A mesoporous ZSM-35 molecular sieve and its preparation method

Abstract

The present invention discloses a mesoporous ZSM-35 molecular sieve and a preparation method thereof. The mesoporous ZSM-35 molecular sieve contains abundant mesoporous channels, and the mesopores are relatively concentratedly distributed, with a most probable pore diameter of 2 to 6 nm and a total specific surface area of ​​400 to 650 m 2 / g, and the mesopore specific surface area is 50-200m 2 / g, and the crystal size is 0.5 to 5 μm. The preparation method mixes an alkali source, a silicon source, an aluminum source, water and a template, performs a crystallization reaction after mixing evenly, and then further separates, washes and dries. The obtained solid phase material is further mixed with a silicon source, an aluminum source, an alkali source and water, mixed evenly and processed, and then separated and dried to obtain a ZSM‑35 molecular sieve. The preparation method of the mesoporous ZSM‑35 molecular sieve can retain the integrity of the ZSM‑35 molecular sieve crystal structure as much as possible while creating mesoporous channels in the molecular sieve crystal.

Description

Technical Field

[0001] The present invention relates to a zeolite molecular sieve and a preparation method thereof, and belongs to the field of molecular sieve synthesis and modification, and specifically relates to a ZSM-35 molecular sieve and a preparation method thereof. Background Art

[0002] Conventional zeolite molecular sieves are microporous materials with narrow pore sizes, making them unsuitable for catalytic reactions involving large hydrocarbons. Therefore, post-processing and modification are often required to create mesopores within the molecular sieve crystals to address this issue. Common methods for creating mesopores include hydrothermal treatment, acid treatment, and alkaline treatment.

[0003] CN108910910A discloses a ZSM-35 molecular sieve and a preparation method thereof. The ZSM-35 molecular sieve is an aggregated ZSM-35 molecular sieve having a macroporous, mesoporous, and microporous composite hierarchical pore structure. The preparation method uses raw materials without organic templates or seed crystals and comprises the following steps: preparing a reactant gel in which the molar ratio of SiO2, Al2O3, Na2O, K2O, oxygen-containing acid radicals, and H2O is (20-40):1.0:(1.5-2.0):(4.0-6.5):(1.0-4.0):(600-1200); subjecting the reactant gel to aging and crystallization treatments, and washing and drying the resulting synthesized product. The ZSM-35 molecular sieve provided by the present invention can be synthesized without the use of organic templates or seed crystals, and its hierarchical pore structure facilitates material diffusion and mass transfer.

[0004] CN109502606A discloses a preparation method of ZSM-35 molecular sieve, comprising the following steps: (a) preparing a solution a with an aluminum source, a complexing agent and water, and aging the solution a at 10-100°C for 1-48 hours to obtain an aged solution; (b) uniformly mixing a silicon source, an aluminum source, an alkali source, a template, water and ZSM-35 molecular sieve seed crystals to obtain a gel b; (c) then transferring the gel b to a crystallization kettle and crystallizing at 50-150°C for 1-36 hours; (d) adding the aged solution obtained in step (a) to the crystallization kettle in step (c) and crystallizing at 150-180°C for 12-72 hours; (e) after the reaction is completed, separating the mother liquor, washing, exchanging, drying and calcining to obtain a ZSM-35 molecular sieve containing mesopores.

[0005] CN109133083A discloses a modified ZSM-35 molecular sieve and a preparation method thereof, wherein a pore-enlarging agent is added during the ZSM-35 molecular sieve forming stage, and the added pore-enlarging agent is gasified by high-temperature roasting to produce pores of a specific size, thereby increasing the range of secondary pore distribution of the molecular sieve.

[0006] CN108147426A discloses a method for synthesizing ZSM-35 molecular sieve using a composite template. The method comprises dissolving sodium metaaluminate or sodium aluminate and an alkali in desalted water to prepare a sodium metaaluminate-alkali aqueous solution or a sodium aluminate-alkali aqueous solution; then adding hexamethyleneimine to cyclohexylamine to prepare a composite template; adding the composite template to silica sol and stirring thoroughly; adding the sodium metaaluminate-alkali aqueous solution or the sodium aluminate-alkali aqueous solution dropwise to the "thick point" and then increasing the stirring speed to open the gel; and slowly adding the remaining sodium metaaluminate-alkali aqueous solution or the sodium aluminate-alkali aqueous solution; then adding NaZSM-35 molecular sieve, stirring, performing gelation and crystallization, and synthesizing a high-purity nano-grade ZSM-35 molecular sieve.

