Hierarchical porous metal-organic framework materials, their preparation methods and applications

Abstract

This invention relates to the field of hydrogen sulfide adsorption, and discloses hierarchical porous metal-organic framework materials, their preparation methods, and applications. The materials comprise at least one bidentate organic carboxylic acid ligand and at least one coordination metal; wherein the coordination metal is selected from at least one of Al, Fe, Cr, Cu, Mg, and Co; wherein the materials simultaneously possess microporous and mesoporous structures; and wherein the BET specific surface area of ​​the materials is 400 m². 2 The multi-level porous MOFs material provided by this invention possesses both micropores and mesopores, exhibiting good stability. Compared to traditional MOFs materials, its dynamic adsorption capacity and adsorption rate for hydrogen sulfide are significantly improved. Furthermore, the preparation process of this material is simple, showing promise for large-scale production and application.

Description

Technical Field

[0001] This invention relates to the field of hydrogen sulfide adsorption, specifically to a hierarchical porous metal-organic framework material, a method for preparing the hierarchical porous metal-organic framework material, and the application of the hierarchical porous metal-organic framework material in the adsorption of hydrogen sulfide. Background Technology

[0002] Hydrogen sulfide is a colorless, highly toxic, and flammable acidic gas that has a rotten egg odor at extremely low concentrations. Hydrogen sulfide mixes with air to form an explosive mixture, and can ignite and explode upon contact with open flames or high heat. Industrially, hydrogen sulfide gas is mainly produced in oil and gas field extraction, natural gas and coalbed methane purification, and hydrodesulfurization processes in refining and chemical plants. Furthermore, due to its strong corrosive properties, it can easily damage industrial pipelines and equipment, leading to hydrogen sulfide leaks. Exposure to hydrogen sulfide concentrations of 5 ppm can cause damage to human organs, and exposure to concentrations of 1000 ppm can cause instantaneous death. Therefore, the emission of hydrogen sulfide must be strictly controlled in areas involving it.

[0003] Over the past decade, porous materials such as zeolites, silica gel, and activated carbon have been applied to desulfurization, demonstrating that the effectiveness of adsorption desulfurization is closely related to the adsorbent used. Subsequently, the development of metal-organic frameworks (MOFs) has further promoted research on nanoporous materials.

[0004] MOFs (Mesoporous Organic Forms) are a class of novel porous crystalline materials developed in recent years. They are constructed by covalent or ionic bonds between inorganic metal centers and organic functional groups in polydentate organic ligands of aromatic acids or bases, forming a regular pore structure. They are also known as porous coordination polymers. Compared to activated carbon and molecular sieves, MOFs have advantages such as high specific surface area, high porosity, and diverse framework structures, making them promising for applications in gas storage and separation. To date, most reported MOFs have microporous structures. Due to their large specific surface area and pore volume, they have significant advantages over traditional adsorbent materials (activated carbon, molecular sieves, etc.) in VOCs adsorption. However, micropores can restrict the diffusion and mass transfer rate of gas molecules, thus affecting their adsorption capacity. Studies have shown that mesoporous MOFs (such as MIL-101) have a stronger VOCs adsorption capacity than microporous MOFs (such as MOF-5 and MOF-177), and their mesoporous channels play a crucial role in the adsorption process. To improve the adsorption capacity of MOFs for gases, studying hierarchical MOFs with both micropores and mesopores plays an important role in enhancing the adsorption capacity of the materials. Summary of the Invention

[0005] The purpose of this invention is to overcome the problems existing in the prior art and provide a hierarchical porous metal-organic framework material, a method for preparing the hierarchical porous metal-organic framework material, and the application of the metal-organic framework material in the adsorption of hydrogen sulfide. The metal-organic framework material has micropores and mesopores, and has a higher dynamic adsorption capacity and adsorption rate for hydrogen sulfide.

[0006] To achieve the above objectives, the present invention provides a hierarchical porous metal-organic framework material, wherein the material comprises at least one bidentate organic carboxylic acid ligand and at least one coordination metal;

[0007] The coordinating metal is selected from at least one of Al, Fe, Cr, Cu, Mg and Co;

[0008] The material has both microporous and mesoporous structures.

