A magnesium-containing catalyst substrate material having mesoporous channels and a method for preparing the same

Abstract

This invention belongs to the field of catalytic materials and relates to a catalyst matrix material with mesoporous channels and its preparation method. The anhydrous chemical formula of the matrix material, based on the mass of oxides, is (0.3-0.7)Al₂O₃·(0.3-0.7)SiO₂·(0.09-0.4)MgO, and it has mesoporous channels with a bimodal pore size distribution. The preparation method includes: (1) mixing magnesium salt and aluminum salt in a certain proportion to obtain solution A; (2) preparing an alkaline solution by dissolving alkali in a certain proportion to obtain solution B; (3) adding solution B to solution A and controlling the final pH to prepare solution C; (4) mixing solution C with silicon species and a second aluminum species, drying, calcining, and washing. The matrix material provided by this invention is highly active for catalytic cracking and has low coke selectivity.

Description

Technical Field

[0001] This invention relates to a method for preparing a catalyst matrix material with mesoporous channels. Background Technology

[0002] Fluidized catalytic cracking is the primary process for converting heavy fractions into smaller molecule fractions, typically requiring catalytic materials with high cracking activity. Initially, acid clay and synthetic silica-alumina could be used directly as cracking catalysts, but their cracking activity was low and the reaction temperature was high. It wasn't until the 1960s that Mobil successfully developed molecular sieve cracking catalysts, which, due to their excellent shape-selective catalytic performance and high reactivity, were widely used in the petroleum processing industry. However, the relatively small pore size of molecular sieve catalytic materials significantly restricts the diffusion of larger reactant molecules, leading to a decrease in apparent reactivity. Therefore, this limits their application in macromolecular catalytic reactions to some extent.

[0003] Catalytic cracking is a parallel sequential reaction. The active center of the catalytic cracking catalyst is mainly a Y-type molecular sieve, with pores consisting of twelve-membered rings and a diameter of approximately 0.7 nm. However, the diameter of heavy oil macromolecules ranges from 1 to 6 nm, preventing them from penetrating the interior of the Y-type molecular sieve. Therefore, the cracking of heavy oil macromolecules primarily occurs on the matrix. Heavy oil macromolecules crack into secondary molecules on the matrix, and these secondary molecules further enter the molecular sieve for further cracking into smaller molecules. Due to diffusion limitations, the ideal pore size for heavy oil cracking is 6 to 10 times the molecular diameter, corresponding to a pore size range of 6 to 60 nm. Simultaneously, to ensure sufficient catalyst abrasion resistance during fluidization, the pore size cannot be too large; therefore, the ideal pore size range for heavy oil cracking is 6 to 20 nm. However, traditional catalytic cracking matrix materials have pore sizes smaller than 5 nm and small pore volumes, which no longer meet the requirements of heavy oil cracking. For heavy oil cracking, the accessibility of heavy oil macromolecules to the active center has become a significant challenge. Catalytic cracking matrix materials with mesoporous channels are one of the main research directions for catalytic cracking catalysts.

[0004] US3157591A discloses a silica-alumina-magnesium oxide catalyst and a method for converting hydrocarbons. This invention allows for the integration of high alumina content with magnesium oxide into the silica structure, resulting in an excellent high-Al₂O₃ amorphous tripartite splitting catalyst. This superiority stems from its high acid stability and strength, as well as its amorphous structure. However, the catalyst exhibits low activity at higher magnesium oxide contents.

[0005] US3267044A discloses a method for preparing a silica-alumina-magnesium oxide pyrolysis catalyst. The method prepares the catalyst by mixing silica hydrogel, which is prepared by treating alkali metal silicates with carbon dioxide, with sufficient aluminum slurry. However, the catalyst has low activity when the magnesium oxide content is high.

[0006] Catalyst matrix materials prepared by existing technologies have problems such as high coke yield and poor coke selectivity when there is no magnesium or low magnesium content; and low activity and poor cracking reaction performance when the magnesium content is high. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide a catalyst matrix material that is different from the prior art and has excellent cracking reaction activity and coke selectivity.

[0008] In this invention, the room temperature is 10–35°C.

