Method for activating metal-organic frameworks using a high gravity rotating packed bed

Abstract

This invention discloses a method for activating metal-organic framework (MOF) materials using a high-gravity rotating packed bed, comprising the following steps: 1) adding the MOF material to a solvent to obtain a MOF material suspension; 2) controlling the temperature and sealing the high-gravity rotating packed bed, and introducing the MOF material suspension into the high-gravity rotating packed bed through the inlet; setting the rotation speed of the high-gravity rotating bed, starting the motor, and continuously activating for 0.05-6 hours, then removing the material to complete the activation; 3) centrifuging, filtering, and drying the activated MOF material suspension to obtain the activated MOF material. This method can accelerate the dissolution / diffusion process of unreacted metal salts, organic ligands, and solvent molecules used in synthesis within the pores of MOF materials in the activation solvent, achieving highly efficient activation of MOF materials and significantly shortening the activation time.

Description

Technical Field

[0001] This invention relates to the field of metal-organic framework material activation technology; more specifically, it relates to a method for activating metal-organic framework materials using a high-gravity rotating packed bed. Background Technology

[0002] Metal-organic frameworks (MOFs) are a class of crystalline materials with a three-dimensional porous structure, centered around metal atoms and connected by organic molecules. Compared with traditional zeolites and porous carbon materials, they have advantages such as large specific surface area, high porosity, and controllable pore size, and have many applications in adsorption and separation, catalysis, sensing and other fields.

[0003] "Activation," a crucial step in achieving high specific surface area and permanent porosity, is key to the application of MOF materials. It refers to the process of guest exchange / dispersion on the surface and internal pores of synthesized MOFs without compromising structural integrity and porosity. Activation removes unreacted metal salt ions, organic ligands, solvent molecules, and even poorly crystallized complexes remaining in the pores, thus opening the pores. In some MOF materials, activation can also expose unsaturated metal sites / active sites. However, due to incomplete activation or pore blockage / collapse in actual processes, the specific surface area and porosity of the materials are often smaller than expected in simulations. To address these discrepancies, researchers have developed various multifunctional activation techniques and made significant progress. However, activation remains the most time-consuming, tedious, and energy-intensive stage in the synthesis of MOF materials to date.

[0004] Currently, activation methods for MOF materials mainly include conventional heating, solvent exchange, supercritical CO2 exchange, freeze-drying, ultrasonic activation, and chemical treatment (Jlwa B, Rsf B, Ia B, et al. Evaluating the purification and activation of metal-organic frameworks from a technical and circular economy perspective – ScienceDirect[J]. Coordination ChemistryReviews, 2021, 428, 213578). These methods each have their own advantages, but also certain limitations. Conventional heating, as one of the earliest activation methods, is beneficial for activating MOF materials containing unsaturated coordination metals, but it requires high stability of the material itself; otherwise, it may lead to a loss of crystallinity and porosity, or even the destruction / collapse of the framework structure. Therefore, most newly developed methods have focused on reducing or eliminating the capillary forces exerted by the solvent during the evacuation process, such as solvent exchange, supercritical CO2 exchange, and freeze-drying. Solvent exchange is currently the most common method in laboratories. It involves immersing the material in a fresh, low-boiling-point solvent for several days to replace the high-boiling-point solvent used in the synthesis process. Generally speaking, the entire activation process requires a large amount of solvent and is time-consuming. While supercritical CO2 exchange can effectively prevent mesopore collapse and enhance the micropore accessibility of MOFs with fine structures, it is not suitable for the activation of some mesoporous materials, such as MIL-100 (Fe) and MIL-101 (Cr). Furthermore, the use of high pressure and liquid carbon dioxide in this process increases costs, limiting its potential for large-scale and sustainable development. In addition, similar to freeze-drying, solvent exchange is still required before final complete activation for some high-boiling / low-melting-point solvent reaction systems, making the process complex.

