0000000000448452
AUTHOR
V. V. Tsyrina
Hierarchical Beta zeolites obtained in concentrated reaction mixtures as catalysts in tetrahydropyranylation of alcohols
Abstract Hierarchical zeolites consisting of Beta nanoparticles (15–40 nm) were obtained via hydrothermal treatment of a concentrated zeolite gel-precursor (H2O/Si = 2.5–14) without utilization of complex SDAs. The proposed approach is based on the formation of a large number of zeolite nuclei under particular crystallization conditions, followed by their agglomeration resulting in the dense packing of the particles preventing their further growth. The micelles of cetyltrimethylammonium bromide (CTAB) can be used to additionally limit the growth of zeolite nanoparticles during hydrothermal treatment of concentrated reaction mixtures. Such deceleration of crystallization promotes the formati…
Synthesis of micro-mesoporous aluminosilicates on the basis of ZSM-5 zeolite using dual-functional templates at presence of micellar and molecular templates
Abstract Micro-mesoporous aluminosilicates consisting of agglomerates of the ZSM-5 nanoparticles were obtained using dual-functional templates [C6H13–N+(CH3)2–C6H12–N+(CH3)2–C6H13](Br−)2 (C6–6–6Br2), [C8H17–N+(CH3)2–C6H12–N+(CH3)2–C8H17](Br−)2 (C8–6–8Br2). Aluminosilicates with randomly oriented flake-like particles built from ZSM-5 layers were obtained using [C16H33–N+(CH3)2–C6H12–N+(CH3)2–C6H13](Br−)2 (C16–6–6Br2). Use of С8–6–8Br2 and additive of cetyltrimethylammonium bromide CTAB (CTAB concentration is lower than the first critical micelle concentration, CMC1) leads to an increase of the total specific surface area, mesopore surface area and the mesopore size uniformity in the product,…