[0009] The first aspect of this invention provides a catalyst matrix material with high magnesium content, whose anhydrous chemical expression, based on the mass of oxides, is (0.30–0.70)Al₂O₃·(0.30–0.70)SiO₂·(0.09–0.40)MgO, for example (0.35–0.65)Al₂O₃·(0.3–0.5)SiO₂·(0.09–0.3)MgO or (0.4–0.6)Al₂O₃·(0.3–0.4)SiO₂·(0.09–0.20)MgO. The matrix material has mesoporous channels and a rich pore structure. The rich pore structure refers to the matrix material having a bimodal distribution in the dV / dlogD versus D pore size distribution diagram. D (pore diameter) and V (pore volume) are measured by nitrogen adsorption capacity method, the pore size distribution is calculated by BJH method, and the specific surface area is calculated by BET formula.

[0010] Optionally, the high magnesium content catalyst matrix material (hereinafter referred to as matrix material) contains 30 to 70% by mass of Al2O3, for example, 40 to 60% by mass or 48 to 58% by mass.

[0011] Optionally, the mass fraction of SiO2 in the matrix material is 30-60% by mass, for example 30-40% by mass or 31-37% by mass.

[0012] The preferred MgO mass fraction in the matrix material is 9–35% by mass, for example 9–30% by mass, 10–25% by mass, 9–20% by mass, or 9–16% by mass.

[0013] Optionally, the mass ratio of SiO2 / Al2O3 in the matrix material is 0.50 to 0.80:1, for example, 0.55 to 0.75:1.

[0014] Optionally, the MgO / Al2O3 mass ratio in the matrix material is 0.10 to 0.50:1, for example, 0.15 to 0.35:1.

[0015] Optionally, the Na2O content in the matrix material preferably does not exceed 0.3% by mass, more preferably not exceeding 0.2% by mass.

[0016] The matrix material exhibits high cracking activity. Optionally, the matrix material has a microreaction activity (MA) of not less than 30, and the microreaction activity (or microreaction activity index) is, for example, 30–40 or 31–36. The method for measuring the microreaction activity is described in NB / SH / T 0952-2017, "Determination of Microreaction Activity Index of Catalytic Cracking Catalyst." The feedstock is Dagang straight-run light diesel oil with a distillation range of 235–337℃. The evaluation conditions are: catalyst-to-oil ratio 3.2 (mass ratio) and mass hourly space velocity 40.11 h⁻¹. -1 The reaction temperature is 460℃.

[0017] The matrix material has a bimodal pore size distribution. Optionally, the bimodal pore size distribution diagram of the matrix material has a peak with D in the range of 5-7 nm and a peak with D in the range of 8-20 nm.

[0018] Optionally, the pore volume of the matrix material is 0.5 to 0.7 mL / g, for example, 0.54 to 0.65 mL / g.

[0019] Optionally, the specific surface area of ​​the matrix material is 225–260 m². 2 / g.

[0020] Optionally, the matrix material exhibits characteristic peaks with 2θ angles of 11.4°, 23.1°, 34.5°, 60.7°, and 62.0° in its XRD spectrum.

[0021] Optionally, the matrix material has channels formed by the accumulation of silica particles and alumina particles. Optionally, the silica particles are derived from silica sol, and the alumina particles are derived from boehmite.

[0022] A second aspect of the present invention provides a method for preparing a matrix material, the method comprising:

[0023] (1) Mix magnesium salt and aluminum salt in a certain proportion to obtain solution A;

[0024] (2) Prepare an alkaline solution of a certain concentration by dissolving the alkaline species to obtain solution B;

[0025] (3) Add solution B to solution A and control the final pH value to prepare dispersion C;

[0026] (4) Mix the C dispersion with the silicon species and the second aluminum species;

[0027] (5) Drying, optional roasting and washing.

[0028] According to the method for preparing matrix materials described in the above technical solution, in step (1), the n(Mg):n(Al) ratio in solution A is 2-6:1, for example, 2-5:1, 2.5-4.5:1, or 2.9-5.5:1 (molar ratio). In one embodiment, the temperature of the mixture formed in step (1) is ≤40°C, preferably 10-35°C; optionally, after mixing, the stirring time (stirring time after mixing) is 15 min or more, preferably 15-30 min.

[0029] Optionally, in solution A, the concentration of magnesium and aluminum salts, calculated as MgO + Al2O3, is 2–15% by mass, for example, 3–10% by mass, 3.5–8% by mass, 4–6.6% by mass, or 4–6% by mass.

[0030] The magnesium salt is, for example, a hydrated magnesium salt, and the aluminum salt is, for example, a hydrated aluminum salt.