[0005] Hypergravity technology is considered a process enhancement approach that enables efficient mixing and mass transfer at the microscale through rotating packed beds (RPBs). This technology has been successfully applied to the preparation, adsorption, polymerization, and enzyme synthesis of nanomaterials. However, there are currently no reports on the application of hypergravity technology to activate porous materials, especially MOFs. Summary of the Invention

[0006] The first technical problem this invention aims to solve is to provide a method for activating metal-organic framework (MOF) materials using a centrifugal rotating packed bed. This method leverages the characteristics of a centrifugal rotating packed bed to greatly enhance intermolecular mass transfer and micro-mixing, accelerating the dissolution / diffusion of unreacted metal salts, organic ligands, and solvent molecules used in synthesis within the pores of the MOF material during activation. This achieves highly efficient activation of MOF materials and significantly shortens the activation time. The activation process employed in this invention is simple, universally applicable, and easily achievable for large-scale production.

[0007] To solve the first technical problem mentioned above, the present invention adopts the following technical solution:

[0008] A method for activating metal-organic framework materials using a high-gravity rotating packed bed includes the following steps:

[0009] 1) The metal-organic framework material is added to a solvent to obtain a metal-organic framework material suspension;

[0010] 2) Control the temperature and seal the centrifugal rotating packed bed. Introduce the metal-organic framework material suspension into the centrifugal rotating packed bed through the feed port. Set the rotation speed of the centrifugal rotating bed, turn on the motor, and continue activation for 0.05-6 hours. Remove the material to complete the activation.

[0011] 3) The activated metal-organic framework material suspension was centrifuged, filtered, and dried to obtain the activated metal-organic framework material.

[0012] Preferably, in step 1), before adding the metal-organic framework material to the solvent, the metal-organic framework material is first ground into powder with a particle size of <1 mm.

[0013] Preferably, in step 1), the solvent is selected from one or more of deionized water, methanol, ethanol, ethylene glycol, glycerol, acetone, ethyl acetate, dichloromethane, chloroform, pyrrolidone, N,N'-dimethylformamide, N,N'-dimethylacetamide, N,N'-diethylformamide, pyridine, piperidine, furan, tetrahydrofuran, dioxane, and dimethyl sulfoxide.

[0014] Preferably, in step 1), the solid content of the metal-organic framework material suspension is 0.1-6 wt%; more preferably, the solid content is 0.5-3 wt%.

[0015] Preferably, in step 2), the supergravity rotating packed bed is selected from one of the following: baffle-type supergravity rotating packed bed, spiral channel supergravity rotating packed bed, stator-rotor supergravity rotating packed bed, rotating disc supergravity rotating packed bed, external circulation rotating packed bed, or internal circulation rotating packed bed.

[0016] Preferably, in step 2), the activation temperature is 20-150 °C.

[0017] Preferably, in step 2), the rotor speed of the supergravity rotating filling bed is 500-2850 rpm; preferably, the rotor speed is 1500-2850 rpm, wherein the rotor speed of the supergravity rotating filling bed is adjusted by a frequency converter.

[0018] Preferably, in step 2), the activation time is 0.1-6 h.

[0019] Preferably, in step 3), the drying method is vacuum drying, the drying temperature is 25-180 ℃, and the drying time is 2-14 h.

[0020] Any range described in this invention includes the endpoint, any value between the endpoints, and any subrange consisting of the endpoint or any value between the endpoints.

[0021] Unless otherwise specified, all raw materials used in this invention can be obtained commercially, and the equipment used in this invention can be conventional equipment in the relevant field or refer to existing technology in the relevant field.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1) The activation method described in this invention can effectively maintain the integrity of the morphology and structure of metal-organic framework materials, and obtain metal-organic framework materials with significantly increased BET specific surface area and porosity;

[0024] 2) This invention utilizes a supergravity rotating packed bed, which can greatly enhance intermolecular mass transfer and micro-mixing processes, and significantly shorten the activation time compared with existing activation methods;

[0025] 3) The activation method described in this invention is based on solvent exchange, has universality, and is applicable to the activation of most MOF materials;

[0026] 4) The process used in this invention is simple, the experimental process is easy to operate, the activation efficiency is high, and it is easy to realize the large-scale industrial production of MOFs materials. Attached Figure Description

[0027] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0028] Figure 1 The PXRD spectra of UiO-66 before and after activation in Example 1 are compared with the simulated spectra.

