Hierarchical porous material and preparation method thereof

Abstract

The invention provides a hierarchical porous material which comprises the following components in percentage by mass: 20-80 percent of amorphous silica-alumina and 80-20 percent of molecular sieve, wherein the mass of the amorphous silica-alumina is 100 percent; the molecular sieve is prepared from the following components in percentage by mass: 5 to 95 percent of a Beta molecular sieve and 95 to 5 percent of a rare earth modified SSZ-13 molecular sieve, wherein the Beta molecular sieve and the rare earth modified SSZ-13 molecular sieve are 100 percent by mass; the content of the rare earth is 0.1 wt%-5wt% on the basis that the mass of the rare earth modified SSZ-13 molecular sieve is 100%. The hierarchical porous material has pore structure characteristics and acidic characteristics of different molecular sieves, and meanwhile, the SSZ-13 molecular sieves with micropores are modified by adopting rare earth metal, so that the pore diameter structure is supported, the acidity of the SSZ-13 molecular sieves is improved, and the SSZ-13 molecular sieves can better adapt to the hydrocracking reaction process of oil products.

Description

Technical Field

[0001] The present invention relates to the technical field of catalyst materials, and particularly relates to a hierarchical pore material and a preparation method thereof. Background Art

[0002] With the accelerating transformation of the refining product structure, the consumption of refined oil has entered a stage of fluctuating decline from high-speed growth, the consumption of gasoline has entered a medium- and low-speed growth range, while the demand for chemical products continues to grow, and the market demand for basic chemical raw materials represented by olefins and aromatics has increased steadily. Therefore, as the proportion of petrochemical raw materials in the petroleum consumption structure gradually increases, how to take measures to convert heavy oil into high-value-added chemical raw materials to the greatest extent has become a research hotspot in the petrochemical field.

[0003] The hydrocracking process is an important means for heavy oil lightening, with many advantages such as strong raw material adaptability, flexible processing schemes, high liquid product yields, and good product quality, and has become the core process of modern refineries. The core of the hydrocracking technology is the hydrocracking catalyst, which is composed of a hydrogenation active center and a cracking active center. Zeolite molecular sieve is the main cracking active component of the catalyst, and its pore structure and acid properties play a decisive role in regulating the yield of distillate oil and the product distribution. The β-type zeolite molecular sieve has a three-dimensional twelve-membered ring pore structure, with a double six-membered ring unit crystal cavity structure composed of two four-membered rings and four five-membered rings. The main pore diameter is 0.56 - 0.75 nm, which is beneficial to the diffusion of molecules; the SSZ-13 zeolite molecular sieve contains ten-membered rings, and the basic structural unit is composed of eight five-membered rings. Its crystal structure belongs to the orthorhombic system, space group Pnma, lattice constants a = 2.01 nm, b = 1.99 nm, c = 1.34 nm. Its pore channels are its cavities. The framework is composed of two intersecting pore channel systems. The straight-through pore channels are elliptical, with a major axis of 0.57 - 0.58 nm and a minor axis of 0.51 - 0.52 nm; the other is a "Z"-shaped transverse pore channel, with a cross-section close to a circle and a pore diameter of 0.54 ± 0.02 nm, belonging to medium-pore zeolite. The amorphous silica-alumina as the cracking component has a relatively large pore diameter, which is beneficial to the diffusion of reactants and products, and has the characteristics of good selectivity, high product yield, low hydrogen consumption, and small change in product distribution during the operation cycle. However, the number of its acid centers is small and the cracking activity is low, so it also limits its application in the catalytic field.

[0004] It can be seen from this that although single zeolite molecular sieves have their own advantages, their disadvantages are also relatively obvious, while catalysts containing composite cracking components can integrate their respective advantages, not only improving the reaction activity but also increasing the yield of target products.

[0005] As disclosed in Chinese Patent Document CN104843730A, a preparation method of Beta / ZSM-5 nano-composite molecular sieve includes preparing a Beta zeolite growth solution, preparing a ZSM-5 growth solution, introducing mesoporous carbon into the beta molecular sieve and performing alkali washing treatment, then infiltrating the mesoporous carbon containing Beta zeolite in the mesopores into the ZSM-5 zeolite growth solution to obtain mesoporous carbon containing Beta and ZSM-5 zeolite seeds in the mesopores, and repeating this process 2 to 5 times. The obtained substance is successively filtered, washed with deionized water, dried, and calcined to obtain the Beta / ZSM-5 nano-composite molecular sieve. This method has a high degree of composite and good crystallinity, shortens the microporous transfer path per unit volume, reduces the mass transfer resistance of macromolecular catalytic reactions, and realizes the mutual cooperation of the acidic centers and microporous structures of the two zeolites, which is beneficial to improving the catalytic activity and selectivity of the target product. However, there are many repeated steps and the operation is cumbersome.

[0006] Chinese Patent Document CN113019426A discloses a hydrocracking catalyst carrier, a hydrocracking catalyst and its preparation method. The carrier includes: Y / Al-SBA-15 composite molecular sieve and alumina. The medium-strong acid amount of the Y / Al-SBA-15 composite molecular sieve is 0.6 to 1.2 mL / g, and the ratio of B acid to L acid is less than 1.2. The preparation method of the Y / Al-SBA-15 composite molecular sieve used in this carrier includes: using amorphous silica-alumina dry gel as the raw material, using P123 triblock copolymer as the template agent for the first crystallization to synthesize Al-SBA-15 molecular sieve, and then adding ultrastable Y molecular sieve slurry, and performing the second crystallization to obtain the Y / Al-SBA-15 composite molecular sieve. When using this hydrocracking catalyst in the hydrocracking reaction process, the yield of heavy naphtha is 35 - 40 wt%, and the aromatic potential is about 60 wt%.

[0007] Chinese Patent Document CN108014843A discloses a Cu-SSZ-13 / M-AlPO composite molecular sieve catalyst, a preparation method and its application, mainly to solve the problems of low stability of methanol-to-olefins catalysts, low selectivity and yield of ethylene, propylene and butene in light olefins in the prior art. By adopting a Cu-SSZ-13 / M-AlPO composite molecular sieve catalyst, the catalyst includes the following components by weight percentage: a) 10 to 100% of a CuSSZ-13 / M-AlPO composite molecular sieve; b) 0 to 90% of a binder. This technical solution preferably solves this problem and can be used in the industrial production of methanol-to-olefins. However, the pore structure of the molecular sieve prepared by this method is relatively small, which is only suitable for the methanol reaction process but difficult to adapt to the oil product reaction process.

