CN106082264A - A kind of multilevel hierarchy molecular sieve bar array, preparation method and applications - Google Patents

Abstract

A molecular sieve rod array with multi-level structure, preparation method and application thereof, molecular sieve nanorods have a diameter of 0.1-5 μm and a length of 1-500 μm, and each rod-like structure is formed by stacking nano-molecular sieves of 20-100 nm, with a specific surface area of 200 ‑1000m ² /g, including micropores, mesopores and macropores. The types of multi-level molecular sieve rod arrays include: ZSM‑5 molecular sieve rod array structure, β-type molecular sieve rod array structure and Y-type molecular sieve rod array structure Any one or more of the array structures, the preparation method adopts seed crystal orientation and steam assistance, the method is simple, and the application range is wide. The application is to load 3% zinc, at 450-500 ° C, methanol weight space velocity 0.5-50h ^-1 , within 40 hours of reaction, the average conversion rate of methanol is 95-100%, and the total carbon-based mass yield of aromatics is 75-80%.

Description

A kind of molecular sieve rod array with multi-level structure, preparation method and application thereof

technical field

The invention relates to the technical field of multi-level molecular sieves, in particular to a rod-shaped array of multi-level molecular sieves, a preparation method and an application thereof.

Background technique

For ordinary microporous molecular sieves, the reactant and product molecules are severely limited in mass transfer in the micropore channel, which greatly limits its application in industry. Researchers have overcome the shortcomings of conventional molecular sieves by synthesizing supercage molecular sieves, nanomolecular sieves, and ordered mesoporous molecular sieves. However, the use of these materials has its own inherent drawbacks. For example, although 12-ring molecular sieves effectively alleviate the problem of mass transfer limitation, their thermal stability and the high price of organic templates severely limit their practical applications. Nano-molecular sieves require a complex centrifugal washing process, and the yield is low, which is limited in practical application. The disadvantage of ordered mesoporous molecular sieves is that their framework is not acidic enough, and the amorphous structure of the framework makes it less hydrothermally stable.

In comparison, multi-level molecular sieves can effectively solve the inherent problems of macroporous molecular sieves, nano-molecular sieves and mesoporous molecular sieves because they can provide effective diffusion channels for macromolecules and avoid rapid carbon deposition and deactivation. application. In order to be able to take full advantage of the advantages of the hierarchical structure in the catalytic process, the connection between the hierarchical pores is crucial. Therefore, the design of multi-stage molecular sieves not only needs to introduce channels at all levels, but more importantly, the channels at all levels need to be fully connected. So far, the preparation of hierarchical molecular sieves with rational structures and high acidic strengths remains a challenge.

Contents of the invention

In order to overcome the above-mentioned shortcomings of the prior art, the object of the present invention is to provide a multi-level structured molecular sieve rod array, a preparation method and its application. The preparation method has a wide range of applications, and ZSM-5, β-type and Y-type molecular sieves can be prepared. ; It can effectively improve the mass transfer, and it is very easy for molecules limited by diffusion to enter the pores and active sites.

To achieve the above object, the present invention adopts the following technical solutions:

A molecular sieve rod array with a multi-level structure, the molecular sieve nanorods have a diameter of 0.1-5 μm and a length of 1-500 μm, and each rod-like structure is formed by stacking nanometer molecular sieves of 20-100 nm.

The molecular sieve rod-like array structure with a multi-level structure has a specific surface area of 200-1000m ² /g, and includes three channels of micropores, mesopores and macropores.

The types of the multi-level structure molecular sieve rod arrays include: any one or more of the ZSM-5 molecular sieve rod array structure, the β-type molecular sieve rod array structure and the Y-type molecular sieve rod array structure, wherein the ZSM-5 type The Si/Al molar ratio range of molecular sieve rod array structure is 8:1-50:1; the Si/Al molar ratio range of β-type molecular sieve rod-like array structure is 10:1-50:1; the Y-type molecular sieve rod-like array structure The Si/Al molar ratio ranges from 4:1-30:1.

