Preparation method and forming process of molecular sieve
The mesomorphic structure ZSM-5 molecular sieve was prepared by baking treatment of rice husk ash and hydrothermal reaction, which solved the problems of pore irregularity and crystallinity reduction caused by alkali metal residues, and achieved efficient and low-cost molecular sieve preparation, which was suitable for large-scale applications.
Patent Information
- Application Number
- CN202510533498.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-25
- Publication Date
- 2025-07-08
AI Technical Summary
When the prior art uses rice husk ash to synthesize molecular sieve, alkali metal residues lead to irregular pore structure and reduced crystallinity, which increases preparation complexity and cost, and limits its large-scale application.
By calcining the rice husks, retaining alkali metals, combining template agents and hydrothermal reactions, a mesomorphic structure ZSM-5 molecular sieve is prepared to avoid pickling steps and improve the utilization rate and crystallinity of the silicon source.
The utilization of highly active silicon source is achieved, the preparation process is simplified, the cost is reduced, the crystallinity and pore structure regularity of the molecular sieve are improved, and it is suitable for large-scale production.
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Figure CN120271008A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the field of synthesis of zeolite molecular sieve materials, and particularly relates to a preparation method and a forming process of a molecular sieve. Background Art
[0002] Alkali metals play an important role in the obtaining of molecular sieves. They mainly play a role by affecting the structural characteristics and catalytic performance of molecular sieves. There are various ways to add alkali metals, such as directly adding alkali metal hydroxides or salts, using the ion exchange method, and the impregnation method, etc. These methods can be selected according to the specific synthesis process and the required characteristics of the molecular sieve to achieve precise control of the structure and performance of the molecular sieve. However, the above methods all need to be achieved by adding an additional alkali metal source.
[0003] Rice husks contain a certain amount of alkali metals. However, when using rice husk ash as a biomass silicon source to synthesize molecular sieves at present, considering that the residual alkali metals may act as "unexpected templates", resulting in irregular pore structures or decreased crystallinity of the molecular sieves, the residual metal oxides may block the pores, reducing the specific surface area and adsorption capacity of the molecular sieves, or affecting the activity of silicon dioxide. Therefore, the rice husks are often first pickled with acid to remove metal impurities (such as K, Ca, etc.) in the rice husks and then calcined to obtain rice husk ash as the silicon source for synthesizing molecular sieves. However, this not only increases the complexity of the molecular sieve preparation process, raises the cost of molecular sieve preparation, but also causes waste of alkali metals in rice husks, greatly limiting the large-scale promotion of using rice husk ash as a biomass silicon source to synthesize molecular sieves. Summary of the Invention
[0004] The purpose of the present invention is to abandon the traditional pickling pretreatment process, obtain a highly active silicon source by only calcining rice husks while retaining alkali metals, synchronously improve the utilization rate of the silicon source and the crystallinity of the molecular sieve, and prepare a high-performance mesoporous structure ZSM-5 molecular sieve by a green and low-cost simplified path.
[0005] The purpose of the present invention is achieved by the following technical solutions:
[0006] The present invention provides a preparation method of a molecular sieve, comprising the following steps:
[0007] (1) Mix rice husk ash with a mass percentage of alkali metal of 0.5wt%-4wt% with water, a template agent, an aluminum source, and an alkali source, and then perform heat treatment to obtain a preliminary ZSM-5 molecular sieve;
[0008] (2) Wash, dry, and calcine the preliminary ZSM-5 molecular sieve to obtain a mesoporous structure ZSM-5 molecular sieve.
[0009] In some embodiments, in step (1), the preparation method of the rice husk ash is as follows: roasting the rice husk at 400 - 600 °C; the molar ratio of the rice husk ash to water, template agent, aluminum source, alkali source is 1 - 10:50 - 300:0.1 - 10:0 - 1:0.1 - 1.
[0010] In some embodiments, in step (1), the template agent is at least one of tetrapropylammonium hydroxide, tetraethylammonium hydroxide, ethylenediamine, cetyltrimethylammonium bromide or pyridine, and the aluminum source is at least one of sodium aluminate, aluminum sulfate, aluminum chloride, aluminum nitrate, pseudoboehmite or aluminum hydroxide.