[0009] The BET specific surface area of ​​the material is 400 m². 2 / g or more.

[0010] Preferably, the coordination metal is Al.

[0011] A second aspect of the present invention provides a method for preparing a hierarchical porous metal-organic framework material, the method comprising: dissolving a template agent and at least one bidentate organic carboxylic acid ligand in an organic solvent to obtain an organic phase;

[0012] An aqueous solution of a metal salt is mixed with the organic phase and reacted to obtain a metal-organic framework material;

[0013] The metal element in the metal salt is selected from at least one of Al, Fe and Cr.

[0014] A third aspect of the present invention provides a metal-organic framework material prepared by the method described above.

[0015] The fourth aspect of the present invention provides the application of the metal-organic framework material as described above in the adsorption of hydrogen sulfide.

[0016] The multi-level porous MOFs material provided by this invention has both micropores and mesopores, and has good chemical and thermal stability. Compared with traditional MOFs materials, its dynamic adsorption capacity and adsorption rate for hydrogen sulfide are significantly improved.

[0017] In addition, the preparation process of this material is simple, and it has the potential for large-scale production and application. Attached Figure Description

[0018] Figure 1 The adsorption isotherm of the hierarchical porous MOFs material prepared by the method described in Example 7 is shown.

[0019] Figure 2 This is the HK (Original) differential-integral pore volume pore size distribution diagram of the hierarchical porous MOFs material prepared by the method described in Example 7.

[0020] Figure 3 This is a BJH method (desorption) differential-integral pore volume pore size distribution diagram of the hierarchical porous MOFs material prepared by the method described in Example 7.

[0021] Figure 4 This is the adsorption-through curve of hydrogen sulfide in the hierarchical porous MOFs material prepared by the method described in Example 7. Detailed Implementation

[0022] 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.

[0023] The first aspect of the present invention provides a hierarchical porous metal-organic framework material, the material comprising at least one bidentate organic carboxylic acid ligand and at least one coordination metal;

[0024] The coordinating metal is selected from at least one of Al, Fe, Cr, Cu, Mg and Co;

[0025] The material has both microporous and mesoporous structures.

[0026] The BET specific surface area of ​​the material is 400 m². 2 / g or more.

[0027] The valence state of the coordinating metal can be its conventional valence state, such as preferably Al. 3+ Fe 3+ Cr 3+ Cu 2+ Mg 2+ Co 3+ .

[0028] Preferably, the coordinating metal is Al. In this preferred embodiment, the dynamic adsorption capacity and adsorption rate of hydrogen sulfide by the hierarchical porous MOFs material can be further improved.

[0029] Preferably, the organic carboxylic acid ligand is selected from one of 2-methylterephthalic acid, 2-aminoterephthalic acid, 2-nitroterephthalic acid, 2,3-dihydroxyterephthalic acid, terephthalic acid, and 2,5-thiophene dicarboxylic acid.

[0030] More preferably, the organic carboxylic acid ligand is 2-aminoterephthalic acid and / or 2,5-thiophene dicarboxylic acid. Even more preferably, the organic carboxylic acid ligand is 2,5-thiophene dicarboxylic acid.

[0031] Preferably, in the material, the molar ratio of the coordinating metal to the organic carboxylic acid ligand is 1-3:1, for example, it can be 1:1, 1.2:1, 1.4:1, 1.6:1, 1.8:1, 2:1, 2.2:1, 2.4:1, 2.6:1, 2.8:1, 3:1, or any range between any two values, preferably 1-2:1.

[0032] In a preferred embodiment of the present invention, the coordination metal is Al, the organic carboxylic acid ligand is 2,5-thiophene dicarboxylic acid, and the molar ratio of the coordination metal to the organic carboxylic acid ligand is 1-2:1.

[0033] Preferably, the pore size distribution of the micropores in the material is in the range of 0.45nm-0.75nm, more preferably 0.55nm-0.65nm.

[0034] Preferably, the pore size distribution range of the mesopores in the material is 2.1 nm-40 nm, more preferably 2.5 nm-10 nm.

[0035] Preferably, the BET specific surface area of ​​the material is 700 m². 2 / g or more, preferably 800-1200m 2 / g.