The preparation method of described ZSM-5 molecular sieve rod-like array structure comprises the steps:

1) Mix ethanol, 0.3mol L ^-1 HNO ₃ and ethyl orthosilicate in a mass ratio of (1-20):(0.2-5):(1-30), stir at room temperature to form a sol, and impregnate the AAO membrane Infiltrated into the sol; then aged and baked to form SiO ₂ hollow tube SiO ₂ /AAO on the AAO pore wall;

2) Mix 10wt%-50wt% tetrapropylammonium hydroxide solution with ethyl orthosilicate at a mass ratio of 1:0.3-5, heat and pre-crystallize to obtain ZSM-5 molecular sieve seed crystals;

3) Mix the ZSM-5 molecular sieve seed crystal, SiO ₂ hollow tube SiO ₂ /AAO and sodium metaaluminate in the mass ratio (0.1~1):(5~50):(0.04~1.7), and dry to obtain the sample ;

4) Place a support in a hydrothermal kettle with a polytetrafluoroethylene liner, and pour water, control the amount of water added to only submerge the support, place a small container above the support, and put the sample obtained in step 3) Put it into a small container so that the water does not come into direct contact with the sample; crystallize at 100-200°C, cool, and filter; wash, dry, and roast the product; dissolve AAO with HCl, wash with deionized water, and obtain sodium ZSM-5 Multi-level structure molecular sieve rod array;

5) The sodium-type ZSM-5 molecular sieve rod-like array with multi-level structure is ion-exchanged with NH ₄ NO ₃ and calcined to finally obtain the ZSM-5 molecular sieve rod-like array structure.

The preparation method of the rod-like array structure of the β-type molecular sieve comprises the following steps:

1) Mix ethanol, 0.3mol L ^-1 HNO ₃ and ethyl orthosilicate in a mass ratio of (1-20):(0.2-5):(1-30), stir at room temperature to form a sol, and impregnate the AAO membrane Infiltrated into the sol; then aged and baked to form SiO ₂ hollow tube SiO ₂ /AAO on the AAO pore wall;

2) Mix tetraethylammonium hydroxide, Al(NO ₃ ) ₃ 9H ₂ O and ethyl orthosilicate in mass ratio (50-100):(0-5):(50-100), heat and dry, Obtain β-type molecular sieve seed crystals;

3) Mix β-type molecular sieve seed crystals, SiO ₂ hollow tube SiO ₂ /AAO and sodium metaaluminate at a mass ratio of (0.02-1):(5-50):(0.003-1.5), and dry to obtain a sample;

4) Place a support in a hydrothermal kettle with a polytetrafluoroethylene liner, and pour water, control the amount of water added to only submerge the support, place a small container above the support, and put the sample obtained in step 3) Put it into a small container so that the water does not come into direct contact with the sample; crystallize at 100-200°C, cool, filter, dry, and roast, dissolve AAO with HCl, wash with deionized water, and obtain a rod-shaped array of sodium-type β-type molecular sieves;

5) The sodium-type β-type molecular sieve rod-like array is ion-exchanged with NH ₄ NO ₃ , and calcined to obtain a β-type molecular sieve rod-like array structure.

The preparation method of the Y-type molecular sieve rod-like array structure comprises the following steps:

1) Mix ethanol, 0.3mol L ^-1 HNO ₃ and ethyl orthosilicate in a mass ratio of (1-20):(0.2-5):(1-30), stir at room temperature to form a sol, and impregnate the AAO membrane Completely infiltrated into the sol; then aged and baked to form SiO ₂ hollow tube SiO ₂ /AAO on the AAO pore wall;

2) Mix NaOH, NaAlO ₂ , Na ₂ SiO ₃ ·9H ₂ O and H ₂ O in mass ratio (1-2):(2-4):(70-90):(40-80) and dry them , to obtain Y molecular sieve seed crystals;

3) Mix Y molecular sieve seed crystals, SiO ₂ hollow tube SiO ₂ /AAO and sodium metaaluminate at a mass ratio of (0.02-1):(5-50):(0.02-1), and dry to obtain a sample;

4) Place a support in a hydrothermal kettle with a polytetrafluoroethylene liner, and pour water, control the amount of water added to only submerge the support, place a small container above the support, and put the sample obtained in step 3) Put it into a small container so that the water does not directly contact with the sample; crystallize at 100-200 ° C, cool, filter, dry, and roast; use HCl to dissolve AAO, wash with deionized water, and obtain a sodium-type Y molecular sieve rod-shaped array;

5) The sodium-type Y molecular sieve rod array is ion-exchanged with NH ₄ NO ₃ and calcined to finally obtain the Y-type molecular sieve rod-like array structure.

In the method for preparing aromatics by converting methanol into aromatics with a rod-shaped array of molecular sieves with a multi-level structure, after loading 3% zinc, at 450-500°C and at a methanol weight space velocity of 0.5-50h ^-1 , the average conversion rate of methanol obtained within 40 hours of reaction is 95-100%, and the total carbon-based mass yield of aromatic hydrocarbons is 75-80%.

