家自然科学基金资助项目 ( 2 0 2 2 5 3 0 9)

摘　　要：采用溶胶 凝胶法制备了硅胶负载Rh(PPh3 ) 3 Cl 离子液体催化剂Rh DMImBF4/SiO2 gel,并对其催化胺类化合物氧化羰化制二取代脲反应的活性进行了考察 .结果表明 ,该催化体系对胺类化合物氧化羰化制二取代脲反应具有较高的催化活性 ,产物分离简单 ,催化剂易回收且具有较好的重复使用性能 .以氧为氧化剂时 ,苯胺转化率可达 95 % ,脲的选择性可达 98%以上 .以硝基苯为氧化剂时 ,苯胺转化率为 93% ,硝基苯转化率为 92 % ,脲的选择性为 98%以上 ,转化频率均超过 110 0 0mol/(mol·h) .此外 ,还制备了Co DMImBF4/SiO2 gel,Pd DMImBF4/SiO2 gel和Ru DMImBF4/SiO2 gel等催化剂 ,并对其催化氧化羰化胺类化合物的性能进行了考察 .The Rh-DMImBF 4/SiO 2-gel ionic liquid catalyst was prepared through sol-gel method, and its catalytic activity in synthesis of N,N′ -disubstituted ureas by oxidative carbonylation of amines was measured. Under typical reaction conditions, the conversion of aniline was 95% and the selectivity for N,N′ -diphenylurea was more than 98% in the oxidative carbonlyation of aniline with CO and O 2 as oxidants, while with nitrobenzene as oxidant, the conversion of aniline and nitrobenzene was 93% and 92% respectively, and the selectivity for N,N′ -diphenylurea was more than 98%. The turnover frequency all exceeded 11*!000 mol/(mol·h) . Furthermore, the Co-DMImBF 4/SiO 2-gel, Pd-DMImBF 4/SiO 2-gel and Ru-DMImBF 4/SiO 2-gel catalysts were also prepared and their catalytic activity for carbonlyation of amine was studied.

关 键 词：溶胶-凝胶法 铑 离子液体 胺 氧化羰化 二取代脲 

分 类 号：O643[理学—物理化学]