Novel route in the synthesis of MCM-41 containing framework aluminum and its characterization

Mesoporous molecular sieve MCM-41 with incorporated structural aluminum (Al-MCM-41) was prepared by hydrolysis of a solution of tetraethoxysilane and aluminum isopropoxide in the presence of ammonia as a catalyst. This method provides Al-MCM-41 of different Si/Al ratios from 13 to 297 corresponding to 0.3-7 mol% Al within an hour. X-ray diffraction and nitrogen adsorption measurements showed that the Al-MCM-41 prepared by this method had a highly ordered structure of pore arrays. Most Al atoms in these samples were incorporated tetrahedrally in the MCM-41 structure, which gave rise to cationic sites in the framework. (C) 1999 Elsevier Science B.V. All rights reserved.