Hierarchical pore-containing small-grain SSZ-13 molecular sieve and synthesis method thereof

Abstract

The invention relates to a hierarchical pore-containing small-grain SSZ-13 molecular sieve and a synthesis method thereof. The synthesis method comprises the following steps: (1) mixing an aluminum source, a silicon source, a structure directing agent, alkali metal hydroxide and water according to a certain proportion, and fully stirring to obtain slurry; (2) adding a certain amount of chloride additive and seed crystal into the slurry in the step (1), and fully stirring to obtain a to-be-crystallized material; and (3) transferring the material to-be-crystallized in the step (2) into a crystallization kettle for crystallization for 4-48h, and then washing, filtering, drying and roasting the crystallized slurry to obtain the SSZ-13 molecular sieve. The synthesis method is short in synthesistime, the SSZ-13 molecular sieve is high in crystallinity and has the characteristic of small crystal grains, the SSZ-13 molecular sieve has a unique hierarchical pore structure, the specific surfacearea is larger than or equal to 700 m<2> / g, and the SSZ-13 molecular sieve has good hydrothermal stability and catalytic activity.

Description

technical field [0001] The invention belongs to the field of preparation of inorganic materials and catalyst materials, and in particular relates to a small-grain SSZ-13 molecular sieve containing hierarchical holes and a synthesis method thereof. Background technique [0002] SSZ-13 molecular sieve has a CHA structure, and its special ordered skeleton composition makes it have a relatively developed pore structure and good thermal stability, and is an excellent adsorbent or catalyst carrier. In recent years, with the continuous deepening of research on molecular sieve materials, the application of SSZ-13 molecular sieves has become more and more extensive. Aromatic structure reaction, adsorption and separation of small molecules (such as CO 2 Separation from methane), environmental engineering (CO and low-carbon hydrocarbon removal) and energy conversion (molecular springs) and other fields are also receiving more and more attention. [0003] The study found that the high...

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Problems solved by technology

CN106629761A also announced a low-cost synthetic method of SSZ-13 with good hydrothermal stability, but the specific surface area of ​​SSZ-13 synthesized by it is still not more than 600m 2 / g

[0004] In addition, the synthesis time of SSZ-13 molecular sieve in the prior art is relatively long. For example, CN 201310645906.4 discloses a method for synthesizing SSZ-13 molecular sieve by using choline cation as template agent

This method uses relatively cheap choline chloride as a template to synthesize SSZ-13 molecular sieves, but the synthesis time is at least 4 days, which leads to an increase in synthesis costs and brings considerable obstacles to the industrial production of SSZ-13 molecular sieves.

[0005] In summary, in the prior art, the synthesis of SSZ-13 molecular sieves has a small specific surface area, resulting in low catalyst activity and poor selectivity; long synthesis time, resulting in increased production costs, hindering industrial production and other technical problems, which urgently need to be solved.

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