[0008] Chinese patent document CN108014841A discloses a Cu-SSZ-13 / ZSM-5 composite structure molecular sieve and its synthesis method. First, an aluminum source is mixed with a solvent to form solution S, and then the solution is divided into two parts, denoted as solution SA and solution SB. b. Add a part of the silicon source, copper salt, chelating agent, and / or copper amine chelate to solution SA, stir well, and add an inorganic base during stirring to adjust the pH value of the system to obtain solution SA'; add the remaining silicon source and the organic template agent required for synthesizing ZSM-5 to solution SB, stir for 0.5 - 5 h to obtain solution SB', pre-crystallize solution SA' and solution SB' respectively, then mix them evenly and stir to form a homogeneous crystallization mixture; the product is filtered, washed, dried, and calcined to obtain the composite molecular sieve. However, the pore structure of the molecular sieve prepared by this method is relatively small and it is difficult to adapt to the oil product reaction process.

[0009] Chinese patent document CN114367307A discloses a preparation method of a core-shell structure M@SSZ-13@NanoBeta. Specifically, a noble metal is in-situ encapsulated in the core layer of SSZ-13 zeolite to form the core layer M@SSZ-13. Take a part of the above core layer sample and put it into the Beta synthesis gel. After crystallization, a core-shell type M@SSZ-13@NanoBeta is formed. The pore orifice of SSZ-13 zeolite is modified by the growth of the shell layer NanoBeta zeolite, which limits the contact between sulfides and noble metals and improves the sulfur resistance of the catalyst. In the hydrogen spillover effect, the active hydrogen component can hydrogenate the polycyclic aromatic hydrocarbons adsorbed on the acidic sites of the shell layer, and then the hydrogenation product is further cracked on the NanoBeta zeolite to achieve the selective hydrocracking of polycyclic aromatic hydrocarbons. However, this scheme uses noble metal encapsulation to limit the contact between sulfides and noble metals, but it is difficult to limit the influence of hydrogen sulfide gas generated during the hydrogenation process on noble metals. At the same time, using noble metals results in a relatively high preparation cost.

[0010] Chinese Patent Document CN114130427A discloses a preparation method of a Y / SSZ-13 / rare earth / ASA composite material. By using Y-type zeolite, SSZ-13 zeolite, rare earth and amorphous silica-alumina as cracking centers together, this composite material not only gives full play to the respective properties of several cracking components, but also enables them to produce a synergistic catalytic effect. That is, Y-type zeolite has a high ring-opening selectivity for aromatics and a strong cracking selectivity for long-chain paraffin olefins; SSZ-13 zeolite has good isomerization and shape-selective properties; amorphous silica-alumina has the characteristics of good selectivity, high liquid yield, low hydrogen consumption and small change in product distribution during the operation cycle. Moreover, amorphous silica-alumina has a dispersing effect on Y-type zeolite and SSZ zeolite, making the zeolite particles far apart from each other. In this way, the products after cracking of feedstock oil molecules on Y-type zeolite diffuse to the surface of SSZ-13, and isomerization and shape-selective reactions occur on the surface of SSZ-13 zeolite, generating lighter components in more jet fuel components. At the same time, rare earth combines with amorphous silica-alumina to improve the acidity of amorphous silica-alumina, making amorphous silica-alumina have a certain cracking activity. The light cracking products on amorphous silica-alumina also diffuse to the surface of SSZ-13 to undergo isomerization and shape-selective reactions, generating heavier components in more jet fuel components. In this way, the components of the catalyst prepared by this invention cooperate with each other, making the catalyst have high activity and good selectivity, and can be used in the process of hydrocracking straight-run diesel to produce high-quality jet fuel. This technology uses rare earth metals to modify amorphous silica-alumina, thereby modulating its acidity and improving the cracking performance of the material. However, in this scheme, the pore diameter and pore volume of amorphous silica-alumina are relatively large. Summary of the Invention

[0011] Aiming at the defects and improvement requirements of the existing technology, the present invention provides a hierarchical pore material, which has the pore structure characteristics and acidic characteristics of different zeolites at the same time. At the same time, rare earth metals are used to modify the microporous SSZ-13 zeolite, and the pore diameter structure is supported and its acidity is enhanced to better adapt to the process of oil product hydrocracking reaction.

[0012] To achieve the above object, the present invention provides the following technical solutions:

[0013] A hierarchical pore material, based on 100% of the mass of the hierarchical pore material, includes 20wt% - 80wt% of amorphous silica-alumina and 80wt% - 20wt% of zeolite;

[0014] Based on 100% of the mass of the zeolite, the zeolite includes 5wt% - 95wt% of Beta zeolite and 95wt% - 5wt% of rare earth-modified SSZ-13 zeolite;

[0015] Based on 100% of the mass of the rare earth-modified SSZ-13 zeolite, calculated as oxides, the content of rare earth is 0.1wt% - 5wt%.

[0016] Optionally, in the porous material provided by the present invention, the average pore diameter of the hierarchical pore material is 3 to 15 nm.

[0017] Optionally, in the porous material provided by the present invention, the silica-alumina ratio of the rare earth modified SSZ-13 molecular sieve is 20 to 100, the specific surface area is 200 to 500 m 2 / g, and the total pore volume is 0.2 to 0.5 mL / g.

[0018] Optionally, in the porous material provided by the present invention, the Beta molecular sieve can be a commercial Beta type molecular sieve with any crystal grain size.

[0019] The present invention also provides a method for preparing the above-mentioned hierarchical pore material, which includes the following steps:

[0020] (1) Disperse the Beta molecular sieve and the rare earth modified SSZ-13 in an acidic aluminum source solution, heat and stir to obtain a molecular sieve mixed slurry;

[0021] (2) While stirring, add an alkaline solution and sodium silicate to the molecular sieve mixed slurry to obtain a mixed material;

[0022] (3) The mixed material is separated, washed, dried, and calcined to obtain the hierarchical pore material.

[0023] Optionally, in step (1) of the method for preparing the hierarchical pore material provided by the present invention, calculated by Al 2 O 3 the concentration of the acidic aluminum source solution is (20 to 71) g / L; the acidic aluminum source solution is selected from any one of aluminum chloride solution, aluminum sulfate solution, and aluminum nitrate solution;

[0024] In step (1), the temperature of the heating and stirring is 60 to 100 °C, and the time is 1 to 8 h.

[0025] Optionally, in step (2) of the method for preparing the hierarchical pore material provided by the present invention, the alkaline solution is added within 0.2 to 8 h under stirring at 60 to 100 °C. After the addition of the alkaline solution is completed, it is maintained at 60 to 100 °C for 0.5 to 8 h, and then the sodium silicate is added within 0.5 to 10 h. After the addition of the sodium silicate is completed, it is maintained at 60 to 100 °C for 0.5 to 8 h; wherein, the alkaline solution is selected from any one of ammonia water, sodium aluminate solution, and sodium hydroxide solution.

