Synthesis, characterization, and catalytic testing of W-MCM-41 mesoporous molecular sieves Original Research Article

A novel tungsten-containing MCM-41 mesoporous molecular sieve was synthesized by the hydrolysis of tetraethylorthosilicate and ammonium tungstate in the presence of cetylpyridinium bromide as template in strongly acidic medium. Physicochemical characterizations of this composite performed by means of powder X-ray diffraction, ICP atomic emission, FT-IR, laser Raman, and diffuse reflectance UV–Vis spectroscopy verified that tungsten ion could be isolated in framework positions of the MCM-41 mesostructure by this approach. Thermo-gravimetric study on this composite suggested that above 90% of the template encapsulated in the as-synthesized mesophase was recoverable by direct ethanol extraction. A catalytic test using hydrogen peroxide hydroxylation of cyclohexene as probe reaction proved that the framework tungsten site in the W-MCM-41 could afford the mesophase with fairly high activity in promoting this reaction, wherein acetic acid was found to be useful as solvent.