A method for preparing a hydrogenation catalyst carrier

Abstract

This invention provides a method for preparing a hydrogenation catalyst support. A pressurized aluminum sol solution is sprayed into a sealed container containing a hierarchical porous Y-type molecular sieve for molding. The hierarchical porous Y-type molecular sieve is obtained by mixing a silicon source, an aluminum source, an alkali source, carbonate, and a Y-type molecular sieve structure directing agent to form a gel, followed by hydrothermal crystallization, separation, washing, and calcination. The molar ratio of SiO2 to carbonate in the silicon source is 100:1-15. By pressurizing and spraying the aluminum sol into a sealed space containing the hierarchical porous Y-type molecular sieve material, the high mesoporous structure of the Y-type molecular sieve material allows the aluminum sol to be highly dispersed on the surface of the material, improving the adhesion effect of the aluminum sol, reducing pore volume loss during support molding, and thus improving the mesoporous stability, specific surface area, pore volume, and pore size of the support.

Description

Technical Field

[0001] This invention belongs to the field of catalyst support synthesis technology, and specifically relates to a method for preparing a hydrogenation catalyst support. Background Technology

[0002] Hydrocracking catalysts are typical dual-center catalysts, possessing both hydrogenation and cracking functions. The cracking function is controlled by the acidity of the support, while the hydrogenation function depends on the metal centers supported on the support. To improve the selectivity of the target product, the catalyst needs suitable acidity and matching hydrogenation activity, a large pore size and specific surface area to facilitate the diffusion of reactants and products, and the ability to enhance the primary cracking of macromolecules in the feedstock while avoiding secondary cracking of intermediate products.

[0003] Therefore, the support plays a crucial role in hydrocracking catalysts. First, the support improves the physical properties of the catalyst particles, providing a suitable pore structure for the reaction, increasing the specific surface area of ​​the catalyst particles, and providing sufficient mechanical strength. Second, as a supporting framework for active metal components, the support promotes good dispersion of the metal components on the catalyst surface. Third, the most important aspect of the hydrocracking catalyst support is providing cracking active centers for the reaction, enabling a better synergistic match between cracking and hydrogenation functions according to different reaction requirements. Fourth, the composition and properties of the support directly affect the thermal stability and poisoning resistance of the catalyst.

[0004] Molecular sieve materials are widely used as carrier components in hydrocracking catalysts due to their strong acid centers, large specific surface area, high hydrothermal stability, and well-ordered microporous channels. Despite the many advantages of traditional molecular sieves, their smaller microporous structure becomes more problematic in the face of increasingly heavier and lower-quality feedstocks, hindering the diffusion and conversion of macromolecules. Furthermore, in hydrocracking reactions requiring reduced secondary reactions and higher yields of middle distillate, traditional molecular sieves exhibit diffusion restriction on product molecules, promoting secondary reactions and decreasing middle distillate yields. Therefore, in recent years, methods have been employed to improve the pore structure and acid properties of molecular sieves, such as modifying them and introducing new structures or materials into microporous molecular sieves. These methods include reducing molecular sieve particle size, increasing pore size, and preparing novel mesoporous materials and micro-mesoporous composites. These approaches aim to reduce diffusion restriction by the pores, shorten diffusion paths, and improve the utilization of active sites, thus adapting to the development trend of heavy oil hydrocracking and achieving ideal conversion and selectivity.

[0005] For example, Chinese patent document CN201410711529 discloses a hydrocracking catalyst support and its preparation method. The catalyst support includes modified Y-type molecular sieve, alumina, and amorphous silica-alumina. A modified Y-type molecular sieve with large grains, high silica content, and concentrated effective pore size distribution is used as the main cracking component. The preparation method of the modified Y-type molecular sieve includes the following steps: (1) preparation of large-grain NaY-type molecular sieve; (2) preparation of large-grain NH4NaY from the large-grain NaY-type molecular sieve obtained in step (1); (3) hydrothermal treatment of the Y-type molecular sieve obtained in step (2); (4) contacting the material obtained in step (3) with an aqueous solution of (NH4)2SiF6, followed by filtration and drying to obtain the Y-type molecular sieve. The hydrocracking catalyst prepared from this support is suitable as a hydrocracking catalyst for the flexible production of high-quality heavy naphtha, jet fuel, and diesel oil, exhibiting high activity and selectivity.