[0007] However, the above methods all create mesopores at the expense of destroying the molecular sieve crystal structure, which can reduce the catalytic performance of the molecular sieve. There is still a need to develop a molecular sieve material and its synthesis method that can provide a higher mesopore specific surface area while maintaining a complete microporous structure. Summary of the Invention

[0008] In response to the deficiencies in the prior art, the present invention provides a mesoporous ZSM-35 molecular sieve and a preparation method thereof. The preparation method of the mesoporous ZSM-35 molecular sieve can produce mesoporous channels in the molecular sieve crystals while retaining the integrity of the ZSM-35 molecular sieve crystal structure as much as possible, and the obtained ZSM-35 molecular sieve has high crystallinity.

[0009] In order to achieve the above object, the present invention provides a mesoporous ZSM-35 molecular sieve, which contains abundant mesoporous channels and relatively concentrated distribution of mesopores, with a maximum pore diameter of 2 to 6 nm and a total specific surface area of ​​400 to 650 m 2 / g, and the mesopore specific surface area is 50-200m 2 / g, and the crystal particle size is 0.5~5μm.

[0010] In order to achieve the above object, the second aspect of the present invention provides a method for preparing a mesoporous ZSM-35 molecular sieve, the preparation method comprising the following contents:

[0011] (1) mixing an alkali source, a silicon source, an aluminum source, water and a template, performing a crystallization reaction after uniform mixing, and then further separating, washing and drying;

[0012] (2) The solid phase material obtained in step (1) is mixed with a silicon source, an aluminum source, an alkali source and water, and the mixture is treated after uniform mixing, and then separated and dried to obtain a ZSM-35 molecular sieve.

[0013] Furthermore, in the above-mentioned preparation method of mesoporous ZSM-35 molecular sieve, the alkali source in step (1) is an inorganic base, and the inorganic base can be selected from sodium hydroxide and / or potassium hydroxide.

[0014] Furthermore, in the above-mentioned preparation method of mesoporous ZSM-35 molecular sieve, the aluminum source in step (1) can be selected from one or more of sodium aluminate, aluminum sulfate, aluminum chloride, and aluminum nitrate, preferably one or more of aluminum chloride and aluminum nitrate.

[0015] Furthermore, in the above-mentioned preparation method of mesoporous ZSM-35 molecular sieve, the silicon source in step (1) can be selected from one or more of white carbon black, silica gel, silica sol or water glass, preferably one or more of white carbon black and silica gel.

[0016] Furthermore, in the above-mentioned method for preparing mesoporous ZSM-35 molecular sieve, the template agent in step (1) is n-butylamine and / or ethylenediamine.

[0017] Furthermore, in the above-mentioned preparation method of mesoporous ZSM-35 molecular sieve, the molar ratio of the alkali source, silicon source, aluminum source, water and template in step (1) is 4~22Na2O:20~60SiO2:A12O3:600~2500H2O:0.1~5 template, preferably 5~20Na2O:30~50SiO2:A12O3:700~2000H2O:0.4~4 template.

[0018] Furthermore, in the above-mentioned preparation method of mesoporous ZSM-35 molecular sieve, the crystallization reaction conditions in step (1) are as follows: the crystallization reaction temperature is 100-180°C, preferably 120-170°C; and the crystallization time is 10-100h, preferably 30-90h.

[0019] Furthermore, in the above-mentioned method for preparing mesoporous ZSM-35 molecular sieve, the separation in step (1) can be performed by filtration, which usually includes multiple filtrations, generally 1 to 10 times.

[0020] Furthermore, in the above-mentioned preparation method of mesoporous ZSM-35 molecular sieve, the drying temperature in step (1) is 100-150° C., and the drying time is 1-10 h.

[0021] Furthermore, in the above-mentioned method for preparing mesoporous ZSM-35 molecular sieve, the alkali source in step (2) is an inorganic base, and the inorganic base can be selected from sodium hydroxide and / or potassium hydroxide. Furthermore, the alkali source in step (2) is the same as or different from the alkali source in step (1), and is preferably the same.

