Method for synthesizing Cu-SSZ-13 in one step under sodium-free system

Abstract

The invention relates to the technical field of molecular sieve synthesis and discloses a method for synthesizing Cu-SSZ-13 in one step under a sodium-free system. Initial gel is prepared from an aluminum source, a silicon source, a copper ammonia complex and a copper ion load regulator; the initial gel is crystallized and then subjected to filtration, washing, drying and calcination, and the Cu-SSZ-13 molecular sieve is obtained. No conventional sodium hydroxide is used as an alkali source, the sodium content of other raw materials is very low, so that synthesis of the Cu-SSZ-13 molecular sieve under the sodium-free system is guaranteed, and copper ion loading and improvement of stability of copper ions in the target product are facilitated; due to addition of the copper ion load regulator, the load of copper ions is regulated freely in a certain range, and different reaction technological condition requirements are met. The method is simple to operate, repeated ion exchange and calcination technologies are avoided, so that the traditional technological process is greatly simplified, the production cost is reduced effectively, and the method is energy-saving and environmentally friendly, and has enormous industrial application prospects.

Description

technical field [0001] The invention relates to the technical field of molecular sieve synthesis, in particular to a method for synthesizing Cu-SSZ-13 in a sodium-free system in one step. Background technique [0002] In 1985, Zones of the American Chevron (Cheron) Petroleum Company reported for the first time in the patent USP4544538 that SSZ-13 molecular sieves with a CHA configuration were synthesized, which belonged to microporous zeolites according to the size of the zeolite channels. Studies have found that SSZ-13 molecular sieve has an orderly pore structure, high specific surface area, ion exchange and acidity adjustability. At present, the industrial application is relatively mature as the carrier of automobile exhaust gas purification catalyst (Cu-SSZ-13) for NH 3 -SCR technology field. [0003] At present, the preparation of Cu-SSZ-13 molecular sieve includes two technical routes: one is the ion exchange method, that is, the prepared Na-SSZ-13 molecular sieve is ...

AI Technical Summary

Problems solved by technology

This patent uses the existing SSZ-13 molecular sieve powder as a raw material, mixes with copper salt, coats, and roasts. This technology belongs to the post-catalyst modification preparation technology, and it is still difficult to solve the SSZ-13 molecular sieve raw powder mentioned above. During the preparation process of the ion exchange, roasting and other complicated problems

[0006] Patent No. CN 109179447 A discloses a method for preparing a mesoporous Cu-ZSM-5 molecular sieve with high copper content. This patent is to prepare a mesoporous Cu-ZSM-5 molecular sieve whose skeleton contains copper. The source can be sodium metaaluminate, and the alkali source can be sodium hydroxide, both of which are Na-containing compound raw materials. It is also difficult to solve the complex problems of ion exchange and roasting in the final catalyst preparation.

Images