[0006] Chinese patent document CN114984938A discloses a silicon-based catalyst support for hydrogenation. Its raw material formulation consists of nano-silica, Al2O3, and silica sol. The silica sol contains 20%-30% silicon and has a particle size of 10-20 nm. The catalyst product prepared from this support has high density, good activity, and high strength, and will not break or pulverize during use. Furthermore, it is inexpensive, offering a significant cost advantage and substantially increasing profit margins.

[0007] Chinese patent document CN114433185A discloses a hydrocracking catalyst comprising a support and an active component. The support is a mixture of molecular sieve and alumina, with the molecular sieve accounting for 5-25 wt% based on the total weight of the support. The active component comprises Group VIB metal sulfides and Group VIII metal oxides, with the Group VIB metal sulfides accounting for 2-30% and the Group VIII metal oxides accounting for 2-10% based on the total weight of the catalyst. The catalyst is prepared by first loading the Group VIB metal onto the molecular sieve, sulfiding it, then mixing it with alumina to obtain the support, and then loading the Group VIII metal onto it. This invention improves the hydrocracking activity of the catalyst and improves the quality of the tail oil by first sulfiding the Group VIB metal and then impregnating it with the Group VIII metal.

[0008] However, most of the catalyst supports disclosed in the aforementioned literature are mixtures of molecular sieves and alumina. A binder, typically nitric acid, is required during the support forming process. However, if the amount of nitric acid used is insufficient, cracks may appear in the formed support, resulting in poor support strength. If the amount of nitric acid used is excessive, it will react with the alumina during the support forming process, leading to significant pore volume loss in the molecular sieves and poor mesoporous stability. This, in turn, reduces the content of the active component supported on the catalyst, thus decreasing catalytic activity. Summary of the Invention

[0009] The purpose of this invention is to provide a method for preparing a hydrogenation catalyst support, which has excellent mesoporous stability. Because the aluminum sol used in the support is highly dispersed and loaded on the surface of the hierarchical Y-type molecular sieve, its bonding effect is significantly improved and the loss of pore volume during the support forming process is reduced.

[0010] To achieve the above objectives, the present invention provides the following technical solution:

[0011] A method for preparing a hydrogenation catalyst support includes the following steps:

[0012] The pressurized aluminum sol solution is sprayed into a sealed container containing a multi-level porous Y-type molecular sieve and shaped (the specific shaping method and shape are not limited, and any conventional method in the industry is acceptable), thus obtaining the hydrogenation catalyst support.

[0013] The multi-level porous Y-type molecular sieve is obtained by mixing silicon source, aluminum source, alkali source, carbonate and Y-type molecular sieve structure guiding agent to form a gel, followed by hydrothermal crystallization, separation, washing and calcination.

[0014] The molar ratio of SiO2 in the silicon source to the carbonate is 100:1-15.

[0015] The pressure and spraying speed of the aluminum sol solution are not specifically limited, but can be adjusted according to actual conditions. For example, the pressure of the aluminum sol can be limited to 2-6 MPa; the spraying speed of the pressurized aluminum sol is 10-20 m / s. 3 / min.

[0016] Optionally, in the preparation process of the above-mentioned hierarchical porous Y-type molecular sieve, the silicon source and the carbonate can be mixed, then the aluminum source and the alkali can be added, and finally the Y-type molecular sieve structure directing agent can be added; or the silicon source and the aluminum source can be mixed, then the carbonate and the alkali can be added, and finally the Y-type molecular sieve structure directing agent can be added.

[0017] Optionally, in the preparation process of the above-mentioned hierarchical porous Y-type molecular sieve, the parameters for gel formation are not specifically limited. Conventional parameters in the industry that can form a gel are acceptable, such as a temperature of 25-50℃ and a time of 1-5h.

[0018] Optionally, in the preparation process of the above-mentioned hierarchical porous Y-type molecular sieve, the molar ratio of the alkali source (based on sodium oxide), the aluminum source (based on aluminum oxide), and the silicon source (based on silicon oxide) in the gel is (0.1-80) Na2O:Al2O3:(1-200)SiO2:(10-800)H2O, preferably (2-30) Na2O:Al2O3:(2-100)SiO2:(50-400)H2O, wherein the H2O includes water added during the preparation of the gel and water introduced into the alkali source, the aluminum source, and the silicon source.

[0019] Optionally, the preparation of the Y-type molecular sieve structure directing agent includes the following steps: mixing a silicon source, an aluminum source, sodium hydroxide and water and then aging the mixture; preferably, the aging temperature is 25-80℃ and the time is 12-36h.

