无机盐的加入对纯硅MCM-41中孔材料合成和稳定性的影响  

EFFECT OF INORGANIC SALT ADDITION ON PORE STRUCTURE AND STABILITY OF MESOPOROUS SILICA MCM-41

作　　者：潘大海[1] 李奠础[1] 马静红[1] 李瑞丰[1] 

机构地区：[1]太原理工大学精细化工研究所,山西太原030024

出　　处：《石油学报（石油加工）》2005年第4期62-66,共5页Acta Petrolei Sinica(Petroleum Processing Section)

基　　金：国家"973"课题资助项目(G20008009)

摘　　要：考察了在水热条件下合成纯硅MCM-41中孔分子筛时,加入NH4Cl、NaCl和NaF对其合成及稳定性的影响。采用XRD、低温N2吸附等手段表征了合成所得样品。结果表明,采用加入无机盐的方法可调节MCM-41的孔径大小;也可导致合成产物中间相发生变化。无机盐的加入可有效地提高所合成样品XRD的特征衍射峰(100)强度和稳定性,且以NH4Cl的加入最为明显。随着NH4Cl加入量的增加,合成产物的物相由一维六方有序结构MCM-41向三维似螺旋结构KIT-1过渡。当NH4Cl与表面活性剂的摩尔比为0.2时,在130℃下水热晶化96h,能制得稳定性好的中孔材料MCM-41,可在沸水中稳定保持2h以上,而不造成孔道结构的明显变化。MCM-41 Mesoporous silica molecular sieves were hydrothermally synthesized. The influences of inorganic salt NH4Cl, NaCl and NaF added to the synthesis system on the crystallization and hydrothermal stability of mesoporous materials were investigated. The pore structure characterization by X-ray diffraction and low temperature nitrogen adsorption indicated that the inorganic salt addition could be used to adjust the pore diameter of MCM-41, and could result in the transformation of mesophase, which is directly depended on the concentration and nature of salt added. Addition of a suitable amount salt can enhance the diffraction peak （100） intensity of XRD and the stability of mesoporous silica notably. Among the three kinds of salts, the effect of NH4Cl was the most outstanding. When added with NH4Cl, the mesoporous materials experienced phase transformations in the sequence MCM-41→KIT-1 as the molar ratio of NH4Cl/surfactant increased. When the molar ratio NH4Cl/surfactant was 0.2, mesoporous MCM-41 with high ordered pores and stability could be prepared by crystallization at 130℃ for 96 h, and the MCM-41 maintained the mesoporous structure after hydrothermal treatment at 100℃ for at least 2 h in a close bottle without obvious changes in pore structure.

关 键 词：中孔分子筛 MCM-41 无机盐 水热稳定性 

分 类 号：TQ426.6[化学工程]