超临界流体干燥技术制备超细Ce-Mn气凝胶  

Preparation and Research on Ultrafine Cerium-Manganese Aerogel by Supercritical Fluid Drying Technology

作　　者：欧阳俊波[1] 余高奇[2] 张光德[1] 余秋兰[1] 汪厚植[2] 

机构地区：[1]武汉科技大学机械自动化学院,湖北武汉430081 [2]武汉科技大学湖北省耐火材料与高温陶瓷重点实验室,湖北武汉430081

出　　处：《中国稀土学报》2006年第z1期27-31,共5页Journal of the Chinese Society of Rare Earths

基　　金：湖北省教育厅大学-企业合作研究基金(2003BC5);湖北省自然科学基金(2005ABA017);武汉科技大学校重点科研基金项目(2004XZ11)资助

摘　　要：以化学纯Ce2(CO3)3·6H2O和Mn(NO3)2为主要原料,采用溶胶-凝胶法结合超临界流体干燥技术制备出铈锰气凝胶,经850℃煅烧后获得纳米粉体.通过TG-DTA,XRD,TEM,FT-IR等方法对样品进行表征,重点考察制备工艺及温度对气凝胶晶态、形貌、尺寸的影响,并通过反应'NO+CO'来检测其催化活性.结果显示:该法能制备出具有较好疏松性、分散性的棕褐色粉末,晶粒呈球状,球径约为10 nm.经850℃煅烧后,物质的主要成分为CeO2和Mn2O3,由于高温烧结,晶粒尺寸明显长大,约为20～30 nm.铈锰气凝胶对反应'NO+CO'有一定的催化作用,但催化效果不够理想.Using Ce2(CO3)3·6H2O and Mn(NO3)2 as raw material, the ultrafine Ce-Mn aerogel was prepared by sol-gel and supercritical fluid drying technology, and calcined the aerogel at 850 ℃ to obtain nanometer powder. The samples were characterized by means of FT-IR, XRD, TEM and TG-DTA. The effect of preparation methodology and temperature on crystalline state, appearance and size were examined, then through 'NO+CO' reaction its catalytic activity was check. The results show as follows: (1) The method can get brown-tan, well-dispersed ultrafine powder which has better fluidity and seems very loose; the sample particles assume globosity and its pellet diameter is about 10 nm. (2) Ultrafine CeO2 and Mn2O3 can be got at 850 ℃ by calcination of Ce-Mn aerogel; however, because of powder sintering, the size of the grain increases to 20～30 nm. (3) The catalytic activity of Ce-Mn aerogel is limited for the reaction 'NO+CO'.

关 键 词：铈锰气凝胶 超临界流体干燥 汽车尾气净化 稀土 

分 类 号：TQ133.3[化学工程—无机化工]