Method for rapidly preparing large-scale metal organic framework materials by using electron beam irradiation technology

Abstract

The invention discloses a method for realizing large-scale rapid synthesis of a metal organic framework by using an electron beam irradiation technology, and belongs to the technical field of radiation chemistry and porous material preparation. Under the conditions of normal temperature and normal pressure, metal salt and a corresponding organic ligand are added into an organic solvent and are mixed according to a set proportion; then, electron beam irradiation is directly accepted, so that the system completes coordination polymerization reaction within a second level, and the efficient large-scale preparation of the metal organic framework material is realized. According to the method, pH adjustment and use of a high-temperature and high-pressure reaction kettle are not needed, the reaction condition is mild, a large-volume precursor system can be continuously treated, and the actual productivity of the metal organic framework is remarkably improved. The method disclosed by the invention has the remarkable advantages of high reaction speed, low energy consumption, simplified process, high yield, capability of realizing gram-level and larger-scale continuous synthesis and the like, and a brand-new technical route is provided for industrialization and green manufacturing of the metal organic framework material.

Description

Technical Field

[0001] This invention belongs to the field of radiation chemistry and porous material preparation technology, specifically relating to a method for rapidly preparing large quantities of metal-organic framework materials using electron beam irradiation technology. Background Technology

[0002] Metal-organic frameworks (MOFs) are a class of highly ordered porous crystalline materials composed of metal ions or metal clusters linked to multidentate organic ligands via coordination bonds. They possess advantages such as large specific surface area, tunable pore size, and diverse structures, exhibiting significant advantages in fields such as gas adsorption and separation, hydrogen and methane storage, catalysis, drug delivery, and sensing. With the rapid growth in application demands, the large-scale, rapid, and green preparation technology of MOFs has become an important research direction in this field.

[0003] Currently, traditional methods for preparing metal-organic frameworks mainly include solvothermal methods, atmospheric pressure heating methods, microwave methods, and mechanochemical methods. Among these, the solvothermal method is widely used due to its mature operation, but it typically requires high temperatures and pressures, long reaction times, and relies on pressure vessels such as closed reactors, which is not conducive to continuous and large-scale production. In addition, the use of large amounts of organic solvents in the solvothermal method leads to environmental burden and increases the cost of material separation and purification. The microwave method can accelerate the reaction to some extent, but its applicability is limited by the dielectric properties of the reaction system, which is not conducive to generalization and expansion. The mechanochemical method reduces the use of solvents, but it is sensitive to equipment conditions and reactant ratios, making large-scale scale-up difficult.

[0004] To address the aforementioned issues, radiation chemistry has gradually attracted attention in recent years. Electron beam irradiation possesses advantages such as high energy deposition density, fast reaction rate, ability to be carried out at room temperature and pressure, and no need for pressure vessels. It can effectively excite active species in solution systems and promote the rapid coordination and combination of metal ions and organic ligands, providing new possibilities for the rapid generation of metal-organic frameworks. However, existing reports mostly focus on exploratory studies with small sample sizes in the laboratory, and systematic methods for the preparation of metal-organic frameworks at the gram scale or even larger scales are still lacking. At the same time, how to achieve uniform irradiation, control the crystallization process, and ensure the crystallization quality and phase purity of the product in a large-volume precursor system remains an important technical challenge in this field.

[0005] Therefore, there is an urgent need to develop a novel electron beam irradiation synthesis method that can operate efficiently under ambient temperature and pressure conditions, is suitable for large-scale metal-organic framework (MOF) preparation at the gram level and above, and simultaneously possesses the characteristics of being green and having a high space-time yield (STY). This technology can not only shorten reaction time and reduce energy consumption, but also overcome the scale-up limitations of traditional solvothermal preparation, providing a feasible technical path for the industrial production of MOFs. Summary of the Invention

[0006] To address the above problems, this invention provides a method for the rapid, large-scale synthesis of metal-organic frameworks using electron beam irradiation technology.

