A method for preparing a composite material having a crystalline pore wall structure

Abstract

The application discloses a preparation method of a composite material containing a crystal pore wall structure, which comprises the following steps: (1) preparing a Y / silica gel solid mixture; (2) mixing the Y / silica gel solid mixture obtained in the step (1) with a template agent, phosphoric acid, an aluminum source and water as a silicon-aluminum source, adjusting pH, and obtaining a Y / SAPO-34 composite material slurry after crystallization; and (3) mixing the Y / SAPO-34 composite material slurry obtained in the step (2) with a silicon source and a long-chain surfactant according to a mass ratio of 1:(0.01-0.1):(0.01-0.1), adjusting pH, and obtaining a Y / SAPO-34 / ASP composite material containing a crystal pore wall structure after crystallization. The prepared composite material has a specific surface area of 500-680 m 2 / g, a pore volume of 0.60-1.0 mL / g, and a pore size distribution of 4-15 nm, and the diffusion property of the pore channel is improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of molecular sieve materials, and particularly relates to a preparation method of a crystal pore wall structure composite material. BACKGROUND

[0002] Molecular sieves are widely used in adsorption, separation, catalysis and other fields due to their unique pore structure, especially in petroleum and chemical industry. With the continuous development of molecular sieve catalytic applications, single-pore molecular sieves cannot meet the needs of various catalyst preparation. Microporous molecular sieves are mainly characterized by strong acidity and high structural stability in heterogeneous catalysis applications. However, due to the small pore size and long and narrow pore channel of microporous molecular sieves, it is difficult for large molecules in heavy oil to diffuse into the pore channel, which reduces the utilization rate of acid sites inside the pore channel of microporous molecular sieves. In addition, the narrow and long pore channel has a large diffusion resistance, which affects the rapid diffusion of reaction product molecules, and easily leads to deep cracking and coking. Mesoporous molecular sieves can make up for the limitations of microporous molecular sieves in internal diffusion of reactants and reaction products, but the structural stability of mesoporous molecular sieves is often poor, which also limits their catalytic applications. Micro-mesoporous composite molecular sieve materials can produce good synergistic effect and catalytic performance by taking the advantages of several single materials, and the comprehensive performance is better than that of the original component materials. This molecular sieve with multiple structures and superimposed functions can avoid the defects of single pore structure, and the multi-level pore channel system can provide different size channels, which will be very helpful to solve the problem of mass transfer of large molecules.

[0003] CN201610452842.X provides a Y / ZSM-22 / SAPO-34 / ASA / MOF composite material and a preparation method thereof, which comprises the following steps: preparing a ZSM-22 / SAPO-34 molecular sieve slurry, synthesizing a Y / ZSM-22 / SAPO-34 composite molecular sieve by using a hydrothermal crystallization method, then adding a surfactant and an alkaline aluminum source into the slurry containing the molecular sieve, adjusting the pH value to obtain a solid product, washing, drying and calcining the product to obtain a Y / ZSM-22 / SAPO-34 / ASA composite material, then mixing and stirring the material with a metal salt aqueous solution uniformly, and drying to obtain a metal-loaded Y / ZSM-22 / SAPO-34 / ASA composite material. A carboxyl-containing organic acid is added into an alcohol and an amide organic solvent to obtain an organic mixture. The metal-loaded Y / ZSM-22 / SAPO-34 / ASA material is added into the above organic mixture, and stirred uniformly to obtain a product. The total pore volume of the composite material is 0.54-0.58 mL / g, which is relatively low.

[0004] CN201710519563.5 provides a preparation method of Y / SAPO-34 / ZSM-11 / ASA multi-level porous material, which comprises the following steps: first, synthesizing a Y molecular sieve directing agent, adding treated SAPO-34 and ZSM-11 molecular sieve mixed slurry into a Y molecular sieve synthesis system, synthesizing Y / SAPO-34 / ZSM-11 composite molecular sieve by using a hydrothermal crystallization method, then adding a surfactant, an alkaline aluminum source and / or an alkaline silicon source solution into the slurry of Y / SAPO-34 / ZSM-11 molecular sieve, and washing, drying and calcining the product to obtain the mesoporous Y / SAPO-34 / ZSM-11 / ASA multi-level porous material; the total pore volume of the composite material is 0.52-0.62 mL / g, and the pore volume is relatively low. SUMMARY

[0005] The present application aims to provide a preparation method of a composite material containing a crystal pore wall structure to solve the problem of relatively low pore volume of the existing porous material.

