Mesoporous alumino silicates synthesized with single molecular precursor (sec-BUO)(2)AlOSi(OEt)(3) as aluminum source

Single molecular precursor bis(sec-butoxy)aluminoxytriethoxysilane [(sec-BUO)(2)AlOSi(OEt)(3)] was used as aluminum source for the synthesis of mesoporous aluminosilicates with low Si/Al ratios from 1.0 to 10.0 via a template-assisted method. The samples with Si/ Al ratios of 1.0 and 3.0 have wormhole-like pore structure, while the samples with Si/Al ratios of 5.0 and 10.0 have ordered hexagonal mesoporous structures with extensive void defects amid the nanochannels. IR spectra of pyridine adsorption and NH3-TPD characterizations suggest that the mesoporous alummosilicates have both Bronsted and Lewis acid sites with medium strength. The amounts of acid sites of the mesoporous aluminosilicates do not run parallel with the concentration of the tetrahedrally coordinated aluminum in the mesoporous framework. (c) 2005 Elsevier Inc. All rights reserved