[0022] Furthermore, in the above-mentioned preparation method of mesoporous ZSM-35 molecular sieve, the aluminum source in step (2) can be selected from one or more of sodium aluminate, aluminum sulfate, aluminum chloride, and aluminum nitrate, preferably one or more of aluminum chloride and aluminum nitrate; further, the aluminum source in step (2) is the same as or different from the aluminum source in step (1), preferably the same.

[0023] Furthermore, in the above-mentioned method for preparing mesoporous ZSM-35 molecular sieve, the silicon source in step (2) can be selected from one or more of white carbon black, silica gel, silica sol or water glass, preferably one or more of white carbon black and silica gel. Furthermore, the silicon source in step (2) is the same as or different from the silicon source in step (1), preferably the same.

[0024] Furthermore, in the above-mentioned method for preparing mesoporous ZSM-35 molecular sieve, the mass ratio of the solid phase material obtained in step (1) to the silicon source in step (2) is 1:0.1 to 1:0.3.

[0025] Furthermore, in the above-mentioned method for preparing mesoporous ZSM-35 molecular sieve, the mass ratio of the solid phase material obtained in step (1) to the aluminum source in step (2) is 1:0.01 to 1:0.02.

[0026] Furthermore, in the above-mentioned preparation method of mesoporous ZSM-35 molecular sieve, the mass ratio of the solid phase material obtained in step (1) to the alkali source in step (2) is 1:0.2 to 1:0.6,

[0027] Furthermore, in the above-mentioned preparation method of mesoporous ZSM-35 molecular sieve, the mass ratio of the solid phase material obtained in step (1) to water in step (2) is 1:15 to 1:25.

[0028] Furthermore, in the above-mentioned method for preparing mesoporous ZSM-35 molecular sieve, the mixing in step (2) is preferably carried out under ultrasonic conditions, with an ultrasonic frequency of 15 kHz to 10 MHz and a power of 20 to 100 W / L based on the volume of the solution. The ultrasonic treatment time is 0.1 to 10 minutes, preferably 1 to 5 minutes. There are no special restrictions or requirements on the order of adding the various materials.

[0029] Furthermore, in the above-mentioned method for preparing mesoporous ZSM-35 molecular sieve, the treatment temperature in step (2) is 130-170°C, preferably 140-160°C; the treatment time is generally 0.5-12 hours, preferably 1-10 hours. The treatment process in step (2) generally needs to be carried out in a pressure-resistant container.

[0030] Furthermore, in the above-mentioned preparation method of mesoporous ZSM-35 molecular sieve, the impurity removal in step (2) is to remove the unreacted raw materials, which can be done by filtering, usually including multiple filtrations, generally 1 to 10 times.

[0031] Furthermore, in the above-mentioned preparation method of mesoporous ZSM-35 molecular sieve, the drying temperature in step (2) is 100-150° C., and the drying time is 1-10 h.

[0032] Furthermore, in the above-mentioned method for preparing mesoporous ZSM-35 molecular sieve, the separation in step (2) can be performed by filtration, which usually includes multiple filtrations, generally 1 to 10 times.

[0033] The third aspect of the present invention provides a mesoporous ZSM-35 molecular sieve prepared by the above preparation method.

[0034] The mesoporous ZSM-35 molecular sieve provided by the present invention has good macromolecular substance transmission capability and can be used as an acidic component of a catalyst or an adsorption separation agent for gases and liquids.

[0035] Compared with existing methods, the mesoporous ZSM-35 molecular sieve and its preparation method of the present invention have the following advantages:

[0036] The preparation method of mesoporous ZSM-35 molecular sieve of the present invention provides a new method for in-situ synthesis of mesoporous ZSM-35 molecular sieve. The preparation method first obtains a ZSM-35 molecular sieve precursor by a first step synthesis, and then in the second step, a small amount of silicon source and aluminum source are added while adding an alkali. In the process of forming mesopores, raw materials such as silicon and aluminum can be re-entered into the crystal skeleton of the molecular sieve, and the crystal structure of the molecular sieve destroyed by the introduction of alkali can be repaired. The mesoporous ZSM-35 molecular sieve obtained by the preparation method of the present invention has a high crystallinity, which can obtain mesopores and maintain the crystallinity of the molecular sieve as much as possible. It can avoid the destruction of the crystal structure of the molecular sieve when preparing the mesoporous molecular sieve by methods such as hydrothermal treatment and acid-base treatment, thereby affecting the performance of the molecular sieve. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is the pore size distribution diagram of the material obtained in Example 1.

