Modified Y-Beta composite molecular sieve as well as preparation method and application thereof

Abstract

The invention discloses a modified Y-Beta composite molecular sieve as well as a preparation method and application thereof. The preparation method comprises the following steps of under a stirring condition, adding a Y-Beta composite molecular sieve into a pressure container full of an organic base solution, sealing a system, pressurizing to 0.2 to 1.0MPa, then heating to 50 to 90 DEG C, treating for 0.5 to 3 hours at constant temperature, depressurizing, carrying out suction filtration, drying, and roasting to obtain the modified Y-Beta composite molecular sieve. The modified Y-Beta composite molecular sieve prepared through the method has mesopore pore size distribution with a larger size, can provide more reaction spaces for macromolecules, and is beneficial to improving a catalytic performance of the molecular sieve, simple in the preparation method, and applicable to industrial application.

Description

technical field

[0001] The invention relates to a modified Y-Beta composite molecular sieve and its preparation method and application, in particular to a modified Y-Beta composite molecular sieve with mesoporous structure characteristics and its preparation method and application. Background technique

[0002] For a long time, the modification of molecular sieves has been widely concerned by researchers. The research on the modification of molecular sieves is mainly through conventional acid, alkali and hydrothermal treatment modification to carry out desilication and dealumination, and at the same time produce a large number of secondary mesoporous structures. The resulting large number of secondary pores facilitate the reaction and diffusion of macromolecules. The current modification methods are mainly hydrothermal treatment at a certain temperature and then acid treatment, which not only deals with the molecular sieve, improves the hydrothermal stability, but also prod...

Examples

Embodiment 1

[0022] Under stirring conditions, mix the hydrogen-type Y-Beta composite molecular sieve and the tetrapropylammonium hydroxide solution in the high-pressure reactor, feed nitrogen to control the system pressure at 0.5MPa, then raise the temperature to 60°C, and continue stirring at constant temperature for 2 hours , pressure relief, cooling, suction filtration until the pH value is less than 9, drying at 120°C for 13 hours, and calcining at 520°C for 3 hours to obtain a modified Y-Beta composite molecular sieve. The concentration of the tetrapropylammonium hydroxide solution is 0.12mol / L, and the mass ratio of the hydrogen-type Y-Beta composite molecular sieve to the water in the solution is 1:9. The specific properties are shown in Table 1.

Embodiment 2

[0024] Under the condition of stirring, mix the hydrogen type Y-Beta composite molecular sieve and the tetrabutylammonium hydroxide solution in the autoclave, feed air to control the system pressure at 0.6MPa, then raise the temperature to 75°C, continue to stir at constant temperature for 1 hour, discharge Pressed, cooled, suction filtered until the pH value was less than 9, dried at 110°C for 18 hours, and calcined at 550°C for 4 hours to obtain a modified Y-Beta composite molecular sieve. The concentration of tetrabutylammonium hydroxide solution is 0.14mol / L, and the mass ratio of hydrogen Y-Beta composite molecular sieve to water in the solution is 1:12. The specific properties are shown in Table 1.

Embodiment 3

[0026] Under stirring conditions, mix the hydrogen-type Y-Beta composite molecular sieve and tetraethylammonium hydroxide solution in a high-pressure reactor, feed nitrogen to control the system pressure at 0.2MPa, then raise the temperature to 65°C, and continue stirring at constant temperature for 3 hours , pressure relief, cooling, suction filtration until the pH value is less than 9, drying at 100°C for 22 hours, and calcining at 520°C for 6 hours to obtain a modified Y-Beta composite molecular sieve. The concentration of the tetraethylammonium hydroxide solution is 0.14mol / L, and the mass ratio of the hydrogen-type Y-Beta composite molecular sieve to the water in the solution is 1:10. The specific properties are shown in Table 1.

technical field

[0001] The invention relates to a modified Y-Beta composite molecular sieve and its preparation method and application, in particular to a modified Y-Beta composite molecular sieve with mesoporous structure characteristics and its preparation method and application. Background technique

[0002] For a long time, the modification of molecular sieves has been widely concerned by researchers. The research on the modification of molecular sieves is mainly through conventional acid, alkali and hydrothermal treatment modification to carry out desilication and dealumination, and at the same time produce a large number of secondary mesoporous structures. The resulting large number of secondary pores facilitate the reaction and diffusion of macromolecules. The current modification methods are mainly hydrothermal treatment at a certain temperature and then acid treatment, which not only deals with the molecular sieve, improves the hydrothermal stability, but also prod...

Examples

Embodiment 1

[0022] Under stirring conditions, mix the hydrogen-type Y-Beta composite molecular sieve and the tetrapropylammonium hydroxide solution in the high-pressure reactor, feed nitrogen to control the system pressure at 0.5MPa, then raise the temperature to 60°C, and continue stirring at constant temperature for 2 hours , pressure relief, cooling, suction filtration until the pH value is less than 9, drying at 120°C for 13 hours, and calcining at 520°C for 3 hours to obtain a modified Y-Beta composite molecular sieve. The concentration of the tetrapropylammonium hydroxide solution is 0.12mol / L, and the mass ratio of the hydrogen-type Y-Beta composite molecular sieve to the water in the solution is 1:9. The specific properties are shown in Table 1.

Embodiment 2

[0024] Under the condition of stirring, mix the hydrogen type Y-Beta composite molecular sieve and the tetrabutylammonium hydroxide solution in the autoclave, feed air to control the system pressure at 0.6MPa, then raise the temperature to 75°C, continue to stir at constant temperature for 1 hour, discharge Pressed, cooled, suction filtered until the pH value was less than 9, dried at 110°C for 18 hours, and calcined at 550°C for 4 hours to obtain a modified Y-Beta composite molecular sieve. The concentration of tetrabutylammonium hydroxide solution is 0.14mol / L, and the mass ratio of hydrogen Y-Beta composite molecular sieve to water in the solution is 1:12. The specific properties are shown in Table 1.

Embodiment 3

[0026] Under stirring conditions, mix the hydrogen-type Y-Beta composite molecular sieve and tetraethylammonium hydroxide solution in a high-pressure reactor, feed nitrogen to control the system pressure at 0.2MPa, then raise the temperature to 65°C, and continue stirring at constant temperature for 3 hours , pressure relief, cooling, suction filtration until the pH value is less than 9, drying at 100°C for 22 hours, and calcining at 520°C for 6 hours to obtain a modified Y-Beta composite molecular sieve. The concentration of the tetraethylammonium hydroxide solution is 0.14mol / L, and the mass ratio of the hydrogen-type Y-Beta composite molecular sieve to the water in the solution is 1:10. The specific properties are shown in Table 1.

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