[0020] Optionally, in the preparation process of the above-mentioned hierarchical porous Y-type molecular sieve, the molar ratio of each component in the Y-type molecular sieve structure directing agent, calculated as oxides (silicon source as SiO2, aluminum source as Al2O3, sodium hydroxide as Na2O, and water as H2O), is: (1-30)Na2O:Al2O3:(1-40)SiO2:(200-800)H2O, preferably (5-20)Na2O:Al2O3:(5-20)SiO2:(200-400)H2O.

[0021] Optionally, in the preparation process of the above-mentioned hierarchical porous Y-type molecular sieve, the alkali can be selected from sodium hydroxide and / or a high-alkali solution. The preparation of the high-alkali solution includes the following steps: heating an aqueous solution of sodium hydroxide, adding aluminum hydroxide powder and stirring until dissolved to obtain the high-alkali solution. The molar ratio of each component in the high-alkali solution, calculated as oxides, is (10-15)Na2O:Al2O3:(100-200)H2O; preferably (10-13)Na2O:Al2O3:(100-160)H2O.

[0022] Optionally, in the preparation of the high-alkalinity solution, the aqueous solution of sodium hydroxide also contains sodium carbonate, and the aluminum hydroxide powder, calculated as oxides, has a molar ratio of sodium carbonate to aluminum hydroxide powder of ≤5, preferably ≤4.

[0023] Optionally, in the preparation process of the above-mentioned hierarchical porous Y-type molecular sieve, the hydrothermal crystallization temperature is 90-150℃ and the time is 12-48h; the calcination temperature is 400-600℃ and the time is 6-10h.

[0024] Optionally, in the preparation process of the above-mentioned hierarchical porous Y-type molecular sieve, the silicon source is selected from one or more of water glass, tetraethyl orthosilicate and silicon powder; the aluminum source is selected from one or more of the above-mentioned high alkaline solution, aluminum sulfate octadecylhydrate, alumina, aluminum chloride and aluminum isopropoxide; and the carbonate is selected from one or more of sodium carbonate, potassium carbonate and ammonium carbonate.

[0025] Optionally, the alumina sol is a colloidal solution formed by mixing boehmite, concentrated nitric acid, and an aqueous solution of citric acid. Preferably, the content of boehmite in the alumina sol is 10wt% to 50wt%, more preferably 15wt% to 45wt%; the content of nitric acid is 0.54wt% to 4wt%, more preferably 0.8wt% to 3wt%; the content of citric acid is 0.5wt% to 4wt%, more preferably 1wt% to 3wt%. The mass ratio of boehmite to the hierarchical Y-type molecular sieve is not specifically limited and can be adjusted according to actual conditions. Preferably, the mass ratio of boehmite to the hierarchical Y-type molecular sieve is 1:(1 to 9); more preferably 1:(2 to 8).

[0026] Optionally, the concentration of the aluminum sol solution can be adjusted according to actual needs, and preferably the content of boehmite in the aluminum sol solution is 10wt% to 30wt%.

[0027] Compared with the prior art, the advantages of the present invention are:

[0028] 1. The method for preparing the hydrogenation catalyst support provided by this invention involves spraying pressurized aluminum sol into a closed space containing a hierarchical porous Y-type molecular sieve material. Utilizing the highly mesoporous structure of the Y-type molecular sieve material, the aluminum sol is highly dispersed on the surface of the material, improving the bonding effect of the aluminum sol, reducing pore volume loss during support formation, and thus improving the mesoporous stability, specific surface area, pore volume, and pore size of the support. The specific surface area of ​​the hydrogenation catalyst support is 450–630 m². 2 / g, pore volume is 0.50~0.90mL / g, pore size distribution is 4~15nm.

[0029] 2. The multi-level porous Y-type molecular sieve used in the preparation of the catalyst support in this invention involves adding carbonate during the formation of the initial framework units of the Y-type molecular sieve. The combination of the Y-type molecular sieve directing agent (containing no organic matter) and the carbonate allows sodium ions and carbonate ions to balance the negative charge of the framework and enter the initial structural units. Combined with the subsequent calcination process, the carbonate ions react with the silica and alumina in the framework to form mesopores. This eliminates the need for organic templates in the preparation of multi-level porous Y-type molecular sieves, overcoming the pollution problems caused by organic templates and significantly reducing costs. If carbonates are directly added to the Y-type molecular sieve directing agent, they cannot play a pore-expanding role during the growth of the Y-type molecular sieve framework. Detailed Implementation

[0030] The present invention will now be described in detail through embodiments. It should be noted that the following embodiments are only for further illustration of the present invention and should not be construed as limiting the scope of protection of the present invention. Those skilled in the art can make some non-essential improvements and adjustments to the present invention based on the above description.