[0038] Figure 2 This is a transmission electron microscope photograph of the material obtained in Example 1. DETAILED DESCRIPTION

[0039] The technical solutions and effects of the present invention are further described below with reference to the following embodiments, but are not limited to the following embodiments.

[0040] Pore ​​structure parameters such as specific surface area of ​​the samples used in this study were measured using low-temperature nitrogen adsorption, using an ASAP2400 physical adsorption instrument produced by Micromeritics Instruments. Prior to measurement, the samples were vacuum-treated at 300°C for at least 4 hours. The total specific surface area was calculated using the BET isotherm equation, the micropore specific surface area and mesopore specific surface area were calculated using the t-plot method, and the pore size distribution was calculated using the BJH method.

[0041] The microscopic morphology of the samples was characterized by high-resolution electron microscopy. A JEM-2100LaB6 high-resolution transmission electron microscope (TEM) from JEOL, Japan, was used for sample morphology observation and electron diffraction analysis. An 832 CCD camera from Gatan, USA, was used to capture images and electron diffraction spectra.

[0042] The crystal structure of the sample in the present invention was characterized by an X-ray diffractometer, using a Japanese Rigaku D / max2500 X-ray diffractometer with a Cu target, a Kα radiation source, a graphite monochromator, a tube voltage of 40 kV, a tube current of 80 mA, a scanning range of 5°~40°, a step size of 0.1°, and a scanning speed of 1° / min.

[0043] Example 1

[0044] 85g of silica, 13g of sodium hydroxide, 5.5g of ethylenediamine, 10g of aluminum chloride, and 860mL of distilled water were placed in a clean container and stirred evenly. The mixture was then transferred to a pressure-resistant reactor and crystallized at 160°C for 35h. The resulting sample was filtered multiple times and then dried in an oven at 110°C for 12h to obtain a solid. 10g of the solid prepared in the previous step, 2.6g of sodium hydroxide, 2.5g of silica, 0.15g of sodium aluminate, and 200mL of distilled water were then placed in a clean container and stirred evenly. The mixture was then placed in an ultrasonic cleaner at a frequency of 10MHz and a power of 100W / L based on the volume of the solution for 3min. The mixture was then transferred to a pressure-resistant reactor and treated at 150°C for 3h. The resulting sample was filtered multiple times and then dried in an oven at 110°C for 12h. The resulting sample is numbered C1.

[0045] Example 2

[0046] 112.5g of silica, 7.5g of sodium hydroxide, 9.0g of ethylenediamine, 10g of aluminum chloride, and 1350mL of distilled water were placed in a clean container and stirred evenly. The mixture was then transferred to a pressure-resistant reactor and treated at 120°C for 90h. The resulting sample was filtered multiple times and then dried in an oven at 110°C for 12h to obtain a solid. 10g of the solid prepared in the previous step, 2.0g of sodium hydroxide, 1g of silica, 0.1g of sodium aluminate, and 150mL of distilled water were then placed in a clean container and stirred evenly. The mixture was then placed in an ultrasonic cleaner at a frequency of 10MHz and a power of 100W / L based on the volume of the solution for 1min. The mixture was then transferred to a pressure-resistant reactor and treated at 140°C for 10h. The resulting sample was filtered multiple times and then dried in an oven at 110°C for 12h. The resulting sample was designated C2.

[0047] Example 3

[0048] 67.5g of silica gel, 13g of sodium hydroxide, 0.9g of ethylenediamine, 10g of aluminum chloride, and 472mL of distilled water were placed in a clean container and stirred evenly. The mixture was then transferred to a pressure-resistant reactor and treated at 170°C for 30h. The resulting sample was filtered multiple times and then dried in an oven at 110°C for 12h to obtain a solid. 10g of the solid prepared in the previous step, 6.0g of sodium hydroxide, 3g of white carbon black, 0.2g of sodium aluminate, and 250mL of distilled water were then placed in a clean container and stirred evenly. The mixture was then placed in an ultrasonic cleaner at a frequency of 10MHz and a power of 100W / L based on the volume of the solution for 5min. The mixture was then transferred to a pressure-resistant reactor and treated at 160°C for 1h. The resulting sample was filtered multiple times and then dried in an oven at 110°C for 12h. The resulting sample was designated C3.