[0026] Specifically, the method for preparing the porous material includes the following steps:

[0027] (1) Disperse Beta zeolite and rare earth - modified SSZ - 13 in an acidic aluminum source solution, heat to 60 - 100 °C, and stir at a constant temperature for 1 - 8 h to obtain a slurry of the zeolite mixture.

[0028] (2) While maintaining the temperature at 60 - 100 °C and stirring, add the alkaline solution to the slurry of the zeolite mixture within 0.2 - 8 h. After the addition of the alkaline solution is complete, keep the pH of the system between 8 - 9.5 and maintain it at 60 - 100 °C for 0.5 - 8 h; then continue to add the sodium silicate solution within 0.5 - 10 h while maintaining the temperature at 60 - 100 °C and stirring. After the addition of the sodium silicate solution is complete, maintain it at 60 - 100 °C for 0.5 - 8 h to obtain a mixed material.

[0029] (3) Filter, wash, dry, and calcine the mixed material to obtain a hierarchical pore material (rare earth - modified SSZ - 13 / Beta / ASA composite material).

[0030] Optionally, the preparation of the rare earth - modified SSZ - 13 zeolite includes the following steps:

[0031] 1) Add a silicon source, an aluminum source, an alkali source, and a template agent to water and mix to form a gel, carry out hydrothermal crystallization, and after washing and separation, obtain a first solid.

[0032] 2) Carry out ion exchange on the first solid with a rare earth precursor solution, and after washing and separation, obtain a second solid.

[0033] 3) After alkali - treating the second solid, carry out washing and separation to obtain a third solid; carry out ammonium exchange on the third solid with an ammonium salt, and after washing, separation, drying, and calcination, obtain the rare earth - modified SSZ - 13.

[0034] Optionally, in step 1) of the preparation of the rare earth - modified SSZ - 13 zeolite provided by the present invention, in terms of oxides, the molar ratio of each component in the gel is (60 - 150)SiO 2 :(1 - 3)Al 2 O 3 :(4 - 20)Na 2 O:(3000 - 4500)H 2 O:(10 - 30) template agent;

[0035] In step 1), the temperature of the hydrothermal crystallization is 80 - 190 °C, and the time is 72 - 170 h.

[0036] Optionally, in step 2) of the preparation of the rare earth - modified SSZ - 13 zeolite provided by the present invention, the temperature of the ion exchange is 50 - 120 °C, and the time is 1 - 10 h;

[0037] The concentration of the rare earth precursor solution is (0.5 - 7.5) g / L;

[0038] The solid - liquid ratio of the first solid to the rare earth precursor solution is 1:8 - 1:40.

[0039] Optionally, in step 3) of the preparation of the rare earth - modified SSZ - 13 molecular sieve provided by the present invention, the alkali treatment includes the following steps: at 50 - 120 °C, soaking the second solid in an alkaline solution of 0.1 wt% - 10 wt% for 1 - 10 h;

[0040] In step 3), the temperature of the ammonium exchange is 50 - 120 °C, and the time is 1 - 10 h.

[0041] Specifically, the preparation of the rare earth - modified SSZ - 13 molecular sieve provided by the present invention includes the following steps:

[0042] 1) Mix a silicon source, an aluminum source, an alkali source, and a template agent in water to form a gel, and then hydrothermally crystallize at 80 - 190 °C for 72 - 170 h. After washing and filtering, a first solid is obtained; preferably, in terms of oxides (the template agent is not in terms of oxides), the molar ratio of each component in the gel is (60 - 150)SiO 2 :(1 - 10)Al 2 O 3 :(5 - 20)Na 2 O:(3000 - 4500)H 2 O:(10 - 30) template agent;

[0043] 2) Carry out ion exchange on the first solid and a 0.1 wt% - 8 wt% rare earth precursor solution at a solid - liquid ratio of 1:8 - 1:40 under stirring conditions at 50 - 120 °C for 1 - 10 h, and then after washing and filtering, a second solid is obtained;

[0044] 3) Soak the second solid in an alkaline solution of 0.1 wt% - 10 wt% at 50 - 120 °C for 1 - 10 h, and then after washing and filtering, a third solid is obtained; carry out ammonium exchange on the third solid with a 0.5 - 4 mol / L ammonium salt solution at 50 - 120 °C for 1 - 10 h, and after washing, filtering, drying, and calcining, a rare earth - modified SSZ - 13 molecular sieve is obtained.

[0045] Optionally, in the preparation process of the rare earth - modified SSZ - 13 molecular sieve, the silicon source is selected from one or more of silica sol, solid silica gel, and fumed silica; preferably silica sol or solid silica gel;

[0046] The aluminum source is selected from any one of aluminum hydroxide, pseudo-boehmite, aluminum isopropoxide, and aluminum sulfate; preferably aluminum hydroxide or pseudo-boehmite;

[0047] The template agent is selected from any one of N,N,N-trimethyl-adamantylammonium, N,N,N-trimethyl-adamantylammonium iodide, and tetraethylammonium hydroxide; preferably N,N,N-trimethyl-adamantylammonium or N,N,N-trimethyl-adamantylammonium iodide;

[0048] The rare earth precursor is selected from chloride salts or nitrate salts of soluble rare earths; preferably one or more of lanthanum chloride, cerium chloride, lanthanum nitrate, and cerium nitrate.

[0049] Compared with the prior art, the present invention has the following advantages:

[0050] Beneficial effect 1: The hierarchical pore material provided by the present invention combines the pore structure characteristics and acidic characteristics of different molecular sieves. At the same time, rare earth metals are used to modify the microporous SSZ-13 molecular sieve, which can support the pore diameter structure and improve its acidity, enabling it to better adapt to the oil hydrocracking reaction process.

[0051] Beneficial effect 2: The preparation method of the hierarchical pore material provided by the present invention uses Beta molecular sieve and rare earth-modified SSZ-13 molecular sieve for mixing, and then in-situ composites with amorphous silica-alumina to form a composite material containing Beta molecular sieve, rare earth-modified SSZ-13 molecular sieve, and amorphous silica-alumina, and having a microporous-mesoporous composite pore size distribution. This method uses a step-by-step synthesis method with a stepped pore distribution, which can exhibit good synergistic effects and improve the molecular diffusion efficiency; the prepared hierarchical pore material has a large specific surface area, a large pore volume, a microporous-mesoporous pore structure distribution, a wide adjustable range of pore diameters, and a large amount of infrared acid. And the proportion of each component in the hierarchical pore material and the two-phase proportion in the molecular sieve can be changed by in-situ regulation and optimization of the synthesis conditions to obtain a hierarchical pore structure material with an optimized pore structure and appropriate acidity. Specific embodiments

[0052] The present invention will be specifically described below through examples. It is necessary to point out here that the following examples are only used to further illustrate the present invention and cannot be understood as limiting the protection scope of the present invention. Those skilled in the art can make some non-essential improvements and adjustments to the present invention according to the above content of the present invention.