[0036] The specific surface area, pore volume, and pore size of the samples were determined using a BSD-PM2 specific surface area analyzer from Best Instruments Technology (Beijing) Co., Ltd. Approximately 100 mg of powder sample was weighed, degassed under vacuum at 150 °C for 12 h, and then molecularly analyzed using nitrogen as a probe at liquid nitrogen temperature (-196 °C) to obtain the corresponding data. Specifically, the isotherm of the material was determined using the dynamic volumetric method, the specific surface area was measured using the BET multi-point method, and the pore size distribution range of the micropores and mesopores was measured using the HK (Original) method and the BJH method, respectively.

[0037] A second aspect of the present invention provides a method for preparing a hierarchical porous metal-organic framework material, the method comprising: dissolving a template agent and at least one bidentate organic carboxylic acid ligand in an organic solvent to obtain an organic phase;

[0038] An aqueous solution of a metal salt is mixed with the organic phase and reacted to obtain a metal-organic framework material;

[0039] The metal element in the metal salt is selected from at least one of Al, Fe, Cr, Cu, Mg and Co.

[0040] In this invention, a template agent is used as a structure directing agent. Metal ions and organic carboxylic acid ligands coordinate on the surface of the template agent. After the reaction is completed, the template agent is removed to form MOFs containing hierarchical pores. Preferably, the template agent is selected from at least one of polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer (P123), dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride, hexadecyltrimethylammonium bromide (CTAB), benzoic acid, sodium dodecylbenzenesulfonate, hexadecyl bromide, diethanolamine, and N,N,N,N-tetramethylhexanediamine.

[0041] More preferably, the template agent is selected from at least one of P123, dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride, CTAB, benzoic acid, hexadecyl bromide, and N,N,N,N-tetramethylhexanediamine; even more preferably, the template agent is CTAB.

[0042] The template agents mentioned above are all commercially available.

[0043] Preferably, the organic carboxylic acid ligand is selected from one of 2-methylterephthalic acid, 2-aminoterephthalic acid, 2-nitroterephthalic acid, 2,3-dihydroxyterephthalic acid, terephthalic acid, and 2,5-thiophene dicarboxylic acid; more preferably, the organic acid ligand is 2-aminoterephthalic acid and / or 2,5-thiophene dicarboxylic acid, and even more preferably 2,5-thiophene dicarboxylic acid.

[0044] In this invention, the metal salt can be any water-soluble salt of the aforementioned metal ions. Preferably, the metal salt is selected from at least one of the chlorides, sulfates, nitrates, and acetates of a metal element, and more preferably, a chloride of a metal element. For example, the aluminum salt is at least one of aluminum trichloride, aluminum trichloride hexahydrate, aluminum nitrate, aluminum sulfate, and aluminum acetate; the iron salt is at least one of ferric trichloride, ferric trichloride hexahydrate, ferric sulfate, ferric nitrate, and ferric acetate; and the chromium salt is at least one of chromium trichloride, chromium sulfate, chromium nitrate, chromium acetate, chromium trichloride hexahydrate, chromium acetate dihydrate, chromium sulfate hydrate, chromium sulfate hexahydrate, and chromium nitrate trihydrate.

[0045] Preferably, the content of the metal salt in the aqueous solution is 5-50 g / L.

[0046] Preferably, the metallic element is Al.

[0047] Preferably, based on molar amounts, the molar ratio of the organic carboxylic acid ligand, the metal salt, and the template agent is 1:1-3 (e.g., it can be 1, 1.2, 1.4, 1.6, 1.8, 2, 2.2, 2.4, 2.6, 2.8, 3, or any range between any two values): 0.2-5 (e.g., it can be 0.2, 0.3, 0.5, 0.7, 0.9, 1, 1.2, 1.4, 1.6, 1.8, 2, 2.2, 2.4, 2.6, 2.8, 3, 3.5, 4, 4.5, 5, or any range between any two values), more preferably 1:1-2:0.5-2.