[0029] Figure 2Examples 1, 2, 3, and 4 show the nitrogen isothermal adsorption-desorption curves of UiO-66 activated for different times and UiO-66 before activation at 77 K.

[0030] Figure 3 Examples 1, 2, 3, and 4 compare the BET specific surface area of ​​UiO-66 activated for different times with that of UiO-66 before activation.

[0031] Figure 4 The BET specific surface area of ​​Examples 1, 6, and 7 is compared with that of Comparative Examples 1 and 2;

[0032] Figure 5 This is a comparison of the complete activation time under the conditions of Examples 1 and 6 and Comparative Examples 1 and 2;

[0033] Figure 6 The images shown are scanning electron microscope (SEM) images and particle size distribution diagrams of the UiO-66 prepared in Example 1 before and after activation. Detailed Implementation

[0034] To more clearly illustrate the present invention, the following description, in conjunction with preferred embodiments, further clarifies the invention. Those skilled in the art should understand that the specific descriptions below are illustrative rather than restrictive, and should not be construed as limiting the scope of protection of the present invention.

[0035] As one aspect of the present invention, a method for activating metal-organic framework materials using a high-gravity rotating packed bed includes the following steps:

[0036] 1) The metal-organic framework material is added to a solvent to obtain a metal-organic framework material suspension;

[0037] 2) Control the temperature and seal the centrifugal rotating packed bed. Introduce the metal-organic framework material suspension into the centrifugal rotating packed bed through the feed port. Set the rotation speed of the centrifugal rotating bed, turn on the motor, and continue activation for 0.05-6 hours. Remove the material to complete the activation.

[0038] 3) The activated metal-organic framework material suspension was centrifuged, filtered, and dried to obtain the activated metal-organic framework material.

[0039] In some embodiments, in step 1), before adding the metal-organic framework material to the solvent, the metal-organic framework material is first ground into powder with a particle size of <1 mm. If grinding is not performed, large pieces of MOF material may clog the packing material in the high-gravity rotating packed bed, making the cyclic activation process impossible.

[0040] In some embodiments, in step 1), the solvent is selected from one or more of deionized water, methanol, ethanol, ethylene glycol, glycerol, acetone, ethyl acetate, dichloromethane, chloroform, pyrrolidone, N,N'-dimethylformamide, N,N'-dimethylacetamide, N,N'-diethylformamide, pyridine, piperidine, furan, tetrahydrofuran, dioxane, and dimethyl sulfoxide.

[0041] In some embodiments, in step 1), the solid content of the metal-organic framework material suspension is 0.1-6 wt%, including but not limited to 0.1-5 wt%, or 0.1-4 wt%, or 0.1-3 wt%, or 0.1-2 wt%, or 0.1-1 wt%, or 1-6 wt%, or 1-5 wt%, or 1-4 wt%, or 1-3 wt%, or 1-2 wt%, or 2-6 wt%, or 2-5 wt%, or 2-4 wt%, or 2-3 wt%, or 3-6 wt%, or 3-5 wt%, or 3-4 wt%.

[0042] In some embodiments, in step 2), the supergravity rotating packed bed is selected from one of the following: baffle-type supergravity rotating packed bed, spiral channel supergravity rotating packed bed, stator-rotor supergravity rotating packed bed, rotating disc supergravity rotating packed bed, external circulation rotating packed bed, or internal circulation rotating packed bed.

[0043] In some embodiments, in step 2), the activation temperature is 20-150°C, including but not limited to 20-140°C, 20-120°C, 20-100°C, 20-80°C, 20-60°C, 20-40°C, 25-150°C, 25-130°C, 25-110°C, 25-90°C, 25-70°C, 25-50°C, 40-150°C, 40-130°C, 40-110°C, 40-90°C, 40-70°C, 60-150°C, 60-130°C, 60-110°C, or 60-90°C.

