A method for preparing a ton-type zeolite molecular sieve

Abstract

The application belongs to the technical field of molecular sieve preparation, and particularly relates to a preparation method of TON type zeolite molecular sieve. A silicon source, an inorganic alkali metal compound, water and an organic template agent are mixed to obtain an aqueous phase solution; an aluminum source and an organic solvent are mixed to obtain an organic phase solution; the aqueous phase solution and the organic phase solution are mixed, and a gel obtained is subjected to dynamic hydrothermal reaction to obtain the TON type zeolite molecular sieve. In the application, a phase transfer method is adopted, the silicon source and the aluminum source are dissolved in the aqueous phase and the organic phase respectively, and the growth process of the zeolite crystal is limited when the aluminum source in the organic phase slowly transfers to the aqueous phase, so that the morphology of nanosheet is obtained. In summary, the TON type zeolite synthesized by the preparation method has the advantages of nanosheet morphology, wide silicon aluminum ratio, high crystallinity and short synthesis time.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of molecular sieve preparation, and particularly relates to a preparation method of TON type zeolite molecular sieve. BACKGROUND

[0002] Zeolite is a kind of inorganic microporous material with regular and uniform pore structure, and has a wide range of applications in the fields of adsorption, catalysis and ion exchange. Among them, TON type zeolite has a one-dimensional ten-membered ring pore structure, and the pore size is about which is slightly smaller than ZSM-5 and ZSM-11. Due to its strong shape selectivity, TON type zeolite has a wide range of industrial applications, such as alkane isomerization reaction, propylene oligomerization reaction, petroleum dewaxing reaction, etc.

[0003] The literature“Wang Y, Wang X, Wu Q, et al. Seed-directed and organotemplate-free synthesis of TON zeolite [J]. Catalysis Today, 2014, 226: 103-108.” discloses a method for dynamically synthesizing high-silicon TON type zeolite under hydrothermal conditions without organic template and only under the guidance of crystal seeds. The literature“Yi Luo, Weimin Yang, et al. Synthesis and crystal growth mechanism of ZSM-22 zeolite nanosheets. Cryst Eng Comm, 2016, 18, 5611.” discloses a method for synthesizing extremely high-silicon (Si / Al = 100) TON type zeolite under hydrothermal conditions. The preparation methods reported in the above two literatures obtain TON type molecular sieves with a high silicon-aluminum ratio (Si / Al > 30), which leads to fewer acid sites and is also not conducive to the progress of catalytic reactions.

[0004] Chinese patent CN111422881A discloses a method for synthesizing low-silicon TON type zeolite using an organic structure directing agent, which comprises: preparing a gel containing a silicon source, an aluminum source, an organic template, a halogen compound, a base and water, then dynamically hydrothermally reacting the gel in a self-generated pressure autoclave reactor, and then separating to obtain a zeolite product with TON topology. The method prepared a low-silicon TON zeolite, and the number of acid reaction sites was increased, but the prepared molecular sieve was a micron-level large-particle crystal. Since the molecular sieve particle size is too large, it cannot fully contact with the reactants, which is not conducive to the progress of catalytic reactions. SUMMARY

[0005] The application aims to provide a preparation method of TON type zeolite molecular sieve.

[0006] To achieve the above-mentioned purpose, the application provides the following technical scheme.

[0007] The application provides a preparation method of TON type zeolite molecular sieve, comprising the following steps.

[0008] Mixing a silicon source, an inorganic alkali metal compound, water and an organic template agent to obtain an aqueous phase solution;

[0009] Mixing an aluminum source and an organic solvent to obtain an organic phase solution;

[0010] Mixing the aqueous phase solution and the organic phase solution, and performing dynamic hydrothermal reaction on the obtained gel to obtain the TON type zeolite molecular sieve.

[0011] Preferably, the organic template agent is tetramethylene bis-(1-methyl imidazole) hydroxide.

[0012] Preferably, the silicon source comprises one or more of sodium silicate, white carbon black, water glass and silica sol.

[0013] Preferably, the inorganic alkali metal compound comprises one or more of sodium carbonate, potassium carbonate, sodium hydroxide and potassium hydroxide.

[0014] Preferably, the aluminum source comprises one or more of sodium aluminate, pseudo-boehmite, aluminum hydroxide, aluminum chloride, aluminum nitrate, aluminum sulfate and aluminum isopropyl alcohol.

