Preparation method of SSZ-13 molecular sieve composite material

Abstract

The invention belongs to the field of molecular sieve synthesis, and particularly relates to a preparation method of an SSZ-13 molecular sieve composite material. The preparation method of the SSZ-13 molecular sieve composite material comprises the following steps: synthesizing an SSZ-13 molecular sieve seed crystal; pretreating halloysite; and synthesizing the SSZ-13 molecular sieve composite material. According to the method, the pretreated halloysite is added into the SSZ-13 growth solution for crystallization reaction, so that the yield is increased, and the production cost is greatly reduced; the SSZ-13 molecular sieve composite material obtained by the invention has the property of a hierarchical porous structure, the porosity of a molecular sieve and a catalyst can be improved, and the yield and the catalytic performance are improved.

Description

technical field [0001] The invention belongs to the field of molecular sieve synthesis, in particular to a preparation method of SSZ-13 molecular sieve composite material. Background technique [0002] SSZ-13 molecular sieve is a molecular sieve with CHA topology, which is composed of AlO 4 and SiO 4 Tetrahedrons are connected end-to-end by oxygen atoms to form an ellipsoid cage with an eight-membered ring structure and a three-dimensional crossed channel structure. The channel size is 0.38nm×0.38nm. SSZ-13 molecular sieve is mainly used in the removal of NOx from automobile exhaust, methanol to light olefins (MTO) and gas separation and adsorption, and it shows good performance. [0003] At present, the template agents used in the synthesis of SSZ-13 molecular sieves are N,N,N,-trimethyl-1-adamantylammonium hydroxide cation, benzyltrimethylammonium cation or hydroxide-N,N-dimethylammonium hydroxide -3,5-Dimethylpiperidine is the template agent, but these three template a...

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Problems solved by technology

[0003] At present, the templates used in the synthesis of SSZ-13 molecular sieves are N,N,N,-trimethyl-1-adamantyl ammonium hydroxide cation, benzyltri Methylammonium cation or hydroxide-N,N-dimethyl-3,5-dimethylpiperidine are used as templates, but these three templates are expensive, and about 1.2 tons are needed to produce one ton of SSZ-13 molecular sieve - 2.4 tons of the above-mentioned template agent, but there are very few domestic manufacturers capable of industrial production, resulting in the high cost of synthesizing SSZ-13 molecular sieve, which seriously limits its industrial production

[0004] The prior art discloses the use of choline chloride or other templates to synthesize SSZ-13 molecular sieves, but choline chloride is unstable under alkaline conditions It is easy to decompose into trimethylamine, ethylene glycol, etc. at high temperature, resulting in the defect of the final SSZ-13 molecular sieve, resulting in a large consumption of template agent and extremely low yield, and the product failure rate is extremely high, so the prospect is limited

[0005]Therefore, the SSZ-13 molecular sieve has a long reaction cycle and a relatively low yield, and the key raw material template agent is used in a large amount and is expensive. There is no mass production in China, so the production The production cost of SSZ-13 molecular sieve remains high

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