Preparation method of metal-doped short b-axis HZSM-5 molecular sieve

Abstract

The invention provides a preparation method of a metal-doped short b-axis HZSM-5 molecular sieve, which comprises the following steps: 1) adding deionized water into a guiding agent, uniformly stirring at room temperature, and then adding a silicon source to obtain silica sol; 2) adding an aluminum source and an inducer into the silica sol, and uniformly stirring to obtain a molecular sieve precursor; 3) adding a metal source into the molecular sieve precursor, and carrying out pre-crystallization; 4) after the pre-crystallization is completed, transferring the mixture into a hydrothermal kettle for hydrothermal crystallization; 5, after hydrothermal crystallization is completed, centrifuging, washing, drying and roasting are conducted, and the metal-doped short b-axis HZSM-5 molecular sieves are obtained.According to the HZSM-5 molecular sieves prepared through the method, active metal and short b-axis hole channel structures are introduced at the same time through in-situ synthesis, the catalytic activity and diffusion performance of the molecular sieves can be improved at the same time, and the application prospects are very good.

Description

Technical Field

[0001] The invention belongs to the field of catalyst preparation, and relates to a method for preparing a metal-doped short b-axis HZSM-5 molecular sieve, in particular to a metal-doped short b-axis HZSM-5 molecular sieve, a preparation method thereof, and an application thereof. Background Art

[0002] HZSM-5 molecular sieve is a microporous molecular sieve with wide applications developed by Mobil in the 1970s. The HZSM-5 framework contains two intersecting ten-membered ring channel systems, of which the pore size of the sinusoidal channel is 5.5Å×5.1Å and the pore size of the straight channel is 5.6Å×5.3Å. Due to its good thermal stability, high specific surface area and suitable acid strength, HZSM-5 molecular sieve is widely used in petrochemical, oil refining and fine chemical industries. However, the longer microporous channels of traditional HZSM-5 molecular sieves limit the diffusion of macromolecular intermediates and reaction products, and reduce the accessibility of the active centers of the molecular sieves, which easily leads to the formation of carbon deposits in the molecular sieve channels and rapid deactivation. In addition, the traditional HZSM-5 molecular sieve has a single active site, and its catalytic activity in aromatization, alkylation and other reactions is not high enough, and it still cannot meet the requirements of industrial production. Therefore, it is of great significance to develop HZSM-5 molecular sieves with both good catalytic activity and diffusion performance.

[0003] In recent years, researchers have carried out a lot of work on the preparation and modification of HZSM-5 molecular sieves. Chinese patent CN 105949019A discloses that HZSM-5 molecular sieves are modified with dehydrogenation metals such as Zn, Ag, Ni, and Ga at different concentrations, and that they also contain high-valent oxides of metals such as V, Ce, Fe, and Cr, and catalyze the aromatization reaction of methanol in a mixed atmosphere of weakly oxidizing gas and other inert diluent gases. The results show that the catalytic activity of the molecular sieve is improved due to the introduction of dehydrogenation metals and high-valent oxides. However, the metal introduced in this patented method does not improve the diffusion performance of the catalyst. Wei Fei et al. (Applied Catalysis B: Environmental, 2019, 243, 721-733) provide a method for preparing a metal-loaded short b-axis HZSM-5 molecular sieve. The method firstly prepares short b-axis HZSM-5 by using an amphiphilic quaternary ammonium salt surfactant; then metal Zn is introduced into the short b-axis HZSM-5 by using the incipient wetness impregnation method to obtain a metal-loaded short b-axis HZSM-5 molecular sieve. This method requires the use of expensive amphiphilic surfactants and requires additional post-processing processes such as incipient wetness impregnation, making the method costly and cumbersome to operate. Summary of the invention

[0004] In order to solve the problem that it is difficult to simultaneously improve the catalytic activity and diffusion performance of the existing HZSM-5 molecular sieve, the present invention provides a method for preparing a metal-doped short b-axis HZSM-5 molecular sieve. The method introduces active metals and short b-axis pore structures into the molecular sieve by adding a metal source and an inducer during an in-situ synthesis process, thereby obtaining a HZSM-5 molecular sieve having both good catalytic activity and diffusion performance through a one-step method.

