Madhusoodana Chengala D, Kameshima Yoshikazu, Nakajima Akira, Okada Kiyoshi, Kogure Toshihiro, Mackenzie Kenneth J D
Ceramic Technological Institute, BHEL, Bangalore 560012, India.
J Colloid Interface Sci. 2006 May 15;297(2):724-31. doi: 10.1016/j.jcis.2005.10.051. Epub 2005 Dec 9.
Al-containing mesoporous silicas were synthesized by hydrothermal treatment of microporous silica prepared by selectively acid leached metakaolinites with Si/Al = 3.9-92.5 mixed with a surfactant of cetyltrimethylammonium bromide (CTABr). The specific surface area of the products increased with higher surfactant/microporous silica (surf/Si) ratio and Si/Al ratio of the microporous silica, reaching about 1400 m2/g at CTABr/Si 0.1 and Si/Al 40. The XRD patterns of these products show a hexagonal (100) peak with the lattice parameter a0=4.2-4.3 nm and the N2 adsorption isotherms show steep increase of adsorption between relative pressure of 0.3 and 0.4. Hexagonal mesoporous microstructure is observed by high resolution TEM. The pore size distributions of the products show a sharp peak at 2.8 nm by the BJH method. The high specific surface area of the present mesoporous samples is attributed to the lower matrix density and surface roughness of mesopore wall. The highest specific surface area of the products reached up to 1420 m2/g and this value is apparently higher than those reported in hexagonal mesoporous silicas. A unique microporous structure of the starting material is thought to be related to achieve such a high specific surface area of the products.
通过对选择性酸浸偏高岭土制备的硅铝比（Si/Al）为3.9 - 92.5的微孔二氧化硅与十六烷基三甲基溴化铵（CTABr）表面活性剂混合进行水热处理，合成了含铝介孔二氧化硅。产物的比表面积随着表面活性剂/微孔二氧化硅（surf/Si）比以及微孔二氧化硅的Si/Al比的增加而增大，在CTABr/Si为0.1且Si/Al为40时达到约1400 m²/g。这些产物的X射线衍射图谱显示出具有晶格参数a0 = 4.2 - 4.3 nm的六方（100）峰，N₂吸附等温线显示在相对压力0.3至0.4之间吸附急剧增加。通过高分辨率透射电子显微镜观察到六方介孔微观结构。产物的孔径分布通过BJH方法在2.8 nm处显示出一个尖锐的峰。当前介孔样品的高比表面积归因于介孔壁较低的基体密度和表面粗糙度。产物的最高比表面积达到1420 m²/g，该值明显高于六方介孔二氧化硅中报道的值。起始材料独特的微孔结构被认为与实现产物如此高的比表面积有关。
