One-step synthesis of hierarchical ZSM-5 zeolites and their catalytic performance on the conversion of methanol to aromatics

摘要

Hierarchical ZSM-5 zeolites were successfully prepared with one-step hydrothermal method by adding MTES to the zeolite precursor. The mesoporous structure of zeolite was formed via organosilane interacts with nanoparticles to form a covalent bond of Si-R, and then the alkyl group was removed by calcination. The influence of methyltriethoxysilane on the mesopores, acidity, morphology of the zeolites, and the catalytic performance of the samples was investigated. A mesoporous size about 6.5 nm was formed in the sample, meanwhile, the Bronsted acid density of zeolite was decreased. The yield of the aromatic compound was increased by about 10% after the introduction of the mesoporous structure. The catalyst's carbon deposition resistance was improved due to a significant decrease of the Bronsted acid density of zeolite, and the catalyst life (methanol conversion rate > 95%) was extended from 41 to 76 h.