[0015] Preferably, the mass of the silicon source is calculated based on silicon dioxide, the mass of the aluminum source is calculated based on diatomic aluminum oxide, the mass of the inorganic alkali metal compound is calculated based on alkali metal oxide, and in the gel: the molar ratio of the inorganic alkali metal compound and the silicon source is 0.049-0.169:1; the molar ratio of the organic template agent and the silicon source is 0.024-0.084:1; the molar ratio of the aluminum source and the silicon source is 0.007-0.084:1.

[0016] Preferably, the organic solvent is toluene; the mass of the silicon source is calculated based on silicon dioxide, and in the gel: the molar ratio of water and the silicon source is 8-29:1; the molar ratio of the organic solvent and the silicon source is 0.54-1.8:1.

[0017] Preferably, the temperature of the dynamic hydrothermal reaction is 130-200 DEG C, and the holding time is 10h-8d; the dynamic hydrothermal reaction is performed under stirring, and the stirring speed is 10-100rpm.

[0018] The application provides the TON type zeolite molecular sieve prepared by the preparation method.

[0019] Preferably, the thickness of the TON type zeolite molecular sieve with the nanosheet morphology is 10-100 nm.

[0020] The application provides a preparation method of a TON type zeolite molecular sieve, which comprises the following steps: mixing a silicon source, an inorganic alkali metal compound, water and an organic template to obtain an aqueous phase solution; mixing an aluminum source and an organic solvent to obtain an organic phase solution; mixing the aqueous phase solution and the organic phase solution, and performing dynamic hydrothermal reaction on the obtained gel to obtain the TON type zeolite molecular sieve. In the application, the phase transfer method is adopted, the silicon source and the aluminum source are dissolved in the aqueous phase and the organic phase respectively, and the growth process of the zeolite crystal is limited when the aluminum source in the organic phase slowly transfers to the aqueous phase, so that the nanosheet morphology is obtained. Compared with the existing zeolite crystallization process including the nucleation process and the crystal growth process, the phase transfer process is adopted in the application, the aluminum source in the organic phase slowly transfers to the aqueous phase, the nucleation process is relatively long, most of the silicate is consumed in the nucleation process, the growth process lacks raw materials, and therefore the growth process is limited and the crystal size is small. Thus, the preparation method provided in the application avoids the direct contact between the silicon source and the aluminum source to form large-particle colloidal particles, and also avoids the direct conversion of the large-particle colloidal particles into large-particle zeolite crystals. Meanwhile, the phase transfer method further improves the crystallization degree of the TON type zeolite. In summary, the TON type zeolite synthesized by the phase transfer method has the advantages of nanosheet morphology, wide silicon-aluminum ratio, high crystallization degree and short synthesis time. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 The XRD spectrum of the TON type zeolite prepared in Examples 1-3;

[0022] Figure 2 The scanning electron microscope image of the TON type zeolite H1 prepared in Example 1;

[0023] Figure 3 The scanning electron microscope image of the TON type zeolite H2 prepared in Example 2;

[0024] Figure 4 The scanning electron microscope image of the TON type zeolite H3 prepared in Example 3;

[0025] Figure 5 The scanning electron microscope image of the TON type zeolite H4 prepared in Comparative Example 1;

[0026] Figure 6 The scanning electron microscope image of the TON type zeolite H5 prepared in Comparative Example 2;

[0027] Figure 7 Scanning electron microscope image of TON type zeolite H6 prepared for Comparative Example 3;

[0028] Figure 8 Scanning electron microscope image of TON type zeolite H8 prepared for Comparative Example 5;

[0029] Figure 9 XRD comparative spectrum of products prepared for Examples and Comparative Examples. DETAILED DESCRIPTION

[0030] The present application provides a preparation method of TON type zeolite molecular sieve, comprising the following steps:

[0031] Mixing a silicon source, an inorganic alkali metal compound, water and an organic template to obtain an aqueous phase solution;

[0032] Mixing an aluminum source and an organic solvent to obtain an organic phase solution;

[0033] Mixing the aqueous phase solution and the organic phase solution, and performing dynamic hydrothermal reaction on the obtained gel to obtain a TON type zeolite molecular sieve.

[0034] In the present application, all the raw materials / components are commercially available products well known to those skilled in the art, unless otherwise specified.

