CuO(CoO,MnO)/SiO_2纳米复合气凝胶催化剂载体的溶胶-凝胶法制备与表征  

Preparation and characterization of CuO(CoO,MnO)/SiO_2 nanocomposite aerogels as catalysts carrier by sol-gel process

作　　者：赵越卿[1,2] 赵海雷[1] 贾千一[3] 梁英华[4] 沈毅[3] 张翠娟[1] 

机构地区：[1]北京科技大学无机非金属材料系,北京100083 [2]河北理工大学轻工学院,河北唐山063000 [3]河北理工大学材料学院,河北唐山063009 [4]河北理工大学化工学院,河北唐山063009

出　　处：《功能材料》2009年第2期317-321,共5页Journal of Functional Materials

基　　金：国家自然科学基金资助项目(50672009);河北省唐山市科技发展计划资助项目(05110301a)

摘　　要：以正硅酸乙酯(tetraethyl orthosilicate,TEOS)、乙酸铜、乙酸钴、乙酸锰为原料,采用溶胶-凝胶法、常压干燥制备了CuO(CoO,MnO)/SiO2纳米复合气凝胶。分析了过渡金属氧化物MO与SiO2的质量比、温度和pH值对凝胶形成的影响。采用场致发射扫描电镜(FE-SEM)、BET、傅里叶变换红外分析(FTIR)、热重-差热分析(TG-DTA)、电子散射能谱分析(EDS)和化学分析等对CuO(CoO,MnO)/SiO2纳米复合气凝胶的微观结构和组成进行了研究。结果表明,纳米复合气凝胶的颗粒约在20~100nm,比表面积为344~733m2/g,孔径范围为2~22nm,而且过渡金属Cu、Co和Mn能够与氧形成部分—O—M—O—桥键连接,并与Si通过化学键形成三维网络结构;纳米复合气凝胶试样中的多元过渡金属氧化物含量可控制在3%~75%(质量分数)。这种结构和组成既有利于提高催化剂负载量,又可充分发挥过渡金属氧化物的助催化作用。CuO（CoO, MnO）/SiO2 nanocomposite aerogels were prepared from tetraethyl orthosilicate （TEOS） and aeetate of Cu,Co and Mn via sol-gel process and ambient pressure drying technique. The effect of mass ratio of transition metal-oxides to SiO2 ,preparation temperature and pH value on gelation was investigated. The microstructure and composition of CuO（CoO,MnO）/SiO2 nanocomposite aerogels were analyzed by field emission scanning electron microscope, BET, Fourier transform infrared spectrum, thermogravimetric and differential thermal analysis,electron dispersive spectrum and chemical analysis. The results show that CuO（CoO, MnO）/ SiO2 nanocomposite aerogels are porous with particle size distribution of 20-100nm, surface area of 344-733m^2/ g,and pore size distribution of 2-16nm. In addition, bridge bonds of -O-M-O- can be formed to some extent by the chemical bonding of transition metals and oxygen,and three-dimensional network structure is formed by the chemical bonding of Si and -O-M-O-. The mass fraction of transition metal-oxides in the nanocomposite aerogels is in the range of 3^-75wt~. This kind of structure and composition is not only favorable to the increase of the catalysts loading,but also to the effective use of transition metal-oxides as catalyst accelerators.

关 键 词：溶胶-凝胶法 常压干燥 纳米复合气凝胶 催化剂载体 表征 

分 类 号：TM285[一般工业技术—材料科学与工程]