表面活性剂在共沉淀法制备Ce_(0.27)Zr_(0.18)Y_(0.025)La_(0.025)Al_(0.5)O_x中的成孔作用  

Effects of Surfactants on the Pore-forming of Ce_(0.27)Zr_(0.18)Y_(0.025)La_(0.025)Al_(0.5)O_x Prepared by Coprecipitation Method

作　　者：刘建英[1,2] 赵明[1] 徐成华[2] 张雪乔[2] 谭显东[2] 龚茂初[1] 陈耀强[1] 

机构地区：[1]四川大学催化材料研究所,四川成都610064 [2]成都信息工程学院资源与环境学院,四川成都610225

出　　处：《四川大学学报（工程科学版）》2012年第3期193-199,共7页Journal of Sichuan University (Engineering Science Edition)

基　　金：国家自然科学基金资助项目(20773090)

摘　　要：以十六烷基三甲基溴化铵(CTAB)和聚乙二醇(PEG)作为表面活性剂,采用共沉淀法制备了Ce0.27Zr0.18Y0.025La0.025Al0.5Ox(CZYLA)材料,详细考察了表面活性剂的种类和添加方式对材料成孔的影响,并推测了成孔机理。采用X射线衍射(XRD),比表面(BET)测定,热重-差热分析(TG-DTA),透射电子显微镜(TEM)对材料进行了表征。结果表明:表面活性剂的添加没有改变材料的物相,均形成立方相铈锆固溶体,经1 000℃高温焙烧后无相分离;采用CTAB和PEG合成的材料经600℃焙烧后分别形成直径为6.6 nm的柱状孔和5.0 nm的狭缝孔;同时表面活性剂可以使部分晶粒由球状变成纤维状,经1 000℃高温老化5 h后采用CTAB制备的材料仍然保持了部分纤维状晶粒,从而维持了部分直径2～5 nm的孔,比表面积可达38.5 m2/g;在沉淀过程中加入表面活性剂对材料的孔结构起决定性作用。Ce0.27Zr0.18Y0.025La0.025Al0.5Ox（CZYLA） material was prepared by coprecipitation method using cetyltrimethylammonium bromide（CTAB） and polyethylene glycol（PEG） as surfactants.The effects of the types and adding methods of surfactants on pore-forming of material were investigated in detail.The pore-forming mechanism was also speculated.The material was characterized by XRD,BET,TG-DTA and TEM.The results showed that cubic ceria-zirconia solid solution could be formed and there is no phase separation after calcined at high temperature whether or not to add the surfactants.When materials calcined at 600 ℃,6.6 nm columnar and 5.0 nm slit pores are formed respectively by using CTAB and PEG in synthetic process.At the same time the shape of particles is transformed from nanoball to nanofiber by adding surfactants.After aged at 1 000 ℃ for 5 h the samples with CTAB still possesses a considerable part of the fibrous grains,resulting in 2~5 nm pores maintain and the surface area as high as 38.5 m2/g.Surfactants added in the precipitation play a decisive role in the pore structures of materials.

关 键 词：表面活性剂 共沉淀 铈 锆 铝 成孔 

分 类 号：O643[理学—物理化学]