A kind of small grain ssz-13 molecular sieve containing hierarchical pores and its synthesis method

Abstract

The invention discloses a small-grain SSZ-13 molecular sieve containing hierarchical pores and a synthesis method thereof, which comprises the following steps: (1) preparing an aluminum source, a silicon source, a structure-directing agent, an alkali metal hydroxide and water according to a certain Proportionally mixed and fully stirred to obtain a slurry; (2) adding a certain amount of chloride additives and seed crystals to the slurry in step (1), and fully stirring to obtain the material to be crystallized; (3) adding The material to be crystallized is transferred into a crystallization kettle for crystallization for 4 to 48 hours, and then the slurry after crystallization is washed, filtered, dried, and roasted to obtain SSZ-13 molecular sieve. The synthesis method of the present invention has a short synthesis time, and the SSZ-13 molecular sieve has high crystallinity, small crystal grains, a unique multi-level pore structure, and a specific surface area greater than >700m 2 / g, 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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