[0007] To achieve the above-mentioned objectives, the technical solution adopted by this invention is as follows: A method for rapidly preparing large quantities of metal-organic framework materials using electron beam irradiation technology includes the following steps: 1) The metal salt and organic ligand used for the preparation of metal-organic framework materials are mixed in an organic solvent system to obtain a reaction solution; 2) The reaction solution was irradiated with an electron beam at room temperature and pressure to obtain the reaction product. After the reaction was completed, the reaction product was mixed with N,N-dimethylformamide for activation treatment. The activated product was washed and dried to finally obtain the metal-organic framework material.

[0008] The metal-organic framework materials include copper-based metal-organic framework materials, zirconium-based metal-organic framework materials, iron-based metal-organic framework materials, cobalt-based metal-organic framework materials, rare earth-based metal-organic framework materials, and zinc-based metal-organic framework materials.

[0009] The metal-organic framework materials prepared by the method described above include HKUST-1, MOF-76, ZIF-8, ZIF-67, Cu-BDC, Cu-NDC, MOF-74, UIO-66, MIL-101, NU-1000, and ZIF-7.

[0010] In the preparation method described above, the organic solvent system in step S1 includes a main solvent and an auxiliary solvent, the amount of the auxiliary solvent is ≥0, the main solvent is N,N-dimethylformamide, and the auxiliary solvent is selected from one or more combinations of methanol, ethanol or water.

[0011] The preparation method described above uses copper acetate and copper nitrate as metal salts for preparing HKUST-1, and 1,3,5-benzenetricarboxylic acid as the organic ligand.

[0012] In the preparation method described above, the molar ratio of the metal salt to the organic ligand of HKUST-1 is (1-1.5):1.

[0013] As described above, the organic solvent system of HKUST-1 includes N,N-dimethylformamide, deionized water, and anhydrous ethanol.

[0014] As described above, the electron beam irradiation dose required for HKUST-1 is 60kGy-270kGy.

[0015] In the preparation method described above, the activation temperature of HKUST-1 is 10-20℃, and the activation time is 1-2h.

[0016] The preparation method described above, which involves mixing the reaction product with N,N-dimethylformamide and performing an activation treatment, includes the following steps: centrifuging the reaction product, removing the supernatant, mixing the reaction product with the N,N-dimethylformamide, and performing an activation treatment.

[0017] The washing solvent for the activated product includes anhydrous ethanol, methanol, acetone, and ethyl acetate, preferably anhydrous ethanol.

[0018] As a further technical solution, the metal salt used to prepare the ZIF-8 is zinc nitrate hexahydrate, and the organic ligand is 2-methylimidazole.

[0019] In the preparation method described above, the molar ratio of the metal salt to the organic ligand of ZIF-8 is (0.5-2.2):1.

[0020] As described above, the organic solvent system of ZIF-8 includes N,N-dimethylformamide.

[0021] As described above, the electron beam irradiation dose required for the ZIF-8 is 60kGy-270kGy, preferably 270kGy.

[0022] In the preparation method described above, the activation temperature of ZIF-8 is 10-20 °C, and the activation time is 1-2 h.

[0023] The preparation method described above, which involves mixing the reaction product with N,N-dimethylformamide and performing an activation treatment, includes the following steps: centrifuging the reaction product, removing the supernatant, mixing the reaction product with the N,N-dimethylformamide, and performing an activation treatment.

[0024] Activation treatment can wash away excess impurities in MOF materials, opening up their pores and improving their performance.

[0025] In the preparation method described above, the washing solvent for the activated product includes anhydrous ethanol, methanol, acetone, and ethyl acetate, preferably anhydrous ethanol.

