Synthetic method for MCM-22 molecular sieve

Abstract

The synthesis process of MCM-22 molecular sieve includes the steps of: ultrasonically treating colloid containing Si source, Al source, alkali and water in water medium at 25-80deg.c at ultrasonic frequency of 40 KHz and ultrasonic power of 1-50 W for 10í½180 min; cooling the colloid to room temperature, adding template agent and mixing homogeneously; and statically hydrothermal crystallizing the mixture in a high pressure caldron at 120-200deg.c and self-produced pressure for 20-140 hr to obtain high quality MCM-22 molecular sieve. The preparation process of the present invention is simple, short in synthesis period and low template agent consumption, and the present invention expands the MCM-22 molecular sieve synthesizing range and opens one new way for synthesizing various kinds of molecular sieve.

Description

technical field

[0001] The invention relates to the synthesis of molecular sieves, in particular to a synthesis method of MCM-22 molecular sieves. The crystallization time of the molecular sieve can be significantly shortened by using ultrasonic waves in the gel preparation process, and the rapid synthesis of the molecular sieve can be realized. Background technique

[0002] Zeolite molecular sieves have been more and more widely used in catalytic reactions due to their high activity, high selectivity and environmental friendliness. MCM-22 molecular sieve was successfully developed by Mobil Company of the United States in 1990. The zeolite has two independent pore systems. One system is a two-dimensional sinusoidal channel structure composed of regular ten-membered rings, and the other is a channel containing supercages that communicate through ten-membered ring windows. Molecular sieves with MWW structure represented by MCM-22 have a unique pore system, excellent thermal / ...

Examples

Embodiment 1

[0029] With 0.84 gram of NaOH (Tianjin Yuanli Chemical Co., Ltd., NaOH≥96.0% by weight), 1.36 gram of NaAlO 2 (Homemade, Al 2 o 3 ≥50.2% by weight), 12.5 grams of coarse-porous silica gel (Qingdao Meigao Trading Co., Ltd., SiO 2 ≥95.8 wt%) and 34.7 g H 2 O mixed to obtain a colloid. Colloids have the following molar composition: OH - :Al 2 o 3 : SiO 2 :H 2O=0.1:0.03:1:10. The colloid was placed in an aqueous medium at 50° C. for 60 minutes with an ultrasonic wave with a power of 50 W. Cool the colloid to room temperature, add 2.25 ml of HMI (hexamethyleneimine), and stir evenly to prepare a reaction mixture. The reaction mixture has the following molar composition: OH - :Al 2 o 3 : SiO 2 :R:H 2 O=0.1:0.03:1:0.1:10. The reaction mixture was transferred to an autoclave for static crystallization at 150°C for 40 hours, and then the crystallization reaction was stopped. After the product was washed and filtered, it was dried at 120°C for 10 hours to obtain MCM-22 m...

Embodiment 2

[0031] 0.41 g NaAlO 2 , 0.42 g NaOH, 28 g H 2 O and 13.8 g of silica sol (industrial grade, SiO 2 ≥43.5% by weight) mixed to obtain a colloid. Colloids have the following molar composition: OH - :Al 2 o 3 : SiO 2 :H 2 O=0.1:0.02:1:20. The colloid was placed in an aqueous medium at 40° C. for 90 minutes using an ultrasonic wave with a power of 25 W. Cool the colloid to room temperature, add 3.38 ml of HMI, and stir evenly to prepare a reaction mixture. The reaction mixture has the following molar composition: OH - :Al 2 o 3 : SiO 2 :R:H 2 O=0.1:0.03:1:0.3:20. The reaction mixture was transferred into an autoclave and statically crystallized at 160°C for 60 hours, then the crystallization reaction was stopped, and the product was washed and filtered, and dried at 120°C for 10 hours to obtain MCM-22 molecular sieve. figure 2 .