[0048] In this invention, the organic solvent can be a solvent capable of dissolving the template agent and the organic carboxylic acid ligand. Preferably, the organic solvent is selected from at least one of methanol, ethanol, N,N-dimethylformamide (DMF), dichloromethane and 1,2-dichloroethane, more preferably ethanol and / or DMF, and even more preferably DMF.

[0049] The ratio of water to organic solvent can be selected within a wide range. Preferably, the ratio of water to organic solvent by volume is 1:0.5-10, more preferably 1:1-5, and even more preferably 1:1.5-3.

[0050] Preferably, the reaction conditions include a temperature of 70-150°C and a time of 6-18 hours; more preferably, a temperature of 80-110°C and a time of 8-14 hours.

[0051] The reaction can be carried out in a conventional container, preferably in a pressure-resistant bottle.

[0052] The temperature can be achieved using an oil bath.

[0053] After the reaction is complete, the reaction products can be post-processed, such as purified. For example, the reaction products can be cooled to room temperature and then subjected to solid-liquid separation. The solid phase can be washed with a washing solvent to remove unreacted raw materials, resulting in purified products.

[0054] There are no particular restrictions on the type of washing solvent, as long as it can wash away unreacted substances without damaging the metal-organic framework material. The washing solvent can be at least one of water, DMF and ethanol, preferably DMF and / or ethanol.

[0055] Preferably, the method further includes: activating the metal-organic framework material before use.

[0056] Preferably, the activation conditions include: a temperature of 80-180℃ and a time of 6-24h.

[0057] More preferably, the activation conditions include: a temperature of 120-160°C and a time of 12-20 hours.

[0058] The activation can be carried out in a vacuum oven.

[0059] A third aspect of the present invention provides a metal-organic framework material prepared by the method described above.

[0060] The properties and related parameters of the metal-organic framework material are described in the first aspect.

[0061] The fourth aspect of the present invention provides the application of the metal-organic framework material as described above in the adsorption of hydrogen sulfide.

[0062] The present invention will be described in detail below through embodiments.

[0063] In the following examples, a multi-component adsorption breakthrough curve analyzer (BSD-MAB) was used to determine the breakthrough curve of the sample to hydrogen sulfide gas, and the amount of hydrogen sulfide adsorbed was calculated.

[0064] The specific operating procedure is as follows: First, weigh approximately 50 mg of sample and activate it at 150℃ for 3 hours to remove impurity gases from the sample surface. After pretreatment, load the sample into a permeation column. Place the permeation column in a 25℃ constant temperature water bath. After the test environment stabilizes, begin the permeation experiment to test the adsorption permeation curve of 100 ppm hydrogen sulfide and calculate the adsorption amount.

[0065] The adsorption capacity of each component is calculated using the following formula:

[0066]

[0067] Note: This calculation formula takes into account the concentration changes caused by real-time changes in the outlet flow rate due to adsorption, which improves the accuracy of calculating the adsorption amount by concentration integral and has no approximation.

[0068] Q n吸附 Adsorption capacity of the adsorbent for adsorbate n (unit: mL)

[0069] Q n入总 Total flow rate of adsorbate n into the breakthrough column over time ΔT (unit: mL)

[0070] Q n出总 : Total flow rate of adsorbate n through the column during time ΔT (unit: mL)

[0071] q 总入 Total gas velocity at the inlet of the penetration column (unit: mL / min)

[0072] q 载气 Carrier gas flow rate (unit: mL / min)

[0073] C n0 : Percentage concentration (%) of adsorbate n at the inlet of the permeation column

[0074] C nt : Percentage concentration (%) of adsorbate n at the outlet of the permeation column at a certain moment.

[0075] ΔT: Total duration of adsorption from start to finish (in seconds)

[0076] Example 1

[0077] Weigh 3.0 mmol (453 mg) of the metal salt AlCl3·6H2O and add it to a beaker containing 5 mL of water. Disperse the solution uniformly by sonication at room temperature. Weigh 2.0 mmol (728 mg) of CTAB and 2,5-thiophene dicarboxylic acid (2.0 mmol (344 mg) and add them to a beaker containing 10 mL of DMF. Disperse the solution uniformly by sonication. Add the metal salt solution, the mixed solution of the organic ligand and the template agent to a pressure-resistant bottle, mix thoroughly, seal, and place in an oil bath. Heat at 100 °C for 9 h. After the reaction is complete, a suspension is obtained. After the reaction system cools to room temperature, the solid product is obtained by centrifugation. Wash the obtained sample twice with DMF to remove unreacted organic ligands and metal salt. Then, place the solid powder in ethanol and wash under reflux three times to remove the high-boiling-point solvent. Finally, the washed solid was placed in a vacuum oven and heated at 160°C for 16 hours to activate it, thus obtaining the hierarchical porous MOF material. Its structural information and adsorption performance are shown in Table 1.