[0026] Due to the adoption of the above technical solution, the technical effects achieved by the present invention are as follows: This invention provides a method for the rapid, high-volume synthesis of metal-organic frameworks (MOFs) using electron beam irradiation. By optimizing the precursor composition, irradiation conditions, and post-processing, rapid crystallization at ambient temperature and pressure is achieved, significantly reducing energy consumption and environmental burden. This method is applicable to large-scale MOF preparation at the gram level and above, and is a novel electron beam irradiation synthesis method that combines green technology with high space-time yield (STY). Provided the solvent is sufficiently capable of dissolving the metal salt and organic ligand, the reaction can be scaled up to the kg level. This method eliminates the need for pH adjustment and high-temperature, high-pressure reactors, offering mild reaction conditions and enabling continuous processing of large-volume precursor systems, significantly improving the actual production capacity of MOFs. This technology not only shortens reaction time and reduces energy consumption but also overcomes the scale-up limitations of traditional solvothermal preparations, providing a feasible technical path for the industrial production of MOFs.

[0027] The method of this invention has significant advantages such as fast reaction speed, low energy consumption, simplified process, high yield, and the ability to achieve continuous synthesis at the gram level and on a larger scale, providing a brand-new technical route for the industrialization and green manufacturing of metal-organic framework materials.

[0028] Compared with traditional solvothermal methods, the reaction time of this invention can be shortened to 1 / 5760-1 / 2880, significantly reducing energy consumption and waste gas treatment volume. This method is applicable to various metal-organic framework systems, achieving stable yields of 75%-99%, and has been successfully scaled up to gram levels and above. The actual yield of HKUST-1 was 63.38 g, and the actual yield of ZIF-8 was 44.95 g, both exhibiting good crystallinity and stability. Attached Figure Description

[0029] Figure 1 These are microscope images of the HKUST-1 material prepared in Examples 1 and 2 of this invention; Figure 2 These are microscope images of the ZIF-8 materials prepared in Examples 3 and 4 of this invention; Figure 3 The X-ray diffraction patterns are those of the metal-organic framework materials prepared in Examples 2 and 4 of this invention. Figure 4 The X-ray diffraction patterns of the ZIF-8 material prepared in Examples 5 and 6 of this invention are shown below. Figure 5 The X-ray diffraction patterns of the HKUST-1 material prepared in Examples 7 and 8 of this invention are shown below. Figure 6 The figure shows the experimental results of static adsorption of iodine vapor in the test examples of this invention. Detailed Implementation

[0030] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below. The specific embodiments listed below are merely descriptions of the principles and features of the present invention, and the examples are only for explaining the present invention and are not intended to limit the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] The technical solution of the present invention will be further described in detail below with reference to the embodiments of the present invention, but the present invention is not limited to the following embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the protection scope of the present invention.

[0032] This invention provides a method for the rapid, large-scale synthesis of metal-organic frameworks using electron beam irradiation technology, comprising the following steps: 1) The metal salt and organic ligand used for the preparation of metal-organic framework materials are mixed in an organic solvent to obtain a reaction solution; 2) The reaction solution was irradiated with an electron beam at room temperature and pressure to obtain the reaction product. After the reaction was completed, the reaction product was mixed with N,N-dimethylformamide for activation treatment. The activated product was washed and dried to finally obtain the metal-organic framework material.

[0033] The metal-organic framework materials described in this embodiment of the invention include HKUST-1 and ZIF-8.

[0034] Unless otherwise specified, the present invention does not have any special limitation on the source of the components, and commercially available products well known to those skilled in the art can be used.

[0035] To clearly and comprehensively illustrate the technical solution of the present invention, a detailed description will be provided below in conjunction with specific embodiments of the present invention. It should be understood that the embodiments described herein cover only a part of the embodiments of the present invention, and not all of them. Based on these embodiments provided by the present invention, all other embodiments that can be obtained by those skilled in the art without creative effort also fall within the protection scope of the present invention.

[0036] Example 1 This invention provides a method for the rapid, large-scale synthesis of metal-organic frameworks using electron beam irradiation technology, comprising the following steps: (1) Dissolve 12.05 g of copper acetate monohydrate and 12.59 g of 1,3,5-benzenetricarboxylic acid in 333 mL of N,N-dimethylformamide, 333 mL of anhydrous ethanol and 333 mL of deionized water.