The beneficial effects of the present invention are:

The seed crystal guiding and steam-assisted methods used in the present invention are simple and widely applicable, and can prepare ZSM-5 rod-shaped array structures, β-type molecular sieve rod-shaped array structures, and Y-type molecular sieve rod-shaped array structures, which are better than those prepared in aqueous solution at present. The molecular sieve approach costs 60-80% less.

The invention uses AAO as a template, and the formed molecular sieve has a three-dimensional ordered macropore structure.

The macropores of the AAO template used in the present invention are interconnected, and the formed molecular sieve rod-like structures can be effectively connected to form an integral structure.

Compared with the original preparation methods of various molecular sieves with multi-level structures, the present invention can prepare multi-level structures with lower silicon-aluminum ratio, has stronger acidity and wider application range.

Description of drawings

Fig. 1 is the ZSM-5 molecular sieve rod array structure prepared in Example 1.

detailed description

The present invention will be described in detail below in conjunction with the embodiments.

Example 1

The preparation method of ZSM-5 molecular sieve rod-like array structure comprises the steps:

1) Mix ethanol, 0.3mol L ^-1 HNO ₃ and ethyl orthosilicate at a mass ratio of 1:0.2:1, stir at room temperature to form a sol, and soak the AAO film into the sol to completely infiltrate; then aging, roasting, and A SiO ₂ hollow tube SiO ₂ /AAO is formed on the AAO pore wall;

2) Mix 10wt% tetrapropylammonium hydroxide solution with ethyl orthosilicate at a mass ratio of 1:0.3, heat and precrystallize to obtain ZSM-5 molecular sieve seed crystals;

3) Mix ZSM-5 molecular sieve seed crystals, SiO ₂ hollow tube SiO ₂ /AAO and sodium metaaluminate at a mass ratio of 0.1:5:0.04, and dry to obtain a sample;

4) Place a support in a hydrothermal kettle with a polytetrafluoroethylene liner, and pour water, control the amount of water added to only submerge the support, place a small container above the support, and put the sample obtained in step 3) Put it into a small container so that the water does not come into direct contact with the sample; crystallize at 100°C, cool, and filter; wash, dry, and roast the product; dissolve AAO with HCl, wash with deionized water, and obtain sodium ZSM-5 multi-stage Structural molecular sieve rod arrays.

5) The sodium-type ZSM-5 molecular sieve rod array with multi-level structure was ion-exchanged with NH ₄ NO ₃ and calcined to finally obtain the ZSM-5 molecular sieve rod array structure, as shown in FIG. 1 .

Beneficial effects of this embodiment: the obtained ZSM-5 molecular sieve rod-like array structure, after loading 3% zinc on the ZSM-5 hollow molecular sieve, at 475 ° C, under the methanol weight space velocity of 0.8h ^-1 , react within 60 hours, the obtained The average conversion rate of methanol is 95%, the total carbon-based mass yield of aromatics is 60%, and the yield of p-xylene is 15%.

Example 2

The preparation method of ZSM-5 molecular sieve rod-like array structure comprises the steps:

1) Mix ethanol, 0.3mol L ^-1 HNO ₃ and ethyl orthosilicate at a mass ratio of 20:5:30, stir at room temperature to form a sol, and soak the AAO film into the sol to completely infiltrate; then aging, roasting, and A SiO ₂ hollow tube SiO ₂ /AAO is formed on the AAO pore wall;

2) Mix 50wt% tetrapropylammonium hydroxide solution and ethyl orthosilicate at a mass ratio of 1:5, heat and precrystallize to obtain ZSM-5 molecular sieve seed crystals;

3) Mix ZSM-5 molecular sieve seed, SiO ₂ hollow tube SiO ₂ /AAO and sodium metaaluminate at a mass ratio of 1:50:1.7, and dry to obtain a sample;

4) Place a support in a hydrothermal kettle with a polytetrafluoroethylene liner, and pour water, control the amount of water added to only submerge the support, place a small container above the support, and put the sample obtained in step 3) Put it into a small container so that the water does not come into direct contact with the sample; crystallize at 120°C, cool, and filter; wash, dry, and roast the product; dissolve AAO with HCl, wash with deionized water, and obtain sodium ZSM-5 multistage Structural molecular sieve rod array;

5) The sodium-type ZSM-5 molecular sieve rod-like array with multi-level structure is ion-exchanged with NH ₄ NO ₃ and calcined to finally obtain the ZSM-5 molecular sieve rod-like array structure.