[0078] Example 2

[0079] The procedure was performed according to the method described in Example 1, except that the volume of DMF was 20 mL.

[0080] The structural information and adsorption properties of the obtained hierarchical porous MOFs materials are shown in Table 1.

[0081] Example 3

[0082] The procedure was performed according to the method described in Example 1, except that the volume of DMF was 5 mL.

[0083] The structural information and adsorption properties of the obtained hierarchical porous MOFs materials are shown in Table 1.

[0084] Example 4

[0085] The procedure was performed according to the method described in Example 1, except that the amount of CTAB used was 4.0 mmol, or 1456 mg.

[0086] The structural information and adsorption properties of the obtained hierarchical porous MOFs materials are shown in Table 1.

[0087] Example 5

[0088] The procedure was performed according to the method described in Example 1, except that the amount of CTAB used was 1.4 mmol, or 510 mg.

[0089] The structural information and adsorption properties of the obtained hierarchical porous MOFs materials are shown in Table 1.

[0090] Example 6

[0091] The procedure was performed according to the method described in Example 1, except that the amount of CTAB used was 1.0 mmol, or 364 mg.

[0092] The structural information and adsorption properties of the obtained hierarchical porous MOFs materials are shown in Table 1.

[0093] Example 7

[0094] The procedure was performed according to the method described in Example 1, except that the amount of CTAB used was 6.0 mmol, or 2184 mg.

[0095] The structural information and adsorption properties of the obtained hierarchical porous MOFs materials are shown in Table 1.

[0096] Comparative Example 1

[0097] Weigh 3.0 mmol (453 mg) of metal salt AlCl3·6H2O and add it to a beaker containing 5 mL of water. Stir well at room temperature. Weigh 2.0 mmol (344 mg) of 2,5-thiophene dicarboxylic acid and add it to a beaker containing 10 mL of DMF. Stir well at room temperature. Add the solutions of metal salt and 2,5-thiophene dicarboxylic acid to a pressure-resistant bottle, seal it, and place it in an oil bath. Heat at 100 °C for 6 h. After the reaction is complete, a suspension is obtained. After the reaction system cools to room temperature, the solid product is obtained by centrifugation. Wash the obtained sample twice with DMF to remove unreacted organic ligands and metal salt. Then, place the solid powder in ethanol and heat under reflux for three times to remove high-boiling-point solvents. Finally, place the washed solid in a vacuum oven and heat at 140 °C for 16 h to activate it, thus obtaining the microporous MOF material. Its structural information and adsorption properties are shown in Table 1.

[0098] Example 8

[0099] Weigh 2.0 mmol (302 mg) of the metal salt AlCl3·6H2O and add it to a beaker containing 5 mL of water. Disperse the solution evenly by sonication at room temperature. Weigh 2.0 mmol (728 mg) of CTAB and 2,5-thiophene dicarboxylic acid (2.0 mmol (344 mg) and add them to a beaker containing 10 mL of DMF. Disperse the solution evenly by sonication. Add the metal salt solution, the mixed solution of the organic ligand and the template agent to a pressure-resistant bottle, mix thoroughly, seal, and place in an oil bath. Heat at 100 °C for 8 h. After the reaction is complete, a suspension is obtained. After the reaction system cools to room temperature, the solid product is obtained by centrifugation. Wash the obtained sample twice with DMF to remove unreacted organic ligands and metal salt. Then, place the solid powder in ethanol and wash under reflux three times to remove the high-boiling-point solvent. Finally, the washed solid was placed in a vacuum oven and heated at 120°C for 13 hours to activate it, thus obtaining the hierarchical porous MOF material. Its structural information and adsorption performance are shown in Table 1.

