CN116376037A

CN116376037A - Preparation method and application of microporous zirconium-based metal organic framework material

Info

Publication number: CN116376037A
Application number: CN202211685644.XA
Authority: CN
Inventors: 苏成勇; 熊小红; 韦张文; 潘梅
Original assignee: Sun Yat Sen University
Current assignee: Sun Yat Sen University
Priority date: 2022-12-27
Filing date: 2022-12-27
Publication date: 2023-07-04

Abstract

The invention belongs to the technical field of gas adsorption and separation, and particularly relates to a preparation method and application of a microporous zirconium-based metal organic framework material. The microporous zirconium-based metal organic framework material DUT-67 is formed by constructing zirconium salt and an organic ligand through coordination, the synthesis method is simple and convenient, the cost is low, and the DUT-67 obtained by the method is a porous material with high crystallinity, high purity and three-dimensional network structure and has excellent SO ₂ The deep removal capability and the selective trapping performance of R22 and R134a have extremely high physicochemical and hydrothermal stability, provide a new method for improving the deep desulfurization of flue gas of the porous solid adsorbent material and the selective trapping and separation of fluorochloroalkane in the atmosphere, and also provide different approaches for developing a new MOF material with high separation performance, high stability and low cost.

Description

Preparation method and application of microporous zirconium-based metal organic framework material

Technical Field

The invention belongs to the technical field of gas adsorption and separation. More particularly, relates to a preparation method and application of a microporous zirconium-based metal organic framework material.

Background

The use of fossil energy and refrigerants in large quantities has resulted in the release of substantial amounts of SO to the atmosphere ₂ And fluorochloroalkane refrigerants, which cause very serious environmental problems such as acid rain, haze, greenhouse effect, global warming, etc., have severely threatened human survival, health and sustainable development. By 2018, 62.7Mt of SO has been available ₂ Is discharged to the atmosphere. SO into the atmosphere ₂ Except for oxidation to SO by ozone and oxygen in the atmosphere ₃ Dissolving in water vapor to form acid rain, and reacting with ammonia in the atmosphere to generate PM 2.5, namely highly toxic haze particles. The former can cause acidification of water and soil, poison surface vegetation, and the latter can enter human lungs through breathing process, cause serious respiratory system lesions, and seriously harm human health. The fluorochloroalkane entering the atmosphere consumes ozone in the atmosphere, so that the ozone layer is hollow, most fluorochloroalkane belongs to greenhouse gases and has a Global Warming Potential (GWP) of CO ₂ Several tens to thousands of times, global warming is seriously aggravated, and melting of two-pole glaciers and elevation of sea level are accelerated. Thus, deep desulfurization of flue gas and efficient capture and recovery of leaked fluorochloroparaffins in the scrapping and dismantling of fluorochloroparaffins production or refrigeration equipment are problems to be solved in industry.

Conventional flue gas desulfurization in the industry today typically employs limestone wet scrubbing or amine-based sorbent treatment, however, these adsorption processes are typically irreversible and are accompanied by energy intensive processes, producing significant amounts of waste liquid and solids. In addition, the limestone elution process does not fully adsorb SO ₂ SO with the SO content of 0.015 to 0.045 percent all the time ₂ Surviving, which will significantly affect the activity of the adsorbent for removing carbon dioxide in other flue gas cleaning processes and will also allow for the reduction of NO _x Or catalytic combustion of CH ₄ Is deactivated by the noble metal-based catalyst. However, no related trapping and recycling technology is known for the refrigerant leaked from the production plant. For recovery of fluorochloroalkane refrigerant in waste refrigerating equipment, the industry mainly adopts a cooling method, a compression condensing method, an adsorption method, a liquid pushing method, a pulling method and a composite recovery method. However, these conventional flue gas desulfurization and refrigerant recovery techniques described above all suffer from the disadvantages of high recovery costs and high energy consumption.