[0053] For those not specifying specific experimental steps or conditions in the examples, the operations or conditions of the conventional experimental steps described in the literature in this field can be followed. For those reagents or instruments not specifying the manufacturer, they are all conventional reagent products that can be obtained through commercial purchase.

[0054] Example 1

[0055] This embodiment provides a hierarchical pore material, and its preparation method includes the following steps:

[0056] Rare earth modified SSZ-13 molecular sieve

[0057] 1) Add 180 g of 30% silica sol, 3.3 g of aluminum hydroxide, 6.7 g of sodium hydroxide, and 43.2 g of N,N,N-trimethyl-adamantylammonium (template agent) to 501 g of water and mix to form a gel. Then, hydrothermally crystallize at 150 °C for 150 h, wash and filter to obtain a first solid;

[0058] In terms of oxides (the template agent is not counted as an oxide), the molar ratio of each component in the gel is 90SiO 2 : 2.1Al 2 O 3 : 8Na 2 O: 3500H 2 O: 20 template agent;

[0059] 2) Take 100 g of the first solid and mix it with 1 L of a lanthanum chloride solution containing 2 g according to a solid-liquid ratio of 1:10. Perform ion exchange at 80 °C with stirring for 4 h, then wash and filter to obtain a second solid;

[0060] 3) Add the obtained second solid to 1000 mL of a 10 wt% sodium hydroxide solution, soak at 80 °C for 3 h, then wash and filter; add the obtained third solid to a 2 mol / L ammonium sulfate solution, perform ammonium exchange at 90 °C for 4 h, wash, filter, dry at 120 °C, and calcine at 500 °C to obtain the rare earth modified SSZ-13 molecular sieve. After detection, the silicon-aluminum ratio of the rare earth modified SSZ-13 molecular sieve is 30, the specific surface area is 500 m 2 / g, the total pore volume is 0.31 mL / g, and the lanthanum oxide content is 1.1 wt%.

[0061] Hierarchical pore material:

[0062] (1) Weigh 18 g of Beta molecular sieve with a silicon-aluminum ratio of 50 and 2 g of the above-prepared rare earth modified SSZ-13 molecular sieve according to the addition amount of the molecular sieve accounting for 20 wt% of the total weight of the hierarchical pore material, disperse them in 1 L of an aluminum sulfate solution with an alumina concentration of 41 g / L, heat to 90 °C, and stir at a constant temperature for 2 h to obtain a slurry of the molecular sieve mixture;

[0063] (2) While maintaining at 60 °C with stirring, add a 5 wt% sodium hydroxide solution to the slurry of the above zeolite mixture (taking 0.5 h), adjust the pH value to 8.5, and maintain at 70 °C for 1 h; then continue to add 203 g of a 40 wt% sodium silicate solution while maintaining at 70 °C with stirring (taking 0.8 h). After the addition of the sodium silicate solution is complete, maintain at 70 °C for 2 h to obtain a mixed material;

[0064] (3) Filter, wash, dry the mixed material at 120 °C for 5 hours, and calcine at 550 °C for 3 hours to obtain a hierarchical pore material (rare earth modified SSZ-13 / Beta / ASA composite material). After testing, the average pore diameter of this hierarchical pore material is 8 nm.

[0065] Example 2

[0066] Rare earth modified SSZ-13 zeolite

[0067] (1) Add 42.4 g of solid silica gel, 2.7 g of aluminum hydroxide, 10.9 g of sodium hydroxide, and 43.2 g of N,N,N-trimethyl-adamantyl ammonium iodide to 687 g of water and mix to form a gel. Then, carry out hydrothermal crystallization at 150 °C for 150 h, wash and filter to obtain a first solid;

[0068] Calculated as oxides (the template agent is not calculated as an oxide), the molar ratio of each component in this gel is 70SiO 2 : 1.7Al 2 O 3 : 13Na 2 O: 4000H 2 O: 25 template agent;

[0069] (2) Take 100 g of the above first solid and mix it with 1000 mL of an aqueous solution containing 0.8 g of cerium chloride according to a solid-liquid ratio of 1:10, and carry out ion exchange at 90 °C with stirring for 4 h, wash and filter to obtain a second solid;

[0070] (3) Add the obtained second solid to 1000 mL of a 1.5 wt% sodium hydroxide solution, soak and treat at 50 °C for 9 h, wash and filter; add the obtained third solid to a 2 mol / L ammonium sulfate solution, carry out ammonium exchange at 110 °C for 2 h, wash, filter, dry at 110 °C, and calcine at 600 °C to obtain a rare earth modified SSZ-13 zeolite. After testing, the silica-alumina ratio of this rare earth modified SSZ-13 zeolite is 25, the specific surface area is 400 m 2 / g, the total pore volume is 0.25 mL / g, and the cerium oxide content is 0.5 wt%.

[0071] Hierarchical pore material:

[0072] (1) Weigh 3.5 g of Beta zeolite with a silica-alumina ratio of 45 and 66.5 g of the above-prepared rare-earth modified SSZ-13 zeolite according to the addition amount of 70 wt% of the total weight of the zeolite molecular sieve in the composite material. Disperse them in 500 mL of an aluminum sulfate solution with an alumina concentration of 38 g / L, heat to 80 °C, and stir at a constant temperature for 1 h to obtain a slurry of the zeolite molecular sieve mixture.

[0073] (2) While maintaining 80 °C and stirring, add 10 wt% dilute ammonia water to the slurry of the above zeolite molecular sieve mixture (used for 0.2 h), adjust the pH value to 9.0. After the addition of the dilute ammonia water is completed, maintain at 80 °C for 1 h; then continue to add 81.3 g of a 30 wt% water glass solution while maintaining 80 °C and stirring (used for 0.5 h). After the addition of the water glass solution is completed, maintain at 80 °C for 7 h to obtain a mixed material.

[0074] (3) Filter, wash, dry at 105 °C for 7 h, and calcine at 550 °C for 3 h the mixed material to obtain a hierarchical pore material (rare-earth modified SSZ-13 / Beta / ASA composite material). After testing, the average pore diameter of this hierarchical pore material is 12 nm.