[0031] Optionally, the magnesium salt is selected from one or more of hydrated magnesium carbonate, hydrated magnesium chloride, hydrated magnesium sulfate, methyl magnesium acetate, and triethyl magnesium.

[0032] Optionally, the aluminum salt is selected from one or more of hydrated aluminum sulfate, hydrated aluminum chloride, and hydrated aluminum nitrate.

[0033] According to the method for preparing matrix materials according to any of the above technical solutions, in step (2), the alkaline species can be selected from one or more of NaOH, KOH, Ca(OH)2, Mg(OH)2, Na2CO3, K2CO3, NH3·H2O, and sodium aluminate, preferably one or more of NaOH, KOH, Mg(OH)2, and Na2CO3; more preferably NaOH and Na2CO3, and the mass ratio of NaOH to Na2CO3 is preferably 1.5 to 2.5. This preferred ratio can result in a larger pore volume.

[0034] Preferably, the concentration of alkaline species in the alkaline solution (i.e., solution B) is 5-25% by mass.

[0035] Optionally, the pH value of the B solution obtained in step (2) is 12-14, for example, 13-14. In one embodiment, the alkaline species can be mixed with water and stirred for a certain time to obtain the alkaline solution. Preferably, the temperature of the mixture formed in step (2) is ≤35°C, preferably 10-35°C. The stirring time (i.e., the stirring time after mixing) is 15 min or more, preferably 15-30 min.

[0036] According to any of the above technical solutions, in the method for preparing the matrix material, in step (3), solution B can be added to solution A at a certain flow rate, for example, solution B can be slowly added to solution A. Optionally, the addition rate of solution B to solution A is 0.05–0.2 mL / s. -1 / 1000g of solution A. Preferably, the endpoint pH value is controlled to be 8-11, preferably 9-10; the mixing temperature (the temperature of the mixture formed during the addition of solution B to solution A) is ≤45℃, preferably 10-35℃. Preferably, the stirring time after adding solution B to solution A is 30 min or more, preferably 40-60 min.

[0037] Optionally, the content of magnesium and aluminum elements in the C dispersion, calculated as MgO+Al2O3, is 2-15% by mass, for example, 2-4% by mass, 4-6% by mass, or 6-10% by mass.

[0038] Optionally, the mass ratio of MgO to Al2O3 in the C dispersion is 1 to 15, for example, 1.1 to 10, 1 to 4.5, 1.1 to 4.4, 2.4 to 3.4, 2.2 to 8, or 3.1 to 4.3.

[0039] According to the method for preparing matrix materials according to any of the above technical solutions, in step (4), the silicon species and the second aluminum species can be selected from one or more of aluminum sol, aluminum oxide, silica sol, and silica-alumina sol, and silicon and the second type of aluminum are introduced through the silicon species and the second aluminum species. In one embodiment, the second aluminum species can be selected from one or more of aluminum sol, aluminum oxide, silica sol, and silica-alumina sol, for example, one or more of aluminum sol and aluminum oxide, and the silicon species can be selected from one or more of silica sol and silica-alumina sol, preferably silica sol.

[0040] Preferably, in step (4), in the mixture formed by mixing the C dispersion with the silicon species and the second aluminum species (referred to as the silicon-aluminum-magnesium dispersion), the C dispersion, calculated as MgO+Al2O3, is 10-25% by mass, for example, 12-20% by mass, of the mixture (silicon-aluminum-magnesium dispersion), calculated as MgO+Al2O3+SiO2. Optionally, the mass ratio of aluminum in the second aluminum species to aluminum in the aluminum salt described in step (1) is 5-18:1 (calculated as alumina).

[0041] Preferably, step (4) involves mixing the C dispersion with a silicon species and a second aluminum species, including adding a silicon species to the C dispersion and then adding the second aluminum species, which can improve the matrix strength and provide a multi-level porous structure.

[0042] According to the method for preparing matrix materials according to any of the above technical solutions, in step (5), the methods of spray drying, optional drying, and washing can refer to the prior art. For example, the drying temperature can be 80-200℃, preferably 80-120℃; the drying time can be selected according to actual needs, and there is no special limitation thereto; the drying is, for example, spray drying. The calcination temperature is, for example, 450-600℃, and the calcination time is, for example, 1-4 hours. The washing is, for example, washing with ammonium salt solution or water.

