A kind of hierarchical porous silicon aluminum molecular sieve nanocluster and its preparation method

Abstract

The invention discloses a hierarchical-pore silicon-aluminum molecular sieve nano-cluster and a preparation method thereof. The hierarchical-pore silicon-aluminum molecular sieve nano-cluster is composed of molecular sieve nanoparticles and has a mesoporous-micropore hierarchical-pore structure, wherein the pore diameter of a mesoporous is 20nm to 30nm. A hierarchical-pore silicon-aluminum molecular sieve with a micropore, the mesoporous and a large pore volume is obtained by adopting a steam assisted crystallization method and taking an ordered macroporous-mesoporous hierarchical-pore carbonmaterial as a hard template agent through adjusting the dosage of a molecular sieve mother solution and a hard template. According to the hierarchical-pore silicon-aluminum molecular sieve nano-cluster prepared by the preparation method, a mesoporous pore channel is introduced into a nano molecular sieve, so that the obtained molecular sieve has properties which are different from a conventional nano molecular sieve; the molecular sieve has excellent acid properties and the structure contains a hierarchically-distributed pore channel structure, so that the molecular sieve has a synergistic effect and a special catalysis property; the preparation method is simple and feasible, synthetic conditions are easy to control and the period is short, so that the preparation method is suitable for popularization and application.

Description

technical field [0001] The invention relates to the technical field of molecular sieve synthesis, in particular to a nano-cluster of multi-level porous silicon-aluminum molecular sieves and a preparation method thereof. Background technique [0002] In recent years, zeolite molecular sieves, as solid acid catalysts, have been widely used in important fields such as petrochemical industry, petroleum cracking and organic macromolecule synthesis. However, the size of the micropores of zeolite molecular sieves greatly limits the material transport performance of guest molecules in the catalyst, making it impossible for macromolecules to reach the active sites inside the micropores of the molecular sieve, which leads to the deactivation of the catalyst due to carbon deposition in the pores, thereby limiting its Therefore, improving the circulation and diffusion properties of zeolite molecular sieves has become one of the important ways to improve their catalytic performance. [...

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Problems solved by technology

However, in the catalytic reaction system, nano-molecular sieves are prone to agglomeration and their separation process is relatively complicated, which greatly limits their wide application.

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