[0011] In some embodiments, in step (1), the heat treatment is to first perform low-temperature heating treatment and then place it in a hydrothermal autoclave for high-temperature hydrothermal reaction; the temperature of the low-temperature heating treatment is 30 - 120 °C, and the temperature of the high-temperature hydrothermal reaction is 120 - 200 °C.
[0012] In some embodiments, in step (2), the cleaning method is centrifugal cleaning with deionized water, and the drying temperature is 60 - 160 °C.
[0013] In some embodiments, in step (2), the calcination temperature is 400 - 900 °C, the heating rate during calcination is 1 - 20 °C / min, and the calcination time is 100 - 800 min.
[0014] The present invention also provides a forming process of the molecular sieve prepared by the above-mentioned preparation method: mixing the mesostructured ZSM-5 molecular sieve with a binder and an extrusion aid, adding the pre-mixed water and peptizing agent, mixing again and kneading to form a sticky mass, then extruding and forming with an extruder to obtain a wet strip material, and then subjecting the wet strip material to cutting, drying and calcination treatments.
[0015] In some embodiments, the molar ratio of the mesostructured ZSM-5 molecular sieve, binder, extrusion aid, water, peptizing agent is 1 - 100:1 - 50:0.1 - 10:0.1 - 10:1 - 50.
[0016] Preferably, the binder is pseudoboehmite, and the extrusion aid is santo powder; the rotation speed of the extruder is 10 - 50 rpm / min.
[0017] Preferably, the drying temperature is 40 - 200 °C, the calcination temperature is 400 - 900 °C, the heating rate during calcination is 1 - 20 °C / min, and the calcination time is 100 - 800 min.
[0018] Compared with the prior art, the beneficial technical effects of the present invention are as follows:
[0019] (1) By regulating the calcination temperature of rice husk, a highly active silicon source and alkali metals are obtained simultaneously. Utilizing the catalytic effect of alkali metals and the synergistic effect of the silicon dissolution rate during the hydrothermal process, the directional growth of the mesostructured zeolite is achieved, and the mesostructured ZSM-5 zeolite with regular crystal form and uniform particle size is obtained.
[0020] (2) This invention does not require pre-treatment of rice husk by pickling, significantly reducing wastewater discharge and silicon source loss (the utilization rate of SiO2 is increased by more than 20%). Moreover, this invention utilizes the waste biomass resource of rice husk to provide part of the alkali metal source, reducing the complexity of the zeolite preparation process, as well as the raw material and preparation costs, which is conducive to the large-scale promotion of the synthesis of mesostructured zeolite using rice husk ash as a biomass silicon source. Description of the Drawings
[0021] Figure 1 It is the thermogravimetric analysis and differential thermal analysis diagram of rice husk in Example 1;
[0022] Figure 2 It is the X-ray diffraction (XRD) diagram of the mesostructured ZSM-5 zeolite in Example 1, Comparative Example 3, and Comparative Example 4;
[0023] Figure 3 It is the scanning electron microscope (SEM) diagram of the mesostructured ZSM-5 zeolite in Example 1;
[0024] Figure 4 It is the transmission electron microscope (TEM) diagram of the mesostructured ZSM-5 zeolite in Example 1;
[0025] Figure 5 It is the sliced transmission electron microscope (TEM) diagram of the mesostructured ZSM-5 zeolite in Example 1;
[0026] Figure 6 It is the (a) N2 adsorption-desorption test (BET) diagram and (b) pore size distribution diagram of the mesostructured ZSM-5 zeolite in Example 1;
[0027] Figure 7 It is the photograph diagram of the shaped mesostructured ZSM-5 zeolite in Example 1;
[0028] Figure 8 It is the SEM diagram of the ZSM-5 zeolite synthesized in Comparative Example 1;
[0029] Figure 9 It is the SEM diagram of the ZSM-5 zeolite synthesized in Comparative Example 2. Detailed Embodiments
[0030] The embodiments of the present invention provide a method for preparing a zeolite, comprising the following steps:
[0031] (1) The rice husk ash containing 0.5 wt% - 4 wt% of alkali metal is mixed with water, a template agent, an aluminum source, and an alkali source, and then heat-treated to obtain a preliminary ZSM-5 molecular sieve.
