关键词: 酸解, 水热合成法, ZSM-5分子筛, 正硅酸乙酯

Abstract:

Tetraethyl orthosilicate（TEOS） is usually used as the silicon source for the synthesis of ZSM-5 zeolite.The polymerization state of the precursors hydrolyzed in different acid-base media had a regulatory effect on the grain size and pore size distribution of ZSM-5.The precursor of hydrolysis and condensation of TEOS in acidic medium was used as the silicon source.ZSM-5 was synthesized under hydrothermal conditions,and the samples at different stages during the reaction were characterized by XRD,SEM,BET and FI-IR.The effects of hydrolysis degree,hydrolysis time,pH of synthesis process,crystallization temperature,crystallization time and template dosage on the synthesis of ZSM-5 zeolite were investigated.The results showed that when the ethanol was used as co-solvent,the precursor of TEOS hydrolyzed for 20 h in sulfuric acid medium（pH=2.0） was used as silicon source,tetrapropylammonium hydroxide（TPAOH） was added during the hydrothermal synthesis process,and Al（OH）₃ was used as aluminum source,the ZSM-5 zeolite with the crystal grain size（about 200 nm） was synthesized that crystallized at 180 ℃ for 30 h.The specific surface area of ZSM-5 zeolite was increased by 35.6% and the average pore size was decreased by 48.6%.

Key words: acid hydrolysis, hydrothermal synthesis, ZSM-5 zeolite, tetraethyl orthosilicate