A kind of modified Y-type molecular sieve and preparation method thereof

Abstract

The invention discloses a modified Y type molecular sieve and a preparation method thereof. The molecular sieve has the following properties: the total pore volume is 0.76-1.25ml / g, wherein the mesoporous volume is 0.55-1.05ml / g and the mesoporous volume is 65-90% of the total pore volume; the mole ratio of silicon oxide to aluminum oxide is 10-35; and the specific surface area is 680-1050m<2> / g. The preparation method comprises the following steps: under a stirring condition, adding the Y type molecular sieve into a pressure container filled with organic aqueous alkali; closing the system; increasing the pressure to 0.2-1.0MPa, and then increasing temperature to 50-90 DEG C and treating for 0.5-3 hours under constant temperature; and relieving pressure, performing suction filtration, drying and roasting, thereby acquiring the modified Y type molecular sieve. The molecular sieve has larger-size mesoporous distribution and can supply much more reaction space for macromolecules; the catalytic performance of the molecular sieve is promoted; and the preparation method is simple and is suitable for industrial application.

Description

technical field

[0001] The invention relates to a modified Y-type molecular sieve and a preparation method thereof. Background technique

[0002] Y-type molecular sieve is formed by octahedral molecular sieve cages interpenetrating with each other along three crystal axis directions through twelve-membered rings. It is an excellent catalyst active component, not only has high cracking activity, but also has good selectivity. Therefore, the discovery and use of Y-type molecular sieve has epoch-making significance in the field of catalysis.

[0003] Since Y-type molecular sieves with a low silicon-aluminum ratio (the molar ratio of silicon oxide to aluminum oxide is between 3 and 4.2) do not have good hydrothermal stability, they have not been widely studied and widely used in the actual synthesis process and application. attention. The high silicon-aluminum ratio Y-type molecular sieve (the molar ratio of silicon oxide to aluminum oxide is above 4.3) has good hydrothermal s...

Examples

Embodiment 1

[0020] Under stirring conditions, mix Y-1 and tetrapropylammonium hydroxide solution in a high-pressure reactor, feed nitrogen to control the system pressure at 0.4MPa, then raise the temperature to 70°C, continue stirring at constant temperature for 2 hours, and release the pressure. Cool, filter with suction until the pH value is less than 9, dry at 120°C for 12 hours, and calcinate at 500°C for 3 hours to obtain a modified Y-type molecular sieve. The concentration of the tetrapropylammonium hydroxide solution is 0.12mol / L, and the mass ratio of Y-1 to water in the solution is 1:9. The specific properties of molecular sieves are shown in Table 1.

Embodiment 2

[0022] Under stirring conditions, Y-1 and tetrabutylammonium hydroxide solution were mixed in a high-pressure reactor, and air was introduced to control the system pressure at 0.6MPa, then the temperature was raised to 80°C, and constant temperature stirring was continued for 1 hour, pressure relief, cooling, Suction filtration until the pH value is less than 9, drying at 110°C for 18 hours, and calcining at 550°C for 4 hours to obtain a modified Y-type molecular sieve. The concentration of tetrabutylammonium hydroxide solution is 0.15mol / L, and the mass ratio of Y-1 to water in the solution is 1:11. The specific properties of molecular sieves are shown in Table 1.

Embodiment 3

[0024] Under stirring conditions, mix Y-1 and tetraethylammonium hydroxide solution in a high-pressure reactor, feed nitrogen to control the system pressure at 0.2MPa, then raise the temperature to 60°C, continue stirring at constant temperature for 3 hours, and release the pressure. Cool, filter with suction until the pH value is less than 9, dry at 100°C for 24 hours, and calcinate at 520°C for 6 hours to obtain a modified Y-type molecular sieve. The concentration of tetraethylammonium hydroxide solution is 0.14mol / L, and the mass ratio of Y-1 to water in the solution is 1:10. The specific properties of molecular sieves are shown in Table 1.

technical field

[0001] The invention relates to a modified Y-type molecular sieve and a preparation method thereof. Background technique

[0002] Y-type molecular sieve is formed by octahedral molecular sieve cages interpenetrating with each other along three crystal axis directions through twelve-membered rings. It is an excellent catalyst active component, not only has high cracking activity, but also has good selectivity. Therefore, the discovery and use of Y-type molecular sieve has epoch-making significance in the field of catalysis.

[0003] Since Y-type molecular sieves with a low silicon-aluminum ratio (the molar ratio of silicon oxide to aluminum oxide is between 3 and 4.2) do not have good hydrothermal stability, they have not been widely studied and widely used in the actual synthesis process and application. attention. The high silicon-aluminum ratio Y-type molecular sieve (the molar ratio of silicon oxide to aluminum oxide is above 4.3) has good hydrothermal s...

Examples

Embodiment 1

[0020] Under stirring conditions, mix Y-1 and tetrapropylammonium hydroxide solution in a high-pressure reactor, feed nitrogen to control the system pressure at 0.4MPa, then raise the temperature to 70°C, continue stirring at constant temperature for 2 hours, and release the pressure. Cool, filter with suction until the pH value is less than 9, dry at 120°C for 12 hours, and calcinate at 500°C for 3 hours to obtain a modified Y-type molecular sieve. The concentration of the tetrapropylammonium hydroxide solution is 0.12mol / L, and the mass ratio of Y-1 to water in the solution is 1:9. The specific properties of molecular sieves are shown in Table 1.

Embodiment 2

[0022] Under stirring conditions, Y-1 and tetrabutylammonium hydroxide solution were mixed in a high-pressure reactor, and air was introduced to control the system pressure at 0.6MPa, then the temperature was raised to 80°C, and constant temperature stirring was continued for 1 hour, pressure relief, cooling, Suction filtration until the pH value is less than 9, drying at 110°C for 18 hours, and calcining at 550°C for 4 hours to obtain a modified Y-type molecular sieve. The concentration of tetrabutylammonium hydroxide solution is 0.15mol / L, and the mass ratio of Y-1 to water in the solution is 1:11. The specific properties of molecular sieves are shown in Table 1.

Embodiment 3

[0024] Under stirring conditions, mix Y-1 and tetraethylammonium hydroxide solution in a high-pressure reactor, feed nitrogen to control the system pressure at 0.2MPa, then raise the temperature to 60°C, continue stirring at constant temperature for 3 hours, and release the pressure. Cool, filter with suction until the pH value is less than 9, dry at 100°C for 24 hours, and calcinate at 520°C for 6 hours to obtain a modified Y-type molecular sieve. The concentration of tetraethylammonium hydroxide solution is 0.14mol / L, and the mass ratio of Y-1 to water in the solution is 1:10. The specific properties of molecular sieves are shown in Table 1.

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