Pore size control of mesoporous molecular sieves using different organic auxiliary chemicals
Pore size control of mesoporous molecular sieves using different organic auxiliary chemicals
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DOI：
10.1016/j.micromeso.2003.12.010
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发表时间：
2004-03-01
影响因子：
5.2
通讯作者：
Namba, S
中科院分区：
文献类型：
--
作者：
Jana, SK;Nishida, R;Namba, S
介孔二氧化硅分子筛：采用四种不同的有机助剂甲基取代苯合成了不同孔径的MCM-41和SBA-15（1，3，5-、1，2，4-或1，2，3-三甲苯），异丙基取代苯（1-、1，3-二-或1，3，5-三-异丙基苯）、烷烃（辛烷、壬烷、癸烷、十三烷、十六烷或二十烷）和1-辛醇。所得材料的特征在于它们的结构规律性，通过X射线衍射和氮吸附研究。以甲基取代苯、异丙基取代苯和烷烃为有机助剂，可以得到孔径增大的介孔材料，其影响程度依次为烷烃<异丙基取代苯<甲基取代苯。目前的合成工艺难以用正辛醇合成具有介孔结构的MCM-41和SBA-15。根据助剂的种类和用量，MCM-41的BJH孔径可控制在9.1 nm，SBA-15的BJH孔径可控制在43.0 nm，但所得介孔材料的X射线衍射、BJH孔径分布和BJH孔的尖锐度发生了显著变化。提出了在不同有机助剂存在下的介孔相形成机理。(C)2003年爱思唯尔公司All rights reserved.
Mesoporous silica molecular sieves: MCM-41 and SBA-15 with various pore sizes were synthesized using four different types of organic auxiliary chemicals-methyl-substituted benzene (1,3,5-, 1,2,4- or 1,2,3-trimethylbenzene), isopropyl-substituted benzene (1-, 1,3-di- or 1,3,5-tri-isopropylbenzene), alkane (octane, nonane, decane, tridecane, hexadecane or eicosane) and 1-octanol under hydrothermal conditions. Resultant materials have been characterized for their structural regularity by X-ray diffraction and nitrogen adsorption studies. Mesoporous materials with enlarged pore diameter can be obtained using methyl-substituted benzene, isopropyl-substituted benzene or alkane as organic auxiliary chemical and the degree of their influence on the pore size is in the following order: alkane < isopropyl-substituted benzene < methyl-substituted benzene. It is difficult to prepare MCM-41 and SBA-15 with mesoporous structures using 1-octanol under the present synthesis process. Depending on the type and amount of auxiliary chemical, the BJH pore diameter of MCM-41 can be controlled up to 9.1 nm and that of SBA-15 up to 43.0 nm; however, the X-ray diffraction, BJH pore size distribution and sharpness of BJH pores of the resulting mesoporous materials changed markedly. A plausible mesoporous phase formation mechanism in the presence of different organic auxiliary chemicals has been suggested. (C) 2003 Elsevier Inc. All rights reserved.