Symbiotic composite molecular sieve catalyst applied to MTO reaction, and preparation method thereof

Abstract

The invention discloses a symbiotic composite molecular sieve catalyst applied to a MTO reaction, and a preparation method thereof. The catalyst is mainly formed by symbiotic compounding of SAPO-34 and RUB-50 molecular sieve structures, wherein the SAPO-34 molecular sieve accounts for 60-99% of the total weight of the catalyst, the RUB-50 molecular sieve accounts for 1.0-40% of the total weight ofthe catalyst, the silicon-to-aluminum molar ratio of the oxide in the symbiotic composite molecular sieve is 20-200, and the X-ray diffraction spectrogram of the symbiotic composite molecular sieve shows that the symbiotic composite molecular sieve has a characteristic diffraction peak with relative intensity at a specific 2theta angle. According to the invention, the RUB-50 with the LEV structure and the SAPO-34 with the CHA structure form a symbiotic composite molecular sieve, and the symbiotic composite molecular sieve has two molecular sieve structure characteristics to generate the specificity of the structure, so that the composite molecular sieve has reasonably distributed acidity and good hydrothermal stability, overcomes the limitations of the components, has good catalytic activity, high ethylene and/or propylene selectivity and excellent service life in MTO reaction, well meets the requirements of industrial application, and has broad application prospects.

Description

technical field [0001] The invention relates to a symbiotic composite molecular sieve catalyst applied to MTO reaction and a preparation method thereof, in particular to a SAPO-34 / RUB-50 symbiotic composite molecular sieve catalyst, and belongs to the field of chemical synthesis technology and its application. Background technique [0002] RUB-50 molecular sieve belongs to the LEV topological configuration type molecular sieve, which has two-dimensional intersecting eight-membered ring channels along the [001] and [010] directions, and relatively small channel size. With a lower skeleton density, its theoretical micropore volume can reach 0.3ml / g. Similar to SAPO-34 molecular sieve, RUB-50 molecular sieve also has a larger molecular sieve cage, indicating that this type of small-pore RUB-50 molecular sieve catalyst with large micropore volume has excellent selection in the conversion of methanol and ethanol to light olefins sex. The RUB-50 molecular sieve cage (0.63nm×0.7...

AI Technical Summary

Problems solved by technology

In the MTO catalytic reaction, the outer surface of the SAPO-34 molecular sieve and the cages and pores tend to form larger carbon deposits, which can easily lead to the deactivation of the catalyst.

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