[0005] The present invention also provides the application of metal-doped short b-axis HZSM-5 molecular sieve in catalyzing the methanol to aromatics reaction. Under the action of the molecular sieve, the methanol conversion rate reaches 99.8%, the aromatics yield reaches 61.4%, and the catalytic life of the molecular sieve reaches more than 60 hours, which has very good application prospects. The present invention is achieved by the following technical solutions:

[0006] A method for preparing a metal-doped short b-axis HZSM-5 molecular sieve comprises the following steps: (1) Add deionized water to the directing agent, stir evenly, and then add a silicon source to obtain a silica sol; (2) adding an aluminum source and an inducing agent to the silica sol described in step (1), stirring evenly, and obtaining a molecular sieve precursor; (3) adding a metal source to the molecular sieve precursor described in step (2) for pre-crystallization; (4) transferring the mixture obtained by pre-crystallization in step (3) to a hydrothermal reactor for hydrothermal crystallization; (5) The product after hydrothermal crystallization in step (4) is centrifuged, washed, dried, and calcined to obtain a metal-doped short b-axis HZSM-5 molecular sieve.

[0007] Furthermore, the directing agent in step (1) is preferably a microporous structure directing agent, which may be tetrapropylammonium hydroxide or tetrapropylammonium bromide; the silicon source is tetraethyl orthosilicate, silica sol or fumed silica; And / or, the molar ratio of the silicon source, the directing agent, and water is 1: (0.1-0.8): (5-100), wherein the molar number of the silicon source is SiO 2 count.

[0008] Furthermore, the aluminum source in step (2) is aluminum isopropoxide, aluminum nitrate nonahydrate, sodium aluminate or aluminum sulfate 18hydrate; the inducing agent is urea, melamine or ethylenediamine; And / or, the molar ratio of the aluminum source, the inducer, and the silicon source is (0.01-0.08): (0.2-1.0): 1, wherein the molar number of the aluminum source is Al 2 O 3 The molar number of silicon source is SiO 2 count.

[0009] Furthermore, the metal source in step (3) is zinc nitrate, zinc acetate, copper nitrate, cobalt nitrate or gallium nitrate. And / or, the molar ratio of the metal source to the silicon source is (0.001-0.05):1.

[0010] Furthermore, the pre-crystallization conditions in step (3) are 20-80°C for 1-24 h.

[0011] Furthermore, the crystallization conditions in step (4) are 100-210 °C, 12-120 h. Furthermore, the drying conditions in step (5) are 60-120°C for 6-24 h; and the roasting conditions are 500-700°C for 3-10 h.

[0012] The present invention introduces active metal and short b-axis pore structure into the molecular sieve by adding metal source and inducer in the in-situ synthesis process, and synthesizes in one step. The molecular sieve prepared by the method has not only high catalytic activity but also good diffusion performance.

[0013] The present invention also provides a metal-doped short b-axis HZSM-5 molecular sieve prepared by the above preparation method.

[0014] The present invention also provides the use of the above-mentioned metal-doped short b-axis HZSM-5 molecular sieve in catalyzing the methanol to aromatics reaction.

[0015] (1) The method of the present invention adds a metal source and an inducer into the in-situ synthesis process of the molecular sieve, thereby simultaneously introducing an active metal and a short b-axis pore structure into the molecular sieve in a one-step method, thereby obtaining a HZSM-5 molecular sieve having both high catalytic activity and diffusion performance. The method of the present invention simultaneously introduces an active metal and a short b-axis structure, thereby simultaneously improving the catalytic activity and diffusion performance of the molecular sieve. In addition, the method does not require the use of expensive inducers and additional metal loading steps, making the operation simple and reducing costs.