In contrast, SO in the flue gas can be realized under the condition of low energy consumption based on the adsorption of porous materials ₂ And the deep separation mode of the fluorochloroalkane in the atmosphere is more energy-saving and environment-friendly. The Metal-organic framework material (MOF for short) is a novel porous material which is the most rapid in development in recent years, and has the advantages of being capable of realizing ordered unification of Metal elements and organic ligands, having extremely high specific surface area, huge pore volume, various topologies, being capable of designing, regulating and controlling structures, being capable of functioning and being a firm framework and the like due to the fact that the Metal-organic framework material is provided with inorganic Metal nodes and organic bridging ligands at the same time, and has great application potential in the aspects of hydrocarbon gas selective adsorption separation, carbon capture, hydrogen/methane storage, natural gas purification and the like in recent decades. For example, chinese patent application CN105727736A discloses a metal organic framework material MOF-5 for removing sulfur dioxide, wherein the removal amount of the sulfur dioxide is 1.5mmol/g at most; chinese patent application CN115160586a discloses a mesoporous metal organic framework material capable of simultaneously realizing modification of pore diameter and functional group by mesoporous MOF, and the MOF material has strong adsorption and storage capacity to freon gas. Although MOF material is at SO ₂ The adsorption separation and the capture of fluorochloroalkane in the atmosphere have been advanced to some extent, but the current research results are still less and not deep, and many MOFs still have low adsorption capacity, poor chemical stability and SO ₂ The adsorption is irreversible, the synthesis cost is high, and the defects of the adsorption is not deep enough, the interference of other coexisting gases and water vapor is rarely considered, and the separation is far from the actual separation requirement and separation scene. In addition to the requirement that MOFs as solid adsorbents have excellent gas separation properties, their physical and chemical stability and hydrothermal stability are also important for their practical industrial application. And most of those reported SO far are for SO ₂ The MOFs material with deep removal and fluorocarbon trapping and separation in the atmosphere has extremely high raw material and synthesis cost, is difficult to realize large-scale production or preparation, and cannot meet the actual industrial application requirements.

Accordingly, there is a strong need to provide a MOF material that has high separation performance, high stability, low regeneration energy consumption and low cost and achieves deep desulfurization of flue gases and efficient capture and recovery of fluorochloroalkanes in the atmosphere.

Disclosure of Invention

The invention aims to overcome the defects and shortcomings of low adsorption capacity, poor chemical stability, irreversible adsorption, poor separation performance, difficult regeneration and high synthesis cost and difficult industrial preparation of the conventional MOF adsorption material, and provides a preparation method of a microporous zirconium-based metal organic framework material (DUT-67) with high separation performance, high stability, low regeneration energy consumption and low cost.

Another object of the present invention is to provide the use of the method for preparing a microporous zirconium-based organic framework material.

The above object of the present invention is achieved by the following technical scheme:

a preparation method of a microporous zirconium-based metal organic framework material comprises the following steps: fully mixing a polar organic solvent with formic acid, adding zirconium salt and thiophene dicarboxylic acid organic ligand, fully mixing, heating at 50-160 ℃ for complete reaction, and carrying out post-treatment to obtain the catalyst;

wherein the polar organic solvent is N, N-Dimethylacetamide (DMAC) or N, N-Dimethylformamide (DMF);

the volume ratio of the polar organic solvent to the formic acid is 2:0.5 to 2;

the molar ratio of the zirconium salt to the thiophene dicarboxylic acid organic ligand is 1:0.67 to 1.5.

The preparation method has the advantages that the porous material DUT-67 with high crystallinity, high purity and three-dimensional network structure is prepared through long-time exploration, kg-level production verification is carried out in a laboratory, and the DUT-67 can be stably prepared; the synthesis process is simple and convenient, low in cost and high in industrial application potential and value.

Further, the molecular formula of the microporous zirconium-based metal organic framework material is Zr ₆ O ₈ (OH) ₈ X ₄ ；

Wherein X is a thiophene dicarboxylic acid organic ligand.

