Preparation method of mesoporous zsm-5 molecular sieve

Abstract

The invention discloses a preparation method for a mesoporous ZSM-5 molecular sieve and relates to a molecular sieve. The method comprises the following steps: (1) fully mixing and grinding a certain amount of white carbon black or silica gel, tetrapropylammonium bromide, ammonium bifluoride and aluminum sulfate, and then putting the mixed raw material after being ground into a polytetrafluoroethylene lining stainless steel reaction kettle and crystallizing for 3-5 days at 145 DEG C under a static condition; (2) moving the products obtained in the step (1) into a beaker, adding water at a certain ratio and stirring for 12 hours; (3) washing the products obtained in the step (2) with deionized water, and drying, thereby obtaining the mesoporous ZSM-5. The method provided by the invention is characterized in that the mesoporous of the ZSM-5 molecular sieve is prepared by only adding water and remained raw material for forming a solution; the preparation method is a simple and economic post-processing method; high degree of crystallinity and few defects are maintained; the mesoporous ZSM-5 molecular sieve has excellent catalytic activity and longer service life.

Description

technical field [0001] The invention relates to a molecular sieve, in particular to a preparation method of a mesoporous ZSM-5 molecular sieve. Background technique [0002] ZSM-5 molecular sieve (R.J Argauer, G.R Landolt, Mobil oil corp, US3702886A, 1972), due to its high silicon-aluminum ratio, unique pore structure, large specific surface area and excellent thermal and hydrothermal structural stability It has been widely used in petrochemical processes such as shape-selective cracking, alkylation, isomerization, disproportionation, catalytic dewaxing and etherification of hydrocarbons. However, with the decrease of petroleum resources and the increase of petroleum consumption, higher requirements are put forward for the catalytic efficiency of petroleum processing catalysts. The pore size of microporous molecular sieves restricts larger molecules from entering its pores and contacting active centers. It is beneficial to the reaction and extraction of macromolecules, so t...

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Problems solved by technology

However, in the process of hydrothermal gel synthesis of ZSM-5 zeolite molecular sieve under traditional alkaline conditions, brominated organic templates need to use silver oxide or ion exchange columns to be converted into hydroxide organic templates, and the reaction cost increases; silicon source and aluminum The hydrolysis process of the source in the alkaline solution takes a long time, the efficiency is low and the energy consumption is large; at the same time, because hydrofluoric acid needs to be added to introduce the fluorine ion mineralizer, which brings harm to the health of the experimenters, it is sought A suitable synthesis method with reduced cost, improved efficiency and safer

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