[0031] For experiments not specifically described in the examples, the procedures or conditions should be followed according to the conventional experimental procedures described in the literature in this field. Reagents or instruments whose manufacturers are not specified are all commercially available conventional reagent products.

[0032] Analytical methods: Adsorption-desorption isotherms of the samples were determined at liquid nitrogen temperature using an ASAP2020M fully automated adsorption instrument manufactured by Micromeritics, USA. Nitrogen was used as the adsorbate. The specific surface area of ​​the samples was calculated based on the adsorption equilibrium isotherms between relative pressures of 0.05 and 0.25 using the Brunauer-Emmett-Teller (BET) equation. The t-plot model was used to distinguish between the internal and external surface areas of the samples. The pore volume and pore size distribution were determined using the static volumetric method, thereby calculating the pore structure parameters.

[0033] Synthesis of Structure Directing Agent 1:

[0034] The product is obtained by mixing water glass, alumina, deionized water, and NaOH in a molar ratio of 16Na2O:Al2O3:15SiO2:320H2O and aging it at 35°C for 16 hours, based on oxides.

[0035] Preparation of high-alkalinity solution 1:

[0036] Sodium hydroxide and sodium carbonate are dissolved in deionized water and heated to 95°C. Aluminum hydroxide powder is then added and stirred until dissolved to obtain the highly alkaline solution. The molar ratio of the materials in this highly alkaline solution, calculated as oxides, is: 10Na₂O:Al₂O₃:150H₂O:2Na₂CO₃.

[0037] The proportions for preparing high-alkalinity solution 2 are as follows:

[0038] Sodium hydroxide is dissolved in deionized water and heated to 95°C. Aluminum hydroxide powder is then added and stirred until dissolved to obtain the highly alkaline solution. The molar ratio of the materials in this highly alkaline solution, calculated as oxides, is 10Na₂O:Al₂O₃:100H₂O.

[0039] Example 1

[0040] Hierarchical Y-type molecular sieve: Based on oxides, the molar ratio of each component in the alkali source, aluminum source, and silicon source is 2.85Na2O:Al2O3:8.4SiO2:200H2O. After mixing 46.75g of water glass with 4g of sodium carbonate until homogeneous, a solution of 10.5g of aluminum sulfate octadecylhydrate and 23.75g of water, and 10.64g of high-alkali solution 1 are added sequentially and mixed until homogeneous to form an initial gel. Finally, 7.4g of structure-directing agent 1 is added and stirred at 35℃ for 3h to form a gel. The amount of sodium carbonate added is 13% of the molar amount of SiO2 in the water ratio. The above gel is transferred to a polytetrafluoroethylene liner and crystallized at 96℃ for 24h. After filtration, washing with water until neutral, drying at 90℃, and calcining at 550℃ for 10h, a hierarchical Y-type molecular sieve is obtained. The specific surface area of ​​this hierarchical Y-type molecular sieve is measured to be 809m². 2 / g, with a mesoporous pore volume of 0.46mL / g.

[0041] Aluminum sol: Prepare a 40g aqueous solution by mixing 2g concentrated nitric acid and 2g citric acid, then add 10g boehmite and stir at room temperature until a sol is formed, thus obtaining an aluminum sol solution with a boehmite mass fraction of 20wt%.

[0042] Hydrogenation catalyst support: After pressurizing the above-mentioned alumina sol solution with a mass fraction of 20 wt% boehmite to 2 MPa, it was then subjected to a 15 m... 3 A flow rate of [flow rate] / min is vertically sprayed into a sealed container containing 40g of the aforementioned hierarchical porous Y-type molecular sieve. An alumina sol-wetting atmosphere is formed within the sealed container, allowing the alumina sol to be uniformly adsorbed onto the surface of the hierarchical porous Y-type molecular sieve. After molding, a hydrogenation catalyst support is obtained. Testing shows that the specific surface area of ​​this hydrogenation catalyst support is 603 m² / min. 2 / g, pore volume is 0.71mL / g.

[0043] Example 2

[0044] The preparation method of the hydrogenation catalyst support in this embodiment is similar to that in Example 1, except that: 1) the structure directing agent used in the preparation of the hierarchical porous Y-type molecular sieve is different; in this embodiment, structure directing agent 2 is used. 2) the pressure of the aluminum sol during the preparation of the hydrogenation catalyst support is different; in this embodiment, the aluminum sol is pressurized to 4 MPa.