The framework of DUT-67 obtained by the preparation method of the invention has rich pore knotsAnd extremely high porosity with 8 terminal H on each metal cluster in the framework ₂ O/OH ^- The radical is to SO ₂ R22 and R134a all have very high adsorption affinity, can form hydrogen bonds with oxygen on sulfur dioxide molecules and Cl and F atoms on R22 and R134a molecules, and can also form non-traditional hydrogen bonds with H atoms on three molecules through O atoms, thereby enhancing the adsorption affinity and separation selectivity of the three gas molecules and having excellent SO ₂ The deep removal capability and the selective trapping performance of R22 and R134a can realize deep desulfurization of industrial flue gas and selective separation and trapping of low-concentration R22 and R134a in the atmosphere, and DUT-67 shows extremely high physical and chemical stability and hydrothermal stability, and can still maintain structural integrity after being soaked in hot water, seawater, acidic or alkaline solution at 85 ℃ at high temperature of 225 ℃.

Preferably, the zirconium salt is ZrOCl ₂ 、ZrCl ₄ 、ZrO(NO ₃ ) ₂ Any one of the following.

More preferably, the zirconium salt is ZrOCl ₂ ·H ₂ O、ZrOCl ₂ ·8H ₂ O、ZrCl ₄ 、ZrO(NO ₃ ) ₂ ·xH ₂ O. Wherein except ZrCl ₄ Zirconium salts, e.g. ZrOCl, partly without water of crystallization ₂ The method is high in price, and the zirconium salt with crystal water is low in price based on the cost.

Most preferably, the zirconium salt is ZrOCl ₂ ·8H ₂ O。

Preferably, the thiophene dicarboxylic acid organic ligand is 2, 5-thiophene dicarboxylic acid.

Preferably, the mixing ratio of the total volume of the polar organic solvent and formic acid to the total mass of zirconium salt and thiophene dicarboxylic acid organic ligand is 6.5mL: 60-450 mg. When the microporous zirconium-based metal organic framework material is produced in small quantities, and a DUT-67 single crystal with large size is to be obtained for structural analysis, and the gas adsorption mechanism is analyzed by using an in-situ X-ray single crystal diffraction technology, namely, the mass of zirconium salt and thiophene dicarboxylic acid organic ligand used for reaction is less than 200mg, the mixing ratio of the total volume of the polar organic solvent and formic acid to the total mass of the zirconium salt and thiophene dicarboxylic acid organic ligand is 6.5mL: 60-200 mg; when DUT-67 in the form of crystalline powder of high purity is synthesized, the mixing ratio of the total volume of the polar organic solvent and formic acid to the total mass of zirconium salt and thiophene dicarboxylic acid organic ligand is 6.5mL: 200-450 mg; when the industrial reaction kettle is adopted, and the microporous zirconium-based metal organic frame material with the Kg grade above is produced singly by stirring and refluxing, namely, when the mass of zirconium salt and thiophene dicarboxylic acid organic ligand used for reaction is more than 1Kg, the mixing ratio of the total volume of the polar organic solvent and formic acid to the total mass of the zirconium salt and the thiophene dicarboxylic acid organic ligand is 6.5mL: 260-450 mg, the ratio of the volume of the aforementioned organic solvent to the total mass of the metal salt and the organic ligand only affects the crystal size and morphology of the synthesized DUT-67, does not affect the framework structure, and does not change the purity and phase of the product.

Preferably, the reaction is completed for a period of 12 to 150 hours.

Preferably, the temperature at which the polar organic solvent and formic acid are thoroughly mixed is 25 to 50 ℃.

Preferably, the time for thorough mixing is 1to 60min.

Further, the means of thorough mixing includes shaking, stirring and ultrasound.

Still further, the means of thorough mixing is ultrasound.

Preferably, the post-treatment further comprises suction filtration, washing, soaking and drying.

