Method for synthesizing multi-stage porous SAPO-41 molecular sieve nanosheet

Abstract

The invention provides a method for synthesizing a multi-stage porous SAPO-41 molecular sieve nanosheet, relates to a synthesis method of a SAPO-41 molecular sieve, and aims to solve the problems of large grain size and poor mass transfer capacity of a microporous SAPO-41 molecular sieve synthesized by an existing method. The synthesis method comprises the steps: 1, weighing 1 part of pseudo-boehmite, 1.4-1.8 parts of phosphoric acid with the mass concentration of 85%, 1.7-2.1 parts of di-n-butylamine, 0.7-1.1 parts of silica sol, 0.4-1.8 parts of a crystal growth inhibitor and 5.7-6.1 parts of deionized water as raw materials by weight; 2, uniformly stirring the raw materials under the stirring condition to obtain initial gel; 3, making the initial gel subjected to a crystallizing reaction under 175-195 DEG C, and then executing calcination treatment to obtain the molecular sieve nanosheet product. According to the method, the crystal growth inhibitor is added in the synthesis process, so that the multi-stage porous SAPO-41 molecular sieve nanosheet with micropores and intergranular mesopores is synthesized in situ.

Description

technical field [0001] The invention relates to a synthesis method of SAPO-41 molecular sieve. Background technique [0002] SAPO-41 is a silicoaluminophosphate molecular sieve with AFO topology. It is composed of one-dimensional elliptical ten-membered ring channels with a channel size of 0.43nm×0.70nm. Due to its mild acidity, the dual-functional The catalyst shows excellent isomerization selectivity and stability in the production of high-quality diesel oil and lubricating oil with good low-temperature fluidity through isomerization dewaxing of petroleum distillate. Therefore, SAPO-41 molecular sieve is a kind of extremely Catalytic materials with development and application potential. [0003] The SAPO-41 molecular sieve with a multi-level channel structure of micropores and intercrystalline mesoporous pores has the advantages of both the shape selectivity of microporous molecular sieves and the good mass transfer characteristics of mesoporous materials. It has signifi...

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Problems solved by technology

[0006] The present invention will solve the problems such as large grain size, poor mass transfer ability, easy carbon deposition and deactivation of the microporous SAPO-41 molecular sieve synthesized by the existing method, and solve the problem of poor skeleton stability and poor skeleton stability of the multi-stage molecular sieve prepared by the post-processing method. A series of problems such as uncontrollable mesopore distribution and unfriendly environment will also solve the problem of poor connectivity between mesopores and micropores of hierarchical molecular sieves with intracrystalline mesopores synthesized by mesoporous template method, and provide a Synthesis method of hierarchically porous SAPO-41 molecular sieve nanosheets

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