[0035] In the present application, a silicon source, an inorganic alkali metal compound, water and an organic template are mixed (denoted as first mixing) to obtain an aqueous phase solution.

[0036] In the present application, the silicon source preferably comprises one or more of sodium silicate, white carbon black, water glass and silica sol, and more preferably is silica sol. In the present application, the mass content of SiO2 in the silica sol is preferably 30-40%, and more preferably is 40%. The balancing cation in the silica sol is preferably ammonium ion. The inorganic alkali metal compound preferably comprises one or more of sodium carbonate, potassium carbonate, sodium hydroxide and potassium hydroxide, and more preferably is sodium hydroxide. The water is preferably deionized water or distilled water. The organic template is preferably tetramethylene bis-(1-methylimidazole) hydroxide. In the specific embodiments of the present application, the tetramethylene bis-(1-methylimidazole) hydroxide is preferably in the form of tetramethylene bis-(1-methylimidazole) hydroxide aqueous solution for the first mixing, and the mass concentration of the tetramethylene bis-(1-methylimidazole) hydroxide aqueous solution is preferably 10-17%, and more preferably is 12%. In the specific embodiments of the present application, the tetramethylene bis-(1-methylimidazole) hydroxide aqueous solution is preferably purchased from Kent Catalytic Materials Corporation.

[0037] In the present invention, the first mixing is preferably carried out in a closed container, the temperature of the first mixing is preferably room temperature, and the first mixing is preferably carried out under stirring conditions. The present invention has no special requirements for the specific implementation of the stirring.

[0038] In the present invention, an aluminum source and an organic solvent are mixed (referred to as the second mixing) to obtain an organic phase solution.

[0039] In the present invention, the aluminum source preferably includes one or more of sodium aluminate, pseudo-boehmite, aluminum hydroxide, aluminum chloride, aluminum nitrate, aluminum sulfate and aluminum isopropoxide, and more preferably aluminum isopropoxide. The organic solvent is toluene.

[0040] In the present invention, the second mixing is preferably carried out in a closed container, the temperature of the second mixing is preferably room temperature, and the second mixing is preferably carried out under stirring conditions. The present invention has no special requirements for the specific implementation of the stirring.

[0041] After obtaining the aqueous phase solution and the organic phase solution, the present invention mixes the aqueous phase solution and the organic phase solution (referred to as the third mixing), and subjects the obtained gel to a dynamic hydrothermal reaction to obtain a TON-type zeolite molecular sieve.

[0042] In the present invention, the mass of the silicon source is calculated as silicon dioxide, the mass of the aluminum source is calculated as aluminum oxide, and the mass of the inorganic alkali metal compound is calculated as alkali metal oxide. In the gel, the molar ratio of the inorganic alkali metal compound to the silicon source is preferably 0.049 to 0.169:1, more preferably 0.05 to 0.16:1, further preferably 0.055 to 0.15:1, and most preferably 0.06 to 0.13:1. The molar ratio of the organic template to the silicon source is preferably 0.024 to 0.084:1, more preferably 0.025 to 0.08:1, further preferably 0.028 to 0.075:1, and most preferably 0.03 to 0.07:1. The molar ratio of the aluminum source to the silicon source is preferably 0.007 to 0.084:1, more preferably 0.008 to 0.08:1, even more preferably 0.009 to 0.07:1, and most preferably 0.01 to 0.06:1. The molar ratio of water to the silicon source is preferably 8 to 29:1, more preferably 10 to 27:1, and even more preferably 12 to 25:1. The molar ratio of the organic solvent to the silicon source is preferably 0.54 to 1.8:1, more preferably 0.55 to 1.7:1, and even more preferably 0.6 to 1.6:1.

[0043] The preparation method provided by the present application can realize the appropriate contact speed of the silicon source and the aluminum source in the phase transfer process by controlling the silicon source, the aluminum source, the inorganic alkali metal compound, the organic template agent, the water and the organic solvent within the above-mentioned molar ratio range, and under the control of the organic phase and the aqueous phase, the growth of the zeolite crystal is a two-dimensional structure, so that the morphology of the nanosheet is obtained.

[0044] In the present application, the third mixing is preferably carried out in a reaction kettle with a polytetrafluoroethylene lining.