[0045] Testing revealed that the specific surface area of ​​the hydrogenation catalyst support prepared in this embodiment is 610 m². 2 / g, pore volume is 0.72mL / g.

[0046] Example 3

[0047] The preparation method of the hydrogenation catalyst support in this embodiment is similar to that in Example 1, except that: 1) the spray velocity of the aluminum sol is different during the preparation of the hydrogenation catalyst support. In this embodiment, the spray velocity of the aluminum sol is 20 m / s. 3 / min.

[0048] Testing revealed that the specific surface area of ​​the hydrogenation catalyst support prepared in this embodiment was 606 m². 2 / g, pore volume is 0.71mL / g.

[0049] Example 4

[0050] The preparation method of the hydrogenation catalyst support in this embodiment is similar to that in Example 1, except that: 1) the pressure and jet velocity of the aluminum sol are different during the preparation of the hydrogenation catalyst support. In this embodiment, the aluminum sol is pressurized to 4 MPa and then sprayed at 20 m 3 Jet flow rate of / min.

[0051] The specific surface area of ​​the hydrogenation catalyst support prepared in this embodiment was measured to be 614 m². 2 / g, pore volume is 0.72mL / g.

[0052] Example 5

[0053] Hierarchical Y-type molecular sieve: Based on oxides, the molar ratio of alkali source, aluminum source, and silicon source is 2.85Na2O:Al2O3:8.4SiO2:200H2O. 25.65g of water glass, 1.02g of alumina, and 17g of water are mixed and stirred until homogeneous. Then, 1.34g of sodium carbonate and 10.64g of high-alkali solution 2 are added sequentially and stirred until homogeneous to form an initial gel. Finally, 2.25g of structure-directing agent 1 is added and stirred at 35℃ for 3 hours to form a final gel. The amount of sodium carbonate added is 15% of the molar amount of SiO2 in the gel. The gel is transferred to a polytetrafluoroethylene liner and crystallized at 120℃ for 12 hours. After filtration, washing with water until neutral, drying at 90℃, and calcining at 600℃ for 6 hours, a hierarchical Y-type molecular sieve is obtained. The specific surface area of ​​this hierarchical Y-type molecular sieve is measured to be 786 m². 2 / g, with a mesoporous pore volume of 0.31mL / g.

[0054] Aluminum sol: Prepare a 30g aqueous solution by mixing 2g concentrated nitric acid and 2g citric acid, then add 20g boehmite and stir at room temperature until a sol is formed, thus obtaining an aluminum sol solution with a boehmite mass fraction of 40wt%.

[0055] Hydrogenation catalyst support: The above-mentioned alumina sol with a mass fraction of 40 wt% boehmite was pressurized to 2 MPa and then subjected to a 15 m... 3A flow rate of [flow rate] / min is vertically sprayed into a sealed container containing 40g of the aforementioned hierarchical porous Y-type molecular sieve. An alumina sol-wetting atmosphere is formed within the sealed container, allowing the alumina sol to be uniformly adsorbed onto the surface of the hierarchical porous Y-type molecular sieve. After molding, a hydrogenation catalyst support is obtained. Testing shows that the specific surface area of ​​this hydrogenation catalyst support is 582 m². 2 / g, pore volume is 0.62mL / g.

[0056] Example 6

[0057] This embodiment is similar to Embodiment 5, except that the pressure of the aluminum sol is different during the preparation of the hydrogenation catalyst support. In this embodiment, the pressure of the aluminum sol is 4 MPa.

[0058] The specific surface area of ​​the hydrogenation catalyst support prepared in this embodiment was measured to be 604 m². 2 / g, pore volume is 0.64mL / g.

[0059] Example 7

[0060] This embodiment is similar to Embodiment 5, except that the jetting velocity of the aluminum sol is different during the preparation of the hydrogenation catalyst support. In this embodiment, the jetting velocity of the aluminum sol is 20 m / s. 3 / min.

[0061] Testing revealed that the specific surface area of ​​the hydrogenation catalyst support prepared in this embodiment was 601 m². 2 / g, pore volume is 0.63mL / g.

[0062] Example 8

[0063] This embodiment is similar to Embodiment 5, except that the pressure and jet velocity of the aluminum sol differ during the preparation of the hydrogenation catalyst support. In this embodiment, the aluminum sol is pressurized to 4 MPa and then sprayed at a flow rate of 20 m³ / h. 3 Jet flow rate of / min.

