A kind of preparation method of self-supporting metal modified ZSM-5 molecular sieve and its application in the synthesis of isoprene

Abstract

The invention provides a method for preparing a self-supporting metal-modified ZSM-5 molecular sieve, comprising the following steps: firstly, immersing silica gel particles in a metal salt solution to obtain a metal-containing precursor; The precursor and the basic template agent used to form the ZSM-5 molecular sieve are mixed and then subjected to crystallization treatment, and then calcined to obtain a self-supporting metal-modified ZSM-5 molecular sieve. In the present invention, the active metal is directly compounded with the silica gel, and then the molecular sieve is synthesized and shaped, so as to realize the one-step preparation of the self-supporting metal-ZSM-5 zeolite molecular sieve catalyst, and avoid the tedious process of the catalyst's post-forming process. The preparation method provided by the invention It is simple, reduces the preparation cost of the catalyst, and has good raw material conversion rate and product yield in the isoprene synthesis reaction, which is beneficial to industrial production and the popularization and application of the metal-ZSM-5 zeolite molecular sieve catalyst.

Description

technical field [0001] The invention relates to the technical field of solid catalyst synthesis, relates to a preparation method and application of a modified ZSM-5 molecular sieve, in particular to a preparation method of a self-supporting metal modified ZSM-5 molecular sieve and its application in the synthesis of isoprene application. Background technique [0002] Isoprene is a colorless and volatile organic chemical raw material with a conjugated double bond structure, which is mainly used in the fields of synthetic rubber and fine chemical products. At present, the main preparation methods of isoprene are divided into physical separation method and chemical synthesis method. The physical separation method is the earliest method to produce isoprene. It extracts its carbon five fraction by cracking naphtha to produce ethylene. With the shortage of petroleum resources and the development of new ethylene technology, the preparation of isoprene by physical separation is gre...

AI Technical Summary

Problems solved by technology

[0005] In the prior art, the modified ZSM-5 molecular sieve has problems such as complex preparation process and long cycle time. Usually, in the synthesis method of ZSM-5 molecular sieve, most of the ZSM-5 molecular sieves are crystallized first to obtain zeolite powder, and then modified with metal or non-metal to have functional Moreover, in the practical application of the catalytic process, it needs to be molded into a catalyst with a certain particle size in the later stage. The preparation process is cumbersome, resulting in high cost of catalyst preparation, which limits further popularization and application in actual production.

Images