[0100] Example 9

[0101] The procedure was performed according to the method described in Example 8, except that the volume of DMF was 5 mL.

[0102] The structural information and adsorption properties of the obtained hierarchical porous MOFs materials are shown in Table 1.

[0103] Example 10

[0104] The procedure was performed according to the method described in Example 8, except that the volume of DMF was 25 mL.

[0105] The structural information and adsorption properties of the obtained hierarchical porous MOFs materials are shown in Table 1.

[0106] Example 11

[0107] The procedure was performed according to the method described in Example 8, except that the amount of CTAB used was 4.0 mmol, or 1456 mg.

[0108] The structural information and adsorption properties of the obtained hierarchical porous MOFs materials are shown in Table 1.

[0109] Example 12

[0110] The procedure was performed according to the method described in Example 8, except that the amount of CTAB used was 6.0 mmol, or 2184 mg.

[0111] The structural information and adsorption properties of the obtained hierarchical porous MOFs materials are shown in Table 1.

[0112] Comparative Example 2

[0113] Weigh 2.0 mmol (302 mg) of metal salt AlCl3·6H2O and add it to a beaker containing 5 mL of water. Stir well at room temperature. Weigh 2.0 mmol (344 mg) of 2,5-thiophene dicarboxylic acid and add it to a beaker containing 10 mL of DMF. Stir well at room temperature. Add the solutions of metal salt and 2,5-thiophene dicarboxylic acid to a pressure-resistant bottle, seal it, and place it in an oil bath. Heat at 90 °C for 7 h. After the reaction is complete, a suspension is obtained. After the reaction system cools to room temperature, the solid product is obtained by centrifugation. Wash the obtained sample twice with DMF to remove unreacted organic ligands and metal salt. Then, place the solid powder in ethanol and heat under reflux for three times to remove high-boiling-point solvents. Finally, place the washed solid in a vacuum oven and heat at 120 °C for 13 h to activate it, thus obtaining the microporous MOF material. Its structural information and adsorption properties are shown in Table 1.

[0114] Comparative Example 3

[0115] Weigh 2.0 mmol (302 mg) of metal salt AlCl3·6H2O and add it to a beaker containing 10 mL of DMF. Stir well at room temperature. Weigh 2.0 mmol (344 mg) of 2,5-thiophene dicarboxylic acid and add it to a beaker containing 5 mL of DMF. Stir well at room temperature. Add the solutions of metal salt and 2,5-thiophene dicarboxylic acid to a pressure-resistant bottle, seal it, and place it in an oil bath. Heat at 90 °C for 7 h. After the reaction is complete, a suspension is obtained. After the reaction system cools to room temperature, the solid product is obtained by centrifugation. Wash the obtained sample twice with DMF to remove unreacted organic ligands and metal salt. Then, place the solid powder in ethanol and heat under reflux for three times to remove high-boiling-point solvents. Finally, place the washed solid in a vacuum oven and heat at 120 °C for 13 h to activate it, thus obtaining the microporous MOF material. Its structural information and adsorption properties are shown in Table 1.

[0116] Example 13

[0117] Weigh 4.0 mmol (604 mg) of the metal salt AlCl3·6H2O and add it to a beaker containing 5 mL of water. Disperse the solution uniformly by sonication at room temperature. Weigh 2.0 mmol (728 mg) of CTAB and 2,5-thiophene dicarboxylic acid (2.0 mmol (344 mg) and add them to a beaker containing 10 mL of DMF. Disperse the solution uniformly by sonication. Add the metal salt solution, the mixed solution of the organic ligand and the template agent to a pressure-resistant bottle, mix thoroughly, seal, and heat in an oil bath at 100 °C for 9 h. After the reaction is complete, a suspension is obtained. After the reaction system cools to room temperature, the solid product is obtained by centrifugation. Wash the obtained sample twice with DMF to remove unreacted organic ligands and metal salt. Then, place the solid powder in ethanol and wash it three times under reflux to remove the high-boiling-point solvent. Finally, the washed solid was placed in a vacuum oven and heated at 150°C for 12 hours to activate it, thus obtaining the hierarchical porous MOF material. Its structural information and adsorption properties are shown in Table 1.

