Mo-fixed H-ZSM-5 zeolites were prepared by contacting H-ZSM-5 and Mo (π-C3-H5)4 and decomposing the surface complex in O2. The reaction between the hydroxyl groups of the zeolite and the Mo in the Mo-fixing process were studied by IR spectroscopy. Seven component bands can be resolved from the υ(OH) band of H-ZSM-5 by computer deconvolution. The intensity of the bands at 3745 cm−1, 3720 cm−1 and at about 3500 cm−1, which bands are attributed to silanol groups, decreases significantly upon Mo-fixing, but only 6% of the ≅ Si-OH-Al ≅ sites are consumed in the reaction. X-ray diffractograms, acidity and catalytic activity of catalysts prepared by Mo-fixing or by the conventional impregnation technique are compared. Data suggest that molybdenum is mainly on the outer surface of the crystallites in the Mo-impregnated catalysts, while it is homogeneously distributed in the Mo-fixed catalysts.
ASJC Scopus subject areas
- Condensed Matter Physics
- Physical and Theoretical Chemistry
- Surfaces, Coatings and Films
- Materials Chemistry