Method for preparing hierarchical pore molecular sieve materials

Abstract

The invention discloses a method for preparing hierarchical pore molecular sieve materials. The method comprises the following steps: reaction premedicant liquid is prepared; high polymer subgrain is prepared in an aging mode; the hierarchical pore molecular sieve materials are prepared; and separation, washing, drying and calcination are conducted. A cationic surface active agent serves as a template agent, and the hierarchical pore molecular sieve materials with good performance are prepared through a single-step hydrothermal method. The problem in the prior art that split-phase exists when the cationic surface active agent serves as the template agent is solved effectively, and meanwhile the prepared materials have good catalytic activity in a macromolecule aldol reaction, hydrothermal stability is good, high catalytic activity is displayed when flavanone and chalcone drug intermediate are prepared, and the heterogeneous catalyst is beneficial for isolation and purification of products, and therefore the method for preparing the hierarchical pore molecular sieve materials has an industrial application value.

Description

technical field [0001] The invention relates to a method for preparing a hierarchical porous molecular sieve material, in particular to a method for directly preparing a hierarchical porous molecular sieve material with excellent performance by using a cationic surfactant as a template agent in one-step hydrothermal method. Background technique [0002] Molecular sieve is a crystalline aluminosilicate compound, also known as zeolite, named for its ability to sieve molecules due to its special pore structure. At the same time, the crystallized skeleton shows the properties of solid acid or base after being replaced by heteroatoms. Therefore, such materials are widely used as catalysts in the fields of petrochemical, fine chemical synthesis, adsorption and separation, etc. However, the pore size of traditional molecular sieves is less than 1.5nm. Such a small pore size limits the reaction of macromolecules and makes the reaction controlled by diffusion. On the one hand, the r...

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Problems solved by technology

[0004] Usually, the preparation of multi-stage molecular sieve materials includes two methods: one is to prepare zeolite first, and then use alkali solution to dissolve silicon, acid solution to dissolve aluminum or water vapor etching, etc. This is the method used in industry, and the obtained mesoporous The pores are disordered and uncontrollable, often undergoing multiple etchings, and the process is complicated; second, in the in situ synthesis of mesoporous zeolites, hard templates such as carbon aerogels, carbon nanotubes or polymer microspheres are used, but The mesopores generated by hard templates are often isolated pores rather than three-dimensional through pores, which are not conducive to the free diffusion of macromolecules

[0005] In addition, due to the weak interaction between the cationic surfactant and the molecular sieve precursor, the crystallization process is likely to generate a huge crystallization pressure, which makes the surfactant micelles break away from the skeleton and form a phase-separated structure. Although the use of cationic surfactants as templates is beneficial to improve The hydrothermal stability of molecular sieve materials, but the mixed phase structure produced still cannot meet the industrial requirements for catalytic performance and recycling

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