[0044] In some embodiments, in step 2), the rotor speed of the supergravity rotating filling bed is 500-2850 rpm; preferably, the rotor speed is 1500-2850 rpm, wherein the rotor speed of the supergravity rotating filling bed is adjusted by a frequency converter.

[0045] In some embodiments, in step 3), the drying method is vacuum drying, the drying temperature is 25-180℃, and the drying time is 2-14 h; preferably, the drying temperature is 80-150℃, and the drying time is 8-12 h.

[0046] The preparation steps of the metal-organic framework material used in this invention are as follows:

[0047] The preparation steps of UiO-66 are as follows: 0.36 g of ZrCl4 and 0.483 g of H2BDC (terephthalic acid) were dissolved in 60 mL of DMF at room temperature and transferred to a polytetrafluoroethylene liner; the hydrothermal reactor was sealed and heated to 120 °C at a heating rate of 1 °C / min, and the reaction was continued for 24 h; the final product was collected by centrifugation at 8000 rpm for 10 min, and dried overnight at 150 °C without washing to obtain UiO-66.

[0048] The preparation steps of ZIF-67 are as follows: 1.436 g of Co(NO3)2·6H2O and 3.244 g of 2-methylimidazole were dissolved in 100 mL of methanol at room temperature; the metal salt solution was added to the ligand solution under stirring to start the reaction, and stirring was continued at room temperature for 20 h; the solid product was separated by centrifugation at 8000 rpm for 10 min, and then vacuum dried at 120 °C overnight to obtain ZIF-67.

[0049] The preparation steps of ZIF-8 are as follows: 1.17 g of Zn(NO3)2·6H2O was dissolved in 8 g of deionized water to form a metal salt solution, and 22.70 g of 2-methylimidazole was dissolved in 80 g of deionized water to form a ligand solution. The metal salt solution was then added to the ligand solution with stirring, and stirring continued for 5 min. The solid product was separated by centrifugation at 12000 rpm for 10 min, and then vacuum dried overnight at 120℃ to obtain ZIF-8.

[0050] The preparation steps of HKUST-1 are as follows: 2.0 g of Cu(NO3)2·2.5H2O and 1.0 g of H3BTC (tricarboxylic acid) were dissolved in 50 mL of solvent, which was a mixture of DMF:ethanol:deionized water = 1:1:1; the mixture was stirred in a polytetrafluoroethylene liner for 1 h; after sealing the hydrothermal reactor, the reaction was continued at 85 °C for 24 h; the suspension was collected by centrifugation at 8000 rpm for 10 min and dried at 150 °C overnight to obtain HKUST-1.

[0051] The preparation steps of MIL-101 are as follows: 1.06 g of Cr(NO3)3·9H2O, 0.44 g of H2BDC and 80 mL of deionized water were added to a polytetrafluoroethylene liner and sonicated for 15 min; after sealing the hydrothermal reactor, the reaction was carried out at 180℃ for 6 h; the suspension was collected by centrifugation at 12000 rpm for 10 min and dried at 150℃ overnight to obtain MIL-101.

[0052] Example 1

[0053] A method for activating metal-organic framework materials using a high-gravity rotating packed bed includes the following steps:

[0054] 1.5 g of the prepared UiO-66 was added to 200 mL of methanol solution and stirred to obtain a UiO-66 suspension. The UiO-66 suspension was added to the cavity of the centrifugal rotating packed bed through the feed port and sealed. The reaction temperature was controlled at 25℃ with circulating water. The rotation speed of the centrifugal rotating packed bed was set to 2500 rpm, the motor was turned on, and the device was turned off after continuous activation for 2 h. The activated UiO-66 suspension was centrifuged and placed in a vacuum drying oven and dried at 150℃ under vacuum for 12 h.