[0064] Testing showed that the specific surface area of ​​the hydrogenation catalyst support prepared in this embodiment was 630 m². 2 / g, pore volume is 0.65mL / g.

[0065] Comparative Example 1

[0066] 40g of hierarchical porous Y molecular sieve (prepared using the same method as in Example 1), 10g of pseudoboehmite, and 4g of microcrystalline cellulose were added to a roller mill and rolled for 15 minutes. Then, an aqueous solution containing guar gum (0.5wt%) and nitric acid (2.5wt%) was added, and the mixture was rolled into a paste. The paste was then extruded into strips, which were dried at 120°C for 3 hours and calcined at 550°C for 3 hours to obtain the hydrogenation catalyst support. The specific surface area of ​​this hydrogenation catalyst support was measured to be 404 m².2 / g, pore volume is 0.68mL / g.

[0067] The effect data of Example 1 and Comparative Example 1 show that the pore volume of the carrier prepared in Comparative Example 1 is similar to that in Example 1, but the specific surface area of ​​Comparative Example 1 is significantly reduced, indicating that the effect of spraying aluminum sol solution in this invention is better and reduces the specific surface area loss during the carrier preparation process.

[0068] Of course, the present invention may have other various embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding changes and modifications should all fall within the protection scope of the claims of the present invention.

Claims

1. A method for preparing a hydrogenation catalyst support, characterized in that, Includes the following steps: The pressurized aluminum sol solution is sprayed into a sealed container containing a multi-level porous Y-type molecular sieve to form a hydrogenation catalyst support. The multi-level porous Y-type molecular sieve is obtained by mixing silicon source, aluminum source, alkali source, carbonate and Y-type molecular sieve structure guiding agent to form a gel, followed by hydrothermal crystallization, separation, washing and calcination. The molar ratio of SiO2 in the silicon source to the carbonate is 100:1-15; The alkali is selected from sodium hydroxide and / or a highly alkaline solution, wherein the molar ratio of each component in the highly alkaline solution, calculated as oxides, is (10-15)Na2O:Al2O3:(100-200)H2O.

2. The preparation method according to claim 1, characterized in that, In the preparation process of the multi-level porous Y-type molecular sieve, the silicon source and the carbonate are mixed, then the aluminum source and the alkali source are added, and finally the Y-type molecular sieve structure directing agent is added; or the silicon source and the aluminum source are mixed, then the carbonate and the alkali source are added, and finally the Y-type molecular sieve structure directing agent is added.

3. The preparation method according to claim 1, characterized in that, Based on oxides, the molar ratio of each component in the alkali source, the aluminum source and the silicon source in the gel is (1-80)Na2O:Al2O3:(1-200)SiO2:(10-800)H2O.

4. The preparation method according to claim 1, characterized in that, The molar ratio of each component in the Y-type molecular sieve structure directing agent, calculated as oxides, is (1-30)Na2O:Al2O3:(1-40)SiO2:(200-800)H2O.

5. The preparation method according to claim 1, characterized in that, The preparation of the Y-type molecular sieve structure directing agent includes the following steps: mixing silicon source, aluminum source, sodium hydroxide and water and then aging.

6. The preparation method according to claim 5, characterized in that, The aging temperature is 25-80℃, and the time is 12-36h.

7. The preparation method according to claim 1, characterized in that, The preparation of the high-alkaline solution includes the following steps: heating an aqueous solution of sodium hydroxide, adding aluminum hydroxide powder and stirring until dissolved.

8. The preparation method according to claim 7, characterized in that, The aqueous solution of sodium hydroxide also contains sodium carbonate, and the aluminum hydroxide powder, calculated as oxides, has a molar ratio of sodium carbonate to aluminum hydroxide powder of ≤5.

9. The preparation method according to claim 1, characterized in that, The aluminum sol is a colloidal solution formed by mixing boehmite, concentrated nitric acid, and citric acid aqueous solution.

10. The preparation method according to claim 9, characterized in that, The content of boehmite in the aluminosilicate solution is 10wt%~30wt%.

11. The preparation method according to claim 9, characterized in that, The alumina sol contains 10wt%~50wt% boehmite, 0.54wt%~4wt% nitric acid, and 0.5wt%~4wt% citric acid. The mass ratio of boehmite to the hierarchical porous Y-type molecular sieve is 1:(1-9).