Composite material as well as preparation method and application thereof

Abstract

The invention relates to the technical field of butadiene rubber tail gas treatment, and discloses a composite material as well as a preparation method and application thereof. The composite material comprises an MCM-41 molecular sieve and an MIL-101 metal organic framework material which grows on the MCM-41 molecular sieve in situ. The composite material provided by the invention comprises the MCM-41 molecular sieve and the MIL-101 metal organic framework material growing on the MCM-41 molecular sieve in situ, the composite material with the structural characteristics is relatively large in specific surface area, rich in pore structure and relatively high in n-hexane adsorption capacity, and compared with the existing traditional adsorption materials such as activated carbon and molecular sieves, the composite material provided by the invention has the advantages that the adsorption efficiency is greatly improved; the adsorption capacity of the n-hexane is greatly improved, and the desorption effect is good.

Description

Technical Field

[0001] The present invention relates to the technical field of tail gas treatment of cis-butadiene rubber, in particular to the technical field of VOCs treatment, and specifically relates to a composite material, a preparation method thereof and an application thereof. Background Art

[0002] In the post-treatment production process of the cis-butadiene rubber production device of petrochemical enterprises, in order to meet the qualified product volatile content, hot air is required to dry the rubber compound, generating a large amount of dry organic waste gas. The discharged tail gas not only causes environmental pollution but also affects human health. The non-methane total hydrocarbon concentration in the discharged waste gas is as high as 2000 - 7000 mg / Nm 3 , in which n-hexane accounts for about 95%, butadiene accounts for 0.1%, and other impurities account for 4.9%, far exceeding the national emission standards. According to the "Emission Standards of Pollutants for the Petroleum Refining Industry" (GB31570-2015) of China's atmospheric emission standards, the removal rate of non-methane total hydrocarbons in waste gas is more than 97%, non-methane total hydrocarbons ≤ 120 mg / Nm 3 , butadiene ≤ 1 mg / Nm 3 , hexane ≤ 100 mg / Nm 3 . The adsorption method is one of the widely used VOCs treatment technologies. Commonly used adsorbents for the adsorption method include activated carbon, zeolite, molecular sieve, etc. Among them, activated carbon is the most widely used in industry due to its low price, stable chemical properties and other advantages.

[0003] Since the tail gas of cis-butadiene rubber contains a small amount of butadiene, if activated carbon is selected as the adsorbent for the adsorption treatment of cis-butadiene rubber tail gas, the following problems will exist: after the butadiene component is adsorbed by the activated carbon, it is very easy to undergo a polymerization reaction in the presence of metal impurities in the activated carbon and during the adsorption exothermic process. The reaction product polybutadiene will cause the blockage of the activated carbon layer, affecting the further adsorption and regeneration of the activated carbon. In addition, there is a risk of spontaneous combustion after the activated carbon adsorbs VOCs. Therefore, it is necessary to develop a porous material with high thermal stability for the adsorption treatment of cis-butadiene rubber tail gas. Zeolite has a through-ordered pore structure, good thermal stability and non-flammability. However, most conventional zeolites have a narrow internal pore size distribution (about 0.3 - 1.0 nm), and only small molecule VOCs can be adsorbed, and desorption is relatively difficult. Therefore, there is an urgent need to provide a material with good adsorption effect on macromolecular VOCs. Summary of the Invention

[0004] The purpose of the present invention is to overcome the problem that the existing adsorption materials have poor adsorption effect on macromolecular VOCs, and provide a composite material, a preparation method thereof and an application thereof. The composite material has a relatively large specific surface area and can significantly improve the adsorption effect of macromolecules such as n-hexane and butadiene.

[0005] To achieve the above object, on the one hand, the present invention provides a composite material, which comprises MCM-41 molecular sieve and MIL-101 metal-organic framework material in-situ grown on the MCM-41 molecular sieve.

[0006] Preferably, the specific surface area of the composite material is 800 - 2000 m 2 / g, and the pore size is 2.0 - 3.6 nm.

[0007] On the second hand, the present invention provides a method for preparing a composite material, which comprises the following steps:

[0008] S1. React MCM-41 molecular sieve, a cyanide-containing linker and a first organic solvent;

[0009] S2. React the reaction product obtained in step S1 with an acidic solution;

[0010] S3. React the reaction product obtained in step S2, a metal salt, an organic ligand and a second organic solvent.

[0011] Preferably, in step S1, the dosage ratio of the MCM-41 molecular sieve to the cyanide-containing linker is 1 g : 0.3 - 0.8 mmol.

[0012] Preferably, the cyanide-containing linker is selected from trimethylsilyl cyanide and / or triethylcyanosilane.

[0013] Preferably, in step S1, the dosage ratio of the MCM-41 molecular sieve to the first organic solvent is 0.02 - 0.05 g : 1 mL.

[0014] Preferably, the first organic solvent is toluene.

[0015] Preferably, in step S1, the reaction conditions include: temperature is 100 - 120 °C; time is 2 - 10 h, preferably 6 - 10 h.

[0016] Preferably, the molar ratio of the cyanide-containing linker in step S1 to the amount of acid in the acidic solution in step S2 is 1 g : 100 mL.

[0017] Preferably, the acidic solution is hydrochloric acid solution.

[0018] Preferably, the concentration of the hydrochloric acid solution is 36 - 38 wt%.

[0019] Preferably, in step S2, the reaction conditions include: temperature is 80 - 120 °C; time is 12 - 24 h.

[0020] Preferably, in step S3, the dosage ratio of the reaction product obtained in step S2 to the organic ligand is 1 g: 0.4 - 2 mmol.

[0021] Preferably, in step S3, the molar ratio of the metal salt to the organic ligand is 1 - 3:1, preferably 1 - 1.5:1.

[0022] Preferably, in step S3, the dosage ratio of the metal salt to the second organic solvent is 0.02 - 0.04 mol: 1 L.

[0023] Preferably, in step S3, the metal salt is selected from one or more of FeCl3·6H2O, CrCl3·6H2O, AlCl3·6H2O, Fe(NO3)3·9H2O, Cr(NO3)3·9H2O, and Al(NO3)3·9H2O.

[0024] Preferably, the organic ligand is selected from one or more of terephthalic acid, 2 - amino - 1,4 - benzenedicarboxylic acid, and 2 - hydroxy - 1,4 - benzenedicarboxylic acid.

[0025] Preferably, the second organic solvent is N,N - dimethylformamide.

[0026] Preferably, in step S3, the conditions of the reaction include: the temperature is 120 - 180 °C, preferably 150 - 180 °C; the time is 8 - 24 h, preferably 12 - 24 h.

[0027] Preferably, the preparation method of the MCM - 41 molecular sieve includes: preparing a solution of cetyltrimethylammonium bromide and water, then adjusting the pH value of the solution to be alkaline, and then adding tetraethyl orthosilicate for crystallization reaction and calcination.

[0028] Preferably, the molar ratio of cetyltrimethylammonium bromide, tetraethyl orthosilicate, and water is 1:(5 - 10):(1000 - 5000), preferably 1:(6 - 8):(1000 - 2000).

[0029] Preferably, the pH value is 10 - 11.

[0030] Preferably, the conditions of the crystallization reaction include: the temperature is 80 - 150 °C, preferably 120 - 150 °C; the time is 12 - 48 h, preferably 24 - 48 h.