Specifically, the post-processing is performed as follows: removing supernatant after the reaction is completed, adding DMF (dimethyl formamide) into the mixture, ultrasonically removing crystals on the bottle wall, performing suction filtration to obtain a solid product, washing the obtained solid product with DMF for 3-5 times, washing unreacted zirconium salt or 2, 5-thiophene dicarboxylic acid organic ligand in a pore canal, soaking with deionized water for 1 day, washing with any one of absolute methanol, ethanol or acetone for 3-5 times, soaking for 3-5 days, replacing fresh soaking solvent for 6 times a day, completely exchanging DMF in the pore canal for the soaking solvent, and performing drying treatment.

Further, the drying is to dry at room temperature and then to dry in vacuum. The purpose of vacuum drying is to activate DUT-67, i.e. remove DMF/DMAC or formic acid and other organic solvents and low boiling point organic solvents (such as absolute methanol, ethanol, acetone, etc.) used in exchange for removing DUT-67 frame channels, empty DUT-67 channels for adsorbing SO ₂ Gas molecules such as R22 and R134a.

Specifically, the drying is to dry for 12 hours at room temperature, then to dry for 12 hours under the vacuum degree of 0.001-0.1 torr at the temperature of 50-120 ℃ to obtain the activated microporous zirconium-based metal organic framework material, namely the activated DUT-67.

In addition, the invention also provides application of the preparation method in adsorption and separation of halogenated alkane gas and sulfur dioxide.

Preferably, the haloalkane gas comprises difluoro-chloromethane (R22), 1, 2-tetrafluoroethane (R134 a), sulfur hexafluoride, and carbon tetrafluoride, monofluorotrichloromethane, hexafluoroethane, tetrafluoromethane, octafluoropropane, dichloro-difluoromethane, chlorotrifluoromethane, pentafluoroethane, trifluoromethane.

More preferably, the haloalkane gas is difluoromethane chloride and 1, 2-tetrafluoroethane.

The invention has the following beneficial effects: the microporous zirconium-based metal organic framework material DUT-67 is formed by constructing zirconium salt and an organic ligand through coordination, the synthesis method is simple and convenient, the cost is low, and the DUT-67 obtained by the method is a porous material with high crystallinity, high purity and three-dimensional network structure and has excellent SO ₂ The deep removal capacity and the selective trapping performance of R22 and R134a, and has extremely high physical and chemical stability and hydrothermal stability, thus providing a new method for improving the deep desulfurization of flue gas of the porous solid adsorbent material and the selective trapping and separation of fluorochloroalkane in the atmosphere, providing different ways for developing a new MOF material with high separation performance, high stability and low cost, and being beneficial to pushing and expanding the application of the MOF material in other industrial gas separation fields.

Drawings

FIG. 1 is a schematic diagram of the microstructure of DUT-67 prepared in example 1.

FIG. 2 is an x-ray diffraction (PXRD) pattern of DUT-67 prepared in example 1.

FIG. 3 is a 77K nitrogen isothermal full adsorption curve (FIG. 3 a) and pore size distribution diagram (FIG. 3 b) of DUT-67 prepared in example 1.

FIG. 4 is a graph of PXRD patterns before and after physical and chemical stability testing of DUT-67 prepared in example 1.

FIG. 5 is a graph of PXRD patterns before and after thermogravimetric analysis and thermal stability testing of DUT-67 prepared in example 1.

FIG. 6 is DUT-67 vs. N prepared in example 1 ₂ 、O ₂ 、CO ₂ 、SO ₂ Gas adsorption/desorption isotherms for R22, R134a.

FIG. 7 shows the SO at 298K calculated by IAST theory for DUT-67 prepared in example 1 at different proportions ₂ /N ₂ And SO ₂ /CO ₂ Adsorption selectivity data map of the mixture.

FIG. 8 shows different ratios of R22/R134a/CO at 298K calculated by IAST theory for DUT-67 prepared in example 1 ₂ Adsorption selectivity data map of the mixture.

FIG. 9 is a packed column of DUT-67 prepared in example 1 at 298K,40mL min ^-1 Air/SO at a flow rate of (3) ₂ (N ₂ ：O ₂ ：CO ₂ ：SO ₂ 81.8:15:3:0.2 SO in the mixed gas ₂ Is a graph of the trap penetration curve.

