摘要
采用天然钙基蒙脱土为原料,经碳酸钠钠化处理、十六烷基三甲基溴化铵有机改性后,以八烷胺做共表面活性剂,将有机土、中性胺和正硅酸乙酯按一定比例混合,搅拌反应4 h,经分离、干燥、焙烧,合成出新型中孔蒙脱土多孔异构材料。用XRD、TG、TG-FTIR、N2等温吸附-脱附和红外酸度分析等手段对产物进行了表征。结果表明,合成材料平均孔径为2.86 nm,达到了IUPAC规定的中孔范围(2~50 nm),且孔径分布较窄,BET比表面积为625 m2.g-1,同时拥有B酸和L酸两种酸性位。该种合成材料有别于酸化蒙脱土和无机交联蒙脱土等传统蒙脱土改性材料,同时其合成过程又为中孔材料的合成提供了一种新途径,在改善微孔(孔径一般小于1.5 nm)沸石分子筛孔径对较大分子进出限制这一方面具有潜在的应用价值。
The natural calcium-montmorillonite was used as the raw materials.After the process of cation exchanging with sodium carbonate,it was modified by cetyltrimethylammonium bromide(CTMAB) forming the organo-montmorillonite.Then mixture of organo-montmorillonite,neutral amine and tetraethylorthosilicate(TEOS) with some molar ratio was allowed to react for 4 h, centrifuged,dried and calcined.Finally a novel mesoporous montmorillonite heterostructured materials was synthesized.The structure of the sample was characterized by XRD,TG,TG-FTIR.N_2 adsorption-desorption and IR acidity analyzer.The results show that the average pore diameter of the synthesized sample is 2.86 nm which belongs to the range of mesopores(2～50 nm) defined by IUPAC,pore distribution is narrow.The BET specific area is 625 m^2·g^(-1) and the surface owns both of brnsted and lewis acidic sites.The novel synthesized materials are different from conventional modified montmorillonite materials such as acidified montmorillonite and pillared inorganic intercalated montmorillonite.Its synthesized processing provides a new method for the preparation of mesoporous materials and such novel materials will also have potential applying values in ameliorating the limitation of bigger molecule passing in and out of the microporous molecular sieves in which the pore size is usually smaller than 1.5 nm.
出处
《石油化工高等学校学报》
CAS
2005年第4期27-30,41,共5页
Journal of Petrochemical Universities
基金
中国石油化工股份有限公司资助项目(总合-090202)
关键词
有机蒙脱土
中孔
多孔异构材料
Organo-montmorillonite
Mesopore
Porous heterostructured material