[0031] Preferably, the conditions of the calcination include: the temperature is 500 - 600 °C; the time is 4 - 10 h, preferably 6 - 8 h.

[0032] The third aspect of the present invention provides a composite material prepared by the method described above.

[0033] In the fourth aspect of the present invention, an adsorbent is provided, and the adsorbent contains the composite material described above.

[0034] In the fifth aspect of the present invention, a method for treating the tail gas of cis-butadiene rubber is provided, and the method includes: adsorbing the tail gas of cis-butadiene rubber by using an adsorption material.

[0035] Wherein, the adsorption material contains the composite material described above or the adsorbent described above.

[0036] Compared with the prior art, the present invention has at least the following advantages:

[0037] (1) The composite material provided by the present invention includes MCM-41 molecular sieve and MIL-101 metal-organic framework material in-situ grown on the MCM-41 molecular sieve. The composite material with this structural feature has a relatively large specific surface area, rich pore structure and high n-hexane adsorption capacity. Compared with traditional adsorption materials such as existing activated carbon and molecular sieve, the adsorption amount of n-hexane is greatly improved, and the desorption effect is good.

[0038] (2) The method of the present invention is simple. By introducing -COOH functional groups on the surface of MCM-41 molecular sieve and then in-situ growing MIL-101 material, the composite material of the present invention can be prepared. Description of the Drawings

[0039] Figure 1 is the nitrogen adsorption and desorption curve of the material of Comparative Example 1;

[0040] Figure 2 is the pore size distribution of the material of Comparative Example 1;

[0041] Figure 3 is the n-hexane adsorption and desorption curve of the material of Comparative Example 1;

[0042] Figure 4 is the pore size distribution diagram of the composite material synthesized in Example 14. Detailed Embodiments

[0043] The following detailed description of the specific embodiments of the present invention is provided with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only for the purpose of illustrating and explaining the present invention, and are not used to limit the present invention.

[0044] In the ranges disclosed herein, the endpoints and any value are not limited to the exact range or value. These ranges or values should be understood to include values close to these ranges or values. For numerical ranges, between the endpoint values of each range, between the endpoint values of each range and individual point values, and between individual point values, they can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein.

[0045] In the first aspect of the present invention, a composite material is provided, which includes MCM-41 molecular sieve and MIL-101 metal-organic framework material grown in-situ on the MCM-41 molecular sieve. The composite material is a porous material containing two materials, MCM-41 molecular sieve and MIL-101 metal-organic framework material, and connecting the MCM-41 molecular sieve and MIL-101 metal-organic framework material into an integral body through chemical bonds.

[0046] In a specific embodiment, the specific surface area of the composite material can be 800-2000m 2 / g. Through research, it is found that the larger the specific surface area of the composite material of the present invention, the higher the adsorption amount of n-hexane. In the preferred embodiment, the specific surface area of the composite material is 1200-1800m 2 / g.

[0047] In the present invention, the pore diameter of the composite material is 2.0-3.6nm.

[0048] In the second aspect of the present invention, a method for preparing a composite material is provided, and the method includes the following steps:

[0049] S1. React MCM-41 molecular sieve, a cyanide-containing linker and a first organic solvent;

[0050] S2. React the reaction product obtained in step S1 with an acidic solution;

[0051] S3. React the reaction product obtained in step S2, a metal salt, an organic ligand and a second organic solvent.

[0052] In the method of the present invention, in step S1, by reacting MCM-41 molecular sieve and a cyanide-containing linker, the hydroxyl group in the MCM-41 molecular sieve is changed to a CN group; in step S2, the CN group is hydrolyzed to a carboxyl group -COOH in an acidic solution, introducing a -COOH functional group on the surface of the MCM-41 molecular sieve to modify the MCM-41 molecular sieve; in step S3, by reacting the modified MCM-41 molecular sieve with a metal salt and an organic ligand, MIL-101 material is grown in-situ, and metal ions are respectively connected to the carboxyl group on the MCM-41 molecular sieve and the organic ligand, thereby obtaining the composite material.

[0053] In the present invention, the cyanide-containing linker can be a conventional selection in the art. In a specific embodiment, the cyanide-containing linker can be selected from trimethylsilyl cyanide and / or triethylcyanosilane, and preferably trimethylsilyl cyanide.

[0054] In a specific embodiment, in step S1, the dosage ratio of the MCM-41 molecular sieve to the cyano-containing linker can be 1 g: 0.3 - 0.8 mmol. In a preferred embodiment, in order to improve the prepared composite material, in step S1, the dosage ratio of the MCM-41 molecular sieve to the cyano-containing linker can be 1 g: 0.5 - 0.8 mmol.

[0055] In the present invention, the first organic solvent can be a conventional choice in the art. In a specific embodiment, the first organic solvent can be toluene.

[0056] In the present invention, in step S1, the dosage of the first organic solvent is not particularly limited as long as it can dissolve the raw materials and ensure the normal progress of the reaction system. In a specific embodiment, in step S1, the dosage ratio of the MCM-41 molecular sieve to the first organic solvent can be 0.02 - 0.05 g: 1 mL.

[0057] In a specific embodiment, in step S1, the temperature of the reaction is 100 - 120 °C; the reaction time is 2 - 10 h, preferably 6 - 10 h. The reaction in step S1 is heated and refluxed using an oil bath.

[0058] In a more specific embodiment, after the reaction in step S1 is completed, the reaction product needs to be cooled to room temperature, the precipitate is filtered, and the product is washed with hot toluene multiple times and dried.

[0059] In a specific embodiment, the molar ratio of the cyano-containing linker in step S1 to the amount of acid in the acidic solution in step S2 can be 1: 2 - 4.

[0060] In step S2, the acidic solution can be a conventional choice in the art. In a preferred embodiment, the acidic solution is a hydrochloric acid solution. Specifically, the concentration of the hydrochloric acid solution can be 36 - 38 wt%, such as 36 wt%, 37 wt% or 38 wt%.

[0061] In the present invention, step S2 is to hydrolyze the CN group into a carboxyl group -COOH, thereby introducing the -COOH functional group on the surface of the MCM-41 molecular sieve.

[0062] In a specific embodiment, in step S2, the temperature of the reaction is 80 - 120 °C; the reaction time is 12 - 24 h.

[0063] In a more specific embodiment, after the reaction in step S2 is completed, the reaction product is subjected to solid-liquid separation, and then the solid product is washed with deionized water multiple times and heated and dried in an oven. In a preferred embodiment, the temperature for heating and drying in the oven is 80-120 °C, preferably 100-120 °C; the time for heating and drying is 8-24 h, preferably 12-24 h.

[0064] In the present invention, the metal salt can be a conventional selection in the art. In a specific embodiment, in step S3, the metal salt can be selected from one or more of FeCl3·6H2O, CrCl3·6H2O, AlCl3·6H2O, Fe(NO3)3·9H2O, Cr(NO3)3·9H2O, and Al(NO3)3·9H2O. In a preferred embodiment, the metal salt is FeCl3·6H2O and / or Fe(NO3)3·9H2O.

[0065] In the present invention, the organic ligand can be a compound containing a benzene ring and a carboxyl group common in the art. In a specific embodiment, the organic ligand can be selected from one or more of terephthalic acid, 2-amino-1,4-benzenedicarboxylic acid, and 2-hydroxy-1,4-benzenedicarboxylic acid, preferably terephthalic acid.