[0055] Analysis and Testing

[0056] In this invention, a small number of samples before and after activation are selected for PXRD testing;

[0057] Figure 1 The PXRD spectra before and after activation in Example 1 are compared with the simulated spectra of UiO-66. As can be seen from the figure, the product before and after activation is UiO-66. The activation process did not affect the structure. Moreover, the diffraction peaks of the activated UiO-66 are sharper and the diffraction intensity is higher, indicating that the material has better crystallinity than before activation.

[0058] In this invention, a small number of samples before and after activation are selected and placed on conductive adhesive for observation. The morphology and size of the particles are observed using a field emission scanning electron microscope.

[0059] Figure 6 The images show scanning electron microscope (SEM) images of the samples before and after activation. As can be seen from the images, the particles of the products obtained before and after activation are square / quasi-spherical, with average particle sizes of 178 and 179 nm, respectively. There is no significant change in size or morphology before and after activation.

[0060] In this invention, a small amount of the sample before and after activation is weighed and subjected to a nitrogen isotherm adsorption-desorption isotherm test at 77 K to obtain... Figure 3 .

[0061] The preparation steps of UiO-66 described in this embodiment are as follows:

[0062] 0.36 g of ZrCl4 and 0.483 g of H2BDC (terephthalic acid) were dissolved in 60 mL of DMF at room temperature and transferred to a polytetrafluoroethylene liner. The hydrothermal reactor was sealed and heated to 120 °C at a heating rate of 1 °C / min, and the reaction was continued for 24 h. The final product was collected by centrifugation at 8000 rpm for 10 min, and dried overnight at 150 °C without washing to obtain UiO-66.

[0063] Example 2

[0064] Example 1 was repeated, except that the activation time was changed from 2 h to 1.5 h.

[0065] Example 3

[0066] Example 1 was repeated, except that the activation time was changed from 2 h to 1.0 h.

[0067] Example 4

[0068] Example 1 was repeated, except that the activation time was changed from 2 h to 0.5 h.

[0069] Example 5

[0070] Example 1 was repeated, except that the solvent used to prepare the metal-organic framework material suspension was selected from one or more of the following substances: ethanol, dichloromethane, chloroform, N,N'-dimethylformamide, and N,N'-dimethylacetamide; the results obtained were similar to those in Example 1.

[0071] Example 6

[0072] Repeat Example 1, except that the rotor speed is changed from 2500 rpm to 500 rpm.

[0073] Example 7

[0074] Repeat Example 1, except that the rotor speed is changed from 2500 rpm to 1500 rpm.

[0075] Example 8

[0076] A method for activating metal-organic framework materials using a high-gravity rotating packed bed includes the following steps:

[0077] 1.5 g of the prepared ZIF-67 was added to 200 mL of methanol solution and stirred to obtain a ZIF-67 suspension. The ZIF-67 suspension was added to the cavity of a high-gravity rotating packed bed through the feed inlet and sealed. The circulating water was adjusted to control the reaction temperature at 25℃. The rotation speed of the high-gravity rotating packed bed was set to 2500 rpm, the motor was turned on, and the device was turned off after continuous activation for 20 min. The activated ZIF-67 suspension was centrifuged and placed in a vacuum drying oven and dried at 150℃ under vacuum for 12 h. The PXRD spectrum of the activated ZIF-67 material was compared with the simulated spectrum. Figure 1The crystallinity was good, with sharp diffraction peaks and high diffraction intensity, indicating better crystallinity than before activation. Nitrogen adsorption-desorption isotherm analysis at 77 K showed that the BET specific surface area after 20 min of activation was 1786.3 m² / g, which is essentially in line with the reported values ​​in the literature.

[0078] The preparation steps of ZIF-67 described in this invention are as follows:

[0079] The preparation steps of ZIF-67 are as follows: 1.436 g of Co(NO3)2·6H2O and 3.244 g of 2-methylimidazole were dissolved in 100 mL of methanol at room temperature; the metal salt solution was added to the ligand solution under stirring to start the reaction, and stirring was continued at room temperature for 20 h; the solid product was separated by centrifugation at 8000 rpm for 10 min, and then vacuum dried at 120 °C overnight to obtain ZIF-67.