Beneficial effects of this embodiment: after loading 3% zinc on the ZSM-5 hollow molecular sieve, at 475°C, under the methanol weight space velocity of 0.8h ^-1 , within 60 hours of reaction, the average conversion rate of methanol obtained is 95%, and the total aromatics The mass yield of carbon base is 60%, and the yield of p-xylene is 15%.

Example 3

The preparation method of ZSM-5 molecular sieve rod-like array structure comprises the steps:

1) Mix ethanol, 0.3mol L ^-1 HNO ₃ and ethyl orthosilicate at a mass ratio of 5:4:5, stir at room temperature to form a sol, and soak the AAO film into the sol to completely infiltrate; then aging, roasting, and A SiO ₂ hollow tube SiO ₂ /AAO is formed on the AAO pore wall;

2) Mix 20wt% tetrapropylammonium hydroxide solution and ethyl orthosilicate at a mass ratio of 1:1, heat and precrystallize to obtain ZSM-5 molecular sieve seed crystals;

3) Mix ZSM-5 molecular sieve seed crystals, SiO ₂ hollow tube SiO ₂ /AAO and sodium metaaluminate at a mass ratio of 0.2:10:0.2, and dry to obtain a sample;

4) Place a support in a hydrothermal kettle with a polytetrafluoroethylene liner, and pour water, control the amount of water added to only submerge the support, place a small container above the support, and put the sample obtained in step 3) Put it into a small container, so that the water does not directly contact with the sample; crystallize at 160 ° C, cool, filter; wash, dry, and roast the product; dissolve AAO with HCl, wash with deionized water, and obtain sodium ZSM-5 multi-stage Structural molecular sieve rod array;

5) The sodium-type ZSM-5 molecular sieve rod-like array with multi-level structure is ion-exchanged with NH ₄ NO ₃ and calcined to finally obtain the ZSM-5 molecular sieve rod-like array structure.

Beneficial effects of this embodiment: after loading 3% zinc on the ZSM-5 hollow molecular sieve, at 475°C, under the methanol weight space velocity of 0.8h ^-1 , within 60 hours of reaction, the average conversion rate of methanol obtained is 95%, and the total aromatics The mass yield of carbon base is 60%, and the yield of p-xylene is 15%.

Example 4

The preparation method of ZSM-5 molecular sieve rod-like array structure comprises the steps:

1) Mix ethanol, 0.3mol L ^-1 HNO ₃ and ethyl orthosilicate at a mass ratio of 15:0.5:25, stir at room temperature to form a sol, and soak the AAO film into the sol to completely infiltrate; then aging, roasting, A SiO ₂ hollow tube SiO ₂ /AAO is formed on the AAO pore wall;

2) Mix 40wt% tetrapropylammonium hydroxide solution and ethyl orthosilicate at a mass ratio of 1:3, heat and precrystallize to obtain ZSM-5 molecular sieve seed crystals;

3) Mix ZSM-5 molecular sieve seed crystals, SiO ₂ hollow tube SiO ₂ /AAO and sodium metaaluminate at a mass ratio of 0.5:25:1.5, and dry to obtain a sample;

4) Place a support in a hydrothermal kettle with a polytetrafluoroethylene liner, and pour water, control the amount of water added to only submerge the support, place a small container above the support, and put the sample obtained in step 3) Put it into a small container so that the water does not come into direct contact with the sample; crystallize at 200 ° C, cool, and filter; wash, dry, and roast the product; dissolve AAO with HCl, wash with deionized water, and obtain sodium ZSM-5 multi-stage Structural molecular sieve rod array;

5) The sodium-type ZSM-5 molecular sieve rod-like array with multi-level structure is ion-exchanged with NH ₄ NO ₃ and calcined to finally obtain the ZSM-5 molecular sieve rod-like array structure.

Beneficial effects of this embodiment: after loading 3% zinc on the ZSM-5 hollow molecular sieve, at 475°C, under the methanol weight space velocity of 0.8h ^-1 , within 60 hours of reaction, the average conversion rate of methanol obtained is 95%, and the total aromatics The mass yield of carbon base is 60%, and the yield of p-xylene is 15%.