[0032] In this embodiment, first, the rice husk is calcined at 400 - 600 °C to obtain rice husk ash containing about 0.5 wt% - 4 wt% of alkali metal. Then, according to the molar ratio of rice husk ash to water, template agent, aluminum source, and sodium hydroxide of 1 - 10:50 - 300:0.1 - 10:0 - 1:0.1 - 1, they are mixed and placed in an oven for low-temperature heat treatment under normal pressure, and then transferred to a hydrothermal autoclave for high-temperature hydrothermal reaction.
[0033] The template agent is at least one of tetrapropylammonium hydroxide, tetraethylammonium hydroxide, ethylenediamine, cetyltrimethylammonium bromide, or pyridine, and the aluminum source is at least one of sodium aluminate, aluminum sulfate, aluminum chloride, aluminum nitrate, pseudoboehmite, or aluminum hydroxide.
[0034] The temperature of the low-temperature heat treatment is 30 - 120 °C, and the temperature of the high-temperature hydrothermal reaction is 120 - 200 °C.
[0035] It should be noted that the calcination temperature and alkali metal content of the rice husk will affect the activity of silicon dioxide in the rice husk ash. When calcined at a low temperature (300 - 500 °C), part of the organic matter decomposes, and the residual carbon may wrap SiO2, resulting in a relatively low mass content of SiO2 in the rice husk ash (70% - 85%). Although silicon is mainly amorphous, the purity is insufficient, and additional acid washing is required to remove metal impurities. Otherwise, the metal impurities may act as "unexpected template agents", resulting in irregular pore structures or decreased crystallinity of the molecular sieve. The residual metal oxides in the molecular sieve may block the pores, reducing the specific surface area and adsorption capacity of the molecular sieve. Medium-temperature (500 - 700 °C) calcination is a better temperature range. At this time, the organic matter completely decomposes, the mass content of SiO2 reaches 90% - 98%, and silicon maintains a highly active amorphous structure and is easily soluble in alkaline solutions. When calcined at a high temperature (>800 °C), SiO2 will undergo a phase change to form crystalline cristobalite. The chemical inertness of crystalline SiO2 increases, the reaction activity significantly decreases, the dissolution rate in alkaline solutions is slow, a higher alkali concentration or an extended reaction time is required, and it is easy to cause uneven grain sizes or more defects in the molecular sieve. Although the mass content of SiO2 in the rice husk ash is still high (>95%) at this time, it is difficult to be used for the synthesis of molecular sieves. Since the purpose of calcining the ZSM-5 molecular sieve at 550 °C is to remove the template agent, and the thermogravimetric curve of the rice husk Figure 1 ) shows that it has basically no weight loss at 550 °C. Considering the production cost and process simplification, the preferred calcination temperature of the rice husk in the present invention is 550 °C.
[0036] When the alkali metal content in rice husk ash is too low (less than 0.5 wt%), during the synthesis of molecular sieves, the alkali metal cannot play the roles of mineralizer and charge balance for synthesizing mesostructured ZSM-5 molecular sieves. The role of the mineralizer is to reduce the viscosity of the synthesis system, accelerate the migration of silicate ions, and promote the oriented arrangement of nanocrystals. The role of charge balance is to balance the negative charge of the molecular sieve framework and stabilize the mesoporous structure. When the alkali metal content is too high (greater than 4 wt%), it will cause the pH of the gel system to get out of control, resulting in a sharp drop in the crystallinity of the molecular sieve, the formation of impurity crystal phases, and it is difficult to accurately control the SiO2 / Al2O3 ratio. Although there are various alkali metal ions in rice husk ash, in terms of content and degree of action, K + plays a major role. First, the radius of potassium ions (133 pm) is significantly larger than that of sodium ions (97 pm). When it occupies the larger voids in the lattice, it can provide a stronger space support effect. Especially in layered materials, the insertion of potassium ions will expand the layer spacing and loosen the overall structure. Second, the coordination tendency of potassium ions is different from that of sodium. It is more inclined to form a relatively loose coordination environment (such as octahedral coordination) with more oxygen atoms, while sodium may enter more tightly sites due to its smaller radius; and the slow exchange rate of potassium ions (compared with the rapid migration of sodium ions) may be the key to the dynamic balance of mesocrystals.
