سال انتشار: ۱۳۸۷

محل انتشار: همایش بین المللی ژئولیت ایران

تعداد صفحات: ۶

نویسنده(ها):

m vaziri –
m.a Zanjanchi – Department of Chemistry, Faculty of Science, University of Guilan,

چکیده:

Framework and extra-framework aluminum species in mesoporous aluminum-containing MCM-41
materials was studied by diffuse reflectance spectroscopy (DRS) employing acetylacetone as a probe agent.
A room temperature synthesis method was used for preparation of purely siliceous MCM-41 and for
aluminum-containing MCM-41 materials. Samples with Si/Al ratios of 50, 20, 10 and 5 were synthesized.
The treatment of the as-synthesized and calcined aluminum-containing MCM-41 samples with acetylacetone
shows a distinct band at ≈ ۲۹۰ nm. This band is assigned to six coordinated aluminum atoms in the
structure. The 290-nm band is disappeared following the successive ethanol washing of the acatylacetonetreated
surfactant-containing samples but its intensity is reduced in acatylacetone-treated calcined samples.
The persisted intensity of 290-nm band in the acatylacetone-treated calcined samples after ethanol washing
can be assigned to framework aluminum.