MCM—41分子筛的改性、表面结构与吸附性质的研究  

Studies on the Modification, Surface Structure and Adsorption of MCM - 41 Mesoporous Molecular Sieve

作　　者：龙英才[1] 许太明[1] 孙尧俊[2] 董维阳[1] 

机构地区：[1]复旦大学化学系,上海200433 [2]复旦大学分析测试中心,上海200433

出　　处：《化学学报》1999年第9期1014-1021,共8页Acta Chimica Sinica

基　　金：国家自然科学基金(29236120-03)重点资助项目

摘　　要：用三甲基氯硅烷、二甲基二氯硅烷、甲基三氯硅烷、四氯化硅与甲基碘改性高硅MCM-41中孔分子筛.XRD,^(29)Si MAS NMR,^(13)C CP MAS NMR,以及N_2、水与环己烷吸附的表征,显示改性不同程度地改变了分子筛的表面组成与结构,减小孔径,增加孔壁厚度,因而影响吸附行为,减小吸附容量.硅烷化减少了MCM-41的表面硅羟基含量,增加其疏水性.用CH_3I改性使孔径减小1.4nm,而硅羟基含量并未显著减少.硅烷化以及用CH_3I改性可提高MCM-41分子筛的热稳定性.SiCl_4的改性作用相对不明显.样品的水及环己烷吸附容量与其表面硅羟基含量呈现不同的线性关系,揭示高硅MCM-41分子筛表面吸附中心的本性.High silica MCM-41 and modified samples were characterized in detail with XRD, 29Si and 13C CP MAS NMR, and adsorption isotherms of nitrogen, water and cyclo - hexane. The modification reagents used were trimethylchlorosilane, dimethyldichlorosilane, methyltrichlorosilane, silicon tetrachloride and methyliodide. The modification greatly varies the surface structure, decreases the pore diameter, and increases the wall thickness. A linear relationship between the contents of silanol groups and the amounts of water and cyclohexane absorbed reveals the nature of adsorption centers in the samples.

关 键 词：MCM-41 中孔分子筛 表面结构 吸附性质 分子筛 

分 类 号：O643.36[理学—物理化学] O647.33[理学—化学]