[0049] Example 4

[0050] 72g of silica, 10g of sodium hydroxide, 2.5g of ethylenediamine, 10g of aluminum chloride, and 700mL of distilled water were placed in a clean container and stirred evenly. The mixture was then transferred to a pressure-resistant reactor and treated at 150°C for 40h. The resulting sample was filtered multiple times and then dried in an oven at 110°C for 12h to obtain a solid. 10g of the solid prepared in the previous step, 5.5g of sodium hydroxide, 2.7g of silica, 0.18g of sodium aluminate, and 210mL of distilled water were then placed in a clean container and stirred evenly. The mixture was then placed in an ultrasonic cleaner at a frequency of 10MHz and a power of 100W / L based on the volume of the solution for 3min. The mixture was then transferred to a pressure-resistant reactor and treated at 155°C for 3.5h. The resulting sample was filtered multiple times and then dried in an oven at 110°C for 12h. The resulting sample was designated C4.

[0051] Example 5

[0052] Place 95g of silica gel, 12g of sodium hydroxide, 6.1g of ethylenediamine, 10g of aluminum chloride, and 750mL of distilled water in a clean container and stir thoroughly. Then, transfer the mixture to a pressure-resistant reactor and heat at 160°C for 38h. Filter the resulting sample several times and dry it in an oven at 110°C for 12h to obtain a solid. Then, place 10g of the solid prepared in the previous step, add 4.3g of potassium hydroxide, 2.1g of silica gel, 0.11g of aluminum sulfate, and 200mL of distilled water to a clean container and stir thoroughly. Then, place the mixture in an ultrasonic cleaner at a frequency of 10MHz and a power of 100W / L per volume of the solution for 3min. Then, transfer the mixture to a pressure-resistant reactor and heat it at 150°C for 5h. Filter the resulting sample several times and dry it in an oven at 110°C for 12h. The resulting sample is designated C5.

[0053] Comparative Example 1

[0054] The process is basically the same as Example 1, except that when the alkali is introduced in the second step, the silicon source and the aluminum source are not introduced.

[0055] 85g of silica, 13g of sodium hydroxide, 5.5g of ethylenediamine, 10g of aluminum chloride, and 860mL of distilled water were placed in a clean container and stirred evenly. The mixture was then transferred to a pressure-resistant reactor and crystallized at 160°C for 35h. The resulting sample was filtered multiple times and then dried in an oven at 110°C for 12h to obtain a solid. 10g of the solid prepared in the previous step, 2.6g of sodium hydroxide, and 200mL of distilled water were then placed in a clean container and stirred evenly. The mixture was then placed in an ultrasonic cleaner with an ultrasonic frequency of 10MHz and a power of 100W / L based on the volume of the solution for 3min. The mixture was then transferred to a pressure-resistant reactor and treated at 150°C for 3h. The resulting sample was filtered multiple times and then dried in an oven at 110°C for 12h. The resulting sample was designated C6.

[0056] Comparative Example 2

[0057] Referring to the raw material ratios in Example 1, 10 g of ZSM-35 molecular sieve (Shanghai Zhuoyue Chemical Co., Ltd.), 2.6 g of sodium hydroxide, and 200 mL of distilled water were placed in a clean container and stirred evenly. The mixture was then placed in an ultrasonic cleaner with an ultrasonic frequency of 10 MHz and a power of 100 W / L based on the volume of the solution, and ultrasonic treatment was performed for 3 minutes. The mixture was then transferred to a pressure-resistant reactor and treated at 150° C. for 3 hours. The obtained sample was then filtered several times and then dried in an oven at 110° C. for 12 hours. The obtained sample was numbered C7.