[0066] In a specific embodiment, the second organic solvent can be a solvent commonly used in the synthesis of metal-organic framework materials in the art. In a preferred embodiment, the second organic solvent can be N,N-dimethylformamide.

[0067] In the present invention, the amounts of the organic ligand and the reaction product obtained in step S2 affect the specific surface area of the composite material prepared. In a specific embodiment, in step S3, the dosage ratio of the reaction product obtained in step S2 to the organic ligand is 1 g: 0.4-2 mmol. In a preferred embodiment, in order to increase the specific surface area of the composite material prepared, the dosage ratio of the reaction product obtained in step S2 to the organic ligand is 1 g: 1.2-2 mmol.

[0068] In a specific embodiment, in step S3, the molar ratio of the metal salt to the organic ligand can be 1-3:1, preferably 1-1.5:1.

[0069] In a specific embodiment, in step S3, the dosage ratio of the metal salt to the second organic solvent can be 0.02-0.04 mol: 1 L.

[0070] Preferably, the reaction in step S3 is carried out in a high-pressure reactor. In a specific embodiment, in step S3, the temperature of the reaction is 120 - 180°C, preferably 150 - 180°C; the time of the reaction is 8 - 24 h, preferably 12 - 24 h.

[0071] In the present invention, step S3 further includes: after the reaction is completed, it is cooled to room temperature, the solid product is separated out, washed twice with DMF, water and ethanol respectively, and then the solid product is heated and dried in an explosion-proof oven. During the washing process, the temperatures of DMF, water and ethanol used for washing the solid product are 25 - 80°C. In a specific embodiment, the heating temperature of the explosion-proof vacuum oven is 80 - 120°C; the time for heating and drying is 6 - 24 h, preferably 12 - 24 h.

[0072] The MCM-41 molecular sieve used in the present invention can be prepared by oneself or purchased commercially. In a preferred embodiment, the MCM-41 molecular sieve is prepared by oneself. Specifically, the preparation method of the MCM-41 molecular sieve includes: preparing a solution of cetyltrimethylammonium bromide and water, then adjusting the pH value of the solution to be alkaline, and then adding tetraethyl orthosilicate (TEOS) for crystallization reaction and calcination.

[0073] In a specific embodiment, the molar ratio of cetyltrimethylammonium bromide, tetraethyl orthosilicate and water can be 1:(5 - 10):(1000 - 5000), preferably 1:(6 - 8):(1000 - 2000).

[0074] In a specific embodiment, the pH value of the solution can be adjusted with a sodium hydroxide solution. In a preferred embodiment, the pH value of the solution can be adjusted to 10 - 11.

[0075] In the present invention, the crystallization reaction for preparing the MCM-41 molecular sieve is carried out in a high-pressure reactor. In a specific embodiment, the temperature of the crystallization reaction can be 80 - 150°C, preferably 120 - 150°C; the time of the crystallization reaction can be 12 - 48 h, preferably 24 - 48 h.

[0076] In the present invention, the conditions for preparing the MCM-41 molecular sieve can be a conventional selection in the art. In a specific embodiment, the temperature of the calcination is 500 - 600°C; the time of the calcination is 4 - 10 h, preferably 6 - 8 h.

[0077] The method for preparing the composite material in the present invention specifically includes:

[0078] (1) Preparation of MCM-41 molecular sieve: Cetyltrimethylammonium bromide and water were formulated into a solution, then the pH value of the solution was adjusted to be alkaline, and then tetraethyl orthosilicate (TEOS) was added for crystallization reaction. After solid-liquid separation, the solid product was washed with deionized water for multiple times and dried, followed by calcination.

[0079] (2) Preparation of MCM-41-COOH: The MCM-41 molecular sieve, a cyanide-containing linker, and a first organic solvent were reacted. After cooling, solid-liquid separation was carried out, and the solid product was washed with hot toluene for multiple times. Then the obtained product was reacted with an acidic solution, followed by solid-liquid separation, and the solid product was washed with deionized water for multiple times and dried.

[0080] (3) Preparation of MCM-41 / MIL-101 composite material: MCM-41-COOH, a metal salt, an organic ligand, and a second organic solvent were reacted. After cooling, solid-liquid separation was carried out, and then the solid product was washed with DMF, water, and ethanol for multiple times respectively. Then the solid product was dried.

[0081] The third aspect of the present invention provides a composite material prepared by the method described above.

[0082] In a preferred embodiment, the composite material includes MCM-41 molecular sieve and MIL-101 metal-organic framework material in-situ grown on the MCM-41 molecular sieve.

[0083] In a preferred embodiment, the specific surface area of the composite material is 800 - 2000 m 2 / g.

[0084] The fourth aspect of the present invention provides an adsorbent, which contains the composite material described above.

[0085] The composite material contained in the adsorbent of the present invention has a relatively large specific surface area and is suitable for adsorbing macromolecular VOCs.

[0086] The fifth aspect of the present invention provides a method for treating the tail gas of cis-butadiene rubber, which includes: adsorbing the tail gas of cis-butadiene rubber by using an adsorption material,

[0087] wherein the adsorption material contains the composite material described above or the adsorbent described above.

[0088] The composite material and adsorbent provided by the present invention can be used in the field of adsorption treatment of the tail gas in the synthetic rubber industry, which can not only bring economic benefits to enterprises but also meet the national atmospheric emission standards.

[0089] The present invention will be described in detail below through examples, but the protection scope of the present invention is not limited thereto. In the following examples, unless otherwise specified, the raw materials used are all common commercially available products.

[0090] In the following examples,

[0091] the molecular weight of the tetraethyl orthosilicate is 208;

[0092] the density of the tetraethyl orthosilicate is 0.9356 g / mL.

[0093] Example 1

[0094] (1) Dissolve cetyltrimethylammonium bromide (1 g) in deionized water (50 mL), and stir evenly. Add sodium hydroxide solution to adjust the pH value of the solution to 11. Slowly add tetraethyl orthosilicate (3.6 mL), and stir evenly. Transfer the evenly stirred solution to an autoclave, and place it in an oven (120 °C) for static heating and crystallization (48 h). Separate the solid from the liquid, and wash the solid twice with deionized water. Dry the solid in an oven (120 °C) for (12 h). Then calcine the solid in a tube furnace (600 °C) for (6 h) to remove the template agent, and thus obtain the MCM-41 molecular sieve.

[0095] (2) Add MCM-41 molecular sieve (1 g) to toluene (35 mL), and then add the linker (0.55 mmol trimethylsilyl cyanide) to the above mixture, and stir evenly. Heat the mixture in an oil bath (120 °C) in a flask for reflux (6 h). After cooling to room temperature, filter the precipitate and wash it several times with hot toluene. Add 20 mL of water to the obtained solid, stir evenly, and then dropwise add 37% hydrochloric acid (0.092 mL). Stir evenly at room temperature, and then heat to 110 °C for reflux for 12 h to hydrolyze the CN group into the COOH group. After cooling to room temperature, separate the solid from the liquid, and wash the solid twice with deionized water. Dry the solid in an oven (120 °C) by heating for (12 h), and thus obtain MCM-41-COOH.

[0096] (3) Add metal salt (0.4 mmol) and organic ligand (0.4 mmol) to N,N-dimethylformamide (20 mL), and stir evenly at room temperature. Add MCM-41-COOH (1 g) to the above solution, and stir evenly. Transfer the mixture to a high-pressure reaction kettle, and heat it in an oven (180 °C) for (12 h). After cooling to room temperature, separate the solid, and wash it twice with DMF, water, and ethanol respectively. Dry the solid in an oven (80 °C) by heating for (24 h), and thus obtain the composite material.