[0037] It should be further noted that there are significant differences between the alkali metals in rice husk ash and the functions of the alkali sources used in the synthesis of ZSM-5 molecular sieves: The alkali sources used in the synthesis of ZSM-5 molecular sieves mainly play a role in adjusting the pH during the crystallization process. By adjusting the pH value, it affects the nucleation and crystal growth rates, and changes the binding mode between the template agent and silicate-aluminate, guiding the crystal to grow along a specific direction to form different morphologies; while for alkali metals such as K in rice husk ash, during the synthesis of molecular sieves, after it is dissolved out with the silicon source, because the potassium ions derived from rice husk ash are close to the dissolved silicon, it can directly act as a structure-directing agent to realize the synthesis of mesostructured molecular sieves.
[0038] The reason for the low-temperature heat treatment first is that at low temperatures (such as 30 - 120 °C), it is beneficial to slow down the nucleation rate, extend the grain growth time, and promote the self-assembly of nanocrystals.
[0039] (2) After cleaning, drying, and calcining the preliminary ZSM-5 molecular sieve, a mesostructured ZSM-5 molecular sieve is obtained.
[0040] In this example, the preliminary ZSM-5 molecular sieve is centrifugally washed with deionized water 1 - 3 times and then dried in a natural air atmosphere at 60 - 160 °C. Finally, it is calcined at a heating rate of 1 - 20 °C / min to 400 - 900 °C for 100 - 800 min.
[0041] It should be noted that compared with traditional ZSM-5 molecular sieves, the mesocrystalline ZSM-5 molecular sieve has a unique microporous-mesoporous composite structure. Its hierarchical pore system with short-range order and long-range disorder not only retains the high specific surface area and shape-selective catalytic ability of microporous molecular sieves but also significantly improves the mass transfer efficiency through mesoporous channels, overcoming the diffusion limitation of traditional microporous ZSM-5 molecular sieves.
[0042] The present invention also provides a forming process for the molecular sieve prepared by the preparation method as described above: mixing the mesocrystalline ZSM-5 molecular sieve with a binder and an extrusion aid, adding the pre-mixed water and peptizing agent, kneading again to form a sticky mass, then extruding and forming with an extruder to obtain a wet strip material, and then subjecting the wet strip material to cutting, drying, and calcination treatments.
[0043] In this embodiment, the mesocrystalline ZSM-5 molecular sieve is mixed with pseudo-boehmite and powdered sesbania, and the pre-mixed water and nitric acid are added. The molar ratio of the mesocrystalline ZSM-5 molecular sieve, pseudo-boehmite, powdered sesbania, water, and nitric acid is 1-100:1-50:0.1-10:0.1-10:1-50. After mixing again, it is kneaded to form a sticky mass, and then extruded and formed with an extruder to obtain a wet strip material. The rotational speed of the extruder is 10-50 rpm / min. Finally, the wet strip material is cut into cylindrical strips of (1-5)×(2-10) mm, then dried at 40-200 °C, and then calcined at 400-900 °C for 100-800 min at a heating rate of 1-20 °C / min.
[0044] In the present invention, unless otherwise specifically stated, the content of all substances mentioned refers to their mass percentage content.
[0045] The present invention has carried out a series of characterization tests on the molecular sieves prepared in the examples and comparative examples:
[0046] The structure of the prepared molecular sieve was characterized by an X-ray diffractometer, the morphology of the prepared molecular sieve was characterized by a scanning electron microscope and a transmission electron microscope, and the pore structure of the prepared molecular sieve was tested by an N2 adsorption-desorption tester.
[0047] The present invention will be further described in detail with specific examples. The following examples can enable those skilled in the art to understand the present invention more comprehensively, but do not limit the present invention in any way.
[0048] Example 1:
[0049] This example provides a preparation method for a molecular sieve, including the following steps:
[0050] (1) Obtaining rice husk ash: First, soak 6 g of rice husks (purchased from Surui Agricultural Products Deep Processing on Taobao) in 30 mL of deionized water for 48 h. After removing the dust from the rice husks, dry them at 100 °C for standby. Then, place the dried rice husks in a muffle furnace and calcine them in a natural air atmosphere at 550 °C for 300 min.
[0051] (2) Obtaining preliminary ZSM-5 molecular sieve: Mix water, tetrapropylammonium hydroxide (brand: Adamas, grade: RG), sodium aluminate (brand: Greagent, grade: AR), rice husk ash (alkali metal content: 2.6 wt%), and sodium hydroxide in a molar ratio of 106:1:0.12:2.3:0.61. Stir the mixture and then heat-treat it in an oven at 80 °C for 2 h. Then, place it in a hydrothermal autoclave and carry out a hydrothermal reaction at 170 °C for 24 h.