[0080] Example 9

[0081] A method for activating metal-organic framework materials using a high-gravity rotating packed bed includes the following steps:

[0082] 1.5 g of the prepared ZIF-8 was added to 200 mL of methanol solution and stirred to obtain a ZIF-8 suspension. The ZIF-8 suspension was added to the cavity of a high-gravity rotating packed bed through the feed inlet and sealed. The circulating water was adjusted to control the reaction temperature at 25℃. The rotation speed of the high-gravity rotating packed bed was set to 2500 rpm, the motor was turned on, and the device was shut off after continuous activation for 2 h. The activated ZIF-8 suspension was centrifuged and placed in a vacuum drying oven and dried under vacuum at 150℃ for 12 h. The PXRD spectrum of the activated ZIF-8 material was compared with the simulated spectrum. Figure 1 The crystallinity was good, with sharp diffraction peaks and high diffraction intensity, indicating better crystallinity than before activation. Nitrogen adsorption-desorption isotherm analysis at 77 K revealed a BET specific surface area of ​​1326 m² / g after 2 h of activation, which essentially meets the reported values ​​in the literature.

[0083] The preparation steps of ZIF-8 according to the present invention are as follows:

[0084] The preparation steps of ZIF-8 are as follows: 1.17 g of Zn(NO3)2·6H2O was dissolved in 8 g of deionized water to form a metal salt solution, and 22.70 g of 2-methylimidazole was dissolved in 80 g of deionized water to form a ligand solution. The metal salt solution was then added to the ligand solution with stirring, and stirring continued for 5 min. The solid product was separated by centrifugation at 12000 rpm for 10 min, and then vacuum dried overnight at 120℃ to obtain ZIF-8.

[0085] Example 10

[0086] A method for activating metal-organic framework materials using a high-gravity rotating packed bed includes the following steps:

[0087] 1.5 g of the prepared HKUST-1 was added to 200 mL of methanol solution and stirred to obtain an HKUST-1 suspension. The ZIF-8 suspension was added to the cavity of the high-gravity rotating packed bed through the feed inlet and sealed. The circulating water was adjusted to control the reaction temperature at 25℃. The rotation speed of the high-gravity rotating packed bed was set to 2500 rpm, the motor was turned on, and the device was turned off after continuous activation for 2 h. The activated HKUST-1 suspension was centrifuged and placed in a vacuum drying oven and dried at 150℃ under vacuum for 12 h. The PXRD spectrum of the activated HKUST-1 material was compared with the simulated spectrum. Figure 1 The crystallinity was good, with sharp diffraction peaks and high diffraction intensity, indicating better crystallinity than before activation. Nitrogen adsorption-desorption isotherm analysis at 77 K revealed a BET specific surface area of ​​1817 m² / g after 2 h of activation, which essentially meets the reported values ​​in the literature.

[0088] The preparation steps of HKUST-1 described in this invention are as follows:

[0089] The preparation steps of ZIF-8 are as follows: 1.17 g of Zn(NO3)2·6H2O was dissolved in 8 g of deionized water to form a metal salt solution, and 22.70 g of 2-methylimidazole was dissolved in 80 g of deionized water to form a ligand solution. The metal salt solution was then added to the ligand solution with stirring, and stirring continued for 5 min. The solid product was separated by centrifugation at 12000 rpm for 10 min, and then vacuum dried overnight at 120℃ to obtain ZIF-8.

[0090] The preparation steps of HKUST-1 are as follows: 2.0 g of Cu(NO3)2·2.5H2O and 1.0 g of H3BTC (tricarboxylic acid) were dissolved in 50 mL of solvent, which was a mixture of DMF:ethanol:deionized water = 1:1:1; the mixture was stirred in a polytetrafluoroethylene liner for 1 h; after sealing the hydrothermal reactor, the reaction was continued at 85 °C for 24 h; the suspension was collected by centrifugation at 8000 rpm for 10 min and dried at 150 °C overnight to obtain HKUST-1.