[0016] (2) The method of the present invention can also achieve the effect of effectively adjusting the active sites and b-axis pore structure of the molecular sieve through the exploration and research of controlling the synthesis process, thereby simultaneously regulating the catalytic activity and diffusion performance of the molecular sieve. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The XRD patterns of the metal-doped short b-axis HZSM-5 molecular sieves obtained in Examples 1 to 6 of the present invention; Figures (a) to (f) represent the XRD patterns of the molecular sieves prepared in Examples 1 to 6, respectively; Figure 2These are SEM images of the metal-doped short b-axis HZSM-5 molecular sieves obtained in Examples 1 to 6 of the present invention; Figures (a) to (f) respectively represent the SEM images of the molecular sieves prepared in Examples 1 to 6. DETAILED DESCRIPTION

[0018] The present invention is further described below through specific implementation modes. It should be noted that the following examples are only used to illustrate the present invention and are not used to limit the scope of the present invention. Example

[0019] A method for preparing a metal-doped short b-axis HZSM-5 molecular sieve, the specific steps are as follows: Take 20.00 g of tetrapropylammonium hydroxide (25w%), add 25.50 g of deionized water, and stir at room temperature for 0.5 h. Then, 14.00 g of tetraethyl orthosilicate was added dropwise, and the mixture was stirred at room temperature for 6 h to obtain silica sol; 0.35 g of aluminum isopropoxide and 2.80 g of urea were added to the silica sol, and the mixture was stirred at room temperature for 0.5 h to obtain a molecular sieve precursor; subsequently, 0.13 g of zinc nitrate hexahydrate was added to the molecular sieve precursor, and the mixture was stirred at 25 °C for 1.5 h for pre-crystallization; then, the mixed solution obtained after the pre-crystallization was transferred to a hydrothermal autoclave with a polytetrafluoroethylene liner, and was allowed to stand at 180 °C for 48 h for hydrothermal crystallization; after the hydrothermal crystallization, the mixture was centrifuged, and the obtained solid was washed with deionized water until it was neutral, placed in an oven at 100 °C for 12 h, and then calcined at 550 °C for 8 h in an air atmosphere in a muffle furnace to remove the template, thereby obtaining 3.95 g of metal-doped short b-axis HZSM-5 molecular sieve.

[0020] The obtained metal-doped short b-axis HZSM-5 molecular sieve was used to catalyze the methanol to aromatics reaction: in a fixed bed reactor, the temperature was 450 °C, the pressure was 0.1 MPa, and the mass space velocity was 2.5 h -1 The catalytic conversion of methanol was carried out under the reaction conditions of ; gas chromatography was used for detection, and the methanol conversion rate reached 99.8%, the aromatics yield reached 61.4%, and the catalytic life reached 60h. The catalytic activity and stability of the catalyst are much better than the catalytic performance of traditional HZSM-5 under the same conditions (methanol conversion rate is 86.9%, aromatics yield is 28.8%, and catalytic life is 22h). Example

[0021] A method for preparing a metal-doped short b-axis HZSM-5 molecular sieve, the specific steps are as follows: Take 6.55 g of tetrapropylammonium bromide, add 25.50 g of deionized water, and stir at room temperature for 0.5 h. Then, add 14.00 g of tetraethyl orthosilicate dropwise, stir at room temperature for 6 h to obtain silica sol. Add 0.35 g of aluminum isopropoxide and 2.80 g of urea to the silica sol, stir at room temperature for 0.5 h to obtain a molecular sieve precursor. Subsequently, add 0.13 g of zinc nitrate hexahydrate to the molecular sieve precursor, stir at 25 ° C for 1.5 h, and pre-crystallize. Then, transfer the mixed solution obtained after pre-crystallization to a hydrothermal autoclave with a polytetrafluoroethylene liner, stand at 180 ° C for 48 h, and perform hydrothermal crystallization. After the hydrothermal crystallization, the mixture was centrifuged, the solid was washed with deionized water until neutral, dried in an oven at 100 °C for 12 h, and then calcined in a muffle furnace at 550 °C for 8 h in an air atmosphere to remove the template, and 3.20 g of metal-doped short b-axis HZSM-5 molecular sieve was obtained.