FIG. 10 shows packed columns of DUT-67 prepared in example 1 at 273, 298 and 303K,40mL min ^-1 Air/SO at a flow rate of (3) ₂ (N ₂ ：O ₂ ：CO ₂ ：SO ₂ 81.8:15:3:0.2 SO in the mixed gas ₂ Is a graph of the trap penetration curve.

FIG. 11 is a packed column of DUT-67 prepared in example 1 at 298K with a humidity of 50% for 40mL min ^-1 Air/SO at a flow rate of (3) ₂ (N ₂ ：O ₂ ：CO ₂ ：SO ₂ 81.8:15:3:0.2 SO in the mixed gas ₂ Is a graph of the capture penetration contrast。

FIG. 12 is a packed column of DUT-67 prepared in example 1 at 298K 40mL min ^-1 Air/SO at a flow rate of (3) ₂ (N ₂ ：O ₂ ：CO ₂ ：SO ₂ 81.8:15:3:0.2 SO in the mixed gas ₂ Is a graph of the cycle trap penetration graph.

FIG. 13 is a packed column of DUT-67 prepared in example 1 at 298K,10mL min ^-1 Is a graph of the selective capture and separation breakthrough of R22 and R134a in an Air/R22/R134a (80:10:10) mixture at a flow rate of (1).

FIG. 14 is a packed column of DUT-67 prepared in example 1 at 298K,20mL min ^-1 Is a graph of the selective capture and separation breakthrough of R22 and R134a in an Air/R22/R134a (98:1:1) mixture.

FIG. 15 is a packed column of DUT-67 prepared in example 1 at 298K,50mL min ^-1 Is a graph of the selective capture and separation breakthrough of R22 and R134a in an Air/R22/R134a (99.96:0.02:0.02) mixture.

FIG. 16 is a packed column of DUT-67 prepared in example 1 at 298K,10mL min ^-1 Is a graph of cyclic breakthrough testing for the selective capture and separation of R22 and R134a in an Air/R22/R134a (80:10:10) mixture.

FIG. 17 is a packed column of DUT-67 prepared in example 1 at 298K,50% relative humidity, 10mL min ^-1 Is a graph of the selective capture and separation breakthrough of R22 and R134a in an Air/R22/R134a (80:10:10) mixture at a flow rate of (1).

FIG. 18 is a photograph of the apparatus (a) and the product (b) used for the enlarged synthesis of DUT-67 prepared in example 7.

FIG. 19 is a PXRD pattern for an extended scale synthesis product of DUT-67 prepared in example 7.

Detailed Description

The invention is further illustrated in the following drawings and specific examples, which are not intended to limit the invention in any way. Unless specifically stated otherwise, the reagents, methods and apparatus employed in the present invention are those conventional in the art.

Reagents and materials used in the following examples are commercially available unless otherwise specified.

ZrO (NO) in example 5 ₃ ) ₂ xH ₂ The relative molecular weight of O was 231.23g/mol.

Example 1 preparation method of microporous zirconium-based Metal organic framework Material

A preparation method of a microporous zirconium-based metal organic framework material comprises the following steps:

a40 mL glass bottle with a polytetrafluoroethylene gasket on the lid was taken, 7.5mL of anhydrous formic acid and 12mL of N, N-Dimethylacetamide (DMAC) were added thereto, shaken well, and ZrOCl was weighed ₂ ·8H ₂ O (120 mg,0.372 mmol), 2, 5-thiophenedicarboxylic acid (60 mg,0.348 mmol) was added to the above mixed solution, the reaction system was uniformly mixed by ultrasonic, and the cap of the glass was closed and reacted at 120℃for 72 hours. The vial was then removed and cooled to room temperature in air. Removing supernatant in a glass bottle, adding N, N-Dimethylformamide (DMF), removing crystals on the bottle wall by ultrasonic, filtering to collect crystals, adding DMF into the obtained crystals, repeatedly washing for three times, soaking for 1 day with deionized water, washing for 3 times with methanol, soaking for 3 days, replacing 6 times of fresh methanol each day, completely exchanging DMF in a pore canal for methanol, drying at room temperature for 12 hours, and then drying at 50 ℃ under vacuum degree of 0.001-0.1 torr for 12 hours to obtain the activated DUT-67.

