Synthesis method of silicoaluminophosphate (SAPO) molecular sieve with CHA structure and catalyst prepared thereby

Abstract

The invention discloses a synthesis method of silicoaluminophosphate (SAPO) molecular sieve with a CHA structure and a catalyst prepared by using the molecular. The synthesis method is characterized in that hexamethyleneimine is adopted as a structure-directing agent, and synthesis of the molecular sieve is carried out in the presence of a little amount of SAPO molecular sieve seed crystal with the CHA structure.

Description

technical field [0001] The invention belongs to the field of SAPO molecular sieves, and in particular relates to a synthesis method of SAPO molecular sieves with a CHA structure, and the catalytic application of the above-mentioned materials in the reaction of converting oxygen-containing compounds into low-carbon olefins. Background technique [0002] In 1984, United Carbide Corporation (UCC) developed the SAPO molecular sieve series of silicoaluminophosphate (USP 4440871). The molecular sieve is a kind of crystalline silicoaluminophosphate, and its three-dimensional framework structure is composed of PO 2 + , AlO 2 - and SiO 2 tetrahedron composition. Among them, SAPO-34 is a chabazite-like structure, the main channel is composed of eight rings, and the orifice is 0.38nm×0.38nm. Due to its suitable acidity and pore structure, SAPO-34 molecular sieve has attracted much attention because of its excellent catalytic performance in the reaction of methanol to light olefin...

AI Technical Summary

Problems solved by technology

But so far, the relationship between the structure of organic amines and the structures of the molecular sieves they lead to is not very clear.

Although many researchers have done a lot of research and attempts in this area, and have made some progress, it is still very difficult to predict the structure between the structure-directing agent and the molecular sieve generated by it.

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