[0045] In the present application, the dynamic hydrothermal reaction is preferably carried out in a reaction kettle with a polytetrafluoroethylene lining. The temperature of the dynamic hydrothermal reaction is preferably 130-200 DEG C, more preferably 150-180 DEG C, and further preferably 150-170 DEG C. The holding time is preferably 10h-8d, more preferably 12h-6d, further preferably 1-5d, and specifically preferably 15h, 72h or 120h. The dynamic hydrothermal reaction is preferably carried out under stirring, and the stirring speed is preferably 10-100rpm, more preferably 20-90rpm, further preferably 30-80rpm, and specifically preferably 60rpm or 80rpm.

[0046] The present application provides the TON-type zeolite molecular sieve prepared by the preparation method described in the above technical solution, and the morphology of the TON-type zeolite molecular sieve is nanosheet; and the silicon-aluminum ratio is 10-60.

[0047] In the present application, the thickness of the TON-type zeolite molecular sieve with the nanosheet morphology is preferably 10-100nm, more preferably 10-80nm, and further preferably 20-60nm. The morphology of the TON-type zeolite molecular sieve prepared by the present application is nanosheet, which is beneficial to increase the contact area during the catalytic reaction and improve the efficiency of the catalytic reaction.

[0048] The silicon-aluminum ratio of the TON-type zeolite molecular sieve prepared by the present application is 10-60. In the specific embodiments in the present application, the silicon-aluminum ratio of the TON-type zeolite molecular sieve is ~10, ~30 or ~60. The preparation method provided by the present application can obtain the TON-type zeolite molecular sieve with the flexible silicon-aluminum ratio according to the mass of the added aluminum source.

[0049] In order to further illustrate the present application, the technical solutions provided by the present application are described in detail below in combination with examples, but they should not be understood as limiting the protection scope of the present application.

[0050] Example 1

[0051] Into a reaction vessel were added 0.0614 g of sodium hydroxide, 1.201 mL of distilled water, 0.908 mL of a 12% by mass aqueous solution of tetramethylphosphonium hydroxide (purchased from Kent Catalysts Materials Corporation), and 1.165 g of silica sol (in which the counter cation is an ammonium ion, and the SiO2 mass is 0.4660 g), which were stirred uniformly at room temperature in a closed state to obtain a phase transfer reaction liquid A-1.

[0052] Into a reaction vessel were added 0.068 g of aluminum isopropoxide and 0.88 g of toluene, which were stirred uniformly at room temperature in a closed state to obtain a phase transfer reaction liquid B-1.

[0053] The phase transfer reaction liquid A-1 and the phase transfer reaction liquid B-1 were sequentially charged into a reaction kettle with a polytetrafluoroethylene liner, and dynamic crystallization was performed at 170°C for 15 h at a rotation speed of 60 rpm.

[0054] After the hydrothermal reaction was completed, a centrifugal device was used for solid-liquid separation, and the solid product was washed with water and then dried in an oven at 75°C for 12 h to obtain a product, which was denoted as H1.

[0055] The crystallinity and the silicon-to-aluminum ratio (Si / Al) of H1 were determined and are listed in Table 1. The crystallinity of H1 was calculated from XRD diffraction data by a method that is conventional in the art, and the silicon-to-aluminum ratio (Si / Al) was calculated from atomic emission spectroscopy (ICP) data by a method that is conventional in the art.

[0056] Figure 1 The X-ray diffraction pattern of H1 is TON (Si / Al = 10), and it can be seen from comparison with the standard diffraction pattern published by the International Zeolite Association that H1 is a zeolite having a TON structure. Figure 2 The scanning electron microscope image of H1 is shown in FIG. 2, and H1 has a nanosheet structure with a sheet thickness of 10 nm.

[0057] Example 2

[0058] Into a reaction vessel were added 0.0620 g of sodium hydroxide, 1.220 mL of distilled water, 0.916 mL of a 12% by mass aqueous solution of tetramethylphosphonium hydroxide (purchased from Kent Catalysts Materials Corporation), and 1.180 g of silica sol (in which the counter cation is an ammonium ion, and the SiO2 mass is 0.4660 g), which were stirred uniformly at room temperature in a closed state to obtain a phase transfer reaction liquid A-2.

[0059] Into a reaction vessel were added 0.043 g of aluminum isopropoxide and 0.87 g of toluene, which were stirred uniformly at room temperature in a closed state to obtain a phase transfer reaction liquid B-2.