[0075] Example 3

[0076] This example provides a hierarchical pore material, and its preparation method includes the following steps:

[0077] Rare-earth modified SSZ-13 zeolite molecular sieve

[0078] (1) Add 220 g of 30% silica sol, 4.7 g of pseudo-boehmite (containing 70% alumina), 8.4 g of sodium hydroxide, and 32.4 g of N,N,N-trimethyl-adamantylammonium to 665 g of water and mix to form a gel. Then hydrothermally crystallize at 90 °C for 160 h, wash and filter to obtain a first solid.

[0079] Calculated as oxides (the template agent is not calculated as oxides), the molar ratio of each component in this gel is 110SiO 2 : 3Al 2 O 3 : 10Na 2 O: 4500H 2 O: 15 template agent;

[0080] (2) Take 100 g of the first solid and mix it with 800 mL of a solution containing 5.8 g of lanthanum nitrate according to a solid-liquid ratio of 1:8, and perform ion exchange under stirring conditions at 120 °C for 1.5 h. Wash and filter to obtain a second solid.

[0081] (3) The obtained second solid was added to 1000 mL of 3 wt% sodium hydroxide solution and soaked at 60 °C for 7 h. After washing and filtering, the obtained third solid was added to 2 mol / L ammonium sulfate solution and subjected to ammonium exchange at 100 °C for 3 h. After washing, filtering, drying at 110 °C, and calcining at 550 °C, a rare earth modified SSZ-13 molecular sieve was obtained. After testing, the silicon-aluminum ratio of the rare earth modified SSZ-13 molecular sieve was 20, the specific surface area was 450 m 2 / g, the total pore volume was 0.43 mL / g, and the lanthanum oxide content was 2.5 wt%.

[0082] Hierarchical porous material:

[0083] (1) According to the addition amount that the total weight of the molecular sieve accounted for 60 wt% of the weight of the composite material, 48 g of Beta molecular sieve with a silicon-aluminum ratio of 55 and 12 g of the above-prepared rare earth modified SSZ-13 molecular sieve were weighed and dispersed in 500 mL of aluminum nitrate solution with a concentration of 54 g / L calculated based on Al 2 O 3 . The mixture was heated to 90 °C and stirred at a constant temperature for 2 h to obtain a slurry of the molecular sieve mixture;

[0084] (2) While maintaining 80 °C and stirring, a 12 wt% sodium hydroxide solution was added to the slurry of the above molecular sieve mixture (used for 1 h). After the addition of the sodium hydroxide solution was completed, the pH value was adjusted to 9.0 and maintained at 90 °C for 7 h; then, while continuing to maintain 90 °C and stirring, 95 g of a 30 wt% water glass solution was added (used for 0.5 h). After the addition of the water glass solution was completed, it was maintained at 90 °C for 6 h to obtain a mixed material;

[0085] (3) The mixed material was filtered, washed, dried at 115 °C for 4 h, and calcined at 600 °C for 5 h to obtain a hierarchical porous material (rare earth modified SSZ-13 / Beta / ASA composite material). After testing, the average pore diameter of the hierarchical porous material was 6 nm.

[0086] Example 4

[0087] This example provides a hierarchical porous material, and its preparation method includes the following steps:

[0088] Rare earth modified SSZ-13 molecular sieve

[0089] (1) 280 g of 30% silica sol, 4.5 g of aluminum sulfate, 4.3 g of sodium carbonate, and 17.9 g of tetraethylammonium hydroxide were added to 539 g of water and mixed to form a gel, which was then hydrothermally crystallized at 110 °C for 120 h. After washing and filtering, a first solid was obtained;

[0090] On an oxide basis (the template is not counted as an oxide), the molar ratio of the components in the gel is 140SiO 2 : 1.3Al 2 O 3 : 4Na 2 O: 3000H 2 O: 12 template;

[0091] 2) Take 100 g of the above-mentioned first solid and 2000 mL of a cerium nitrate solution containing 8.5 g, and carry out ion exchange at a solid-liquid ratio of 1:20 under stirring conditions at 100 °C for 3 h. After washing and filtering, a second solid is obtained;

[0092] 3) Add the obtained second solid to 1000 mL of 5 wt% sodium hydroxide solution, soak and treat it at 70 °C for 5 h. After washing and filtering, the obtained third solid is added to 2 mol / L ammonium sulfate solution, and ammonium exchange is carried out at 80 °C for 5 h. After washing, filtering, drying at 115 °C, and calcining at 650 °C, a rare earth-modified SSZ-13 molecular sieve is obtained. After testing, the silica-alumina ratio of the rare earth-modified SSZ-13 molecular sieve is 65, the specific surface area is 250 m 2 / g, the total pore volume is 0.47 mL / g, and the cerium oxide content is 4.1 wt%.

[0093] Hierarchical porous material:

[0094] (1) Weigh 24 g of Beta molecular sieve with a silica-alumina ratio of 50 and 16 g of the above-mentioned obtained rare earth-modified SSZ-13 molecular sieve according to the addition amount of the molecular sieve accounting for 40 wt% of the total weight of the composite material, disperse them in 1 L of aluminum sulfate solution with an alumina concentration of 34 g / L, heat to 60 °C, and stir at a constant temperature for 7 h to obtain a slurry of the molecular sieve mixture;

[0095] (2) While maintaining 90 °C and stirring, add 8 wt% dilute ammonia water solution to the slurry of the above-mentioned molecular sieve mixture (it takes 3 h). After the addition of the dilute ammonia water solution is completed, adjust the pH value to 9.5 and maintain it at 100 °C for 5 h; then continue to add 137.3 g of 40 wt% water glass solution at 100 °C and under stirring conditions (it takes 5 h). After the addition of the water glass solution is completed, maintain it at 100 °C for 5 h to obtain a mixed material;

[0096] (3) Filter, wash, dry the mixed material at 120 °C for 5 hours, and calcine it at 650 °C for 2 hours to obtain a hierarchical porous material (rare earth-modified SSZ-13 / Beta / ASA composite material). After testing, the average pore diameter of the hierarchical porous material is 4 nm.