[0091] Example 11

[0092] A method for activating metal-organic framework materials using a high-gravity rotating packed bed includes the following steps:

[0093] 1.0 g of prepared MIL-101 was added to 200 mL of N,N'-dimethylformamide solution and stirred to obtain a MIL-101 suspension. The MIL-101 suspension was added to the cavity of a high-gravity rotating packed bed through the feed inlet and sealed. The reaction temperature was controlled at 60℃ by adjusting the circulating water. The rotation speed of the high-gravity rotating packed bed was set to 2500 rpm, the motor was turned on, and the device was turned off after continuous activation for 3 h. The activated MIL-101 suspension was centrifuged and placed in a vacuum drying oven and dried under vacuum at 150℃ for 12 h. The PXRD spectrum of the activated MIL-101 material was compared with the simulated spectrum. Figure 1 The crystallinity is consistent, with sharp diffraction peaks and high diffraction intensity, indicating better crystallinity than before activation. Nitrogen adsorption-desorption isotherm analysis revealed a BET specific surface area of ​​3698 m² / g, which essentially meets the values ​​reported in the literature.

[0094] The preparation steps of MIL-101 described in this invention are as follows:

[0095] The preparation steps of MIL-101 are as follows: 1.06 g of Cr(NO3)3·9H2O, 0.44 g of H2BDC and 80 mL of deionized water were added to a polytetrafluoroethylene liner and sonicated for 15 min; after sealing the hydrothermal reactor, the reaction was carried out at 180℃ for 6 h; the suspension was collected by centrifugation at 12000 rpm for 10 min and dried at 150℃ overnight to obtain MIL-101.

[0096] Comparative Example 1

[0097] 1.5 g of the prepared UiO-66 was added to 200 mL of methanol solution to obtain a UiO-66 suspension, which was then sealed and allowed to stand at room temperature for 2 h. The activated UiO-66 suspension was then centrifuged and placed in a vacuum drying oven at 150 °C for 12 h to obtain the UiO-66 material activated by solvent exchange (standing condition). Nitrogen adsorption-desorption isotherm analysis showed that its BET specific surface area was 469 m² / g, which is significantly lower than the value reported in the literature.

[0098] Comparative Example 2

[0099] 1.5 g of the prepared UiO-66 was added to 200 mL of methanol solution to obtain a UiO-66 suspension, which was then sealed and magnetically stirred at 500 rpm for 2 h at room temperature. The resulting activated UiO-66 suspension was centrifuged and placed in a vacuum drying oven at 150 °C for 12 h to obtain the UiO-66 material activated by solvent exchange (stirring conditions). Nitrogen adsorption-desorption isotherm analysis showed that its BET specific surface area was 591 m² / g, which is significantly lower than the reported value in the literature.

[0100] In summary, Comparative Examples 1 and 2 were not activated by a supergravity rotating packed bed, but by a conventional solvent exchange method, and their BET specific surface area was much lower than that of Example 1.

[0101] Comparative Example 3

[0102] Example 1 was repeated, except that the metal-organic framework material UiO-66 was not ground before being added to the solvent (i.e., the particle size was > 1 micrometer). The result was that a significant amount of UiO-66 accumulated inside the filler, and no cyclic activation process was formed. Nitrogen adsorption-desorption isotherm analysis revealed a BET specific surface area of ​​738 m² / g, far lower than the reported value in the literature.

[0103] in conclusion:

[0104] 1) By comparing the nitrogen isothermal adsorption-desorption curves and BET specific surface area of ​​the particles in Examples 1, 2, 3, 4 and before activation (…),… Figure 2 and Figure 3 As can be seen, the longer the activation time of metal-organic framework materials, the larger their BET specific surface area becomes, gradually reaching the value reported in the literature.