[0043] The present invention also provides the application of the matrix material described in any of the above technical solutions or the matrix material obtained by the method for preparing the matrix material described in any of the above technical solutions in the preparation of catalytic cracking catalysts.

[0044] The matrix material provided by this invention has a high magnesium content, a suitable pore structure and high hydrocarbon cracking reactivity. It can simultaneously have acidic centers and a certain amount of basic centers. When used for heavy oil conversion, it can enable the pre-cracking of heavy oil macromolecules while exhibiting excellent activity and low coke selectivity.

[0045] The matrix material provided by this invention has a high magnesium content and can be used in heavy oil conversion that requires reducing coke yield and utilizing different properties of magnesium, such as heavy oil conversion that also takes into account sulfur transfer or metal capture.

[0046] The catalytic cracking catalyst prepared using the matrix material provided by this invention has high heavy oil conversion activity and low coke selectivity. For example, it can have low coke selectivity while having high heavy oil conversion rate. Surprisingly, it has high gasoline yield and high propylene yield when used for heavy oil conversion.

[0047] The method for preparing the matrix material provided by this invention can obtain a matrix material with a high magnesium content and a dual mesoporous structure, which can have a high pore volume. This material can simultaneously have acidic centers and a certain amount of basic centers, and has high cracking activity and low coke selectivity. Attached Figure Description

[0048] Figure 1 The mesopore size distribution of the samples provided in the embodiments and comparative examples of this invention was obtained by N2 adsorption-desorption testing and calculated using the BJH method. Detailed Implementation

[0049] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0050] The following examples provide a further detailed description of the invention. The specifications of the raw materials used in the examples and comparative examples are shown below:

[0051] MgSO4·7H2O: 99.5% by mass, produced by Maclean Biochemical Technology Co., Ltd.

[0052] MgCl2·6H2O: 98% by mass concentration, produced by Maclean Biochemical Technology Co., Ltd.

[0053] MgO: 98% by mass concentration, produced by McLean Biotech Co., Ltd.

[0054] Al2(SO4)3·18H2O: Concentration of 99% by mass, Tianjin Damao Chemical Reagent Co., Ltd.

[0055] AlCl3·6H2O: 97% by mass concentration, produced by Maclean Biochemical Technology Co., Ltd.

[0056] Sodium hydroxide: 96% by mass, manufactured by Maclean Biotech Co., Ltd.

[0057] Na2CO3: Concentration 99.5% by mass, produced by Thermo Fisher Scientific (China) Co., Ltd.

[0058] Alkaline silica sol: analytical grade, SiO2 content 30% by mass, pH 9.8; produced by Xilong Scientific Reagent Factory;

[0059] Boehmite: Al2O3 content 66.36% by mass, produced by Shanxi Jinlu of China Aluminum Group;

[0060] Aluminum isopropoxide: 99% by mass, manufactured by Inokai Chemical Reagent Co., Ltd.

[0061] Acetic acid: AR, produced by Tianjin Damao Chemical Reagent Co., Ltd.;

[0062] Sulfuric acid: AR, produced by Beijing Chemical Plant;

[0063] Hydrochloric acid, HCl concentration 36% by mass, produced by Beijing Chemical Plant;

[0064] Water glass: 20% by mass (as SiO2), modulus 3.1, manufactured by Thermo Fisher Scientific (China) Co., Ltd.

[0065] Molecular sieve: RE2O3 content 8.0% by mass%, crystallinity 51.7%, SiO2:Al2O3 molar ratio 4.89, produced by Qilu Branch of Sinopec Catalyst Co., Ltd.

[0066] Kaolin: Solid content 78% by mass, produced by Suzhou Kaolin Company.

[0067] Analysis method:

[0068] (1) The composition of each material was determined by XRF fluorescence analysis (RIPP 117-90 standard method (see Petrochemical Analysis Methods (RIPP Test Methods) edited by Yang Cuiding et al., Science Press, 1990)).

[0069] (2) Physicochemical data such as specific surface area and pore volume were measured using the nitrogen adsorption-desorption method (ASTM D4365 standard).

[0070] In the following examples, the room temperature is 25°C.

[0071] Examples 1-4 illustrate the preparation of the catalyst matrix material provided by the present invention.

[0072] Example 1

[0073] (1) Weigh 180g MgSO4·7H2O and 60g MgCl2·6H2O and dissolve them in 600g water. Stir well at room temperature for 20min to obtain solution A.

