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

摘要

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. Graphical abstract.