[0097] Example 5

[0098] This embodiment provides a hierarchical pore material, and its preparation method includes the following steps:

[0099] Rare earth modified SSZ-13 molecular sieve

[0100] 1) Add 81 g of fumed silica, 1.6 g of pseudoboehmite, 30.54 g of sodium bicarbonate, and 60.5 g of N,N,N-trimethyl-adamantylammonium iodide to 562 g of water and mix to form a gel. Then, hydrothermally crystallize at 130 °C for 100 h, wash and filter to obtain a first solid;

[0101] In terms of oxides (the template agent is not counted as an oxide), the molar ratio of each component in the gel is 130SiO 2 : 1Al 2 O 3 : 18Na 2 O: 3200H 2 O: 28 template agent;

[0102] 2) Take 100 g of the above first solid and 3000 mL of a solution containing 10.6 g of cerium nitrate, and perform ion exchange at a solid-liquid ratio of 1:30 under stirring conditions at 60 °C for 7 h. Wash and filter to obtain a second solid;

[0103] 3) Add the obtained second solid to 1000 mL of 8 wt% sodium hydroxide solution, soak at 100 °C for 3 h, wash and filter; add the obtained third solid to 2 mol / L ammonium sulfate solution, perform ammonium exchange at 70 °C for 7 h, wash, filter, dry at 120 °C, and calcine at 500 °C to obtain a rare earth modified SSZ-13 molecular sieve. After testing, the silicon-aluminum ratio of the rare earth modified SSZ-13 molecular sieve is 80, the specific surface area is 300 m 2 / g, the total pore volume is 0.27 mL / g, and the cerium oxide content is 5.0 wt%.

[0104] Hierarchical pore material:

[0105] (1) Weigh 12 g of Beta molecular sieve with a silicon-aluminum ratio of 50 and 18 g of the above-prepared rare earth modified SSZ-13 molecular sieve according to the addition amount of 30 wt% of the total weight of the molecular sieve in the composite material, disperse them in 500 g of Al 2 O 3 solution of aluminum chloride with a concentration of 70.7 g / L, heat to 70 °C, and stir constantly at a constant temperature for 3 h to obtain a slurry of the molecular sieve mixture;

[0106] (2) While maintaining at 100 °C with stirring, add a 15 wt% sodium hydroxide solution to the slurry of the above zeolite mixture (over 5 h). After the addition of the sodium hydroxide solution is complete, adjust the pH value to 9.0 and maintain at 100 °C for 3 h; then continue to add 178 g of a 40 wt% water glass solution while maintaining at 100 °C with stirring (over 9 h). After the addition of the water glass solution is complete, maintain at 100 °C for 1 h to obtain a mixed material;

[0107] (3) Filter, wash, dry the mixed material at 100 °C for 3 hours, and calcine at 550 °C for 3 hours to obtain a hierarchical pore material (rare earth modified SSZ-13 / Beta / ASA composite material). After testing, the average pore diameter of this hierarchical pore material is 10 nm.

[0108] Example 6

[0109] This example provides a hierarchical pore material, and its preparation method includes the following steps:

[0110] Rare earth modified SSZ-13 zeolite

[0111] (1) Add 90 g of solid silica gel, 4.1 g of aluminum isopropoxide, 12.6 g of sodium hydroxide, and 64.8 g of N,N,N-trimethyl-adamantylammonium to 751 g of water and mix to form a gel. Then hydrothermally crystallize at 180 °C for 80 h, wash and filter to obtain a first solid;

[0112] Calculated as oxides (the template agent is not calculated as oxides), the molar ratio of each component in this gel is 150SiO 2 : 1Al 2 O 3 : 15Na 2 O: 4200H 2 O: 30 template agent;

[0113] (2) Take 100 g of the above first solid and 4000 mL of a solution containing 11 g of lanthanum nitrate and carry out ion exchange at 50 °C with stirring for 9 h according to a solid-liquid ratio of 1:40. After washing and filtering, obtain a second solid;

[0114] (3) Add the obtained second solid to 1000 mL of a 0.1 wt% sodium hydroxide solution, soak and treat at 120 °C for 1 h, wash and filter; add the obtained third solid to a 2 mol / L ammonium sulfate solution, carry out ammonium exchange at 50 °C for 9 h, wash, filter, dry at 120 °C, and calcine at 500 °C to obtain a rare earth modified SSZ-13 zeolite. After testing, the silica-alumina ratio of this rare earth modified SSZ-13 zeolite is 95, the specific surface area is 350 m 2 / g, the total pore volume is 0.41 mL / g, and the lanthanum oxide content is 5 wt%.

[0115] Hierarchical porous material:

[0116] (1) Weigh 12 g of Beta zeolite with a silica-alumina ratio of 50 and 68 g of the above-prepared rare-earth modified SSZ-13 zeolite according to the addition amount of the total weight of the zeolite accounting for 80 wt% of the weight of the composite material, and disperse them in 500 mL of an aluminum 2 O 3 sulfate solution with a concentration of 20 g / L, heat to 80 °C, and stir at a constant temperature for 1 h to obtain a slurry of the zeolite mixture;

[0117] (2) While maintaining 60 °C and stirring, add a 10 wt% sodium aluminate solution to the slurry of the above zeolite mixture (it takes 7 h), adjust the pH value to 8.0, and keep it at 60 °C for 1 h; then continue to add 67.8 g of a 30 wt% water glass solution while maintaining 60 °C and stirring (it takes 3 h). After the addition of the water glass solution is completed, keep it at 60 °C for 1 h to obtain a mixed material;

[0118] (3) Filter, wash, dry the mixed material at 110 °C for 6 hours, and calcine it at 550 °C for 3 hours to obtain a hierarchical porous material (rare-earth modified SSZ-13 / Beta / ASA composite material). After testing, the average pore diameter of this hierarchical porous material is 3 nm, and it contains 3.4 wt% of lanthanum oxide.

[0119] Comparative Example 1

[0120] This comparative example provides a hierarchical porous material, and its preparation method includes the following steps:

[0121] Rare-earth modified SSZ-13 zeolite

[0122] 1) Add 180 g of 30% silica sol, 3.3 g of aluminum hydroxide, 6.7 g of sodium hydroxide, and 43.2 g of N,N,N-trimethyl-adamantylammonium (template agent) to 501 g of water and mix to form a gel, then hydrothermally crystallize at 150 °C for 150 h, and after washing and filtering, obtain a first solid;

[0123] Calculated as oxides (the template agent is not calculated as an oxide), the molar ratio of each component in this gel is 90SiO 2 : 2.1Al 2 O 3 : 8Na 2 O: 3500H 2 O: 20 template agent;

[0124] 2) Take 100 g of the first solid and mix it with 1 L of a lanthanum chloride solution containing 2 g according to a solid-liquid ratio of 1:10, perform ion exchange under stirring conditions at 80 °C for 4 h, and then after washing and filtering, obtain a second solid;

[0125] 3) The obtained second solid is added to 1000 mL of 10 wt% sodium hydroxide solution, soaked at 80 °C for 3 h, then washed and filtered; the obtained third solid is added to 2 mol / L ammonium sulfate solution, and ammonium exchange is carried out at 90 °C for 4 h, followed by washing, filtering, drying at 120 °C, and calcining at 500 °C to obtain rare earth modified SSZ-13 zeolite. After testing, the silicon-aluminum ratio of the rare earth modified SSZ-13 zeolite is 30, the specific surface area is 500 m 2 / g, the total pore volume is 0.31 mL / g, and the lanthanum oxide content is 1.1 wt%.