[0097] Example 2

[0098] (1) Dissolve cetyltrimethylammonium bromide (1 g) in deionized water (50 mL), and stir evenly. Add sodium hydroxide solution to adjust the pH value of the solution to 10.5. Slowly add tetraethyl orthosilicate (3.6 mL) and stir evenly. Transfer the evenly stirred solution to an autoclave, and place it in an oven (135 °C) for static heating and crystallization (36 h). Perform solid-liquid separation, and wash the solid twice with deionized water. Dry the solid in an oven (100 °C) for 24 h. Then calcine the solid in a tube furnace (550 °C) for 8 h to remove the template agent, and MCM-41 molecular sieve is obtained.

[0099] (2) Add MCM-41 molecular sieve (1 g) to toluene (35 mL), and then add the linker (0.55 mmol trimethylsilyl cyanide) to the above mixture and stir evenly. Heat the mixture in an oil bath (100 °C) in a flask for reflux (10 h). After cooling to room temperature, filter the precipitate and wash it several times with hot toluene. Add 20 mL of water to the obtained solid, stir evenly, and then dropwise add 37% hydrochloric acid (0.092 mL). Stir evenly at room temperature, and then heat to 100 °C for reflux for 15 h to hydrolyze the CN group into the COOH group. After cooling to room temperature, perform solid-liquid separation, and wash the solid twice with deionized water. Dry the solid in an oven (120 °C) for 12 h to obtain MCM-41-COOH.

[0100] (3) Add metal salt (1.2 mmol) and organic ligand (1.2 mmol) to N,N-dimethylformamide (50 mL), and stir evenly at room temperature. Add MCM-41-COOH (1 g) to the above solution and stir evenly. Transfer the mixture to a high-pressure reaction kettle, and heat it in an oven (150 °C) for 24 h. After cooling to room temperature, separate the solid, and wash it twice with DMF, water, and ethanol respectively. Dry the solid in an oven (100 °C) for 12 h to obtain the composite material.

[0101] Example 3

[0102] (1) Dissolve cetyltrimethylammonium bromide (1 g) in deionized water (50 mL), and stir evenly. Add sodium hydroxide solution to adjust the pH value of the solution to 11. Slowly add tetraethyl orthosilicate (3.6 mL) and stir evenly. Transfer the evenly stirred solution to an autoclave, and place it in an oven (150 °C) for static heating and crystallization (24 h). Perform solid-liquid separation, and wash the solid twice with deionized water. Dry the solid in an oven (120 °C) for 12 h. Then calcine the solid in a tube furnace (600 °C) for 6 h to remove the template agent, and MCM-41 molecular sieve is obtained.

[0103] (2) Add MCM-41 molecular sieve (1 g) to toluene (35 mL), and then add the linker (0.55 mmol trimethylsilyl cyanide) to the above mixture and stir evenly. Heat the mixture in an oil bath (120 °C) in a flask under reflux for 6 h. After cooling to room temperature, filter the precipitate and wash it several times with hot toluene. Add 20 mL of water to the obtained solid, stir evenly and then dropwise add 37% hydrochloric acid (0.092 mL). Stir evenly at room temperature and then heat to 110 °C under reflux for 12 h to hydrolyze the CN group into the COOH group. After cooling to room temperature, separate the solid and liquid, and wash the solid twice with deionized water. Heat and dry the solid in an oven (120 °C) for 12 h to obtain MCM-41-COOH.

[0104] (3) Add metal salt (2 mmol) and organic ligand (2 mmol) to N,N-dimethylformamide (80 mL), and stir evenly at room temperature. Add MCM-41-COOH (1 g) to the above solution and stir evenly. Transfer the mixture to a high-pressure reaction kettle and heat it in an oven (180 °C) for 12 h. Cool to room temperature, separate the solid, and wash it twice with DMF, water, and ethanol respectively. Heat and dry the solid in an oven (80 °C) for 24 h to obtain the composite material.

[0105] Example 4

[0106] (1) Dissolve cetyltrimethylammonium bromide (1 g) in deionized water (50 mL) and stir evenly. Add sodium hydroxide solution to adjust the pH value of the solution to 10.5. Slowly add tetraethyl orthosilicate (3.6 mL) and stir evenly. Transfer the evenly stirred solution to an autoclave and place it in an oven (120 °C) for static heating and crystallization for 48 h. Separate the solid and liquid, and wash the solid twice with deionized water. Dry the solid in an oven (100 °C) for 24 h. Then calcine the solid in a tubular furnace (550 °C) for 8 h to remove the template agent to obtain MCM-41 molecular sieve.

[0107] (2) Add MCM-41 molecular sieve (1 g) to toluene (50 mL), and then add the linker (0.8 mmol trimethylsilyl cyanide) to the above mixture and stir evenly. Heat the mixture in an oil bath (100 °C) in a flask under reflux for 10 h. After cooling to room temperature, filter the precipitate and wash it several times with hot toluene. Add 20 mL of water to the obtained solid, stir evenly and then dropwise add 37% hydrochloric acid (0.13 mL). Stir evenly at room temperature and then heat to 100 °C under reflux for 15 h to hydrolyze the CN group into the COOH group. After cooling to room temperature, separate the solid and liquid, and wash the solid twice with deionized water. Heat and dry the solid in an oven (120 °C) for 12 h to obtain MCM-41-COOH.

[0108] (3) Add metal salt (0.4 mmol) and organic ligand (0.4 mmol) to N,N-dimethylformamide (20 mL), and stir evenly at room temperature. Add MCM-41-COOH (1 g) to the above solution and stir evenly. Transfer the mixture to a high-pressure reactor and heat it in an oven (150 °C) for (24 h). Cool to room temperature, separate the solid, and wash it twice with DMF, water, and ethanol respectively. Dry the solid by heating in an oven (100 °C) for (12 h) to obtain the composite material.

[0109] Example 5

[0110] (1) Dissolve cetyltrimethylammonium bromide (1 g) in deionized water (50 mL) and stir evenly. Add sodium hydroxide solution to adjust the pH value of the solution to 11. Slowly add tetraethyl orthosilicate (3.6 ml) and stir evenly. Transfer the evenly stirred solution to a high-pressure autoclave and place it in an oven (135 °C) for static heating and crystallization (36 h). Separate the solid and liquid, and wash the solid twice with deionized water. Dry the solid in an oven (120 °C) for (12 h). Then calcine the solid in a tube furnace (600 °C) for (6 h) to remove the template agent to obtain MCM-41 molecular sieve.

[0111] (2) Add MCM-41 molecular sieve (1 g) to toluene (50 mL), and then add the linker (0.8 mmol trimethylsilyl cyanide) to the above mixture and stir evenly. Heat the mixture in an oil bath (120 °C) in a flask and reflux for (6 h). After cooling to room temperature, filter the precipitate and wash it several times with hot toluene. Add 20 mL of water to the obtained solid, stir evenly, and then dropwise add 37% hydrochloric acid (0.13 mL). Stir evenly at room temperature and then heat to 110 °C and reflux for 12 h to hydrolyze the CN group to the COOH group. After cooling to room temperature, separate the solid and liquid, and wash the solid twice with deionized water. Dry the solid by heating in an oven (120 °C) for (12 h) to obtain MCM-41-COOH.

