A high-efficiency synthesis method of dual-silicon source and amine-free large-size mordenite with controllable morphology

Abstract

The invention relates to an efficient two-silicon-source amine-free synthesis method for morphology-controllable large-size mordenite. The method comprises specific steps as follows: two kinds of different silicon sources are added sequentially, and large-size mordenite with different morphology is obtained through hydro-thermal synthesis. According to the synthesis method, tetraethoxysilane and pretreated sodium silicate are used as the silicon sources, no organic amine, inorganic ammonia or toxic fluoride is required in the synthesis method, the synthesis process is environment-friendly, the operation process is convenient, the synthesis time is short, and synthesized molecular sieve crystalline grains have the uniform size.

Description

technical field [0001] The invention relates to the field of synthesis of zeolite molecular sieves, in particular to a high-efficiency method for synthesizing a large-size mordenite with controllable morphology using dual silicon sources without amines. Background technique [0002] Zeolite molecular sieve is a microporous crystalline aluminosilicate material, which is used as an important catalyst in modern industry due to its strong acidity, high stability, excellent shape selectivity and reproducibility. Mordenite (MOR structure) is one of the earliest zeolites recognized by humans. It belongs to the orthorhombic crystal system and the space group is C. m C m ,Cell parameters Mordenite has a two-dimensional channel structure, in which the main channel is 12-membered ring channel; the other side-grown channel is a twisted pocket-shaped hole with a size of about Because the pore size on its side is too small, most reactant molecules cannot pass through, so MOR zeol...

AI Technical Summary

Problems solved by technology

However, there are many problems in the synthesis process of mordenite in the prior art. (1) Most of the synthesis of mordenite will rely on organic amines, inorganic ammonia or fluorides as templates, which are very easy to pollute the environment; (2) The crystallization time of ordinary mordenite is long, and the crystallization time is generally more than 24h. Although large-size mordenite can be synthesized, the crystallization time of large-size mordenite crystals is often more than 3-8 days; (3) preparing large-size mordenite crystals Zeolite is commonly used with organic substances such as alcohols, and the operation process is complicated

Images