[0074] (2) Weigh 72g NaOH and 40g Na2CO3 and dissolve them in 600g water. Stir well at room temperature for 20min to obtain solution B.

[0075] (3) Slowly add solution B to solution A, control the endpoint pH to 9.5, and prepare dispersion C;

[0076] (4) Dissolve 198g of boehmite in 1539g of water, mix and stir at room temperature for 30min, then add 26g of hydrochloric acid, mix and stir for 30min to prepare boehmite;

[0077] (5) Add 300g of alkaline silica sol to C dispersion and stir at room temperature for 30min. Then add alumina and stir at room temperature for 30min.

[0078] (6) The above solution was spray-dried, calcined at 500°C for 2 hours, washed until the Na2O content was less than 0.3%, and dried at 90°C for 2 hours. The resulting matrix material was named M-1.

[0079] Example 2

[0080] (1) Weigh 150g MgSO4·7H2O and 50g Al2(SO4)3·18H2O and dissolve them in 600g water. Stir well at room temperature for 20min to obtain solution A.

[0081] (2) Weigh 92g NaOH and 50g Na2CO3 and dissolve them in 600g water. Stir well at room temperature for 20min to obtain solution B.

[0082] (3) Slowly add solution B to solution A, control the endpoint pH to 10.0, and prepare dispersion C;

[0083] (4) Dissolve 198g of boehmite in 1539g of water, mix and stir at room temperature for 30min, then add 26g of hydrochloric acid, mix and stir for 30min to prepare boehmite;

[0084] (5) Add 300g of alkaline silica sol to C dispersion and stir at room temperature for 30min. Then add alumina and stir at room temperature for 30min.

[0085] (6) The above solution was spray-dried, calcined at 500°C for 2 hours, washed until the Na2O content was less than 0.3%, and dried at 90°C for 2 hours. The resulting matrix material was named M-2.

[0086] Example 3

[0087] (1) Weigh 148g MgCl2·6H2O and 60g Al2(SO4)3·18H2O and dissolve them in 600g water. Stir well at room temperature for 20min to obtain solution A.

[0088] (2) Weigh 42g NaOH and 20g Na2CO3 and dissolve them in 600g water. Stir well at room temperature for 20min to obtain solution B.

[0089] (3) Slowly add solution B to solution A, control the endpoint pH to 10.0, and prepare dispersion C;

[0090] (4) Dissolve 198g of boehmite in 1539g of water, mix and stir at room temperature for 30min, then add 26g of hydrochloric acid, mix and stir for 30min to prepare boehmite;

[0091] (5) Add 320g of alkaline silica sol to C dispersion and stir at room temperature for 30min. Then add aluminum oxide and stir at room temperature for 30min.

[0092] (6) The above solution was spray-dried, calcined at 500°C for 2 hours, washed until the Na2O content was less than 0.3%, and dried at 90°C for 2 hours. The resulting matrix material was named M-3.

[0093] Example 4

[0094] (1) Weigh 200g MgCl2·6H2O and 60g Al2(SO4)3·18H2O and dissolve them in 600g water. Stir well at room temperature for 20min to obtain solution A.

[0095] (2) Weigh 60g NaOH and 25g Na2CO3 and dissolve them in 600g water. Stir well at room temperature for 20min to obtain solution B.

[0096] (3) Slowly add solution B to solution A, control the endpoint pH to 9.5, and prepare dispersion C;

[0097] (4) Dissolve 181g of boehmite in 1539g of water, mix and stir at room temperature for 30min, then add 24g of hydrochloric acid, mix and stir for 30min to prepare boehmite;

[0098] (5) Add 310g of alkaline silica sol to C dispersion and stir for 30min at room temperature. Then add aluminum oxide and stir for 30min at room temperature.

[0099] (6) The above solution was spray-dried, calcined at 500°C for 2 hours, washed until the Na2O content was less than 0.3%, and dried at 90°C for 2 hours. The resulting matrix material was named M-4.

[0100] Comparative Example 1 (US3157591)

[0101] 160g of silica sol was added to water and stirred for 5 minutes. Then, 113g of aluminum isopropoxide was added slowly in batches, and the hydrolysis reaction was carried out for 1 hour. Then, 22g of magnesium acetate was added and stirred, and the pH was adjusted to 7 with acetic acid to obtain a gel. The gel was aged at room temperature for 48 hours, dried at 90℃, and then calcined at 500℃ for 2 hours to obtain the matrix material, named DB-M-1.