[0022] The obtained metal-doped short b-axis HZSM-5 molecular sieve was used to catalyze the methanol to aromatics reaction. Under the reaction conditions of Example 1, the methanol conversion rate reached 99.2%, the aromatics yield reached 57.3%, and the catalytic life reached 54 h. Example

[0023] A method for preparing a metal-doped short b-axis HZSM-5 molecular sieve, the specific steps are as follows: Take 20.00 g of tetrapropylammonium hydroxide (25w%), add 25.50 g of deionized water, and stir at room temperature for 0.5 h. Then, add 4.04 g of fumed silica dropwise, stir at room temperature for 6 h to obtain silica sol. Add 0.35 g of aluminum isopropoxide and 2.80 g of urea to the silica sol, stir at room temperature for 0.5 h to obtain a molecular sieve precursor. Subsequently, add 0.13 g of zinc nitrate hexahydrate to the molecular sieve precursor, stir at 25 °C for 1.5 h, and pre-crystallize. Then, transfer the mixed solution obtained after pre-crystallization to a hydrothermal autoclave with a polytetrafluoroethylene liner, stand at 180 °C for 48 h, and perform hydrothermal crystallization. After the hydrothermal crystallization, the mixture was centrifuged, the solid was washed with deionized water until neutral, dried in an oven at 100 °C for 12 h, and then calcined in a muffle furnace at 550 °C for 8 h in an air atmosphere to remove the template, and 2.85 g of metal-doped short b-axis HZSM-5 molecular sieve was obtained.

[0024] The obtained metal-doped short b-axis HZSM-5 molecular sieve was used to catalyze the methanol to aromatics reaction. Under the reaction conditions of Example 1, the methanol conversion rate reached 99.5%, the aromatics yield reached 59.1%, and the catalytic life reached 56 h. Example

[0025] A method for preparing a metal-doped short b-axis HZSM-5 molecular sieve, the specific steps are as follows: Take 20.00 g of tetrapropylammonium hydroxide (25w%), add 25.50 g of deionized water, and stir at room temperature for 0.5 h. Then, add 14.00 g of tetraethyl orthosilicate dropwise, stir at room temperature for 6 h to obtain silica sol. Add 0.64 g of aluminum nitrate nine hydrate and 2.80 g of urea to the silica sol, stir at room temperature for 0.5 h to obtain a molecular sieve precursor. Subsequently, add 0.13 g of zinc nitrate hexahydrate to the molecular sieve precursor, stir at 25 ° C for 1.5 h, and pre-crystallize. Then, transfer the mixed solution obtained after pre-crystallization to a hydrothermal autoclave with a polytetrafluoroethylene liner, stand at 180 ° C for 48 h, and perform hydrothermal crystallization. After the hydrothermal crystallization, the mixture was centrifuged, the solid was washed with deionized water until neutral, dried in an oven at 100 °C for 12 h, and then calcined in a muffle furnace at 550 °C for 8 h in an air atmosphere to remove the template, and 3.34 g of metal-doped short b-axis HZSM-5 molecular sieve was obtained.

