Nanosheet self-assembled SAPO-34 molecular sieve and preparation method thereof

Abstract

The invention relates to a nanosheet self-assembled SAPO-34 molecular sieve and a preparation method thereof. According to the nanosheet self-assembled SAPO-34 molecular sieve, nanosheets with the average thickness of 10-100nm are adopted to form the SAPO-34 molecular sieve with the granular size of 0.5-7mu m through self-assembling, the molecular sieve takes the shape of a sphere, a sphere-like body, a cube, a cube-like body or a spindle in morphology. The molecular sieve is accordant in structure and good in dispersity. The preparation method is simple and easy to operate, the prepared SAPO-34 molecular sieve material is large in specific surface and high in acid content, can be used in catalysis processes such as low-carbon olefin (MTO) preparation through methanol conversion and automobile tail gas treatment, and has potential industrial development prospect.

Description

technical field [0001] The invention relates to a nanosheet self-assembled SAPO-34 molecular sieve and a preparation method thereof, belonging to the field of chemistry. Background technique [0002] SAPO-34 molecular sieve is one of the series of microporous SAPO silicoaluminophosphate molecular sieves. It was developed by Union Carbide Corporation (UCC) in 1984. It has a microporous structure similar to that of CHA. It is used in catalytic methanol production. When olefin (MTO) reacts, its medium-strength acid center is conducive to the generation of C1-C5 hydrocarbons, and its eight-membered ring opening is not conducive to the diffusion of macromolecules. Only C1-C3 can easily diffuse out of the crystal. For low-carbon Olefin selectivity is as high as 90%. Therefore, SAPO-34 molecular sieve has become the preferred catalyst for methanol-to-olefins (MTO) technology in the world, and has been well applied in industry. [0003] Judging from the current research results, t...

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Problems solved by technology

[0008] The SAPO-34 molecular sieves with special morphology (generally speaking, the SAPO-34 molecular sieve has a cubic shape) prepared by the above disclosed technology are mostly spherical, microspherical and sheet-like, and the process is relatively complicated.

So far, there has been no SAPO-34 molecular sieve prepared by self-assembly of nanosheets with a thickness of 10-100 nm by simple hydrothermal crystallization, and its shape and size can be controlled by adjusting the reaction conditions

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