[0102] Comparative Example 2 (US3267044)

[0103] 25g of boehmite was dissolved in 200g of water, and 22g of sulfuric acid was dissolved in 1000g of water. The sulfuric acid solution was added to the alumina solution and stirred for 30 minutes to prepare an aluminum paste. Water glass was diluted to 10% by mass and stirred for 10 minutes. Then, CO2 was introduced until the pH reached 10.0 to prepare a silica sol. The aluminum paste was added to the silica sol, with a mass ratio of silica sol (as SiO2) to aluminum paste (as Al2O3) of 3.6. The mixture was stirred for 10 minutes at pH 5. Then, 4g of MgO was added, and the mixture was aged at 80℃ for 4 hours. After aging, the mixture was filtered, ground, dried at 90℃, and then calcined at 500℃ for 2 hours to obtain the matrix material, named DB-M-2.

[0104] The analytical results of the matrix materials obtained in Examples 1-4 and Comparative Examples 1-2 are shown in Table 1.

[0105] The silicon-aluminum material was aged for 17 hours at 800°C under a 100% (v / v) water vapor atmosphere in a fixed-bed aging apparatus. Its microreactor activity was then evaluated in a fixed-bed microreactor, and the results are shown in Table 1. The feedstock used was Dagang straight-run light diesel oil with a distillation range of 235–337°C. The evaluation conditions were: a catalyst-to-oil ratio of 3.2 and a mass hourly space velocity (MHSV) of 40.11 h⁻¹. -1 The reaction temperature is 460℃.

[0106] Table 1

[0107]

[0108] Table 1. Continued XRD characteristic peaks

[0109]

[0110] In addition, the above matrix materials were used to prepare catalytic materials according to a dry basis ratio of molecular sieve: matrix material: kaolin = 20:50:30. The catalytic materials were aged at 800°C and 100% volumetric water vapor for 17 hours, and then packed into small fixed fluidized bed ACE devices (purchased from KTI, USA), with a packing amount of 9 g each. Then, the reaction was carried out at a reaction temperature of 520°C and a weight hourly space velocity of 12 h⁻¹. -1 With a catalyst-to-oil ratio (mass) of 6, the catalytic feedstock was injected into the ACE unit for catalytic cracking. The results are shown in Table 3.

[0111] The composition and properties of the catalytic feedstock are shown in Table 2.

[0112] Table 2

[0113]

[0114] Table 3

[0115]

[0116] From Table 1, Table 3 and Figure 1 As can be seen, the matrix material provided by this invention has a relatively abundant pore structure, including mesoporous channels. This allows heavy oil macromolecules to rapidly reach the active sites for reaction, and enables the products to diffuse out after the reaction, avoiding secondary reactions and coking. The matrix material provided by this invention exhibits high micro-reaction activity. It demonstrates a high reaction conversion rate in the heavy oil catalytic cracking process and maintains excellent coke and propylene selectivity. Surprisingly, it also exhibits a significantly higher gasoline yield.

[0117] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A catalyst matrix material with high magnesium content, wherein the anhydrous chemical formula, based on the mass of oxides, is (0.3–0.7)Al₂O₃·(0.3–0.7)SiO₂·(0.09–0.4)MgO. The matrix material has mesoporous channels, and the pore size distribution diagram of the matrix material dV / dlogD versus D has a bimodal pattern.

2. The matrix material according to claim 1, wherein, The matrix material contains 30-70% Al2O3 by mass, for example, 40-60% or 48-58% by mass. The mass fraction of SiO2 in the matrix material is 30-60% by mass, for example, 30-40% by mass or 31-37% by mass; The preferred MgO mass fraction in the matrix material is 9-35% by mass, for example 9-20% by mass or 9-16% by mass; Optionally, the mass ratio of SiO2 / Al2O3 in the matrix material is 0.50 to 0.80:1, for example, 0.55 to 0.75:1; Optionally, the MgO / Al2O3 mass ratio in the matrix material is 0.10–0.50:1, for example, 0.15–0.35:1; Optionally, the Na2O content in the matrix material preferably does not exceed 0.3% by mass, more preferably not exceeding 0.2% by mass.

3. The matrix material according to claim 1, wherein, The matrix material has a microreactivity of not less than 30, for example, 30-40 or 31-36.