[0060] The phase transfer reaction liquid A-2 and the phase transfer reaction liquid B-2 were sequentially loaded into a reaction kettle with a polytetrafluoroethylene lining, and dynamically crystallized at 170°C for 72h with a rotation speed of 80rpm.

[0061] After the hydrothermal reaction was completed, the solid-liquid separation was performed using a centrifugal device, the solid product was washed with water, and then dried in an oven at 100°C for 6 hours to obtain the product, denoted as H2.

[0062] The crystallinity and the silicon aluminum ratio (Si / Al) of H2 were measured and listed in Table 1.

[0063] Figure 1 The X-ray diffraction pattern of TON (Si / Al = 30) is the X-ray diffraction pattern of H2. By comparing with the standard diffraction pattern published by the International Zeolite Association, it can be seen that H2 is a zeolite with TON structure. Figure 3 The scanning electron microscope image of H2 is shown in FIG. 2, and H2 has a nanosheet structure with a sheet thickness of 20nm.

[0064] Example 3

[0065] 0.0614g of sodium hydroxide, 1.923mL of distilled water, 0.900mL of a 12% tetramethylene bis(1-methylimidazole) hydroxide aqueous solution (purchased from Kent Catalyst Materials Co., Ltd.), and 1.174g of silica sol (in which the equilibrium cation is ammonium ion, and the SiO2 mass is 0.4660g) were added to a reaction container, and stirred uniformly under a closed and room temperature condition to obtain a phase transfer reaction liquid A-3.

[0066] 0.023g of aluminum isopropoxide and 0.90g of toluene were added to a reaction container, and stirred uniformly under a closed and room temperature condition to obtain a phase transfer reaction liquid B-3.

[0067] The phase transfer reaction liquid A-3 and the phase transfer reaction liquid B-3 were sequentially loaded into a reaction kettle with a polytetrafluoroethylene lining, and dynamically crystallized at 170°C for 120h with a rotation speed of 60rpm.

[0068] After the hydrothermal reaction was completed, the solid-liquid separation was performed using a centrifugal device, the solid product was washed with water, and then dried in an oven at 120°C for 3 hours to obtain the product, denoted as H3.

[0069] The crystallinity and the silicon aluminum ratio (Si / Al) of H3 were measured and listed in Table 1.

[0070] Figure 1 The X-ray diffraction pattern of TON (Si / Al = 60) is the X-ray diffraction pattern of H3. By comparing with the standard diffraction pattern published by the International Zeolite Association, it can be seen that H3 is a zeolite with TON structure. Figure 4 The scanning electron microscope image of H3 is shown in FIG. 3, and H3 has a nanosheet structure with a sheet thickness of 20nm.

[0071] Comparative Example 1

[0072] Synthesized according to the method of Example 2 disclosed in Chinese patent CN111422881A, the product obtained is denoted as H4.

[0073] The crystallinity and the silicon to aluminum ratio (Si / Al) of H4 were determined and are listed in Table 1. Figure 5 The scanning electron micrograph of H4 is shown in Figure 1. H4 has a spindle-like structure with a particle size of 2-5 pm.

[0074] Comparative Example 2

[0075] A commercially available zeolite TON synthesized using a conventional method (purchased from Dalian Zhuoran Company) was ground into powder, dispersed in distilled water and stirred for 4 h, then solid-liquid separation was performed using a centrifuge, and the solid product was dried in an oven at 100 °C for 4 hours to obtain the product, denoted as H5. The crystallinity and the silicon to aluminum ratio (Si / Al) of H5 were determined and are listed in Table 1. Figure 6 The scanning electron micrograph of H5 is shown in Figure 2. H5 has a rod-like structure with a length of 5 pm.

[0076] Comparative Example 3

[0077] Comparative Example 3 was prepared in the same way as Example 2 except that 0.87 g of toluene was not added. The product obtained is denoted as H6. The crystallinity and the silicon to aluminum ratio (Si / Al) of H6 were determined and are listed in Table 1. Figure 7 The scanning electron micrograph of H6 is shown in Figure 3. H6 has a spindle-like structure with a particle size of 2-5 pm.