[0026] The obtained metal-doped short b-axis HZSM-5 molecular sieve was used to catalyze the methanol to aromatics reaction. Under the reaction conditions of Example 1, the methanol conversion rate reached 99.7%, the aromatics yield reached 61.7%, and the catalytic life reached 51 h. Example

[0027] A method for preparing a metal-doped short b-axis HZSM-5 molecular sieve, the specific steps are as follows: Take 20.00 g of tetrapropylammonium hydroxide (25w%), add 25.50 g of deionized water, and stir at room temperature for 0.5 h. Then, add 14.00 g of tetraethyl orthosilicate dropwise, stir at room temperature for 6 h to obtain silica sol. Add 0.35 g of aluminum isopropoxide and 5.88 g of melamine to the silica sol, stir at room temperature for 0.5 h to obtain a molecular sieve precursor. Subsequently, add 0.13 g of zinc nitrate hexahydrate to the molecular sieve precursor, stir at 25 ° C for 1.5 h, and pre-crystallize. Then, transfer the mixed solution obtained after pre-crystallization to a hydrothermal autoclave with a polytetrafluoroethylene liner, stand at 180 ° C for 48 h, and perform hydrothermal crystallization. After the hydrothermal crystallization, the mixture was centrifuged, the solid was washed with deionized water until neutral, dried in an oven at 100 °C for 12 h, and then calcined in a muffle furnace at 550 °C for 8 h in an air atmosphere to remove the template, and 2.85 g of metal-doped short b-axis HZSM-5 molecular sieve was obtained.

[0028] The obtained metal-doped short b-axis HZSM-5 molecular sieve was used to catalyze the methanol to aromatics reaction. Under the reaction conditions of Example 1, the methanol conversion rate reached 98.9%, the aromatics yield reached 53.7%, and the catalytic life reached 48 h. Example

[0029] A method for preparing a metal-doped short b-axis HZSM-5 molecular sieve, the specific steps are as follows: Take 20.00 g of tetrapropylammonium hydroxide (25w%), add 25.50 g of deionized water, and stir at room temperature for 0.5 h. Then, add 14.00 g of tetraethyl orthosilicate dropwise, stir at room temperature for 6 h to obtain silica sol. Add 0.35 g of aluminum isopropoxide and 2.80 g of urea to the silica sol, stir at room temperature for 0.5 h to obtain a molecular sieve precursor. Subsequently, add 0.10 g of zinc acetate dihydrate to the molecular sieve precursor, stir at 25 ° C for 1.5 h, and pre-crystallize. Then, transfer the mixed solution obtained after pre-crystallization to a hydrothermal autoclave with a polytetrafluoroethylene liner, stand at 180 ° C for 48 h, and perform hydrothermal crystallization. After the hydrothermal crystallization, the mixture was centrifuged, the solid was washed with deionized water until neutral, dried in an oven at 100 °C for 12 h, and then calcined in a muffle furnace at 550 °C for 8 h in an air atmosphere to remove the template, and 3.32 g of metal-doped short b-axis HZSM-5 molecular sieve was obtained.

[0030] The obtained metal-doped short b-axis HZSM-5 molecular sieve was used to catalyze the methanol to aromatics reaction. Under the reaction conditions of Example 1, the methanol conversion rate reached 98.5%, the aromatics yield reached 55.5%, and the catalytic life reached 50 h. Example

[0031] A method for preparing a metal-doped short b-axis HZSM-5 molecular sieve, the specific steps are as follows: Take 5.45 g of tetrapropylammonium hydroxide (25w%), add 25.50 g of deionized water, and stir at room temperature for 0.5 h. Then, add 14.00 g of tetraethyl orthosilicate dropwise, stir at room temperature for 6 h to obtain silica sol. Add 0.14 g of aluminum isopropoxide and 0.81 g of urea to the silica sol, stir at room temperature for 0.5 h to obtain a molecular sieve precursor. Subsequently, add 0.02 g of zinc nitrate hexahydrate to the molecular sieve precursor, stir at 25 ° C for 1.5 h, and pre-crystallize. Then, transfer the mixed solution obtained after pre-crystallization to a hydrothermal autoclave with a polytetrafluoroethylene liner, stand at 180 ° C for 48 h, and perform hydrothermal crystallization. After the hydrothermal crystallization, the mixture was centrifuged, the solid was washed with deionized water until neutral, dried in an oven at 100 °C for 12 h, and then calcined in a muffle furnace at 550 °C for 8 h in an air atmosphere to remove the template, and 2.15 g of metal-doped short b-axis HZSM-5 molecular sieve was obtained.