[0006] To achieve the above-mentioned purpose, the present application provides a preparation method of a composite material containing a crystal pore wall structure, which comprises the following steps:

[0007] (1) uniformly adsorbing the slurry of Y molecular sieve, long-chain surfactant and alkaline aqueous solution after mixing treatment to macroporous silica gel to prepare a Y / silica gel solid mixture;

[0008] (2) mixing the Y / silica gel solid mixture obtained in step (1) as a silicon-aluminum source with a template agent, phosphoric acid, an aluminum source and water, controlling the molar ratio of the silicon-aluminum source (calculated as SiO2), the phosphoric acid (calculated as P2O5) and the aluminum source (calculated as Al2O3) to be (1-1.5) Al2O3:(1-1.5) P2O5:(1-1.5) SiO2:(1-2) template agent:(40-80) H2O, adjusting the pH, and obtaining a Y / SAPO-34 composite material slurry after crystallization;

[0009] (3) mixing the Y / SAPO-34 composite material slurry obtained in step (2) with a silicon source and a long-chain surfactant according to a mass ratio of 1:(0.01-0.1):(0.01-0.1), adjusting the pH, and obtaining a Y / SAPO-34 / ASP composite material containing a crystal pore wall structure after crystallization.

[0010] The preparation method of the crystal pore wall structure composite material comprises the following steps: (1) preparing materials according to the mass ratio of Y molecular sieve: long-chain surfactant: alkali: water = 1: (0.05-0.1): (0.05-0.2): (5-10), mixing the above-mentioned materials, stirring at 70-90 DEG C for 4-10 hours to obtain a mixed slurry containing Y molecular sieve microcrystals, dispersing the mixed slurry in a container by high pressure and airflow breaking method to form a humid atmosphere, and then adsorbing on macroporous silica gel to obtain a Y / silica gel solid mixture, wherein the alkali can be sodium hydroxide or potassium hydroxide.

[0011] The preparation method of the crystal pore wall structure composite material comprises the following steps: (2) adding phosphoric acid into water, then adding an aluminum source and stirring to form a solution B; mixing the Y / silica gel solid mixture, a template agent and water to obtain a solid-liquid mixture C, adding the solid-liquid mixture C into the solution B, adjusting pH value, and crystallizing.

[0012] The preparation method of the crystal pore wall structure composite material comprises the following steps: (2) adjusting the pH value to 6.5-7.5, and crystallizing at 150-200 DEG C for 12-24 hours to obtain a Y / SAPO-34 composite material slurry.

[0013] The preparation method of the crystal pore wall structure composite material comprises the following steps: (3) adjusting the pH value to 8-10, stirring and crystallizing at 80-100 DEG C for 10-24 hours to obtain a Y / SAPO-34 / ASP composite material containing a crystal pore wall structure, wherein the ASP is mesoporous amorphous silicon aluminum phosphorus oxide.

[0014] The preparation method of the crystal pore wall structure composite material comprises the following steps: (3) after crystallizing, further comprising the steps of filtering, washing, ammonium ion exchange and calcining.

[0015] The preparation method of the crystal pore wall structure composite material comprises the following steps: the calcining condition is calcining at 500-550 DEG C for 3-5 hours.

[0016] The preparation method of the crystal pore wall structure composite material comprises the following steps: the long-chain surfactant comprises one or more of cetyltrimethylammonium bromide, PEG1000 and PEG2000; the aluminum source comprises aluminum sol; the silicon source comprises silica sol and / or water glass; and the template agent comprises one or more of triethylamine, morpholine and tetraethylammonium hydroxide.

[0017] The preparation method of the crystal pore wall structure composite material comprises the following steps: the specific surface area of the Y / SAPO-34 / ASP composite material is 500-680 m 2 / g, the pore volume is 0.60-1.0 mL / g, and the pore size distribution is 4-15 nm.

[0018] Beneficial effects of this invention:

[0019] This invention employs in-situ synthesis technology to prepare a Y / SAPO-34 / ASP composite material containing a crystalline pore wall structure. By constructing a mesoporous composite material containing Y molecular sieve and SAPO-34 molecular sieve microcrystals, the stability of the mesoporous channels is improved, and the specific surface area, pore volume, and pore size of the individual microporous material are increased. The prepared Y / SAPO-34 / ASP composite material has a specific surface area of ​​500–680 m². 2 / g, pore volume 0.60~1.0mL / g, pore size distribution 4~15nm, which improves the diffusion of the pores. Attached Figure Description

[0020] Figure 1 This is a pore distribution diagram of a composite material with a crystalline pore wall structure prepared in Example 1 of the present invention. Detailed Implementation

[0021] 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.