[0058] Comparative Example 3

[0059] Place 1.2 g of sodium hydroxide and 0.53 g of sodium aluminate in 50 mL of distilled water and stir vigorously until completely dissolved. Slowly add 4.7 g of silica and stir vigorously for 30 minutes. Then, add 0.12 g of ZSM-35 molecular sieve and stir vigorously for 30 minutes. The mixture is then placed in a sealed reactor and crystallized in an oven at 150°C for 4 days. The resulting sample is filtered several times and then dried in an oven at 110°C for 12 hours. The resulting sample is designated C8.

[0060] Wherein, comparative example 3 is the scheme of preparing molecular sieve by a typical seed crystal method.The material proportion of comparative example 3 is very different from that of the present invention, so the reaction mechanism of the two is completely different. In comparative example 3, the proportion of ZSM-35 molecular sieve in raw material is very low, and what is played in comparative example 3 is the seed crystal effect, which mainly plays an inductive role, and the main raw materials such as silicon and aluminum are converted into ZSM-35 molecular sieve end products. And in the present invention, ZSM-35 molecular sieve exists as the most important raw material, and the proportion of raw materials such as silicon and aluminum in the preparation system is less. Through the inventive method process, ZSM-35 molecular sieve in raw material becomes end product as main body and is retained, and the raw materials such as silicon and aluminum added only have a small amount of entering ZSM-35 molecular sieve crystals, which plays the effect of repairing crystal skeleton.

[0061] Table 1 Pore structure properties of samples of Examples and Comparative Examples

[0062]

[0063] Note: In the present invention, the crystallinity of the commercial ZSM-35 molecular sieve used in Comparative Example 2 is 100%, and the crystallinity of all samples is obtained by comparing with the crystallinity of the commercial ZSM-35 molecular sieve.

[0064] By comparing the examples and comparative examples, it can be seen that the method of the present invention can not only produce perfect mesoporous channels, but also maintain a high degree of crystallinity.

Claims

1. A mesoporous ZSM-35 molecular sieve with abundant mesoporous channels and relatively concentrated distribution of mesopores, with a maximum pore diameter of 2 to 6 nm and a total specific surface area of ​​400 to 650 m 2 / g, and the mesopore specific surface area is 50-200m 2 / g, and the crystal particle size is 0.5~5μm.

2. A method for preparing the mesoporous ZSM-35 molecular sieve according to claim 1, comprising the following steps: (1) mixing an alkali source, a silicon source, an aluminum source, water and a template, performing a crystallization reaction after uniform mixing, and then further separating, washing and drying; (2) mixing the solid phase material obtained in step (1) with a silicon source, an aluminum source, an alkali source and water, treating the mixture after uniform mixing, and then separating and drying to obtain a ZSM-35 molecular sieve; in, The alkali source in step (2) is an inorganic base.

3. The method for preparing the mesoporous ZSM-35 molecular sieve according to claim 2, wherein: In step (1), the alkali source is an inorganic base, and the inorganic base is further selected from sodium hydroxide and / or potassium hydroxide.

4. The method for preparing the mesoporous ZSM-35 molecular sieve according to claim 2, wherein: In step (1), the aluminum source is selected from one or more of sodium aluminate, aluminum sulfate, aluminum chloride, and aluminum nitrate.

5. The method for preparing the mesoporous ZSM-35 molecular sieve according to claim 2, wherein: In step (1), the aluminum source is selected from one or more of aluminum chloride and aluminum nitrate.

6. The method for preparing the mesoporous ZSM-35 molecular sieve according to claim 2, wherein: In step (1), the silicon source is selected from one or more of white carbon black, silica gel, silica sol or water glass.

7. The method for preparing the mesoporous ZSM-35 molecular sieve according to claim 2, wherein: In step (1), the silicon source is selected from one or more of white carbon black and silica gel.

8. The method for preparing the mesoporous ZSM-35 molecular sieve according to claim 2, wherein: In step (1), the template agent is n-butylamine and / or ethylenediamine.

9. The method for preparing the mesoporous ZSM-35 molecular sieve according to claim 2, wherein: In step (1), the molar ratio of the alkali source, silicon source, aluminum source, water and template is 4-22Na2O: 20-60SiO2: A12O3: 600-2500H2O: 0.1-5 template.

10. The method for preparing the mesoporous ZSM-35 molecular sieve according to claim 2, wherein: In step (1), the molar ratio of the alkali source, silicon source, aluminum source, water and template is 5-20Na2O: 30-50SiO2: Al2O3: 700-2000H2O: 0.4-4 template.