[0126] Hierarchical porous material:

[0127] (1) Weigh 18 g of Beta zeolite with a silicon-aluminum ratio of 50, 2 g of the above-prepared rare earth modified SSZ-13 zeolite, and 80 g of amorphous silica-aluminum material with 50% silicon oxide content;

[0128] (2) At room temperature, add the three materials to 400 g of water, stir and make a slurry to obtain a mixed material;

[0129] (3) The mixed material is filtered, washed, dried at 120 °C for 5 h, and calcined at 550 °C for 3 h to obtain a hierarchical porous material. After testing, the average pore diameter of the hierarchical porous material is 8 nm.

[0130] Comparative Example 2

[0131] This comparative example provides a hierarchical porous material, and its preparation method includes the following steps:

[0132] SSZ-13 zeolite

[0133] 1) Add 90 g of solid silica gel, 4.1 g of aluminum isopropoxide, 12.6 g of sodium hydroxide, and 64.8 g of N,N,N-trimethyl-adamantylammonium to 751 g of water and mix to form a gel, then hydrothermally crystallize at 180 °C for 80 h, wash and filter to obtain the first solid;

[0134] Calculated as oxides (the template agent is not calculated as oxides), the molar ratio of each component in the gel is 150SiO 2 : 1Al 2 O 3 : 15Na 2 O: 4200H 2 O: 30 template agent;

[0135] (3) Add 100 g of the above-mentioned first solid to 1000 mL of 0.1 wt% sodium hydroxide solution, soak and treat at 120 °C for 1 h, wash and filter; add the obtained second solid to 2 mol / L ammonium sulfate solution, carry out ammonium exchange at 50 °C for 9 h, wash, filter, dry at 120 °C, and calcine at 500 °C to obtain SSZ-13 molecular sieve. After detection, the silicon-aluminum ratio of this SSZ-13 molecular sieve is 95, the specific surface area is 350 m 2 / g, and the total pore volume is 0.41 mL / g.

[0136] Hierarchical pore material:

[0137] (1) Weigh 12 g of Beta molecular sieve with a silicon-aluminum ratio of 50 and 68 g of the above-prepared SSZ-13 molecular sieve according to the addition amount that the total weight of the molecular sieve accounts for 80 wt% of the weight of the composite material, disperse them in 500 mL of Al 2 O 3 sulfate solution with a concentration of 20 g / L, heat to 80 °C, and stir at a constant temperature for 1 h to obtain a slurry of the molecular sieve mixture;

[0138] (2) While maintaining 60 °C and stirring, add 10 wt% sodium aluminate solution to the slurry of the above molecular sieve mixture (used for 7 h), adjust the pH value to 8.0, and keep it at 60 °C for 1 h; then continue to add 67.8 g of 30 wt% water glass solution while maintaining 60 °C and stirring (used for 3 h). After the addition of the water glass solution is completed, keep it at 60 °C for 1 h to obtain a mixed material;

[0139] (3) Mix the above mixed material with 800 mL of a solution containing 7.6 g of lanthanum nitrate according to a solid-liquid ratio of 1:8, carry out ion exchange at 120 °C under stirring conditions for 1.5 h, filter, wash, dry the mixed material at 110 °C for 6 hours, and calcine at 550 °C for 3 hours to obtain a hierarchical pore material (SSZ-13 / Beta / rare earth / ASA composite material). After detection, the average pore diameter of this hierarchical pore material is 3 nm, and it contains 3.5 wt% of lanthanum oxide.

[0140] Comparative Example 3

[0141] This comparative example provides a hierarchical pore material, and its preparation method includes the following steps:

[0142] Rare earth modified SSZ-13 molecular sieve

[0143] (1) Add 180 g of 30% silica sol, 3.3 g of aluminum hydroxide, 6.7 g of sodium hydroxide, and 43.2 g of N,N,N-trimethyl-adamantylammonium (template agent) to 501 g of water and mix to form a gel, then carry out hydrothermal crystallization at 150 °C for 150 h, wash and filter to obtain the first solid;

[0144] On an oxide basis (the template is not counted as an oxide), the molar ratio of each component in the gel is 90SiO 2 : 2.1Al 2 O 3 : 8Na 2 O: 3500H 2 O: 20 template;

[0145] 2) Take 100 g of the first solid and mix it with 1 L of a lanthanum chloride solution containing 2 g according to a solid-liquid ratio of 1:10. Perform ion exchange at 80 °C with stirring for 4 h, then wash and filter to obtain a second solid;

[0146] 3) Add the obtained second solid to 1000 mL of a 10 wt% sodium hydroxide solution, soak it at 80 °C for 3 h, then wash and filter; add the obtained third solid to a 2 mol / L ammonium sulfate solution, perform ammonium exchange at 90 °C for 4 h, wash, filter, dry at 120 °C, and calcine at 500 °C to obtain a rare earth-modified SSZ-13 molecular sieve. After testing, the silicon-aluminum ratio of this rare earth-modified SSZ-13 molecular sieve is 30, the specific surface area is 500 m 2 / g, the total pore volume is 0.31 mL / g, and the lanthanum oxide content is 1.1 wt%.

[0147] Hierarchical porous material:

[0148] (1) Weigh 3.4 g of Beta molecular sieve with a silicon-aluminum ratio of 50 and 81.6 g of the above-prepared rare earth-modified SSZ-13 molecular sieve according to the addition amount that the total weight of the molecular sieve accounts for 85 wt% of the weight of the hierarchical porous material. Disperse them in 500 mL of an aluminum sulfate solution with an alumina concentration of 22 g / L, heat to 90 °C, and stir constantly at a constant temperature for 2 h to obtain a slurry of the molecular sieve mixture;

[0149] (2) While maintaining 60 °C and stirring, add a 5 wt% sodium hydroxide solution to the slurry of the above molecular sieve mixture (it takes 0.5 h). After the addition of the sodium hydroxide solution is complete, adjust the pH value to 8.5 and maintain it at 70 °C for 1 h; then continue to maintain at 70 °C and stir, and add 35.7 g of a 28 wt% sodium silicate solution (it takes 0.8 h). After the addition of the sodium silicate solution is complete, maintain it at 70 °C for 2 h to obtain a mixed material;

[0150] (3) Filter, wash, dry the mixed material at 120 °C for 5 h, and calcine at 550 °C for 3 h to obtain a hierarchical porous material (rare earth-modified SSZ-13 / Beta / ASA composite material). After testing, the average pore diameter of this hierarchical porous material is 1 nm.