Example 5

A method for preparing a rod-like array structure of a β-type molecular sieve, comprising the steps of:

1) Mix ethanol, 0.3mol L ^-1 HNO ₃ and ethyl orthosilicate at a mass ratio of 1:0.2:1, stir at room temperature to form a sol, and soak the AAO film into the sol to completely infiltrate; then aging, roasting, and A SiO ₂ hollow tube SiO ₂ /AAO is formed on the AAO pore wall;

2) Mix tetraethylammonium hydroxide, Al(NO ₃ ) ₃ .9H ₂ O and ethyl orthosilicate at a mass ratio of 50:0:50, heat and dry to obtain β-type molecular sieve seed crystals;

3) Mix β-type molecular sieve seed crystals, SiO ₂ hollow tube SiO ₂ /AAO and sodium metaaluminate at a mass ratio of 0.02:5:0.003, and dry to obtain a sample;

4) Place a support in a hydrothermal kettle with a polytetrafluoroethylene liner, and pour water, control the amount of water added to only submerge the support, place a small container above the support, and put the sample obtained in step 3) Put it into a small container so that the water does not come into direct contact with the sample; crystallize at 130°C, cool, filter, dry, and roast, dissolve AAO with HCl, and wash with deionized water to obtain a rod-shaped array of sodium-type β-type molecular sieves;

5) The sodium-type β-type molecular sieve rod-like array is ion-exchanged with NH ₄ NO ₃ , and calcined to obtain a β-type molecular sieve rod-like array structure.

Example 6

A method for preparing a rod-like array structure of a β-type molecular sieve, comprising the steps of:

1) Mix ethanol, 0.3mol L ^-1 HNO ₃ and ethyl orthosilicate at a mass ratio of 20:5:30, stir at room temperature to form a sol, and soak the AAO film into the sol to completely infiltrate; then aging, roasting, and A SiO ₂ hollow tube SiO ₂ /AAO is formed on the AAO pore wall;

2) Mix tetraethylammonium hydroxide, Al(NO ₃ ) ₃ .9H ₂ O and ethyl orthosilicate at a mass ratio of 100:5:100, heat and dry to obtain β-type molecular sieve seed crystals;

3) Mix β-type molecular sieve seed crystals, SiO ₂ hollow tube SiO ₂ /AAO and sodium metaaluminate at a mass ratio of 1:50:1.5, and dry to obtain a sample;

4) Place a support in a hydrothermal kettle with a polytetrafluoroethylene liner, and pour water, control the amount of water added to only submerge the support, place a small container above the support, and put the sample obtained in step 3) Put it into a small container so that the water does not come into direct contact with the sample; crystallize at 180°C, cool, filter, dry, and roast, dissolve AAO with HCl, and wash with deionized water to obtain a rod-shaped array of sodium-type β-type molecular sieves;

5) The sodium-type β-type molecular sieve rod-like array is ion-exchanged with NH ₄ NO ₃ , and calcined to obtain a β-type molecular sieve rod-like array structure.

Example 7

A method for preparing a rod-like array structure of a β-type molecular sieve, comprising the steps of:

1) Mix ethanol, 0.3mol L ^-1 HNO ₃ and ethyl orthosilicate at a mass ratio of 5:4:2, stir at room temperature to form a sol, and soak the AAO film into the sol to completely infiltrate; then aging, roasting, and A SiO ₂ hollow tube SiO ₂ /AAO is formed on the AAO pore wall;

2) Mix tetraethylammonium hydroxide, Al(NO ₃ ) ₃ .9H ₂ O and ethyl orthosilicate at a mass ratio of 60:1:70, heat and dry to obtain β-type molecular sieve seed crystals;

3) Mix β-type molecular sieve seed crystals, SiO ₂ hollow tube SiO ₂ /AAO and sodium metaaluminate at a mass ratio of 0.1:40:0.012, and dry to obtain a sample;

4) Place a support in a hydrothermal kettle with a polytetrafluoroethylene liner, and pour water, control the amount of water added to only submerge the support, place a small container above the support, and put the sample obtained in step 3) Put it into a small container so that the water does not come into direct contact with the sample; crystallize at 150°C, cool, filter, dry, and roast, dissolve AAO with HCl, and wash with deionized water to obtain a rod-shaped array of sodium-type β-type molecular sieves;

5) The sodium-type β-type molecular sieve rod-like array is ion-exchanged with NH ₄ NO ₃ , and calcined to obtain a β-type molecular sieve rod-like array structure.