Example 2 preparation method of microporous zirconium-based Metal organic framework Material

a40 mL glass bottle with a polytetrafluoroethylene gasket on the lid was taken, 4mL of anhydrous formic acid and 12.5mL of N, N-Dimethylacetamide (DMAC) were added thereto, shaken well, and ZrOCl was weighed ₂ ·8H ₂ O (200 mg,0.620 mmol), 2, 5-thiophenedicarboxylic acid (100 mg,0.581 mmol) was added to the above mixed solution, the reaction system was uniformly mixed by ultrasonic, and the glass bottle was closed with a cap and reacted at 80℃for 140 hours. The vial was then removed and cooled in airCooling to room temperature. Removing supernatant in a glass bottle, adding N, N-Dimethylformamide (DMF), removing crystals on the bottle wall by ultrasonic, filtering to collect crystals, adding DMF into the obtained crystals, repeatedly washing for three times, soaking for 1 day with deionized water, washing for 3 times with methanol, soaking for 3 days, replacing 6 times of fresh methanol each day, completely exchanging DMF in a pore canal for methanol, drying at room temperature for 12 hours, and then drying at 50 ℃ under vacuum degree of 0.001-0.1 torr for 12 hours to obtain the activated DUT-67.

Example 3 preparation method of microporous zirconium-based Metal organic framework Material

a40 mL glass bottle with a polytetrafluoroethylene gasket on the lid was taken, 12.5mL of anhydrous formic acid and 12.5mL of N, N-Dimethylacetamide (DMAC) were added thereto, and the mixture was shaken well to weigh ZrOCl ₂ ·8H ₂ O (230 mg,0.714 mmol), 2, 5-thiophenedicarboxylic acid (110 mg,0.639 mmol) was added to the above mixed solution, the reaction system was uniformly mixed by ultrasonic, and the glass bottle was capped and reacted at 150℃for 12 hours. The vial was then removed and cooled to room temperature in air. Removing supernatant in a glass bottle, adding N, N-Dimethylformamide (DMF), removing crystals on the bottle wall by ultrasonic, filtering to collect crystals, adding DMF into the obtained crystals, repeatedly washing for three times, soaking for 1 day with deionized water, washing for 3 times with methanol, soaking for 3 days, replacing 6 times of fresh methanol each day, completely exchanging DMF in a pore canal for methanol, drying at room temperature for 12 hours, and then drying at 50 ℃ under vacuum degree of 0.001-0.1 torr for 12 hours to obtain the activated DUT-67.

Example 4 preparation method of microporous zirconium-based Metal organic framework Material

a40 mL glass bottle with a polytetrafluoroethylene gasket on the lid was taken, 7.5mL of anhydrous formic acid and 12mL of N, N-Dimethylformamide (DMF) were added thereto, and shaking was performed, and the flask was weighedTaking ZrOCl ₂ ·8H ₂ O (120 mg,0.372 mmol), 2, 5-thiophenedicarboxylic acid (60 mg,0.348 mmol) was added to the above mixed solution, the reaction system was uniformly mixed by ultrasonic, and the cap of the glass was closed and reacted at 120℃for 72 hours. The vial was then removed and cooled to room temperature in air. Removing supernatant in a glass bottle, adding N, N-Dimethylformamide (DMF), removing crystals on the bottle wall by ultrasonic, filtering to collect crystals, adding DMF into the obtained crystals, repeatedly washing for three times, soaking for 1 day with deionized water, washing for 3 times with methanol, soaking for 3 days, replacing 6 times of fresh methanol each day, completely exchanging DMF in a pore canal for methanol, drying at room temperature for 12 hours, and then drying at 50 ℃ under vacuum degree of 0.001-0.1 torr for 12 hours to obtain the activated DUT-67.