[0118] Example 14

[0119] The procedure was performed according to the method described in Example 13, except that the volume of DMF was 5 mL.

[0120] The structural information and adsorption properties of the obtained hierarchical porous MOFs materials are shown in Table 1.

[0121] Example 15

[0122] The procedure was performed according to the method described in Example 13, except that the volume of DMF was 25 mL.

[0123] The structural information and adsorption properties of the obtained hierarchical porous MOFs materials are shown in Table 1.

[0124] Example 16

[0125] The procedure was performed according to the method described in Example 13, except that the amount of CTAB used was 4.0 mmol, or 1456 mg.

[0126] The structural information and adsorption properties of the obtained hierarchical porous MOFs materials are shown in Table 1.

[0127] Comparative Example 4

[0128] Weigh 4.0 mmol (604 mg) of metal salt AlCl3·6H2O and add it to a beaker containing 5 mL of water. Stir well at room temperature. Weigh 2.0 mmol (344 mg) of 2,5-thiophene dicarboxylic acid and add it to a beaker containing 10 mL of DMF. Stir well at room temperature. Add the solutions of metal salt and 2,5-thiophene dicarboxylic acid to a pressure-resistant bottle, seal it, and place it in an oil bath. Heat at 100 °C for 7 h. After the reaction is complete, a suspension is obtained. After the reaction system cools to room temperature, the solid product is obtained by centrifugation. Wash the obtained sample twice with DMF to remove unreacted organic ligands and metal salt. Then, place the solid powder in ethanol and heat under reflux for three times to remove high-boiling-point solvents. Finally, place the washed solid in a vacuum oven and heat at 160 °C for 12 h to activate it, thus obtaining the microporous MOF material. Its structural information and adsorption properties are shown in Table 1.

[0129] Table 1

[0130]

[0131]

[0132] Examples 17-18

[0133] The procedure is performed according to the method described in Example 1, except that the type of template agent used is different, as detailed in Table 2.

[0134] The structural information and adsorption properties of the obtained hierarchical porous MOFs materials are shown in Table 2.

[0135] Table 2

[0136] Example template agent <![CDATA[Specific surface area (m 2 / g)]]> Aperture distribution (nm) Hydrogen sulfide adsorption capacity (mL / g) 17 P123 615 0.60,18.35 263 18 Sodium dodecylbenzenesulfonate 717 0.61,21.12 286

[0137] in, Figure 1 This is the adsorption isotherm of the hierarchical porous MOFs material prepared by the method described in Example 7; Figure 2 This is a diagram of the HK (Original) differential-integral pore volume and pore size distribution of the hierarchical porous MOFs material prepared by the method described in Example 7; Figure 3 This is a BJH method (desorption) differential-integral pore volume pore size distribution diagram of the hierarchical porous MOFs material prepared by the method described in Example 7; Figure 4 This is the adsorption-through curve of hydrogen sulfide in the hierarchical porous MOFs material prepared by the method described in Example 7.

[0138] The results in Table 1 show that adding the template agent CTAB can induce the formation of mesoporous channels in MOFs, while simultaneously reducing some specific surface area. The pore size can be controlled by adjusting the solvent ratio; increasing the proportion of DMF causes the mesoporous pore size to first expand and then shrink.

[0139] In addition, the addition ratio of metal salts, organic ligands and template agents all affect the specific surface area and pore size of MOFs. Increasing the amount of template agent or organic ligand increases the specific surface area and mesopore size of MOF materials accordingly. After reaching the optimal ratio, further increasing the amount of template agent or organic ligand will have a negative impact on the specific surface area and mesopore size.

[0140] Finally, both pore size and specific surface area affect the amount of hydrogen sulfide adsorbed. Under the condition of comparable specific surface area, a larger pore size is beneficial to increasing the dynamic adsorption of hydrogen sulfide; when the pore size is comparable, the specific surface area is the most important factor affecting the dynamic adsorption of hydrogen sulfide.