[0037] (2) Place the dissolved reaction solution in a corrosion-resistant homogenizing bag and irradiate the reaction solution obtained in step (1) with an electron beam dose of 270 kGy. Then, take out the reactants, centrifuge, take out the supernatant, activate the reactants with 100 mL of N,N-dimethylformamide for 1 h, and finally wash with 100 mL of anhydrous ethanol and dry to obtain the final product HKUST-1 (yield: 99.75%).

[0038] Example 2 A method for preparing the copper-based metal-organic framework material HKUST-1 using electron beam irradiation technology, comprising the following steps: (1) Dissolve 63.255 g of copper acetate monohydrate and 44.3 g of 1,3,5-benzenetricarboxylic acid in 600 mL of N,N-dimethylformamide, 600 mL of anhydrous ethanol and 600 mL of deionized water.

[0039] (2) Place the dissolved reaction solution in a corrosion-resistant homogenizing bag and irradiate the reaction solution obtained in step (1) with an electron beam dose of 270 kGy. Then, take out the reactants, centrifuge, take out the supernatant, activate the reactants with 300 mL of N,N-dimethylformamide for 1 h, and finally wash with 300 mL of anhydrous ethanol and dry to obtain the final product HKUST-1 (yield: 99.34%).

[0040] Example 3 A method for preparing zinc-based metal-organic framework material ZIF-8 using electron beam irradiation technology, comprising the following steps: (1) Dissolve 40.34 g of zinc nitrate hexahydrate and 12.58 g of 2-methylimidazole in 1200 mL of N,N-dimethylformamide.

[0041] (2) Place the dissolved reaction solution in a corrosion-resistant homogenizing bag and irradiate the reaction solution obtained in step (1) with an electron beam dose of 270 kGy. Then, take out the reactants, centrifuge, take out the supernatant, activate the reactants with 100 mL of N,N-dimethylformamide for 1 h, and finally wash with 100 mL of anhydrous ethanol and dry to obtain the final product ZIF-8 (yield: 71.67%).

[0042] Example 4 A method for preparing ZIF-8 using electron beam irradiation technology, comprising the following steps: (1) Dissolve 78.4 g of zinc nitrate hexahydrate and 60 g of 2-methylimidazole in 1800 mL of N,N-dimethylformamide.

[0043] (2) Place the dissolved reaction solution in a corrosion-resistant homogenizing bag and irradiate the reaction solution obtained in step (1) with an electron beam dose of 270 kGy. Then, take out the reactants, centrifuge, take out the supernatant, activate the reactants with 300 mL of N,N-dimethylformamide for 1 h, and finally wash with 300 mL of anhydrous ethanol and dry to obtain the final product ZIF-8 (yield: 75%).

[0044] Table 1. Reaction yields of Examples 1-4

[0045] Example 5 A method for preparing ZIF-8 using electron beam irradiation technology, comprising the following steps: (1) Dissolve 78.4 g of zinc nitrate hexahydrate and 60 g of 2-methylimidazole in 1800 mL of N,N-dimethylformamide.

[0046] (2) Place the dissolved reaction solution in a corrosion-resistant homogenizing bag and irradiate the reaction solution obtained in step (1) with an electron beam dose of 60 kGy. Then, take out the reactants, centrifuge, take out the supernatant, activate the reactants with 300 mL of N,N-dimethylformamide for 1 h, and finally wash with 300 mL of anhydrous ethanol and dry to obtain the final product ZIF-8 (yield: 28.67%).

[0047] Example 6 A method for preparing ZIF-8 using electron beam irradiation technology, comprising the following steps: (1) Dissolve 78.4 g of zinc nitrate hexahydrate and 60 g of 2-methylimidazole in 1800 mL of N,N-dimethylformamide.

[0048] (2) Place the dissolved reaction solution in a corrosion-resistant homogenizing bag and irradiate the reaction solution obtained in step (1) with an electron beam dose of 180 kGy. Then, take out the reactants, centrifuge, take out the supernatant, activate the reactants with 300 mL of N,N-dimethylformamide for 1 h, and finally wash with 300 mL of anhydrous ethanol and dry to obtain the final product ZIF-8 (yield: 42.07%).