[0112] (3) Add metal salt (1.2 mmol) and organic ligand (1.2 mmol) to N,N-dimethylformamide (50 mL), and stir evenly at room temperature. Add MCM-41-COOH (1 g) to the above solution and stir evenly. Transfer the mixture to a high-pressure reactor and heat it in an oven (180 °C) for (12 h). Cool to room temperature, separate the solid, and wash it twice with DMF, water, and ethanol respectively. Dry the solid by heating in an oven (80 °C) for (24 h) to obtain the composite material.

[0113] Example 6

[0114] (1) Dissolve cetyltrimethylammonium bromide (1 g) in deionized water (50 ml), and stir evenly. Add sodium hydroxide solution to adjust the pH value of the solution to 10.5. Slowly add tetraethyl orthosilicate (3.6 mL), and stir evenly. Transfer the evenly stirred solution to an autoclave, and place it in an oven (150 °C) for static heating and crystallization (24 h). Perform solid-liquid separation, and wash the solid twice with deionized water. Dry the solid in an oven (100 °C) for 24 h. Then calcine the solid in a tube furnace (550 °C) for 8 h to remove the template agent, and MCM-41 molecular sieve is obtained.

[0115] (2) Add MCM-41 molecular sieve (1 g) to toluene (50 mL), and then add the linker (0.8 mmol trimethylsilyl cyanide) to the above mixture, and stir evenly. Heat the mixture in an oil bath (100 °C) in a flask for reflux (10 h). After cooling to room temperature, filter the precipitate and wash it several times with hot toluene. Add 20 mL of water to the obtained solid, stir evenly, and then dropwise add 37% hydrochloric acid (0.13 mL). Stir evenly at room temperature, and then heat to 100 °C for reflux for 15 h to hydrolyze the CN group into the COOH group. After cooling to room temperature, perform solid-liquid separation, and wash the solid twice with deionized water. Dry the solid in an oven (120 °C) for 12 h, and MCM-41-COOH is obtained.

[0116] (3) Add metal salt (2 mmol) and organic ligand (2 mmol) to N,N-dimethylformamide (80 mL), and stir evenly at room temperature. Add MCM-41-COOH (1 g) to the above solution, and stir evenly. Transfer the mixture to a high-pressure reactor, and heat it in an oven (150 °C) for 24 h. After cooling to room temperature, separate the solid, and wash it twice with DMF, water, and ethanol respectively. Dry the solid in an oven (100 °C) for 12 h, and the composite material is obtained.

[0117] Example 7

[0118] (1) Dissolve cetyltrimethylammonium bromide (1 g) in deionized water (100 mL), and stir evenly. Add sodium hydroxide solution to adjust the pH value of the solution to 11. Slowly add tetraethyl orthosilicate (4.8 mL), and stir evenly. Transfer the evenly stirred solution to an autoclave, and place it in an oven (120 °C) for static heating and crystallization (48 h). Perform solid-liquid separation, and wash the solid twice with deionized water. Dry the solid in an oven (120 °C) for 12 h. Then calcine the solid in a tube furnace (600 °C) for 6 h to remove the template agent, and MCM-41 molecular sieve is obtained.

[0119] (2) Add MCM-41 molecular sieve (1 g) to toluene (20 mL), and then add the linker (0.3 mmol trimethylsilyl cyanide) to the above mixture and stir evenly. Heat the mixture in an oil bath (120 °C) in a flask under reflux for 6 h. After cooling to room temperature, filter the precipitate and wash it several times with hot toluene. Add 20 mL of water to the obtained solid, stir evenly, and then dropwise add 37% hydrochloric acid (0.075 mL). Stir evenly at room temperature and then heat to 110 °C under reflux for 12 h to hydrolyze the CN group into the COOH group. After cooling to room temperature, separate the solid and liquid, and wash the solid twice with deionized water. Dry the solid in an oven (120 °C) for 12 h to obtain MCM-41-COOH.

[0120] (3) Add metal salt (0.4 mmol) and organic ligand (0.4 mmol) to N,N-dimethylformamide (20 mL) and stir evenly at room temperature. Add MCM-41-COOH (1 g) to the above solution and stir evenly. Transfer the mixture to a high-pressure reaction kettle and heat it in an oven (180 °C) for 12 h. Cool to room temperature, separate the solid, and wash it twice with DMF, water, and ethanol respectively. Dry the solid in an oven (80 °C) for 24 h to obtain the composite material.

[0121] Example 8

[0122] (1) Dissolve cetyltrimethylammonium bromide (1 g) in deionized water (100 mL) and stir evenly. Add sodium hydroxide solution to adjust the pH value of the solution to 10.5. Slowly add tetraethyl orthosilicate (4.8 mL) and stir evenly. Transfer the stirred solution to an autoclave and place it in an oven (135 °C) for static heating and crystallization for 36 h. Separate the solid and liquid, and wash the solid twice with deionized water. Dry the solid in an oven (100 °C) for 24 h. Then calcine the solid in a tube furnace (550 °C) for 8 h to remove the template agent to obtain MCM-41 molecular sieve.

[0123] (2) Add MCM-41 molecular sieve (1 g) to toluene (20 mL), and then add the linker (0.3 mmol trimethylsilyl cyanide) to the above mixture and stir evenly. Heat the mixture in an oil bath (100 °C) in a flask under reflux for 10 h. After cooling to room temperature, filter the precipitate and wash it several times with hot toluene. Add 20 mL of water to the obtained solid, stir evenly, and then dropwise add 37% hydrochloric acid (0.075 mL). Stir evenly at room temperature and then heat to 100 °C under reflux for 15 h to hydrolyze the CN group into the COOH group. After cooling to room temperature, separate the solid and liquid, and wash the solid twice with deionized water. Dry the solid in an oven (120 °C) for 12 h to obtain MCM-41-COOH.

[0124] (3) Add metal salt (1.2 mmol) and organic ligand (1.2 mmol) to N,N-dimethylformamide (50 mL), and stir evenly at room temperature. Add MCM-41-COOH (1 g) to the above solution and stir evenly. Transfer the mixture to a high-pressure reaction kettle and heat it in an oven (150 °C) for (24 h). Cool to room temperature, separate the solid, and wash it twice with DMF, water, and ethanol respectively. Heat and dry the solid in an oven (100 °C) for (12 h) to obtain the composite material.

[0125] Example 9

[0126] (1) Dissolve cetyltrimethylammonium bromide (1 g) in deionized water (100 mL) and stir evenly. Add sodium hydroxide solution to adjust the pH value of the solution to 11. Slowly add tetraethyl orthosilicate (4.8 mL) and stir evenly. Transfer the evenly stirred solution to a high-pressure kettle and place it in an oven (150 °C) for static heating and crystallization for (24 h). Separate the solid and liquid, and wash the solid twice with deionized water. Dry the solid in an oven (120 °C) for (12 h). Then calcine the solid in a tube furnace (600 °C) for (6 h) to remove the template agent to obtain MCM-41 molecular sieve.

[0127] (2) Add MCM-41 molecular sieve (1 g) to toluene (20 mL), and then add the linker (0.3 mmol trimethylsilyl cyanide) to the above mixture and stir evenly. Heat and reflux the mixture in an oil bath (120 °C) in a flask for (6 h). After cooling to room temperature, filter the precipitate and wash it several times with hot toluene. Add 20 mL of water to the obtained solid, stir evenly, and then dropwise add 37% hydrochloric acid (0.075 mL). Stir evenly at room temperature and then heat to 110 °C for reflux for 12 h to hydrolyze the CN group into COOH group. After cooling to room temperature, separate the solid and liquid, and wash the solid twice with deionized water. Heat and dry the solid in an oven (120 °C) for (12 h) to obtain MCM-41-COOH.