[0052] (3) Obtaining mesoporous structure ZSM-5 molecular sieve: Centrifuge and wash the preliminary ZSM-5 molecular sieve 3 times with deionized water and then dry it at 100 °C. Then, heat it to 550 °C at a heating rate of 5 °C / min and calcine it for 300 min.
[0053] Using X-ray diffraction to characterize the structure of the obtained material, it is a typical MFI structure. The results are as Figure 2 shown. The obtained material is ZSM-5 molecular sieve; it can be seen from Figures 3 - 6 that the morphology of the obtained molecular sieve is nano microspheres. In addition to micropores, the obtained ZSM-5 molecular sieve also contains a large number of mesopores and macropore structures, which confirms that the obtained molecular sieve is a mesoporous structure ZSM-5 molecular sieve.
[0054] This example also provides a molecular sieve forming process, which specifically includes mixing the mesoporous structure ZSM-5 molecular sieve with pseudoboehmite and sesbania powder, adding the pre-mixed water and nitric acid, mixing again and then kneading to form a sticky material mass (the mass ratio of the mesoporous structure ZSM-5 molecular sieve, pseudoboehmite, sesbania powder, water, and nitric acid is 10:4.4:0.267:0.72:9). Then, put it into an extruder and start extruding at a rotation speed of 50 rpm / min to obtain a wet strip material. Finally, cut the wet strip material into 3×5 mm cylindrical strips, dry them at 40 °C, and then heat them to 550 °C at a heating rate of 5 °C / min and calcine them for 300 min.
[0055] As Figure 7 shown, after forming, the mesoporous structure ZSM-5 molecular sieve is a uniform cylindrical structure.
[0056] Comparative Example 1:
[0057] This comparative example provides a method for preparing a molecular sieve.
[0058] Compared with Example 1, the rice husk used needs to be pickled in 5wt% HCl for 6h before roasting, the temperature during pickling is 100°C, and the alkali metal content in the obtained rice husk ash is 0, with other conditions being the same. The obtained molecular sieve is denoted as ZSM-5-0 molecular sieve.
[0059] Comparative Example 2:
[0060] This comparative example provides a method for preparing a molecular sieve.
[0061] (1) Obtaining rice husk ash: First, soak 6g of rice husk (purchased from Surui Agricultural Products Deep Processing on Taobao) in 30mL of deionized water for 48h, remove the dust from the rice husk, and then dry it at 100°C for later use.
[0062] (2) Obtaining the preliminary ZSM-5 molecular sieve: Mix water, tetrapropylammonium hydroxide (purchased from Adamas, grade RG), sodium aluminate (purchased from Greagent, grade AR), and rice husk (alkali metal content 0.49wt%) in a molar ratio of 106:1:0.12:2.3, stir, and then place it in an oven for heat treatment at a low temperature of 80°C for 2h, and then place it in a hydrothermal kettle for hydrothermal reaction at 170°C for 24h.
[0063] (3) Obtaining the ZSM-5 molecular sieve: Centrifuge and wash the preliminary ZSM-5 molecular sieve with deionized water 3 times, then dry it at 100°C, and then raise the temperature to 550°C at a heating rate of 5°C / min and roast for 300min. The obtained molecular sieve is denoted as ZSM-5-(0NaOH) molecular sieve.
[0064] Comparative Example 3:
[0065] This comparative example provides a method for preparing a molecular sieve.
[0066] Compared with Comparative Example 2, add 0.3g of NaOH during the synthesis process of the preliminary ZSM-5 molecular sieve in step (2), with other conditions being the same.
[0067] Comparative Example 4:
[0068] This comparative example provides a method for preparing a molecular sieve.
[0069] Compared with Comparative Example 2, add 0.4g of NaOH during the synthesis process of the preliminary ZSM-5 molecular sieve in step (2), with other conditions being the same.