[0032] The obtained metal-doped short b-axis HZSM-5 molecular sieve was used to catalyze the methanol to aromatics reaction. Under the reaction conditions of Example 1, the methanol conversion rate reached 98.1%, the aromatics yield reached 53.1%, and the catalytic life reached 45 h. Example

[0033] A method for preparing a metal-doped short b-axis HZSM-5 molecular sieve, the specific steps are as follows: Take 43.60 g of tetrapropylammonium hydroxide (25w%), add 25.50 g of deionized water, and stir at room temperature for 0.5 h. Then, add 14.00 g of tetraethyl orthosilicate dropwise, stir at room temperature for 6 h to obtain silica sol. Add 1.09 g of aluminum isopropoxide and 4.02 g of urea to the silica sol, stir at room temperature for 0.5 h to obtain a molecular sieve precursor. Subsequently, add 0.99 g of zinc nitrate hexahydrate to the molecular sieve precursor, stir at 25 ° C for 1.5 h, and pre-crystallize. Then, transfer the mixed solution obtained after pre-crystallization to a hydrothermal autoclave with a polytetrafluoroethylene liner, stand at 180 ° C for 48 h, and perform hydrothermal crystallization. After the hydrothermal crystallization, the mixture was centrifuged, the solid was washed with deionized water until neutral, dried in an oven at 100 °C for 12 h, and then calcined in a muffle furnace at 550 °C for 8 h in an air atmosphere to remove the template, and 3.31 g of metal-doped short b-axis HZSM-5 molecular sieve was obtained.

[0034] The obtained metal-doped short b-axis HZSM-5 molecular sieve was used to catalyze the methanol to aromatics reaction. Under the reaction conditions of Example 1, the methanol conversion rate reached 97.9%, the aromatics yield reached 46.7%, and the catalytic life reached 47 h. Example

[0035] A method for preparing a metal-doped short b-axis HZSM-5 molecular sieve, the specific steps are as follows: Take 20.00 g of tetrapropylammonium hydroxide (25w%), add 25.50 g of deionized water, and stir at room temperature for 0.5 h. Then, add 14.00 g of tetraethyl orthosilicate dropwise, stir at room temperature for 6 h to obtain silica sol. Add 0.35 g of aluminum isopropoxide and 2.80 g of urea to the silica sol, stir at room temperature for 0.5 h to obtain a molecular sieve precursor. Subsequently, add 0.13 g of zinc nitrate hexahydrate to the molecular sieve precursor, stir at 20 ° C for 1.5 h, and pre-crystallize. Then, transfer the mixed solution obtained after pre-crystallization to a hydrothermal autoclave with a polytetrafluoroethylene liner, stand at 100 ° C for 48 h, and perform hydrothermal crystallization. After the hydrothermal crystallization, the mixture was centrifuged, the solid was washed with deionized water until neutral, dried in an oven at 100 °C for 12 h, and then calcined in a muffle furnace at 500 °C for 8 h in an air atmosphere to remove the template, and 2.65 g of metal-doped short b-axis HZSM-5 molecular sieve was obtained.