4. The matrix material according to claim 1, wherein, The pore size distribution diagram shows the positions of the two peaks: a peak with a diameter of 5–7 nm and a peak with a diameter of 8–20 nm. Optionally, the pore volume of the matrix material is 0.5 to 0.7 mL / g, for example, 0.54 to 0.65 mL / g; Optionally, the specific surface area of ​​the matrix material is 225–260 m². 2 / g.

5. The matrix material according to claim 1, wherein, The matrix material exhibits characteristic peaks with 2θ angles of 11.4°, 23.1°, 34.5°, 60.7°, and 62.0° in its XRD spectrum; optionally, the matrix material has acidic and basic centers.

6. A method for preparing a matrix material, characterized in that, The method includes: (1) Mix magnesium salt and aluminum salt in a certain proportion to obtain solution A; (2) Prepare an alkaline solution of a certain concentration by dissolving the alkaline species to obtain solution B; (3) Add solution B to solution A and control the endpoint pH to prepare dispersion C; (4) Mix the C dispersion with the silicon species and the second aluminum species; (5) Drying, optionally roasting and washing.

7. The method according to claim 6, wherein, In step (1), the Mg:Al molar ratio in solution A is 2-6:1, for example 2-5:1 or 2.9-5.5:1; In one embodiment, the temperature of the mixture formed in step (1) is ≤40°C, preferably 10-35°C; Optionally, in solution A, the concentrations of magnesium salt and aluminum salt are 2-15% by mass, for example, 3-10% by mass or 4-6.6% by mass, calculated as MgO+Al2O3. Preferably, the magnesium salt is selected from one or more of hydrated magnesium carbonate, hydrated magnesium chloride, hydrated magnesium sulfate, methyl magnesium acetate, and triethyl magnesium; the aluminum salt is selected from one or more of hydrated aluminum sulfate, hydrated aluminum chloride, and hydrated aluminum nitrate.

8. The method according to claim 6 or 7, wherein, In step (2), the alkaline species is selected from one or more of NaOH, KOH, Ca(OH)2, Mg(OH)2, Na2CO3, K2CO3, NH3·H2O, and sodium aluminate, preferably one or more of NaOH, KOH, Mg(OH)2, and Na2CO3; more preferably NaOH and Na2CO3; the mass ratio of NaOH to Na2CO3 is preferably 1.5 to 2.

5. Preferably, the concentration of alkaline species in solution B is 5-25% by mass; Optionally, the temperature of the mixture formed in step (2) is ≤35°C, preferably 10 to 35°C.

9. The method according to any one of claims 6 to 8, wherein, In step (3), the final pH value is controlled to be 8-11, preferably 9-10; the mixing temperature (the temperature of the mixture formed during the addition of solution B to solution A) is ≤45℃, preferably 10-35℃; preferably, the stirring time after adding solution B to solution A is 30 min or more, preferably 40-60 min; in one embodiment, solution B is added to solution A at a certain flow rate, optionally, the addition rate of solution B to solution A is 0.05-0.2 mL / s of solution B. -1 / 1000g A solution; Optionally, the content of magnesium and aluminum elements in the C dispersion, calculated as MgO+Al2O3, is 2-15% by mass, for example, 2-4% by mass, 4-6% by mass, or 6-10% by mass. Optionally, the mass ratio of MgO to Al2O3 in the C dispersion is 1 to 15, for example, 1.1 to 10 or 1 to 4.

5.

10. The method according to any one of claims 6 to 9, wherein, In step (4), the silicon species is selected from one or more of silica sol and aluminosilicate sol, for example, silica sol; the second aluminum species is selected from one or more of aluminosilicate sol, aluminum osmide, and aluminosilicate sol, for example, one or more of aluminum sol and aluminum osmide; optionally, the mass ratio of aluminum in the second aluminum species to aluminum in the aluminum salt is 5 to 18:1 (calculated as alumina); optionally, in the mixture formed by mixing the C dispersion with the silicon species and the second aluminum species, the mass percentage of the C dispersion as MgO+Al2O3 is 10 to 25% by mass of the mixture as MgO+Al2O3+SiO2; preferably, the mixing includes adding the silicon species to the C dispersion and then adding the second aluminum species; In step (5), the drying temperature can be 80-200℃, for example, 80-120℃; the calcination temperature is, for example, 450-600℃, and the calcination time is, for example, 1-4 hours.

11. The application of the matrix material according to claims 1 to 5 or the matrix material obtained by any one of claims 6 to 10 in the preparation of catalytic cracking catalysts.

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