Embodiment 3

[0033] 0.81 g NaAlO 2 , 1.67 g NaOH, 287 g H 2 O and 26.2 grams of silica (Hunan Yiyang, SiO 2 ≥91.2% by weight) mixed to obtain a colloid. Colloids have the following molar composition: OH - :Al 2 o 3 : SiO 2 :H 2 O=0.1:0.01:1:40. The colloid was placed in an aqueous medium at 30° C. for 60 minutes with an ultrasonic wave with a power of 50 W. Cool the colloid to room temperature, add 22.5 ml of HMI, and stir evenly to prepare a reaction mixture. The reaction mixture has the following molar composition: OH - :Al 2 o 3 : SiO 2 :R:H 2 O=0.1:0.01:1:0.5:40. The reaction mixture was transferred to an autoclave for static crystallization at 150°C for 96 hours, and then the crystallization reaction was stopped. After the product was washed and filtered, it was dried at 120°C for 10 hours to obtain MCM-22 molecular sieve. image 3 .

technical field

[0001] The invention relates to the synthesis of molecular sieves, in particular to a synthesis method of MCM-22 molecular sieves. The crystallization time of the molecular sieve can be significantly shortened by using ultrasonic waves in the gel preparation process, and the rapid synthesis of the molecular sieve can be realized. Background technique

[0002] Zeolite molecular sieves have been more and more widely used in catalytic reactions due to their high activity, high selectivity and environmental friendliness. MCM-22 molecular sieve was successfully developed by Mobil Company of the United States in 1990. The zeolite has two independent pore systems. One system is a two-dimensional sinusoidal channel structure composed of regular ten-membered rings, and the other is a channel containing supercages that communicate through ten-membered ring windows. Molecular sieves with MWW structure represented by MCM-22 have a unique pore system, excellent thermal / ...

Examples

Embodiment 1

[0029] With 0.84 gram of NaOH (Tianjin Yuanli Chemical Co., Ltd., NaOH≥96.0% by weight), 1.36 gram of NaAlO 2 (Homemade, Al 2 o 3 ≥50.2% by weight), 12.5 grams of coarse-porous silica gel (Qingdao Meigao Trading Co., Ltd., SiO 2 ≥95.8 wt%) and 34.7 g H 2 O mixed to obtain a colloid. Colloids have the following molar composition: OH - :Al 2 o 3 : SiO 2 :H 2O=0.1:0.03:1:10. The colloid was placed in an aqueous medium at 50° C. for 60 minutes with an ultrasonic wave with a power of 50 W. Cool the colloid to room temperature, add 2.25 ml of HMI (hexamethyleneimine), and stir evenly to prepare a reaction mixture. The reaction mixture has the following molar composition: OH - :Al 2 o 3 : SiO 2 :R:H 2 O=0.1:0.03:1:0.1:10. The reaction mixture was transferred to an autoclave for static crystallization at 150°C for 40 hours, and then the crystallization reaction was stopped. After the product was washed and filtered, it was dried at 120°C for 10 hours to obtain MCM-22 m...

Embodiment 2

[0031] 0.41 g NaAlO 2 , 0.42 g NaOH, 28 g H 2 O and 13.8 g of silica sol (industrial grade, SiO 2 ≥43.5% by weight) mixed to obtain a colloid. Colloids have the following molar composition: OH - :Al 2 o 3 : SiO 2 :H 2 O=0.1:0.02:1:20. The colloid was placed in an aqueous medium at 40° C. for 90 minutes using an ultrasonic wave with a power of 25 W. Cool the colloid to room temperature, add 3.38 ml of HMI, and stir evenly to prepare a reaction mixture. The reaction mixture has the following molar composition: OH - :Al 2 o 3 : SiO 2 :R:H 2 O=0.1:0.03:1:0.3:20. The reaction mixture was transferred into an autoclave and statically crystallized at 160°C for 60 hours, then the crystallization reaction was stopped, and the product was washed and filtered, and dried at 120°C for 10 hours to obtain MCM-22 molecular sieve. figure 2 .

Embodiment 3

[0033] 0.81 g NaAlO 2 , 1.67 g NaOH, 287 g H 2 O and 26.2 grams of silica (Hunan Yiyang, SiO 2 ≥91.2% by weight) mixed to obtain a colloid. Colloids have the following molar composition: OH - :Al 2 o 3 : SiO 2 :H 2 O=0.1:0.01:1:40. The colloid was placed in an aqueous medium at 30° C. for 60 minutes with an ultrasonic wave with a power of 50 W. Cool the colloid to room temperature, add 22.5 ml of HMI, and stir evenly to prepare a reaction mixture. The reaction mixture has the following molar composition: OH - :Al 2 o 3 : SiO 2 :R:H 2 O=0.1:0.01:1:0.5:40. The reaction mixture was transferred to an autoclave for static crystallization at 150°C for 96 hours, and then the crystallization reaction was stopped. After the product was washed and filtered, it was dried at 120°C for 10 hours to obtain MCM-22 molecular sieve. image 3 .

Images