[0128] (3) Add metal salt (2 mmol) and organic ligand (2 mmol) to N,N-dimethylformamide (80 mL), and stir evenly at room temperature. Add MCM-41-COOH (1 g) to the above solution and stir evenly. Transfer the mixture to a high-pressure reaction kettle and heat it in an oven (180 °C) for (12 h). Cool to room temperature, separate the solid, and wash it twice with DMF, water, and ethanol respectively. Heat and dry the solid in an oven (80 °C) for (24 h) to obtain the composite material.

[0129] Example 10

[0130] (1) Dissolve cetyltrimethylammonium bromide (1 g) in deionized water (100 mL), and stir evenly. Add sodium hydroxide solution to adjust the pH value of the solution to 10.5. Slowly add tetraethyl orthosilicate (4.8 mL) and stir evenly. Transfer the evenly stirred solution to an autoclave, place it in an oven (120 °C) and let it stand for heat crystallization (48 h). Separate the solid from the liquid, and wash the solid twice with deionized water. Dry the solid in an oven (100 °C) for (24 h). Then calcine the solid in a tube furnace (550 °C) for (8 h) to remove the template agent, and MCM-41 molecular sieve is obtained.

[0131] (2) Add MCM-41 molecular sieve (1 g) to toluene (35 mL), and then add the linker (0.55 mmol trimethylsilyl cyanide) to the above mixture and stir evenly. Heat the mixture to reflux in an oil bath (100 °C) in a flask for (10 h). After cooling to room temperature, filter the precipitate and wash it several times with hot toluene. Add 20 mL of water to the obtained solid, stir evenly and then dropwise add 37% hydrochloric acid (0.14 mL). Stir evenly at room temperature and then heat to 100 °C for reflux for 15 h to hydrolyze the CN group into the COOH group. After cooling to room temperature, separate the solid from the liquid, and wash the solid twice with deionized water. Dry the solid in an oven (120 °C) by heating for (12 h) to obtain MCM-41-COOH.

[0132] (3) Add metal salt (0.4 mmol) and organic ligand (0.4 mmol) to N,N-dimethylformamide (20 mL), and stir evenly at room temperature. Add MCM-41-COOH (1 g) to the above solution and stir evenly. Transfer the mixture to a high-pressure reaction kettle and heat it in an oven (150 °C) for (24 h). After cooling to room temperature, separate the solid, and wash it twice with DMF, water, and ethanol respectively. Dry the solid in an oven (100 °C) by heating for (12 h) to obtain the composite material.

[0133] Example 11

[0134] (1) Dissolve cetyltrimethylammonium bromide (1 g) in deionized water (100 mL), and stir evenly. Add sodium hydroxide solution to adjust the pH value of the solution to 11. Slowly add tetraethyl orthosilicate (4.8 mL) and stir evenly. Transfer the evenly stirred solution to an autoclave, place it in an oven (135 °C) and let it stand for heat crystallization (36 h). Separate the solid from the liquid, and wash the solid twice with deionized water. Dry the solid in an oven (120 °C) for (12 h). Then calcine the solid in a tube furnace (600 °C) for (6 h) to remove the template agent, and MCM-41 molecular sieve is obtained.

[0135] (2) Add MCM-41 molecular sieve (1 g) to toluene (35 mL), and then add the linker (0.55 mmol trimethylsilyl cyanide) to the above mixture and stir evenly. Heat the mixture in an oil bath (120 °C) in a flask under reflux for 6 h. After cooling to room temperature, filter the precipitate and wash it several times with hot toluene. Add 20 mL of water to the obtained solid, stir evenly and then dropwise add 37% hydrochloric acid (0.14 mL). After stirring evenly at room temperature, heat to 110 °C and reflux for 12 h to hydrolyze the CN group into the COOH group. After cooling to room temperature, separate the solid and liquid, and wash the solid twice with deionized water. Heat and dry the solid in an oven (120 °C) for 12 h to obtain MCM-41-COOH.

[0136] (3) Add metal salt (1.2 mmol) and organic ligand (1.2 mmol) to N,N-dimethylformamide (50 mL), and stir evenly at room temperature. Add MCM-41-COOH (1 g) to the above solution and stir evenly. Transfer the mixture to a high-pressure reaction kettle and heat it in an oven (180 °C) for 12 h. After cooling to room temperature, separate the solid and wash it twice with DMF, water, and ethanol respectively. Heat and dry the solid in an oven (80 °C) for 24 h to obtain the composite material.

[0137] Example 12

[0138] (1) Dissolve cetyltrimethylammonium bromide (1 g) in deionized water (100 mL) and stir evenly. Add sodium hydroxide solution to adjust the pH value of the solution to 10.5. Slowly add tetraethyl orthosilicate (4.8 mL) and stir evenly. Transfer the stirred solution to a high-pressure kettle and place it in an oven (150 °C) for static heating and crystallization for 24 h. Separate the solid and liquid, and wash the solid twice with deionized water. Dry the solid in an oven (100 °C) for 24 h. Then calcine the solid in a tubular furnace (550 °C) for 8 h to remove the template agent to obtain MCM-41 molecular sieve.

[0139] (2) Add MCM-41 molecular sieve (1 g) to toluene (35 mL), and then add the linker (0.55 mmol trimethylsilyl cyanide) to the above mixture and stir evenly. Heat the mixture in an oil bath (100 °C) in a flask under reflux for 10 h. After cooling to room temperature, filter the precipitate and wash it several times with hot toluene. Add 20 mL of water to the obtained solid, stir evenly and then dropwise add 37% hydrochloric acid (0.14 mL). After stirring evenly at room temperature, heat to 100 °C and reflux for 15 h to hydrolyze the CN group into the COOH group. After cooling to room temperature, separate the solid and liquid, and wash the solid twice with deionized water. Heat and dry the solid in an oven (120 °C) for 12 h to obtain MCM-41-COOH.

[0140] (3) Add metal salt (2 mmol) and organic ligand (2 mmol) to N,N-dimethylformamide (80 mL), and stir evenly at room temperature. Add MCM-41-COOH (1 g) to the above solution and stir evenly. Transfer the mixture to a high-pressure reaction kettle and heat it in an oven (150 °C) for (24 h). Cool to room temperature, separate the solid, and wash it twice with DMF, water, and ethanol respectively. Dry the solid in an oven (100 °C) for (12 h) to obtain the composite material.

[0141] The pore structure parameters and adsorption properties of the obtained composite material are shown in Table 1.

[0142] Example 13

[0143] (1) Dissolve cetyltrimethylammonium bromide (1 g) in deionized water (100 mL) and stir evenly. Add sodium hydroxide solution to adjust the pH value of the solution to 11. Slowly add tetraethyl orthosilicate (4.8 mL) and stir evenly. Transfer the stirred solution to a high-pressure kettle and place it in an oven (120 °C) for static heating and crystallization for (48 h). Separate the solid and liquid, and wash the solid twice with deionized water. Dry the solid in an oven (120 °C) for (12 h). Then calcine the solid in a tubular furnace (600 °C) for (6 h) to remove the template agent to obtain MCM-41 molecular sieve.