[0049] Example 7 A method for preparing HKUST-1 using electron beam irradiation technology, comprising the following steps: (1) Dissolve 63.255 g of copper acetate monohydrate and 44.3 g of 1,3,5-benzenetricarboxylic acid in 600 mL of N,N-dimethylformamide, 600 mL of anhydrous ethanol and 600 mL of deionized water.

[0050] (2) Place the dissolved reaction solution in a corrosion-resistant homogenizing bag and irradiate the reaction solution obtained in step (1) with an electron beam dose of 60 kGy. Then, take out the reactants, centrifuge, take out the supernatant, activate the reactants with 300 mL of N,N-dimethylformamide for 1 h, and finally wash with 300 mL of anhydrous ethanol and dry to obtain the final product HKUST-1 (yield: 99.26%).

[0051] Example 8 A method for preparing HKUST-1 using electron beam irradiation technology, comprising the following steps: (1) Dissolve 63.255 g of copper acetate monohydrate and 44.3 g of 1,3,5-benzenetricarboxylic acid in 600 mL of N,N-dimethylformamide, 600 mL of anhydrous ethanol and 600 mL of deionized water.

[0052] (2) Place the dissolved reaction solution in a corrosion-resistant homogenizing bag and irradiate the reaction solution obtained in step (1) with an electron beam dose of 180 kGy. Then, take out the reactants, centrifuge, take out the supernatant, activate the reactants with 300 mL of N,N-dimethylformamide for 1 h, and finally wash with 300 mL of anhydrous ethanol and dry to obtain the final product HKUST-1 (yield: 99.54%).

[0053] The HKUST-1 and ZIF-8 materials prepared in Examples 1-8 were subjected to performance tests, such as... Figure 1 , 2 Images of the materials prepared in Examples 1-4 under a microscope. Figure 3 The X-ray diffraction patterns are those of the metal-organic framework materials prepared in Examples 2 and 4. Figure 4 , 5 X-ray diffraction patterns of the materials prepared in Examples 5-8.

[0054] Experimental Example: Static Adsorption of Iodine Vapor Materials used in the experiment: HKUST-1 and ZIF-8 materials prepared in this application, and HKUST-1 and ZIF-8 materials prepared by conventional methods. HKUST-1 and ZIF-8 materials prepared by conventional methods were prepared by solvothermal synthesis, as follows: Dissolution: The metal salt and organic ligand are dissolved separately in a specific solvent; Mixing: Mix the two solutions thoroughly to form a precursor solution; Heating: Transfer the mixture to a polytetrafluoroethylene-lined autoclave and place it in an oven for heating; Cooling and Collection: Allow to cool naturally to room temperature, then collect the solids by centrifugation or filtration; Washing and activation: Wash repeatedly with fresh solvent (such as ethanol) to remove unreacted raw materials, and finally obtain the final product by vacuum drying or solvent exchange activation.

[0055] 1. Place an iodine generator bottle (with excess iodine) in the adsorption chamber and heat it to the set temperature (70°C) until the iodine vapor pressure stabilizes.

[0056] 2. Weigh out equal amounts of HKUST-1 and ZIF-8 materials prepared in this application, labeled as HKUST-1-EB and ZIF-8-EB, as well as HKUST-1 and ZIF-8 materials prepared by conventional methods (m0=0.05g), place them in a sample boat, put them into the adsorption chamber, seal them, and adsorb them at a constant temperature.

[0057] 3. Take out the sample at regular intervals, weigh it quickly (m), and calculate the adsorption capacity q = (m / m). m0), until the mass remains constant (equilibrium time 6-24h).

[0058] Compared with HKUST-1 and ZIF-8 materials prepared by conventional methods, the HKUST-1 and ZIF-8 synthesized in this application show significantly improved performance in practical applications of iodine vapor adsorption. Figure 6 As shown, the HKUST-1 material prepared in this application has an increase of 370 mg / g, and the ZIF-8 material has an increase of 1340 mg / g.