[0151] The hierarchical pore materials prepared in the above-mentioned examples and comparative examples were respectively tested. The specific test methods are as follows, and the test results are shown in Table 1 below.

[0152] The specific surface area and pore structure of the hierarchical pore materials were determined by a Tristar 3000 specific surface area and pore structure analyzer from Micromeritics Instrument Corporation, USA.

[0153] X-ray fluorescence spectroscopy (XRF)

[0154] The content of rare earth metals in the hierarchical pore materials was determined by a Magix601 X-ray fluorescence spectrometer from Philips Company, Netherlands.

[0155] Pyridine-infrared spectroscopy (Py-IR)

[0156] Take about 10 mg of the sample to be tested and press it into a self-supporting film, fix it in an infrared cell, desorb for 2 hours at a vacuum of 0.01 Pa and a temperature of 400 °C to purify the surface, cool to room temperature, and measure the background infrared spectrum of the sample. After adsorbing pyridine at room temperature, equilibrate for 0.5 hour, then heat the sample to 200 °C and 350 °C at a programmed rate and desorb under vacuum (0.01 Pa) for 2 hours, and then cool to room temperature and measure the spectra respectively. Use the integrated intensities of the infrared bands at 1450 cm -1 and 1540 cm -1 to determine the amounts of Bronsted acid and Lewis acid, and use the integrated extinction coefficients given by Emeis for quantitative calculation of the acid amounts.

[0157] Table 1 Test Results

[0158]

[0159]

[0160] It can be seen from the data in the above table that the catalyst containing the Beta / rare earth-SSZ-13 / ASA composite material has the characteristics of a large specific surface area, a large pore volume, a wide pore size range distribution, and a large acid amount adjustment range, and can adapt to the oil product hydrocracking reaction process.

[0161] Of course, the present invention can also have many other embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and deformations according to the present invention, but these corresponding changes and deformations should all fall within the protection scope of the claims of the present invention.

Claims

1. A hierarchical pore material, characterized in that calculated based on the mass of the hierarchical pore material being 100%, it comprises 20 wt% - 80 wt% of amorphous silica-alumina and 80 wt% - 20 wt% of molecular sieve; calculated based on the mass of the molecular sieve being 100%, the molecular sieve comprises 5 wt% - 95 wt% of Beta molecular sieve and 95 wt% - 5 wt% of rare earth modified SSZ-13 molecular sieve; calculated based on the mass of the rare earth modified SSZ-13 molecular sieve being 100%, calculated as oxides, the content of rare earth is 0.1 wt% - 5 wt%.

2. The porous material according to claim 1, characterized in that The silicon-aluminum ratio of the rare earth modified SSZ-13 molecular sieve is 20 to 100, the specific surface area is 200 to 500 m 2 / g, and the total pore volume is 0.2 to 0.5 mL / g.

3. A preparation method of the hierarchical pore material according to claim 1 or 2, characterized in that comprises the following steps: (1) Disperse Beta molecular sieve and rare earth modified SSZ-13 molecular sieve in an acidic aluminum source solution, heat and stir to obtain a molecular sieve mixed slurry; (2) Under stirring, add an alkaline solution and sodium silicate to the molecular sieve mixed slurry to obtain a mixed material; (3) The mixed material is separated, washed, dried, and calcined to obtain the hierarchical pore material.

4. The preparation method according to claim 3, characterized in that In step (1), taking Al 2 O 3 into account, the concentration of the acidic aluminum source solution is (20 - 71) g / L; and / or in step (1), the temperature of the heating and stirring is 60 - 100 °C, and the time is 1 - 8 h.

5. The preparation method according to claim 3, characterized in that in step (2), under stirring at 60 - 100 °C, add the alkaline solution within 0.2 - 8 h. After the addition of the alkaline solution is completed, keep it at 60 - 100 °C for 0.5 - 8 h, then add the sodium silicate within 0.5 - 10 h. After the addition of the sodium silicate is completed, keep it at 60 - 100 °C for 0.5 - 8 h.

6. The preparation method according to claim 3, characterized in that the preparation of the rare earth modified SSZ-13 molecular sieve comprises the following steps: 1) Add a silicon source, an aluminum source, an alkali source, and a template agent to water and mix to form a gel, carry out hydrothermal crystallization, and after washing and separation, obtain a first solid; 2) Carry out ion exchange on the first solid with a rare earth precursor solution, and after washing and separation, obtain a second solid; 3) After alkali treatment of the second solid, and after washing and separation, obtain a third solid; Carry out ammonium exchange on the third solid with an ammonium salt, and after washing, separation, drying, and calcination, obtain the rare earth modified SSZ-13 molecular sieve.

7. The preparation method according to claim 6, characterized in that In step 1), based on oxides, the molar ratio of each component in the gel is (60-150)SiO 2 :(1-3)Al 2 O 3 :(4-20)Na 2 O:(3000-4500)H 2 O:(10-30) templating agent; and / or in step 1), the temperature of the hydrothermal crystallization is 80 - 190 °C, and the time is 72 - 170 h.

8. The preparation method according to claim 6, characterized in that in step 2), the temperature of the ion exchange is 50 - 120 °C, and the time is 1 - 10 h; the concentration of the rare earth precursor solution is (0.5 - 7.5) g / L; the solid-liquid ratio of the first solid to the rare earth precursor solution is 1:8 - 1:

40.

9. The preparation method according to claim 6, characterized in that In step 3), the alkali treatment comprises the following steps: soaking the second solid in an alkaline solution with a concentration of 0.1 wt% to 10 wt% at 50 to 120 °C for 1 to 10 h; In step 3), the temperature of the ammonium exchange is 50 to 120 °C, and the time is 1 to 10 h.

10. The preparation method according to claim 6, characterized in that the silicon source is selected from any one of sodium silicate, silica sol, solid silica gel and fumed silica; the aluminum source is selected from any one of aluminum hydroxide, pseudo-boehmite, aluminum isopropoxide and aluminum sulfate; the template agent is selected from one or more of N,N,N-trimethyl-adamantylammonium, N,N,N-trimethyl-adamantylammonium iodide and tetraethylammonium hydroxide; and / or the rare earth precursor is selected from the chloride or nitrate of soluble rare earth.

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