[0144] (2) Add MCM-41 molecular sieve (1 g) to toluene (50 mL), and then add the linker (0.8 mmol trimethylsilyl cyanide) to the above mixture and stir evenly. Heat the mixture in an oil bath (120 °C) in a flask for reflux for (6 h). After cooling to room temperature, filter the precipitate and wash it several times with hot toluene. Add 20 mL of water to the obtained solid, stir evenly, and then dropwise add 37% hydrochloric acid (0.2 mL). Stir evenly at room temperature and then heat to 110 °C for reflux for 12 h to hydrolyze the CN group into COOH group. After cooling to room temperature, separate the solid and liquid, and wash the solid twice with deionized water. Dry the solid in an oven (120 °C) for (12 h) to obtain MCM-41-COOH.

[0145] (3) Add metal salt (0.4 mmol) and organic ligand (0.4 mmol) to N,N-dimethylformamide (20 mL), and stir evenly at room temperature. Add MCM-41-COOH (1 g) to the above solution and stir evenly. Transfer the mixture to a high-pressure reaction kettle and heat it in an oven (180 °C) for (12 h). Cool to room temperature, separate the solid, and wash it twice with DMF, water, and ethanol respectively. Dry the solid in an oven (80 °C) for (24 h) to obtain the composite material.

[0146] Example 14

[0147] (1) Dissolve cetyltrimethylammonium bromide (1 g) in deionized water (100 mL), and stir evenly. Add sodium hydroxide solution to adjust the pH value of the solution to 10.5. Slowly add tetraethyl orthosilicate (4.8 mL) and stir evenly. Transfer the evenly stirred solution to an autoclave, and place it in an oven (135 °C) for static heating and crystallization (36 h). Perform solid-liquid separation, and wash the solid twice with deionized water. Dry the solid in an oven (100 °C) for (24 h). Then calcine the solid in a tubular furnace (550 °C) for (8 h) to remove the template agent, and MCM-41 molecular sieve is obtained.

[0148] (2) Add MCM-41 molecular sieve (1 g) to toluene (50 mL), and then add the linker (0.8 mmol trimethylsilyl cyanide) to the above mixture and stir evenly. Heat the mixture in an oil bath (100 °C) in a flask under reflux for (10 h). After cooling to room temperature, filter the precipitate and wash it several times with hot toluene. Add 20 mL of water to the obtained solid, stir evenly, and then dropwise add 37% hydrochloric acid (0.2 mL). Stir evenly at room temperature, and then heat to 100 °C under reflux for 15 h to hydrolyze the CN group into the COOH group. After cooling to room temperature, perform solid-liquid separation, and wash the solid twice with deionized water. Dry the solid in an oven (120 °C) for (12 h) to obtain MCM-41-COOH.

[0149] (3) Add metal salt (1.2 mmol) and organic ligand (1.2 mmol) to N,N-dimethylformamide (50 mL), and stir evenly at room temperature. Add MCM-41-COOH (1 g) to the above solution and stir evenly. Transfer the mixture to a high-pressure reaction kettle, and heat it in an oven (150 °C) for (24 h). After cooling to room temperature, separate the solid, and wash it twice with DMF, water, and ethanol respectively. Dry the solid in an oven (100 °C) for (12 h) to obtain the composite material.

[0150] Example 15

[0151] (1) Dissolve cetyltrimethylammonium bromide (1 g) in deionized water (100 mL), and stir evenly. Add sodium hydroxide solution to adjust the pH value of the solution to 11. Slowly add tetraethyl orthosilicate (4.8 mL) and stir evenly. Transfer the evenly stirred solution to an autoclave, and place it in an oven (150 °C) for static heating and crystallization (24 h). Perform solid-liquid separation, and wash the solid twice with deionized water. Dry the solid in an oven (120 °C) for (12 h). Then calcine the solid in a tubular furnace (600 °C) for (6 h) to remove the template agent, and MCM-41 molecular sieve is obtained.

[0152] (2) Add MCM-41 molecular sieve (1 g) to toluene (50 mL), and then add the linker (0.8 mmol trimethylsilyl cyanide) to the above mixture and stir evenly. Heat the mixture to reflux (6 h) in an oil bath (120 °C) in a flask. After cooling to room temperature, filter the precipitate and wash it several times with hot toluene. Add 20 mL of water to the obtained solid, stir evenly and then dropwise add 37% hydrochloric acid (0.2 mL). After stirring evenly at room temperature, heat to 110 °C and reflux for 12 h to hydrolyze the CN group into the COOH group. After cooling to room temperature, separate the solid and liquid, and wash the solid twice with deionized water. Heat and dry the solid in an oven (120 °C) for 12 h to obtain MCM-41-COOH.

[0153] (3) Add metal salt (2 mmol) and organic ligand (2 mmol) to N,N-dimethylformamide (80 mL), and stir evenly at room temperature. Add MCM-41-COOH (1 g) to the above solution and stir evenly. Transfer the mixture to a high-pressure reactor and heat it in an oven (180 °C) for 12 h. After cooling to room temperature, separate the solid and wash it twice with DMF, water, and ethanol respectively. Heat and dry the solid in an oven (80 °C) for 24 h to obtain the composite material.

[0154] Comparative Example 1

[0155] Directly use the MCM-41 molecular sieve prepared according to the example as the adsorbent.

[0156] Comparative Example 2

[0157] Directly use 5A molecular sieve as the adsorbent (purchased from Jiangsu Xianfeng Nanomaterials Technology Co., Ltd.).

[0158] Comparative Example 3

[0159] Directly use ZSM-5 molecular sieve as the adsorbent (purchased from Jiangsu Xianfeng Nanomaterials Technology Co., Ltd.).

[0160] Comparative Example 4

[0161] Directly use Calgon activated carbon as the adsorbent (purchased from Suzhou Calgon Activated Carbon Co., Ltd.).

[0162] Test Example

[0163] (1) Use a physical adsorption instrument to measure the specific surface area of each material in the examples and comparative examples by the low-temperature nitrogen adsorption method. The results are shown in Table 1.

[0164] The test method is as follows: The N2 adsorption-desorption curve of the samples in the examples was tested on a Micromeritics ASAP 2020 specific surface area analyzer in the United States. Before the test, the samples need to be activated and pretreated at 150 °C under vacuum for 6 h, and then the N2 adsorption isotherm test was carried out at 77 K. The BET and Langmuir specific surface areas of the materials were calculated using the BET and Langmuir equations respectively, the micropore volume (<2 nm) was calculated using the t-plot model, and the pore size in the micropore range was calculated using the H-K equation.

[0165] (2) The adsorption amount of n-hexane by each material in the examples and comparative examples was measured using a Beishide gravimetric vapor adsorption instrument. The results are shown in Table 1.

[0166] The test method is as follows: The static adsorption-desorption curve of n-hexane was tested using a Beijing Beishide gravimetric vapor adsorption instrument (BSD-DVS). First, the sample was evacuated and degassed at 150 °C for 12 h, weighed, and then transferred to the analysis station; the adsorption-desorption isotherm curve of n-hexane of the sample was measured in the pressure range of 298 K and 0-20.192 kPa, and the maximum adsorption amount of the sample in this pressure range can be obtained from the curve.

[0167] Table 1

[0168]

[0169] As can be seen from Table 1, the composite material prepared by the method of the present invention has a relatively large specific surface area and a high n-hexane adsorption amount.