11. The method for preparing the mesoporous ZSM-35 molecular sieve according to claim 2, wherein: The crystallization reaction conditions in step (1) are as follows: crystallization reaction temperature 100-180° C.; crystallization time 10-100 h.

12. The method for preparing the mesoporous ZSM-35 molecular sieve according to claim 2, wherein: The crystallization reaction conditions in step (1) are as follows: crystallization reaction temperature 120-170° C.; crystallization time 30-90 h.

13. The method for preparing the mesoporous ZSM-35 molecular sieve according to claim 2, wherein: The drying temperature in step (1) is 100-150° C., and the drying time is 1-10 hours.

14. The method for preparing the mesoporous ZSM-35 molecular sieve according to claim 2, wherein: The alkali source in step (2) is selected from sodium hydroxide and / or potassium hydroxide.

15. The method for preparing the mesoporous ZSM-35 molecular sieve according to claim 2, wherein: The alkali source in step (2) is the same as or different from the alkali source in step (1).

16. The method for preparing the mesoporous ZSM-35 molecular sieve according to claim 2, wherein: The alkali source in step (2) is the same as the alkali source in step (1).

17. The method for preparing the mesoporous ZSM-35 molecular sieve according to claim 2, wherein: The aluminum source in step (2) is selected from one or more of sodium aluminate, aluminum sulfate, aluminum chloride, and aluminum nitrate.

18. The method for preparing the mesoporous ZSM-35 molecular sieve according to claim 2, wherein: The aluminum source in step (2) is selected from one or more of aluminum chloride and aluminum nitrate.

19. The method for preparing the mesoporous ZSM-35 molecular sieve according to claim 2, wherein: The aluminum source in step (2) is the same as or different from the aluminum source in step (1).

20. The method for preparing the mesoporous ZSM-35 molecular sieve according to claim 2, wherein: The aluminum source in step (2) is the same as the aluminum source in step (1).

21. The method for preparing the mesoporous ZSM-35 molecular sieve according to claim 2, wherein: The silicon source in step (2) is selected from one or more of white carbon black, silica gel, silica sol or water glass.

22. The method for preparing the mesoporous ZSM-35 molecular sieve according to claim 2, wherein: The silicon source in step (2) is selected from one or more of white carbon black and silica gel.

23. The method for preparing the mesoporous ZSM-35 molecular sieve according to claim 2, wherein: The silicon source in step (2) is the same as or different from the silicon source in step (1).

24. The method for preparing the mesoporous ZSM-35 molecular sieve according to claim 2, wherein: The silicon source in step (2) is the same as the silicon source in step (1).

25. The method for preparing the mesoporous ZSM-35 molecular sieve according to claim 2, wherein: In step (2), the mass ratio of the solid phase material obtained in step (1) to the silicon source is 1:0.1 to 1:0.

3.

26. The method for preparing the mesoporous ZSM-35 molecular sieve according to claim 2, wherein: In step (2), the mass ratio of the solid phase material obtained in step (1) to the aluminum source is 1:0.01 to 1:0.

02.

27. The method for preparing the mesoporous ZSM-35 molecular sieve according to claim 2, wherein: In step (2), the mass ratio of the solid phase material obtained in step (1) to the alkali source is 1:0.2 to 1:0.

6.

28. The method for preparing the mesoporous ZSM-35 molecular sieve according to claim 2, wherein: In step (2), the mass ratio of the solid phase material obtained in step (1) to water is 1:15 to 1:

25.

29. The method for preparing the mesoporous ZSM-35 molecular sieve according to claim 2, wherein: The treatment temperature in step (2) is 130-170° C., and the treatment time is 0.5-12 h.

30. The method for preparing the mesoporous ZSM-35 molecular sieve according to claim 2, wherein: The treatment temperature in step (2) is 140-160° C., and the treatment time is 1-10 hours.

31. The method for preparing the mesoporous ZSM-35 molecular sieve according to claim 2, wherein: The drying temperature in step (2) is 100-150° C., and the drying time is 1-10 hours.

32. A mesoporous ZSM-35 molecular sieve obtained by the preparation method according to any one of claims 2 to 31.

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