Example 8

A method for preparing a rod-like array structure of a β-type molecular sieve, comprising the steps of:

1) Mix ethanol, 0.3mol L ^-1 HNO ₃ and ethyl orthosilicate at a mass ratio of 15:1:20, stir at room temperature to form a sol, and soak the AAO film into the sol to completely infiltrate; then aging, roasting, and A SiO ₂ hollow tube SiO ₂ /AAO is formed on the AAO pore wall;

2) Mix tetraethylammonium hydroxide, Al(NO ₃ ) ₃ .9H ₂ O and ethyl orthosilicate at a mass ratio of 80:4:80, heat and dry to obtain β-type molecular sieve seed crystals;

3) Mix β-type molecular sieve seed crystals, SiO ₂ hollow tube SiO ₂ /AAO and sodium metaaluminate at a mass ratio of 0.8:40:1.0, and dry to obtain a sample;

4) Place a support in a hydrothermal kettle with a polytetrafluoroethylene liner, and pour water, control the amount of water added to only submerge the support, place a small container above the support, and put the sample obtained in step 3) Put it into a small container so that the water does not come into direct contact with the sample; crystallize at 160°C, cool, filter, dry, and roast, dissolve AAO with HCl, and wash with deionized water to obtain a rod-shaped array of sodium-type β-type molecular sieves;

5) The sodium-type β-type molecular sieve rod-like array is ion-exchanged with NH ₄ NO ₃ , and calcined to obtain a β-type molecular sieve rod-like array structure.

Example 9

A method for preparing a Y-type molecular sieve rod-like array structure, comprising the steps of:

1) Mix ethanol, 0.3mol L ^-1 HNO ₃ and ethyl orthosilicate at a mass ratio of 1:0.2:1, stir at room temperature to form a sol, and soak the AAO film into the sol to completely infiltrate; then aging, roasting, and A SiO ₂ hollow tube SiO ₂ /AAO is formed on the AAO pore wall;

2) NaOH, NaAlO ₂ , Na ₂ SiO ₃ .9H ₂ O and H ₂ O were mixed in a mass ratio of 1:2:70:40, and dried to obtain Y molecular sieve seed crystals;

3) Mix Y molecular sieve seed crystals, SiO ₂ hollow tube SiO ₂ /AAO and sodium metaaluminate at a mass ratio of 0.02:5:0.02, and dry to obtain a sample;

4) Place a support in a hydrothermal kettle with a polytetrafluoroethylene liner, and pour water, control the amount of water added to only submerge the support, place a small container above the support, and put the sample obtained in step 3) Put it into a small container so that the water does not come into direct contact with the sample; crystallize at 100°C, cool, filter, dry, and roast; dissolve AAO with HCl, wash with deionized water, and obtain a rod-shaped array of sodium Y molecular sieves;

5) The sodium-type Y molecular sieve rod array is ion-exchanged with NH ₄ NO ₃ and calcined to finally obtain the Y-type molecular sieve rod-like array structure.

Example 10

A method for preparing a Y-type molecular sieve rod-like array structure, comprising the steps of:

1) Mix ethanol, 0.3mol L ^-1 HNO ₃ and ethyl orthosilicate at a mass ratio of 20:5:30, stir at room temperature to form a sol, and soak the AAO film into the sol to completely infiltrate; then aging, roasting, and A SiO ₂ hollow tube SiO ₂ /AAO is formed on the AAO pore wall;

2) NaOH, NaAlO ₂ , Na ₂ SiO ₃ .9H ₂ O and H ₂ O were mixed in a mass ratio of 2:4:90:80, and dried to obtain Y molecular sieve seed crystals;

3) Mix Y molecular sieve seed crystals, SiO ₂ hollow tube SiO ₂ /AAO and sodium metaaluminate at a mass ratio of 1:50:1, and dry to obtain a sample;

4) Place a support in a hydrothermal kettle with a polytetrafluoroethylene liner, and pour water, control the amount of water added to only submerge the support, place a small container above the support, and put the sample obtained in step 3) Put it into a small container so that the water does not come into direct contact with the sample; crystallize at 130 ° C, cool, filter, dry, and roast; use HCl to dissolve AAO, wash with deionized water, and obtain a sodium-type Y molecular sieve rod-shaped array;

5) The sodium-type Y molecular sieve rod array is ion-exchanged with NH ₄ NO ₃ and calcined to finally obtain the Y-type molecular sieve rod-like array structure.