[0036] The obtained metal-doped short b-axis HZSM-5 molecular sieve was used to catalyze the methanol to aromatics reaction. Under the reaction conditions of Example 1, the methanol conversion rate reached 98.4%, the aromatics yield reached 43.3%, and the catalytic life reached 38 h. Example

[0037] A method for preparing a metal-doped short b-axis HZSM-5 molecular sieve, the specific steps are as follows: Take 20.00 g of tetrapropylammonium hydroxide (25w%), add 25.50 g of deionized water, and stir at room temperature for 0.5 h. Then, add 14.00 g of tetraethyl orthosilicate dropwise, stir at room temperature for 6 h to obtain silica sol. Add 0.35 g of aluminum isopropoxide and 2.80 g of urea to the silica sol, stir at room temperature for 0.5 h to obtain a molecular sieve precursor. Subsequently, add 0.13 g of zinc nitrate hexahydrate to the molecular sieve precursor, stir at 80 ° C for 1.5 h, and pre-crystallize. Then, transfer the mixed solution obtained after pre-crystallization to a hydrothermal autoclave with a polytetrafluoroethylene liner, stand at 210 ° C for 48 h, and perform hydrothermal crystallization. After the hydrothermal crystallization, the mixture was centrifuged, the solid was washed with deionized water until neutral, dried in an oven at 100 °C for 12 h, and then calcined in a muffle furnace at 700 °C for 8 h in an air atmosphere to remove the template, and 3.24 g of metal-doped short b-axis HZSM-5 molecular sieve was obtained.

[0038] The obtained metal-doped short b-axis HZSM-5 molecular sieve was used to catalyze the methanol to aromatics reaction. Under the reaction conditions of Example 1, the methanol conversion rate reached 98.9%, the aromatics yield reached 47.1%, and the catalytic life reached 48 h.

Claims

1. A method for preparing a metal-doped short b-axis HZSM-5 molecular sieve, characterized in that: The method comprises the following steps: (1) Add deionized water to the directing agent, stir evenly, and then add a silicon source to obtain a silica sol; (2) adding an aluminum source and an inducing agent to the silica sol described in step (1), stirring evenly, and obtaining a molecular sieve precursor; (3) adding a metal source to the molecular sieve precursor described in step (2) for pre-crystallization; (4) transferring the mixture obtained by pre-crystallization in step (3) to a hydrothermal reactor for hydrothermal crystallization; (5) The product after hydrothermal crystallization in step (4) is centrifuged, washed, dried, and calcined to obtain a metal-doped short b-axis HZSM-5 molecular sieve.

2. The preparation method according to claim 1, characterized in that: The directing agent in step (1) is preferably a microporous structure directing agent, which may be tetrapropylammonium hydroxide or tetrapropylammonium bromide; the silicon source is tetraethyl orthosilicate, silica sol or fumed silica; And / or, the molar ratio of the silicon source, the directing agent and the deionized water is 1:(0.1-0.8):(5-100).

3. The preparation method according to claim 1, characterized in that: The aluminum source in step (2) is aluminum isopropoxide, aluminum nitrate nonahydrate, sodium aluminate or aluminum sulfate 18hydrate; the inducing agent is urea, melamine or ethylenediamine; And / or, the molar ratio of the aluminum source, the inducer, and the silicon source is (0.01-0.08): (0.2-1.0):

1.

4. The preparation method according to claim 1, characterized in that: The metal source in step (3) is zinc nitrate, zinc acetate, copper nitrate, cobalt nitrate or gallium nitrate; And / or, the molar ratio of the metal source to the silicon source is (0.001-0.05):

1.

5. The preparation method according to claim 1, characterized in that: The pre-crystallization conditions in step (3) are 20-80°C for 1-24 h.

6. The preparation method according to claim 1, characterized in that: The crystallization conditions in step (4) are 100-210° C. for 12-120 h.

7. The preparation method according to claim 1, characterized in that: The drying conditions in step (5) are 60-120°C for 6-24 h; and the roasting conditions are 500-700°C for 3-10 h.

8. A metal-doped short b-axis HZSM-5 molecular sieve prepared by the preparation method according to any one of claims 1 to 7.

9. Use of the metal-doped short b-axis HZSM-5 molecular sieve according to any one of claims 1 to 8 in catalyzing the methanol to aromatics reaction.

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