[0022] Example 1

[0023] (1) Using a cell size of 24.32 and a specific surface area of ​​550 m² 2 Y molecular sieve with a pore volume of 0.40 mL / g and an average pore size of 2.6 nm was dispersed in an aqueous solution of hexadecyltrimethylammonium bromide and potassium hydroxide according to the mass ratio of Y molecular sieve: hexadecyltrimethylammonium bromide: potassium hydroxide: water of 1:0.05:0.05:5. The mixture was stirred at a constant temperature of 70 °C for 10 h to obtain a mixed slurry containing Y molecular sieve microcrystals.

[0024] (2) Add the mixed slurry containing Y molecular sieve microcrystals to a container, pressurize to 2 MPa, spray the solution, and then allow it to be sprayed by a flow at a velocity of 10 m / s perpendicular to the spray direction of the mixed slurry. 3 After being broken up, the high-speed airflow of / min is ejected and forms a humid atmosphere in the container. Macroporous silica gel with a pore volume of 1.0 ml / g is placed in this humid atmosphere, allowing the macroporous silica gel to fully adsorb the above mixed slurry. The mass of the mixed slurry is 1% of the mass of the macroporous silica gel, resulting in Y / silica gel solid mixture A.

[0025] (3) 23 g of phosphoric acid was added to 41 g of deionized water, and 13.5 g of aluminum sol (65% Al203) was added, and stirred for 5 hours to form solution B. 6 g of Y / silica gel solid mixture A was mixed with 15 g of triethylamine and 50 g of water to form solid-liquid mixture C. Solid-liquid mixture C was added to solution B, and the pH was adjusted to 6.5 to form solid-liquid mixture D, which was crystallized at 200°C for 12 hours to form a slurry of Y / SAPO-34 molecular sieve composite material.

[0026] (4) 10 g of silica sol (30 wt% Si02) and 3 g of PEG2000 were added to the slurry of Y / SAPO-34 molecular sieve composite material, and the pH of the system was adjusted to 10. The slurry was crystallized at 80°C for 24 hours, and the product was filtered, washed, and exchanged with ammonium ions, and then calcined at 500°C for 4 hours to form a mesoporous Y / SAPO-34 / ASP composite material having a crystalline pore wall structure, which had a specific surface area of 680 m 2 / g, a pore volume of 0.60 mL / g, and a pore size distribution of 4-12 nm.

[0027] Figure 1 A pore distribution diagram of a composite material having a crystalline pore wall structure prepared in Example 1. As shown in the diagram, the prepared composite material has a clear mesoporous pore size distribution.

[0028] Example 2

[0029] (1) A Y molecular sieve having a unit cell of 24.37, a specific surface area of 560 m 2 / g, a pore volume of 0.41 mL / g, and an average pore diameter of 2.7 nm was dispersed in a PEG2000 and potassium hydroxide aqueous solution in a mass ratio of Y molecular sieve: PEG2000: potassium hydroxide: water = 1:0.07:0.07:5, and the mixture was stirred at 80°C for 7 hours to form a mixed slurry containing Y molecular sieve microcrystals;

[0030] (2) The mixed slurry containing Y molecular sieve microcrystals was added to a container, and the solution was sprayed and broken by a high-speed gas stream at a flow rate of 15 m 3 / min perpendicular to the spraying direction of the mixed slurry to form a wet atmosphere in the container. A macroporous silica gel having a pore volume of 2.5 mL / g was placed in the wet atmosphere, and the macroporous silica gel was fully adsorbed with the mixed slurry, and the mass of the mixed slurry was 10% of the mass of the macroporous silica gel to form a Y / silica gel solid mixture A.

[0031] (3) 28.7 g of phosphoric acid was added to 51 g of deionized water, and then 16.8 g of aluminum sol (65% Al203) was added, and stirred for 7.5 hours to form solution B. 6.5 g of the Y / silica gel solid mixture A was mixed with 17 g of tetraethylammonium hydroxide and 55 g of water to obtain a solid-liquid mixture C. The solid-liquid mixture C was added to solution B, and the pH was adjusted to 7.5 to obtain a solid-liquid mixture D, which was crystallized at 200°C for 18 hours to obtain a Y / SAPO-34 molecular sieve composite slurry.

