SYNTHESIS AND PHYSICOCHEMICAL CHARACTERISTICS OF MESOPOROUS ALUMINOSILICATES
Ключевые слова:
Mesoporous aluminosilicates, template, bifunctional catalysts, porosity, Lewis and Brønsted acid sites.Аннотация
In the article, the synthesis of mesoporous aluminosilicates was carried out according to the
developed methods, in which tetraethylorthosilicate Si(OC2H5)4 was used as a source of silicon, secondary aluminum
butoxide (sec-BuO)3Al and aluminum triisopropoxide Al(i-OPr)3 were used as aluminum's sources. The synthesis of
mesostructured aluminosilicate is based on the method of copolycondensation of silicon and aluminum sources in the
presence of alcohol. Hexadecylamine (HDA, C16H33NH2) was used as a template for the formation of a porous
structure. The physicochemical characteristics of the synthesized structured mesoporous aluminosilicates have been
studied. It was found that the synthesized materials MAS-1 and MAS-2 possess high specific surface area from 511
to 1170.0 m2
/g. The presence of a mesoporous and ordered structure in the synthesized aluminosilicates is confirmed
by the data of low-temperature nitrogen adsorption/desorption, X-ray diffraction and FT-IR. To determine the
relative strength of Brønsted and Lewis acid sites on the surface of mesoporous aluminosilicates, diffuse reflectance
infrared Fourier transform spectroscopy (DRIFT) of adsorbed pyridine samples was carried out. DRIFT analysis data
demonstrated a majority of Lewis acid sites on the surface of the synthesized materials. We are currently studying
the possibility of applying these materials as acidic components of bifunctional catalysts for petrochemical processes.