[0059] In the preparation method of this application, there is no need to introduce an inert gas to remove oxygen. In an aerobic environment, the superoxide radicals generated by irradiation are not only oxidants but also Brønsted acids in organic solvents. The formation of MOFs typically requires the deprotonation of organic ligands to coordinate with metal ions. Superoxide radicals can assist in the deprotonation of ligands, accelerating the coordination reaction between ligands and metal ions. The method of this application can achieve "irradiation on-demand" coordination. This allows the technology to be directly applied to the conveyor belt mode of industrial electron accelerators, greatly improving production efficiency.

[0060] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for rapid preparation of large batches of metal-organic framework materials using electron beam irradiation technology, characterized in that, The method comprises the following steps: S1, dissolving a metal salt and a corresponding organic ligand in an organic solvent system to obtain a reaction solution; S2, obtaining a reaction product by electron beam irradiation of the reaction solution at normal temperature and pressure, mixing the reaction product with N,N-dimethylformamide, activating the product, washing and drying the activated product to obtain the metal organic framework material; The metal organic framework material includes a copper-based metal organic framework material, a zirconium-based metal organic framework material, an iron-based metal organic framework material, a cobalt-based metal organic framework material, a rare earth-based metal organic framework material, and a zinc-based metal organic framework material.

2. The method for rapidly preparing large batches of metal-organic framework materials using electron beam irradiation technology according to claim 1, characterized in that: The metal organic framework material includes HKUST-1, MOF-76, ZIF-8, ZIF-67, Cu-BDC, Cu-NDC, MOF-74, UIO-66, MIL-101, NU-1000, and ZIF-7.

3. The method for rapid preparation of large batches of metal-organic framework materials using electron beam irradiation technology according to claim 2, characterized in that: The organic solvent system in step S1 comprises a main solvent and an auxiliary solvent, and the amount of the auxiliary solvent is ≥0; the main solvent is N,N-dimethylformamide, and the auxiliary solvent is selected from one or more of methanol, ethanol, or water.

4. The method for rapidly preparing large batches of metal-organic framework materials using electron beam irradiation technology according to claim 2, characterized in that: The metal salt for preparing HKUST-1 includes copper acetate and copper nitrate, and the corresponding organic ligand includes 1,3,5-benzenetricarboxylic acid; the molar ratio of the metal salt of HKUST-1 to the organic ligand is 1-1.5:

1.

5. The method for rapidly preparing large batches of metal-organic framework materials using electron beam irradiation technology according to claim 3, characterized in that: The organic solvent system for preparing HKUST-1 in step S1 includes N,N-dimethylformamide, deionized water, and anhydrous ethanol.

6. The method for rapidly preparing large batches of metal-organic framework materials using electron beam irradiation technology according to claim 2, characterized in that: The metal salt for preparing ZIF-8 includes zinc nitrate hexahydrate, and the organic ligand includes 2-methylimidazole; the molar ratio of the metal salt to the organic ligand is 0.5-2.2:

1.

7. The method for rapidly preparing large batches of metal-organic framework materials using electron beam irradiation technology according to claim 3, characterized in that: The organic solvent system for preparing ZIF-8 in step S1 includes N,N-dimethylformamide.

8. The method for rapid preparation of large batches of metal-organic framework materials using electron beam irradiation technology according to claim 1, characterized in that: The dose of electron beam irradiation in step S2 is 60 kGy-270 kGy.

9. The method for rapid preparation of large batches of metal-organic framework materials using electron beam irradiation technology according to claim 1, characterized in that: The temperature of the activation treatment in step S2 is 10-20°C, and the time of the activation treatment is 1-2 h; wherein the washing solvent of the activated product includes anhydrous ethanol, methanol, acetone, and ethyl acetate.

10. The method for rapid preparation of large batches of metal-organic framework materials using electron beam irradiation technology according to claim 9, wherein, The activation treatment step is as follows: centrifuging the reaction product, taking the supernatant, mixing the reaction product with N,N-dimethylformamide, and performing the activation treatment.

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