Low-temperature and alkali-free dual template synthesis of micro-mesoporous aluminosilicates based on precursors of zeolite ZSM-5

• Published in: Journal of materials science 2016-04, Vol.51 (8), p.4002-4020
• Main Authors: Barakov, Roman, Shcherban, Nataliya, Yaremov, Pavel, Gryn, Svitlana, Solomakha, Vladimir, Bezverkhyy, Igor, Kasian, Nataliia, Ilyin, Vladimir
• Format: Article
• Language: English
• Subjects: acidity; adsorption; Aluminosilicates; Aluminum silicates; Ammonia; Characterization and Evaluation of Materials; Chemistry and Materials Science; Classical Mechanics; Crystallography and Scattering Methods; desorption; Energy dispersive X ray spectroscopy; Energy transmission; hot water treatment; Hydrothermal treatment; Infrared spectroscopy; Lewis acid; Lewis acids; Light diffraction; light scattering; Low temperature; Materials Science; Molecular sieves; nitrogen; NMR spectroscopy; nuclear magnetic resonance spectroscopy; organic matter; Original Paper; Phase composition; Photon correlation spectroscopy; Polymer Sciences; Precursors; Properties (attributes); pyridines; Scanning electron microscopy; sieves; Solid Mechanics; Sorption; Spectral control; Spectroscopic analysis; Spectrum analysis; Synthesis; temperature; Transmission electron microscopy; X ray powder diffraction; X-radiation; X-ray diffraction; X-rays; Zeolites
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/s10853-015-9719-0

The aim of this study was to determine the influence of the conditions of low-temperature sequential dual template synthesis of micro-mesoporous aluminosilicates based on precursors of ZSM-5 on their phase composition, structure, sorption properties, and acidity. The methods of X-ray powder diffraction and volumetric adsorption (N₂, 77 K) analysis, dynamic light scattering (for characterization of sol-precursors), IR-spectroscopy, energy-dispersive X-ray spectroscopy, scanning and transmission electron microscopy, solid-state ²⁹Si MAS NMR and ²⁹Si{1H} cross-polarization MAS NMR spectroscopy, temperature-programmed desorption of ammonia, ad(de)sorption of pyridine and 2,6-di-tert-butylpyridine with IR-spectral control were used for characterization of the obtained micro-mesoporous aluminosilicates. It was shown that the convergence of compositions of the reaction mixtures and conditions of formation of zeolites and mesoporous molecular sieves, in particular, the use of alkali-free reaction medium and relatively low temperature of hydrothermal treatment (100 °C) allowed to obtain the X-ray amorphous and partially zeolitized micro-mesoporous aluminosilicates. Such aluminosilicates have appropriate structural and sorption properties and the acidity inherent to ZSM-5 and MCM-41, including the Brønsted and Lewis acid sites which are accessible for bulk molecules of organic substances. The possibility of purposeful regulation of characteristics of micro-mesoporous aluminosilicates depending on the conditions of their preparation was confirmed. Herewith the investigated aluminosilicates possess the sorption and acidic properties which are different from the mechanical mixture of two phases.