Two-step sol–gel synthesis of mesoporous aluminosilicates: highly efficient catalysts for the preparation of 3,5-dialkylpyridines

Abstract

The microstructure, acid properties and characteristics of the porous structure of sol-gel-synthesized mesoporous aluminosilicates with Si/Al ratios of 40, 80, and 120 have been investigated. It was illustrated that the main reason for the formation of a narrow mesopore size distribution in the investigated aluminosilicates is related to the close size of the secondary particles of the prepared xerogels. The research revealed that an increase in the Si/A1 ratio leads to a slight decrease in the specific surface and mesopore volume. An increase in the Si/Al ratio from 40 to 120 has proved to reduce the total acidity in ammonia from 554 to 324 μmol/g. It is shown that mesoporous aluminosilicates prepared by two-step sol-gel synthesis show high activity and selectivity in the synthesis of 3,5-dialkylpyridines.

Fundamentals and recent progress relating to the fabrication, functionalization and characterization of mesostructured materials using diverse synthetic methodologies

“…125 Aluminosilica is a very common example of this type, where AlCl 3 or Al(NO 3 ) 3 reacts with silanol species to synthesize mesoporous aluminosilica materials. [126][127][128][129][130] In comparison with the one-pot co-condensation method, this approach provides for the better diffusion of reactants into active sites due to modied surface Lewis/Brønsted acid spots. 131 As another example, Cheralathan et al 132 accomplished postfunctionalization alumina distribution on the pore walls of mesoporous silica in the presence of inorganic aluminum salts using H 2 O/NH 3 vapour as a hydrolyzing mediator at high temperature via an autoclave-assisted technique followed by calcination.…”

Optimised Condition Catalytic Upgrading of Agbabu Bitumen in the Presence of Rice Husks

“…This can be attributed to the fact that the catalyst NiMo/ZSM-5 has more pore volume and surface area distribution than the other catalysts (Co-Mo/HZSM-5 and Mo/HZSM-5), thus more upgrade and yield. In addition, such catalysts are very effective in the catalytic transformations of bulk molecules of the bitumen due to the efficient transportation and diffusion of the reactants to the active sites and the reverse diffusion of the resulting reaction products [18]. Asphaltenes Reduction and Sulfur Removal.…”

Obtaining and research of aluminosilicate sorbent

“…Анализ литературных и патентных источников показывает, что широко варьируемый химический состав алюмосиликатного сорбента позволяет модифицировать физико-химические свойства материалов. Нано размеры полостей, возможность упорядоченного расположения активных центров, селективность и направленность воздействия на химические группы молекул делают алюмосиликатные сорбенты не только инструментом нано технологий, но и их объектом [6]. База данных о синтезированных алюмосиликатных сорбентах регулярно обновляется и публикуется под названием «Atlas of Zeolite Structures».…”