Preparation method of spherical MFI topological structure all-silicon molecular sieve catalyst containing trace rare earth ions and preparation method of caprolactam

Abstract

The invention relates to the field of all-silicon molecular sieves, and discloses a preparation method of a spherical MFI topological structure all-silicon molecular sieve catalyst containing trace rare earth ions and a caprolactam preparation method. The preparation method of the spherical MFI topological structure all-silicon molecular sieve catalyst comprises: a. Silicon source, rare earth ion source, organic template and water are mixed to obtain a colloidal mixture; b. The colloidal mixture is subjected to two-stage variable temperature hydrothermal crystallization to obtain a crystallization product; c. Washing and separation of the crystallization product to obtain a rare earth-containing ionic all-silicon molecular sieve; d, the all-silicon molecular sieve containing rare earth ions is shaped, roasted, and post-treated with an alkaline buffer solution of nitrogen-containing compounds, and then washed, separated, and dried to obtain a spherical all-silicon molecular sieve containing a very small amount of rare earth ions Silicon molecular sieve catalyst. The method can effectively change the performance of the all-silicon molecular sieve catalyst, and the application of the catalyst in the production of caprolactam can achieve better results.

Description

technical field [0001] The invention relates to the field of all-silicon molecular sieves, in particular to a preparation method of a spherical MFI topological structure all-silicon molecular sieve catalyst containing trace rare earth ions and a preparation method of caprolactam. Background technique [0002] The all-silicon molecular sieve with MFI topology was successfully synthesized for the first time in 1978 by E.M.Flanigen of UCC, etc., and belongs to the last member of the "Pentasil" family. All-silicon molecular sieve is an aluminum-free molecular sieve. It is the simplest molecular sieve in the ZSM-5 structural molecular sieve family. Its skeleton only contains silicon atoms and oxygen atoms, and the basic structural unit is SiO 4 tetrahedron. All-silicon molecular sieve has rich microporous structure and regular and uniform three-dimensional fine channels, and has a definite crystal structure of ZSM-5 molecular sieve, high internal specific surface area, good ther...

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Problems solved by technology

So far, there have been no related literatures or patents on the rolling molding of all-silicon molecular sieves with MFI topological structure containing extremely small amounts of rare earth ions and then applied to the gas-phase Beckmann rearrangement reaction of cyclohexanone oxime.

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