Synthesis and formation mechanism analysis of meso‐microporous ZSM‐5 with controllable mesoporous volume

Abstract BACKGROUND ZSM‐5 molecular sieve has an important application value in industrial adsorption. Due to the existence of micropores, it is hard for larger molecules to enter the ZSM‐5 molecular sieve. Meso‐microporous MFI zeolite was prepared by hydrothermal crystallization regarding the organosilane as the structure‐directing agent. Then the samples were characterized by X‐ray diffraction, infrared spectroscopy and so on. The effect of organosilane on mesoporous volume and the mechanism of mesoporous formation were further investigated. Finally the performance of adsorption for volatile organic compounds (VOCs) on meso‐microporous ZSM‐5 were analyzed by static adsorption and dynamic adsorption experiments. RESULTS The meso‐microporous ZSM‐5, which were prepared with the organosilanes, contained not only large and uniform mesopores but also certain amounts of micropores. The results of N 2 physisorption showed that the meso‐microporous ZSM‐5 obtained by propyl trimethoxy silane had the highest specific surface area (438.19 m 2 g −1 ) and mesoporous volume (0.15 cm 3 g −1 ). When the molar ratio of SiO 2 : octyl trimethoxy silane was 1: 0.1, the specific surface area (508.03 m 2 g −1 ) and mesoporous volume (0.23 cm 3 g −1 ) of the O‐ZSM‐5 were maximum. Compared with traditional ZSM‐5, the toluene adsorption performance of meso‐microporous ZSM‐5 had been effectively improved. CONCLUSION This research focused on offering the simple and high efficiency meso‐ microporous ZSM‐5 synthetic routes. The newly intercrystalline mesoporosity in ZSM‐5 zeolite showed a controllable mesoporous channel, which was better than traditional ZSM‐5. The prepared molecular sieve was a promising adsorption material for the volatile organic compounds. © 2021 Society of Chemical Industry (SCI).