[0078] Comparative Example 4

[0079] Comparative Example 4 was prepared in the same way as Example 2 except that 0.916 mL of a 12% mass concentration aqueous solution of tetramethylene bis(1-methylimidazole) hydroxide was not added. The product obtained is denoted as H7. As can be seen from the PXRD pattern of H7 (Figure 4), H7 is not a zeolite TON. Figure 9

[0080] Comparative Example 5

[0081] Comparative Example 5 was prepared in the same way as Example 2 except that static crystallization (no stirring, static condition) was used instead of dynamic crystallization. The product obtained is denoted as H8. The crystallinity and the silicon to aluminum ratio (Si / Al) of H8 were determined and are listed in Table 1. Figure 8 The scanning electron micrograph of H8 is shown in Figure 5. H8 has a spindle-like structure with a particle size of 2-5 pm.

[0082] Comparative Example 6

[0083] ​Comparative product, noted H9, was prepared by comparing with example 2, crystallization at 120℃ in comparative example 6, the rest of the scheme is the same as example 2. From the PXRD pattern of H9 ( Figure 9 ) it can be seen that H9 is not pure TON type zeolite.

[0084] Comparative example 7

[0085] Comparative product, noted H10, was prepared by comparing with example 2, crystallization time is 8h in comparative example 7, the rest of the scheme is the same as example 2. From the PXRD pattern of H10 ( Figure 9 ) it can be seen that H10 is not pure TON type zeolite.

[0086] Table 1 is the determination results of the silicon aluminum ratio of the products prepared by the examples and comparative examples.

[0087] Table 1 is the determination results of the silicon aluminum ratio of the products prepared by the examples and comparative examples.

[0088] Product H1 H2 H3 H4 H5 H6 H7 H8 H9 H10 Si / Al 9.3 28.0 58.3 22.3 35.0 29.1 - 27.8 - -

[0089] From the data of table 1, it can be seen that by adjusting the mass of aluminum source, TON type zeolite molecular sieve with silicon aluminum ratio of 9.3, 28 or 58.3 can be obtained by examples 1-3 of the present application, therefore, the preparation method provided by the present application can flexibly control the silicon aluminum ratio of TON type zeolite molecular sieve.

[0090] Although the above examples have made a detailed description of the present application, it is only a part of the examples of the present application, not all examples, and other examples can be obtained according to the present examples without creativity, which all belong to the protection scope of the present application.

Claims

1. A method for preparing a TON type zeolite molecular sieve, characterized in that: The following steps are involved: Mixing a silicon source, an inorganic alkali metal compound, water and an organic template to obtain an aqueous solution, wherein the organic template is tetramethylene bis-(1-methylimidazole) hydroxide and the silicon source is silica sol; mixing an aluminum source and an organic solvent to obtain an organic phase solution, wherein the aluminum source is aluminum isopropoxide and the organic solvent is toluene; The mass of the silicon source is calculated as silicon dioxide, the mass of the aluminum source is calculated as aluminum oxide, and the mass of the inorganic alkali metal compound is calculated as alkali metal oxide. In the gel, the molar ratio of the inorganic alkali metal compound to the silicon source is 0.049-0.169:1; the molar ratio of the organic template to the silicon source is 0.024-0.084:1; the molar ratio of the aluminum source to the silicon source is 0.007-0.084:1; the mass of the silicon source is calculated as silicon dioxide, and the molar ratio of water to the silicon source is 8-29:1; and the molar ratio of the organic solvent to the silicon source is 0.54-1.8:

1. The aqueous phase solution and the organic phase solution are mixed, and the obtained gel is subjected to a dynamic hydrothermal reaction to obtain a TON type zeolite molecular sieve. The temperature of the dynamic hydrothermal reaction is 130 to 200° C., and the insulation time is 10 hours to 8 days. The dynamic hydrothermal reaction is carried out under stirring conditions, and the stirring speed is 10 to 100 rpm. The morphology of the TON type zeolite molecular sieve is nanosheets.

2. The preparation method according to claim 1, characterized in that The inorganic alkali metal compound includes one or more of sodium carbonate, potassium carbonate, sodium hydroxide and potassium hydroxide.

3. The preparation method according to claim 1, characterized in that The silicon-aluminum ratio of the TON type zeolite molecular sieve is 10-60.

4. The preparation method according to claim 1, characterized in that The thickness of the nanosheet-shaped TON zeolite molecular sieve is 10 to 100 nm.

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