[0032] (4) 10 g of silica sol (Si02 content 30 wt%) and 5 g of PEG1000 were added to the Y / SAPO-34 molecular sieve composite slurry, and the pH of the system was adjusted to 8, and the product was crystallized at 90°C for 16 hours. The product was filtered, washed, and ammonium ion exchanged, and then calcined at 550°C for 3 hours to obtain a mesoporous Y / SAPO-34 / ASP composite material having a crystal pore wall structure, with a specific surface area of 590 m 2 / g, a pore volume of 0.80 mL / g, and a pore size distribution of 4-14 nm.

[0033] Example 3

[0034] (1) Y molecular sieve with a unit cell of 24.42, a specific surface area of 580 m 2 / g, a pore volume of 0.42 mL / g, and an average pore size of 3.0 nm was dispersed in a PEG1000 and potassium hydroxide aqueous solution in a mass ratio of Y molecular sieve: PEG1000: potassium hydroxide: water = 1:0.1:0.2:10, and the mixture was stirred at 90°C for 4 hours to obtain a mixed slurry containing Y molecular sieve microcrystals;

[0035] (2) The mixed slurry containing Y molecular sieve microcrystals was added to a container, and the pressure was increased to 6 MPa. The high-pressure solution was sprayed out, directly collided with a smooth metal wall, and then broken by a high-speed gas flow with a flow rate of 20 m 3 / min, which was perpendicular to the spraying direction of the mixed slurry, and then carried out. A macroporous silica gel with a pore volume of 3.5 mL / g was placed in the humid atmosphere to allow the macroporous silica gel to fully contact and adsorb the mixed slurry, and the mass of the mixed slurry was 30% of the mass of the macroporous silica gel to obtain a Y / silica gel solid mixture A.

[0036] (3) 28.7 g of phosphoric acid was added to 51 g of deionized water, and then 16.8 g of aluminum sol (65% Al203) was added, and stirred for 7.5 hours to form solution B. 6.5 g of the Y / silica gel solid mixture A was mixed with 17 g of tetraethylammonium hydroxide and 55 g of water to obtain a solid-liquid mixture C. The solid-liquid mixture C was added to solution B, and the pH was adjusted to 7.5 to obtain a solid-liquid mixture D, which was crystallized at 200°C for 18 hours to obtain a Y / SAPO-34 molecular sieve composite slurry.

[0037] (4) Add 15g of water glass (SiO2 content 35wt%) and 8g of hexadecyltrimethylammonium bromide to the above Y / SAPO-34 molecular sieve composite slurry, adjust the pH of the system to 9, crystallize at 100℃ for 10 hours, filter, wash and exchange ammonium ions in the product, and calcine at 600℃ for 2 hours to obtain a mesoporous Y / SAPO-34 / ASP composite material with crystal pore wall structure and a specific surface area of ​​500 m². 2 / g, pore volume 1.0mL / g, pore size distribution 4~15nm.

[0038] Comparative Example 1

[0039] (1) Using a cell size of 24.32 and a specific surface area of ​​550 m² 2 Y molecular sieve with a pore volume of 0.40 mL / g and an average pore size of 2.6 nm was dispersed in an aqueous solution of hexadecyltrimethylammonium bromide and potassium hydroxide according to a mass ratio of Y molecular sieve: hexadecyltrimethylammonium bromide: potassium hydroxide: water of 1:0.03:0.03:15. The mixture was stirred at a constant temperature of 70 °C for 10 h to obtain a mixed slurry containing Y molecular sieve microcrystals.

[0040] (2) Add the mixed slurry containing Y molecular sieve microcrystals to a container, pressurize to 2 MPa, spray the solution, and then allow it to be sprayed by a flow at a velocity of 10 m / s perpendicular to the spray direction of the mixed slurry. 3 After being broken up, the high-speed airflow of / min is ejected and forms a humid atmosphere in the container. Macroporous silica gel with a pore volume of 1.0 ml / g is placed in this humid atmosphere, allowing the macroporous silica gel to fully adsorb the above mixed slurry. The mass of the mixed slurry is 1% of the mass of the macroporous silica gel, resulting in Y / silica gel solid mixture A'.

[0041] (3) Add 11g of phosphoric acid to 20g of deionized water, then add 7g of aluminum sol (65% Al2O3), and stir thoroughly for 3 hours to form solution B'. Mix 3g of Y / silica gel solid mixture A' with 7g of triethylamine and 25g of water to obtain solid-liquid mixture C'. Add solid-liquid mixture C' to solution B', adjust the pH to 6.5, and obtain solid-liquid mixture D. Crystallize at 200℃ for 12 hours to obtain Y / SAPO-34 molecular sieve composite slurry.