[0141] A comparison of the data in Tables 1 and 2 shows that different template agents affect both the pore size and the adsorption capacity for hydrogen sulfide in porous MOFs materials. When CTAB is preferred as the template agent, the prepared porous MOFs are more suitable for the adsorption of hydrogen sulfide.

[0142] Furthermore, the hierarchical porous MOFs material provided by this invention exhibits good chemical and thermal stability and can be stably stored in air for a long time. Moreover, compared to traditional MOFs materials, its adsorption rate for hydrogen sulfide is significantly improved.

[0143] 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 hierarchically porous metal-organic framework material, characterized in that, The material comprises at least one bidentate organic carboxylic acid ligand and at least one coordination metal; The coordination metal is Al; and the organic carboxylic acid ligand is 2,5-thiophenedicarboxylic acid. The material has both microporous and mesoporous structures; the micropores have a pore size distribution range of 0.45-0.75 nm; and the mesopores have a pore size distribution range of 2.1-40 nm. wherein the material has a BET specific surface area of 400 m 2 / g or more.

2. The material of claim 1, wherein, The molar ratio of the coordination metal to the organic carboxylic acid ligand in the material is 1-3:

1.

3. The material of claim 2, wherein, The molar ratio of the coordination metal to the organic carboxylic acid ligand in the material is 1-2:

1.

4. The material according to any one of claims 1 to 3, wherein, The BET specific surface area of the material is 700 m 2 / g or more.

5. The material of claim 4, wherein, The micropores have a pore size distribution range of 0.55-0.65 nm; and / or The mesopores have a pore size distribution range of 2.5-10 nm; and / or The BET specific surface area of the material is 800-1200 m 2 / g.

6. A method for preparing a hierarchical porous metal organic framework material, characterized in that, The method comprises: dissolving a template agent and at least one bidentate organic carboxylic acid ligand in an organic solvent to obtain an organic phase; Mixing an aqueous solution of a metal salt with the organic phase and reacting to obtain a metal organic framework material; The metal element in the metal salt is Al, the template agent is CTAB, and the bidentate organic acid ligand is 2,5-thiophenedicarboxylic acid.

7. The method of claim 6, wherein, The organic solvent is selected from at least one of methanol, ethanol, N,N-dimethylformamide (DMF), dichloromethane and 1,2-dichloroethane.

8. The method of claim 7, wherein, The organic solvent is ethanol and / or DMF.

9. The method of claim 8, wherein, The organic solvent is DMF.

10. The method of claim 6, wherein, The metal salt is selected from at least one of chlorides, sulfates, nitrates and acetates of the metal element.

11. The method of claim 10, wherein, The metal salt is a chloride of the metal element; and / or The content of the metal salt in the aqueous solution of the metal salt is 5-50 g / L.

12. The method of any of claims 6-11, wherein, The molar ratio of the amount of the organic carboxylic acid ligand, the metal salt and the template agent is 1:1-3:0.2-5 on the basis of molar amount.

13. The method of claim 12, wherein, The molar ratio of the amount of the organic carboxylic acid ligand, the metal salt and the template agent is 1:1-2:0.5-2 on the basis of molar amount.

14. The method of any one of claims 6-11, wherein, The amount ratio of water to the organic solvent is 1:0.5-10 by volume.

15. The method of claim 14, wherein, The amount ratio of water to the organic solvent is 1:1-5 by volume.

16. The method of claim 15, wherein, The amount ratio of water to the organic solvent is 1:1.5-3 by volume.

17. The method of any one of claims 6-11, wherein, The reaction conditions include a temperature of 70-150°C and a time of 6-18 h.

18. The method of claim 17, wherein, The reaction conditions include a temperature of 80-110°C and a time of 8-14 h; and / or The reaction is carried out in a pressure-resistant bottle.

19. The method of any one of claims 6-11, wherein, The method further comprises: activating the metal organic framework material before use.

20. The method of claim 19, wherein, The activation conditions include a temperature of 80-180°C and a time of 6-24 h.

21. The method of claim 20, wherein, The activation conditions include a temperature of 120-160°C and a time of 12-20 h.

22. The metal organic framework material prepared by the method according to any one of claims 6-21.

23. Use of the metal organic framework material according to any one of claims 1-5 and 22 for adsorbing hydrogen sulfide.

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