Ti−MCM-41 Synthesized from Colloidal Silica and Titanium Trichloride: Synthesis, Characterization, and Catalysis

Titanium-containing mesoporous molecular sieve Ti−MCM-41 has been synthesized using colloidal silica as the silicon source and TiCl 3 solution as the titanium source and was characterized by X-ray diffraction, N 2 adsorption, UV−vis, and UV−Raman spectroscopies. The formation of anatase TiO 2 can be avoided during the synthesis and the crystallization of the molecular sieve because of the relatively low hydrolysis rate of an inorganic TiCl 3 solution. The characterization results confirm that most Ti 4+ ions are isolated and tetrahedrally coordinated in the framework of MCM-41. Different auxiliary templates, tetramethylammonium hydroxide (TMAOH), tetraethylammonium hydroxide (TEAOH), tetrabutylammonium hydroxide, and NH 3 ·H 2 O were used to synthesize the Ti−MCM-41 molecular sieve. Among them, TMAOH and TEAOH were found to be the most effective auxiliary templates to improve the long-ranged order of the molecular sieves.