[0042] (4) Add 5g of silica sol (SiO2 content 30wt%) and 2g of PEG2000 to the above Y / SAPO-34 molecular sieve composite slurry, adjust the pH of the system to 10, stir and crystallize at 80℃ for 24 hours, filter, wash and exchange ammonium ions in the product, and calcine at 500℃ for 4 hours to obtain a mesoporous Y / SAPO-34 / ASP composite material with crystal pore wall structure and a specific surface area of ​​640m². 2g, pore volume 0.50 mL / g, pore size distribution 4-8 nm.

[0043] Of course, the present application also has other various embodiments, and those skilled in the art can make various corresponding changes and modifications according to the present application without departing from the spirit and essence of the present application, but these corresponding changes and modifications should all belong to the protection scope of the claims of the present application.

Claims

1. A method for preparing a composite material containing a crystalline pore wall structure, characterized in that, Includes the following steps: (1) The slurry after being mixed with Y molecular sieve, surfactant and alkaline aqueous solution was uniformly adsorbed onto macroporous silica gel to prepare Y / silica gel solid mixture; (2) Using the Y / silica gel solid mixture obtained in step (1) as the silicon-aluminum source, it is mixed with template agent, phosphoric acid, aluminum source and water. The silicon-aluminum source is calculated as SiO2, the phosphoric acid is calculated as P2O5 and the aluminum source is calculated as Al2O3. The molar ratio of the feed is controlled as (1~1.5)Al2O3:(1~1.5)P2O5:(1~1.5)SiO2:(1~2)template agent:(40~80)H2O. After adjusting the pH and crystallizing, the Y / SAPO-34 composite material slurry is obtained. (3) The Y / SAPO-34 composite material slurry obtained in step (2) is mixed with silicon source and surfactant in a mass ratio of 1:(0.01~0.1):(0.01~0.1), the pH is adjusted, and after crystallization, Y / SAPO-34 / ASP composite material with crystal pore wall structure is obtained; The template agent is one or more of triethylamine, morpholine and tetraethylammonium hydroxide; Surfactants include one or more of hexadecyltrimethylammonium bromide, PEG1000, and PEG2000.

2. The method for preparing the composite material containing a crystalline porous wall structure according to claim 1, characterized in that, Step (1) Prepare materials according to the mass ratio of Y molecular sieve: surfactant: alkali: water as 1: (0.05~0.1): (0.05~0.2): (5~10). Mix the above materials and stir at 70~90℃ for 4~10h to obtain a mixed slurry containing Y molecular sieve microcrystals. Disperse the slurry in a container to form a humid atmosphere by high pressure and airflow crushing method, and then adsorb it onto macroporous silica gel to obtain a Y / silica gel solid mixture.

3. The method for preparing the composite material containing a crystalline porous wall structure according to claim 1, characterized in that, In step (2), phosphoric acid is added to water, then aluminum source is added and stirred to form solution B; Y / silica gel solid mixture, template agent and water are mixed to obtain solid-liquid mixture C, solid-liquid mixture C is added to solution B, pH is adjusted and crystallization is performed.

4. The method for preparing a composite material containing a crystalline porous wall structure according to claim 1 or 3, characterized in that, Step (2) Adjust the pH value to 6.5~7.5 and crystallize at 150~200℃ for 12~24 hours to obtain Y / SAPO-34 composite material slurry.

5. The method for preparing the composite material containing a crystalline porous wall structure according to claim 1, characterized in that, Step (3) Adjust the pH to 8-10 and stir and crystallize at 80-100℃ for 10-24 hours to obtain Y / SAPO-34 / ASP composite material with crystal pore wall structure, wherein ASP is mesoporous amorphous silicon-phosphorus-aluminum oxide.

6. The method for preparing the composite material containing a crystalline porous wall structure according to claim 1, characterized in that, Step (3) after crystallization also includes filtration, washing, ammonium ion exchange and calcination steps.

7. The method for preparing the composite material containing a crystalline porous wall structure according to claim 6, characterized in that, The roasting conditions are 500~550℃ for 3~5 hours.

8. The method for preparing a composite material containing a crystalline porous wall structure according to claim 1, characterized in that, Aluminum sources include aluminum sol; silicon sources include silica sol and / or water glass.

9. The method for preparing the composite material containing a crystalline porous wall structure according to claim 1, characterized in that, The Y / SAPO-34 / ASP composite material has a specific surface area of ​​500-680 m². 2 / g, pore volume 0.60~1.0mL / g, pore size distribution 4~15nm.

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