[0105] 2) By comparing the BET specific surface area of ​​Examples 1, 6, 7 and Comparative Examples 1, 2 ( Figure 4 ) and full activation time ( Figure 5 It can be seen that the activation effect of static or magnetic stirring at the same speed is not as good as that of the supergravity rotating packed bed, and the complete activation time is reduced by more than 80%; and the supergravity rotating packed bed has a more significant activation effect on metal-organic framework materials at higher speeds.

[0106] 3) By comparing the PXRD spectra of particles before and after activation in the high-gravity rotating packed bed of Example 1 ( Figure 1 ) and size and morphology in scanning electron microscope images ( Figure 6 As can be seen, this method has no significant impact on the morphology and structural integrity of metal-organic framework materials.

[0107] 4) By comparing Examples 1, 8, 9, 10 and 11, it can be seen that the activation method described in this invention has universality, is applicable to the activation of most MOFs materials, and is easy to scale up for production.

[0108] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is impossible to exhaustively list all embodiments here. All obvious variations or modifications derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. A method for activating metal-organic framework materials using a high-gravity rotating packed bed, characterized in that, Includes the following steps: 1) The metal-organic framework material is added to a solvent to obtain a metal-organic framework material suspension; 2) Control the temperature and seal the centrifugal rotating packed bed. Introduce the metal-organic framework material suspension into the centrifugal rotating packed bed through the feed port. Set the rotation speed of the centrifugal rotating bed, turn on the motor, and continue activation for 0.05-6 hours. Remove the material to complete the activation. 3) The activated metal-organic framework material suspension was centrifuged, filtered, and dried to obtain the activated metal-organic framework material; In step 1), before adding the metal-organic framework material to the solvent, the metal-organic framework material is first ground into powder with a particle size of <1 mm.

2. The method for activating metal-organic framework materials using a high-gravity rotating packed bed according to claim 1, characterized in that: In step 1), the solvent is selected from one or more of deionized water, methanol, ethanol, ethylene glycol, glycerol, acetone, ethyl acetate, dichloromethane, chloroform, pyrrolidone, N,N'-dimethylformamide, N,N'-dimethylacetamide, N,N'-diethylformamide, pyridine, piperidine, furan, tetrahydrofuran, dioxane, and dimethyl sulfoxide.

3. The method for activating metal-organic framework materials using a high-gravity rotating packed bed according to claim 1, characterized in that: In step 1), the solid content of the metal-organic framework material suspension is 0.1-6 wt%.

4. The method for activating metal-organic framework materials using a high-gravity rotating packed bed according to claim 3, characterized in that: The solid content of the metal-organic framework material suspension is 0.5-3 wt%.

5. The method for activating metal-organic framework materials using a high-gravity rotating packed bed according to claim 1, characterized in that: In step 2), the supergravity rotating packed bed is selected from one of the following: baffle-type supergravity rotating packed bed, spiral channel supergravity rotating packed bed, stator-rotor supergravity rotating packed bed, rotating disc supergravity rotating packed bed, external circulation rotating packed bed, or internal circulation rotating packed bed.

6. The method for activating metal-organic framework materials using a high-gravity rotating packed bed according to claim 1, characterized in that: In step 2), the activation temperature is 20-150 ℃.

7. The method for activating metal-organic framework materials using a high-gravity rotating packed bed according to claim 1, characterized in that: In step 2), the rotor speed of the supergravity rotating filling bed is 500-2850 rpm, and the rotor speed of the supergravity rotating filling bed is adjusted by a frequency converter.

8. The method for activating metal-organic framework materials using a high-gravity rotating packed bed according to claim 7, characterized in that: The rotor speed of the supergravity rotating packed bed is 1500-2850 rpm.

9. The method for activating metal-organic framework materials using a high-gravity rotating packed bed according to claim 1, characterized in that: In step 2), the activation time is 0.1-6 hours.

10. The method for activating metal-organic framework materials using a high-gravity rotating packed bed according to claim 1, characterized in that: In step 3), the drying method is vacuum drying, the drying temperature is 25-180 ℃, and the drying time is 2-14h.

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