ZSM-5/ZSM-23/Y zeolite triphase coexisting molecular sieve and method for synthesizing same

Abstract

The invention relates to a ZSM-5/ZSM-23/Y zeolite triphase coexisting molecular sieve and a method for synthesizing the same, and mainly solves the problems that a porous material synthesized by the prior art is single in pore-size, weak in acid and low in activity. The method prepares the ZSM-5/ZSM-23/Y zeolite triphase coexisting molecular sieve by adding a seed crystal containing a Y zeolite precursor during a synthesis process of triphase coexisting molecular sieve, and well controlling the nucleating and growing process of a molecular sieve during a synthesis process of triphase coexisting molecular sieve. The coexistence phase ratio of the ZSM-5/ZSM-23/Y zeolite triphase coexisting molecular sieve is adjustable, and a mole relation of the components of the synthesized triphase coexisting molecular sieve is nSiO2 :Al2O3, wherein n is between 10 and 1,000; the triphase coexisting molecular sieve has more than three phases; the XRD diffraction pattern of the triphase coexisting molecular sieve comprises a technical proposal that a maximum value of a distance d is at positions between 14.52-0.1 and 14.52+0.1 A, 11.22-0.1 and 11.22+0.1 A, 10.1-0.05 and 10.1+0.1 A, 9.97-0.05 and 9.97+0.05 A, 7.87-0.2 and 7.87+0.2 A, 5.98-0.1 and 5.98+0.1 A, 5.71-0.1 and 5.71+0.1 A, 5.59-0.1 and 5.59+0.1 A, 4.53-0.1 and 4.53+0.1 A, 3.90-0.1 and 3.90+0.1 A, 3.71-0.05 and 3.71+0.05 A, 3.43-0.05 and 3.43 +0.05 A, 2.99-0.05 and 2.99+0.05A, 2.86-0.05 and 2.86+0.05 A, and 2.53-0.1 and 2.53+0.1 A; therefore, the problems are solved well. The triphase coexisting molecular sieve can be used in the industrial production of ethylene and propylene through the catalytic pyrolysis of naphtha.

Description

technical field [0001] The invention relates to a ZSM-5 / ZSM-23 / Y zeolite three-phase symbiotic molecular sieve and a synthesis method thereof. Background technique [0002] ZSM-23, Y zeolite and ZSM-5 porous materials are widely used in petrochemical and other fields due to their good shape-selective catalytic performance and good thermal stability. However, because the two molecular sieve materials have uniform and single pore size, weak acidity, low activity and poor selectivity, they cannot process complex components separately, and their catalytic properties for the same reactant are different. The three-phase symbiotic molecular sieve containing more than two components has a multi-level pore structure and a wide range of strong and weak acids. It can handle complex components with different molecular diameters and exert their synergistic catalytic effect. [0003] Documents CN1565967A and CN1565970A report using mordenite or ZSM-5 as a seed crystal, respectively addin...

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Problems solved by technology

[0007] One of the technical problems to be solved by the present invention is that the porous material synthesized by the prior art has a single pore size, weak acidity and low activity, and a new ZSM-5 / ZSM-23 / Y zeolite three-phase symbiotic molecular sieve is provided

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