Example 11

A method for preparing a Y-type molecular sieve rod-like array structure, comprising the steps of:

1) Mix ethanol, 0.3mol L ^-1 HNO ₃ and ethyl orthosilicate at a mass ratio of 1:4:5, stir at room temperature to form a sol, and soak the AAO film into the sol to completely infiltrate; then aging, roasting, and A SiO ₂ hollow tube SiO ₂ /AAO is formed on the AAO pore wall;

2) NaOH, NaAlO ₂ , Na ₂ SiO ₃ .9H ₂ O and H ₂ O were mixed at a mass ratio of 1.5:3:75:50, and dried to obtain Y molecular sieve seed crystals;

3) Mix Y molecular sieve seed crystals, SiO ₂ hollow tube SiO ₂ /AAO and sodium metaaluminate at a mass ratio of 0.05:10:0.1, and dry to obtain a sample;

4) Place a support in a hydrothermal kettle with a polytetrafluoroethylene liner, and pour water, control the amount of water added to only submerge the support, place a small container above the support, and put the sample obtained in step 3) Put it into a small container so that the water does not come into direct contact with the sample; crystallize at 150°C, cool, filter, dry, and roast; dissolve AAO with HCl, wash with deionized water, and obtain a rod-shaped array of sodium Y molecular sieves;

5) The sodium-type Y molecular sieve rod array is ion-exchanged with NH ₄ NO ₃ and calcined to finally obtain the Y-type molecular sieve rod-like array structure.

Example 12

A method for preparing a Y-type molecular sieve rod-like array structure, comprising the steps of:

1) Mix ethanol, 0.3mol L ^-1 HNO ₃ and ethyl orthosilicate at a mass ratio of 15:4:25, stir at room temperature to form a sol, and soak the AAO film into the sol to completely infiltrate; then aging, roasting, and A SiO ₂ hollow tube SiO ₂ /AAO is formed on the AAO pore wall;

2) NaOH, NaAlO ₂ , Na ₂ SiO ₃ .9H ₂ O and H ₂ O were mixed at a mass ratio of 1.5:3.5:85:70, and dried to obtain Y molecular sieve seed crystals;

3) Mix Y molecular sieve seed crystals, SiO ₂ hollow tube SiO ₂ /AAO and sodium metaaluminate at a mass ratio of 0.8:48:0.8, and dry to obtain a sample;

4) Place a support in a hydrothermal kettle with a polytetrafluoroethylene liner, and pour water, control the amount of water added to only submerge the support, place a small container above the support, and put the sample obtained in step 3) Put it into a small container so that the water does not come into direct contact with the sample; crystallize at 200°C, cool, filter, dry, and roast; dissolve AAO with HCl, wash with deionized water, and obtain a rod-shaped array of sodium Y molecular sieves;

5) The sodium-type Y molecular sieve rod array is ion-exchanged with NH ₄ NO ₃ and calcined to finally obtain the Y-type molecular sieve rod-like array structure.

Claims (7)

1. a multilevel hierarchy molecular sieve bar array, it is characterised in that: a diameter of 0.1-5 μm of molecular sieve nanometer rods, length For 1-500 μm, each club shaped structure is piled up by the nano molecular sieve of 20-100nm and is formed.

2. a kind of multilevel hierarchy molecular sieve bar array according to claim 1, it is characterised in that: described multilevel hierarchy Molecular sieve bar array structure, specific surface area is 200-1000m²/ g, includes micropore, mesoporous and macropore three cell channels.

3. a kind of multilevel hierarchy molecular sieve bar array according to claim 1, it is characterised in that: described multilevel hierarchy divides The species of son sieve bar array includes: type ZSM 5 molecular sieve bar array structure, beta molecular sieve bar array structure and Y type divide Any one or more in son sieve bar array structure, wherein, the Si/Al of type ZSM 5 molecular sieve bar array structure rubs You are 8:1-50:1 than scope；The molar ratio range of the Si/Al of beta molecular sieve bar array structure is 10:1-50:1；Y type divides The molar ratio range of the Si/Al of son sieve bar array structure is 4:1-30:1.