[0170] Through the experimental data analysis of Examples 1-6 and 7-15, it can be seen that as the proportion of cetyltrimethylammonium bromide in the synthesis of MCM-41 increases, the BET specific surface area of the synthesized material decreases. This is because CTAB, as a pore-expanding agent, too much will cause the formation of larger pores, resulting in a decrease in the porosity of the material and a decrease in the specific surface area.

[0171] Through the comparison of the experimental data of Examples 1-3, 4-6, and 7-9, it can be seen that as the addition ratio of the linker trimethylsilyl cyanide increases, the number of -COOH functional groups loaded on the surface modification of MCM-41 increases, and the amount of MIL-101 grown on the surface of MCM-41 increases, resulting in an increase in the specific surface area and n-hexane adsorption amount of the synthesized MCM-41 / MIL-101 composite material.

[0172] Analysis of the data of Examples 13 - 15 shows that as the ratio of the metal salt and the organic ligand terephthalic acid for synthesizing MIL-101 increases, the BET specific surface area of the synthesized composite material increases, and the n-hexane adsorption capacity increases. This is because the proportion of MIL-101 in the composite material increases, improving the overall pore structure of the composite material. By comparing the synthesized composite materials of each example with the MCM-41 molecular sieve of Comparative Example 1, although the BET specific surface area of the composite materials synthesized in some examples decreases, the n-hexane adsorption capacity still increases. This is because after loading MIL-101, the pore structure of the material is more suitable for the adsorption of n-hexane.

[0173] Compared with other molecular sieves in Comparative Examples 2 - 3, the BET specific surface area and n-hexane adsorption capacity of the composite material far exceed those of other molecular sieves. Compared with activated carbon, although the BET specific surface area of some composite materials is lower than that of activated carbon, the n-hexane adsorption capacity is higher than that of activated carbon, further verifying the importance of a suitable pore size for n-hexane adsorption.

[0174] Through testing, it can be known that the pore sizes of the composite materials prepared in the examples are all between 2.0 - 3.6 nm.

[0175] Figure 1 Is the nitrogen adsorption - desorption curve of the material of Comparative Example 1; Figure 2 Is the pore size distribution of the material of Comparative Example 1; Figure 3 Is the n-hexane adsorption - desorption curve of the material of Comparative Example 1, Figure 4 Is the pore size distribution diagram of the composite material synthesized in Example 14. From Figure 2 、 Figure 4 It can be seen that the pore size of the composite material becomes smaller. This is because after growing MIL-101 on the surface of the pores of large-pore MCM-41, the pore channels become narrower and the pore size becomes smaller. From the n-hexane adsorption data, it can be seen that the MCM-41 composite material loaded with MIL-101 is more suitable for the adsorption of n-hexane.

[0176] 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 technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, including any other suitable combination of each technical feature. These simple modifications and combinations should also be regarded as the content disclosed by the present invention and fall within the protection scope of the present invention.

Claims

1. A composite material, characterized in that, The composite material includes MCM-41 molecular sieve and MIL-101 metal-organic framework material grown in-situ on the MCM-41 molecular sieve.

2. The composite material according to claim 1, characterized in that, The specific surface area of the composite material is 800 - 2000 m 2 / g, and the pore size is 2.0 - 3.6 nm.

3. A method for preparing a composite material, characterized in that, The method includes the following steps: S1. React MCM-41 molecular sieve, a cyano-containing linker, and a first organic solvent; S2. React the reaction product obtained in step S1 with an acidic solution; S3. React the reaction product obtained in step S2, a metal salt, an organic ligand, and a second organic solvent.

4. The method according to claim 3, characterized in that In step S1, the dosage ratio of the MCM-41 molecular sieve to the cyano-containing linker is 1 g: 0.3 - 0.8 mmol; Preferably, the cyano-containing linker is selected from trimethylsilyl cyanide and / or triethylcyanosilane.

5. The method according to claim 3 or 4, characterized in that, In step S1, the dosage ratio of the MCM-41 molecular sieve to the first organic solvent is 0.02 - 0.05 g: 1 mL; Preferably, the first organic solvent is toluene.

6. The method according to any one of claims 3 to 5, characterized in that, In step S1, the reaction conditions include: temperature is 100 - 120 °C; time is 2 - 10 h, preferably 6 - 10 h.

7. The method according to any one of claims 3-6, characterized in that, The molar ratio of the cyano-containing linker in step S1 to the amount of acid in the acidic solution in step S2 is 1: 2 - 4; Preferably, the acidic solution is a hydrochloric acid solution; Preferably, the concentration of the hydrochloric acid solution is 36 - 38 wt%.

8. The method according to any one of claims 3-7, characterized in that, In step S2, the reaction conditions include: temperature is 80 - 120 °C; time is 12 - 24 h.

9. The method according to any one of claims 3-8, characterized in that, In step S3, the dosage ratio of the reaction product obtained in step S2 to the organic ligand is 1 g: 0.4 - 2 mmol; Preferably, in step S3, the molar ratio of the metal salt to the organic ligand is 1 - 3:1, preferably 1 - 1.5:1; Preferably, in step S3, the dosage ratio of the metal salt to the second organic solvent is 0.02 - 0.04 mol: 1 L.

10. The method according to any one of claims 3-9, characterized in that, In step S3, the metal salt is selected from one or more of FeCl3·6H2O, CrCl3·6H2O, AlCl3·6H2O, Fe(NO3)3·9H2O, Cr(NO3)3·9H2O, and Al(NO3)3·9H2O; Preferably, the organic ligand is selected from one or more of terephthalic acid, 2-amino-1,4-benzenedicarboxylic acid, and 2-hydroxy-1,4-benzenedicarboxylic acid; Preferably, the second organic solvent is N,N-dimethylformamide.

11. The method according to any one of claims 3 to 10, characterized in that, In step S3, the reaction conditions include: temperature is 120 - 180 °C, preferably 150 - 180 °C; time is 8 - 24 h, preferably 12 - 24 h.

12. The method according to any one of claims 3 to 11, characterized in that The preparation method of the MCM-41 molecular sieve includes: preparing a solution of cetyltrimethylammonium bromide and water, then adjusting the pH value of the solution to be alkaline, and then adding tetraethyl orthosilicate for crystallization reaction and calcination.

13. The method according to claim 12, wherein The molar ratio of cetyltrimethylammonium bromide, tetraethyl orthosilicate, and water is 1: (5 - 10): (1000 - 5000), preferably 1: (6 - 8): (1000 - 2000); Preferably, the pH value is 10 - 11; Preferably, the conditions for the crystallization reaction include: temperature is 80 - 150 °C, preferably 120 - 150 °C; time is 12 - 48 h, preferably 24 - 48 h. Preferably, the conditions for the calcination include: temperature is 500 - 600 °C; time is 4 - 10 h, preferably 6 - 8 h.

14. A composite material prepared by the method according to any one of claims 3 - 13.

15. An adsorbent, characterized in that, The adsorbent contains the composite material according to any one of claims 1, 2 or 14.

16. A method for treating the tail gas of cis-1,4-polybutadiene rubber, characterized in that, The method includes: using an adsorption material to adsorb the tail gas of cis - 1,4 - polybutadiene rubber. Wherein, the adsorption material contains the composite material according to any one of claims 1, 2 or 14 or the adsorbent according to claim 15.

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