[0070] Comparing Example 1 with Comparative Example 1, it was found that when the rice husk ash lacked alkali metals, although the ZSM-5 molecular sieve could still be obtained, the molecular sieve prepared from the rice husk ash with alkali metals removed could not form spherical shapes, only plate-shaped molecular sieves were seen, and the ZSM-5 molecular sieve with a nano-spherical structure could not be obtained. Figure 8); Comparing Example 1 with Comparative Example 2, it was found that the synthesized zeolite without adding NaOH was a short cylindrical zeolite, and it was impossible to obtain the nano-microspherical ZSM-5 zeolite. Figure 9 ). Moreover, from the pore structures of the zeolites obtained in Comparative Example 1 and Comparative Example 2, it can be seen that when rice husk ash lacks alkali metals and lacks additionally added alkali metals, there are almost no mesopores or the content of mesopores is extremely small in the obtained zeolites. That is, when lacking any one of the above alkali metals, it is impossible to obtain the zeolite with a mesocrystalline structure.
[0071] In addition, from Figure 2 it can be seen that, compared with Example 1, after adding a high content of additional alkali metals in the preparation process of the zeolite in Comparative Examples 3 and 4, it affects the crystal configuration of the ZSM-5 zeolite, which further shows that if the alkali metal content is too high, it will reduce the crystallinity of the zeolite and generate impurity crystal phases.
[0072] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention without departing from the principles and purposes of the present invention.
Claims
1. A method for preparing a molecular sieve, characterized in that, It includes the following steps: (1) Mix rice husk ash with a mass percentage of alkali metal of 0.5 wt% - 4 wt% with water, a template agent, an aluminum source, and an alkali source, and then perform heat treatment to obtain preliminary ZSM-5 molecular sieve; (2) Clean, dry, and calcine the preliminary ZSM-5 molecular sieve to obtain ZSM-5 molecular sieve with a mesocrystalline structure.
2. The preparation method of the molecular sieve according to claim 1, wherein, In step (1), the preparation method of the rice husk ash is: roast the rice husk at 400 - 600 °C; the molar ratio of the rice husk ash to water, the template agent, the aluminum source, and the alkali source is 1 - 10:50 - 300:0.1 - 10:0 - 1:0.1 - 1.
3. The preparation method of the molecular sieve according to claim 1, characterized in that, In step (1), the template agent is at least one of tetrapropylammonium hydroxide, tetraethylammonium hydroxide, ethylenediamine, cetyltrimethylammonium bromide, or pyridine, and the aluminum source is at least one of sodium aluminate, aluminum sulfate, aluminum chloride, aluminum nitrate, pseudoboehmite, or aluminum hydroxide.
4. The preparation method of the molecular sieve according to claim 1, wherein In step (1), the heat treatment is to first perform low-temperature heating treatment and then place it in a hydrothermal autoclave for high-temperature hydrothermal reaction; the temperature of the low-temperature heating treatment is 30 - 120 °C, and the temperature of the high-temperature hydrothermal reaction is 120 - 200 °C.
5. The preparation method of the molecular sieve according to claim 1, characterized in that, In step (2), the cleaning method is centrifugal cleaning with deionized water, and the drying temperature is 60 - 160 °C.
6. The preparation method of the molecular sieve according to claim 1, characterized in that, In step (2), the calcination temperature is 400 - 900 °C, the heating rate during calcination is 1 - 20 °C / min, and the calcination time is 100 - 800 min.
7. The shaping process of the molecular sieve prepared by the preparation method according to any one of claims 1-6, characterized in that, Mix the ZSM-5 molecular sieve with a mesocrystalline structure with a binder and an extrusion aid, add the pre-mixed water and peptizing agent, mix again and then knead to form a sticky mass, then extrude and shape it with an extruder to obtain a wet bar material, and then subject the wet bar material to cutting, drying, and calcination treatments.
8. The shaping process of the molecular sieve according to claim 7, characterized in that, The molar ratio of the ZSM-5 molecular sieve with a mesocrystalline structure, the binder, the extrusion aid, water, and the peptizing agent is 1 - 100:1 - 50:0.1 - 10:0.1 - 10:1 - 50.
9. The shaping process of the molecular sieve according to claim 7, characterized in that, The binder is pseudoboehmite, and the extrusion aid is sesbania powder; the rotation speed of the extruder is 10 - 50 rpm / min.
10. The shaping process of the molecular sieve according to claim 7, characterized in that, The drying temperature is 40 - 200 °C, the calcination temperature is 400 - 900 °C, the heating rate during calcination is 1 - 20 °C / min, and the calcination time is 100 - 800 min.