4. the preparation method of ZSM-5 molecular sieve bar array structure according to claim 3, it is characterised in that include as Lower step:

1) by ethanol, 0.3mol L^-1HNO₃With tetraethyl orthosilicate with mass ratio (1-20): (0.2-5): (1-30) mixes, Formation colloidal sol is stirred at room temperature, by infiltration in the middle of AAO film immersion to colloidal sol；Then aging, roasting, forms SiO on AAO hole wall₂ Hollow pipe SiO₂/AAO；

2) 10wt%-50wt% TPAOH solution is mixed with mass ratio 1:0.3～5 with tetraethyl orthosilicate, add The pre-crystallization of heat, obtains ZSM-5 molecular sieve crystal seed；

3) by ZSM-5 molecular sieve crystal seed, SiO₂Hollow pipe SiO₂/ AAO and sodium metaaluminate are with mass ratio (0.1～1): (5～ 50): (0.04～1.7) mixes, dry, obtain sample；

4) placing a support in a band teflon-lined water heating kettle, and pouring water into, the addition of control water is only Flooding into support, above support, place a small container, by step 3) gained sample puts in small container, makes water not straight with sample Contact；Crystallization at 100-200 DEG C, cooling, filtration；By product washing, dry, roasting；HCl is used to dissolve AAO, deionization Water washs, and obtains sodium form ZSM-5 multilevel hierarchy molecular sieve bar array；

5) by sodium form ZSM-5 multilevel hierarchy molecular sieve bar array NH₄NO₃Ion exchanges, and roasting finally gives ZSM-5 molecule Sieve bar array structure.

5. the preparation method of beta molecular sieve bar array structure according to claim 3, it is characterised in that include as follows Step:

1) by ethanol, 0.3mol L^-1HNO₃With tetraethyl orthosilicate with mass ratio (1-20): (0.2-5): (1-30) mixes, Formation colloidal sol is stirred at room temperature, by infiltration in the middle of AAO film immersion to colloidal sol；Then aging, roasting, forms SiO on AAO hole wall₂ Hollow pipe SiO₂/AAO；

2) by tetraethyl ammonium hydroxide, Al (NO₃)₃·9H₂O and tetraethyl orthosilicate are with mass ratio (50-100): (0-5): (50- 100) mix, heat drying, obtain beta molecular sieve crystal seed；

3) by beta molecular sieve crystal seed, SiO₂Hollow pipe SiO₂/ AAO and sodium metaaluminate are with mass ratio (0.02～1): (5～50): (0.003～1.5) mixes, and dries, obtains sample；

4) placing a support in a band teflon-lined water heating kettle, and pouring water into, the addition of control water is only Flooding into support, above support, place a small container, by step 3) gained sample puts in small container, makes water not straight with sample Contact；Crystallization at 100-200 DEG C, cooling, filtration, dry, roasting, use HCl to dissolve AAO, deionized water is washed, and obtains Sodium form beta molecular sieve bar array；

5) by sodium form beta molecular sieve bar array and NH₄NO₃Ion exchanges, and roasting obtains beta molecular sieve bar array structure.

6. the preparation method of Y type molecular sieve bar array structure according to claim 3, it is characterised in that include as follows Step:

1) by ethanol, 0.3mol L^-1HNO₃With tetraethyl orthosilicate with mass ratio (1-20): (0.2-5): (1-30) mixes, Formation colloidal sol is stirred at room temperature, by complete wetting in the middle of AAO film immersion to colloidal sol；Then aging, roasting, forms on AAO hole wall SiO₂Hollow pipe SiO₂/AAO；

2) by NaOH, NaAlO₂、Na₂SiO₃·9H₂O and H₂O is with mass ratio (1-2): (2-4): (70-90): (40-80) mixes Close, be dried and process, obtain Y molecular sieve crystal seed；

3) by Y molecular sieve crystal seed, SiO₂Hollow pipe SiO₂/ AAO and sodium metaaluminate are with mass ratio (0.02～1): (5～50): (0.02～1) mixes, and dries, obtains sample；

4) placing a support in a band teflon-lined water heating kettle, and pouring water into, the addition of control water is only Flooding into support, above support, place a small container, by step 3) gained sample puts in small container, makes water not straight with sample Contact；Crystallization at 100-200 DEG C, cooling, filtration, dry, roasting；Using HCl to dissolve AAO, deionized water is washed, and obtains Sodium form Y molecular sieve bar array；

5) by sodium form Y molecular sieve bar array and NH₄NO₃Ion exchanges, roasting, finally gives Y type molecular sieve bar array knot Structure.

7. a kind of multilevel hierarchy molecular sieve bar array according to claim 1, it is characterised in that: described multilevel hierarchy The method that molecular sieve bar array conversion methyl alcohol prepares aromatic hydrocarbons, after loading 3% zinc, at 450-500 DEG C, methanol weight air speed 0.5-50h^-1Under, in reacting 40 hours, gained methyl alcohol average conversion 95-100%, aromatic hydrocarbons total carbon matrix amount yield 75-80%.