Example 5 preparation method of microporous zirconium-based Metal organic framework Material

a40 mL glass bottle with a polytetrafluoroethylene gasket on a cap was taken, 7.5mL of anhydrous formic acid and 12mL of N, N-Dimethylacetamide (DMAC) were added thereto, shaken well, and ZrO (NO ₃ ) ₂ xH ₂ O (120 mg, 0.399 mmol), 2, 5-thiophenedicarboxylic acid (60 mg,0.348 mmol) was added to the above mixed solution, the reaction system was uniformly mixed by ultrasonic, and the cap was closed with the glass bottle and reacted at 120℃for 72 hours. The vial was then removed and cooled to room temperature in air. Removing supernatant in a glass bottle, adding N, N-Dimethylformamide (DMF), removing crystals on the bottle wall by ultrasonic, filtering to collect crystals, adding DMF into the obtained crystals, repeatedly washing for three times, soaking for 1 day with deionized water, washing for 3 times with methanol, soaking for 3 days, replacing 6 times of fresh methanol each day, completely exchanging DMF in a pore canal for methanol, drying at room temperature for 12 hours, and then drying at 50 ℃ under vacuum degree of 0.001-0.1 torr for 12 hours to obtain the activated DUT-67.

Example 6 preparation method of microporous zirconium-based Metal organic framework Material

a40 mL glass bottle with a polytetrafluoroethylene gasket on a cover was taken, 7.5mL of anhydrous formic acid and 12mL of N, N-Dimethylacetamide (DMAC) were added thereto, and the mixture was shaken well to weigh ZrCl ₄ (100 mg,0.429 mmol) and 2, 5-thiophenedicarboxylic acid (60 mg,0.348 mmol) were added to the above mixed solution, the reaction system was uniformly mixed by ultrasonic, and the cap of the glass bottle was closed and reacted at 120℃for 72 hours. The vial was then removed and cooled to room temperature in air. Removing supernatant in a glass bottle, adding N, N-Dimethylformamide (DMF), removing crystals on the bottle wall by ultrasonic, filtering to collect crystals, adding DMF into the obtained crystals, repeatedly washing for three times, soaking for 1 day with deionized water, washing for 3 times with methanol, soaking for 3 days, replacing 6 times of fresh methanol each day, completely exchanging DMF in a pore canal for methanol, drying at room temperature for 12 hours, and then drying at 50 ℃ under vacuum degree of 0.001-0.1 torr for 12 hours to obtain the activated DUT-67.

Example 7 preparation method of Kg grade microporous zirconium-based organic frame Material

A preparation method of Kg-level microporous zirconium-based metal organic framework material comprises the following steps:

10L of anhydrous formic acid and 15L of N, N-Dimethylacetamide (DMAC) are added into a 40L industrial reaction kettle, stirred uniformly and ZrOCl is added into the mixture ₂ ·8H ₂ O (1.20 kg,3.72 mol), 2, 5-thiophenedicarboxylic acid (500 g,2.9 mol), stirring well, heating the reaction vessel to 120℃and stirring and refluxing for reaction for 72 hours. Cooled to room temperature in air. And (3) filtering to separate out a product, washing the product with DMF for three times, soaking the product in deionized water for 1 day, filtering to separate out the product, washing the product with methanol for 3 times, soaking the product in absolute methanol for 3 days, replacing fresh methanol for 3 times each day, completely exchanging DMF in a pore channel for methanol, and drying the product at room temperature for 12 hours to obtain the pure DUT-67. And weighing the DUT-67 prepared by the expanded production according to the actual situation, and further carrying out vacuum drying to obtain the activated DUT-67.

Characterization and performance testing of experimental example DUT-67

The microstructure of the obtained DUT-67 was confirmed by X-ray diffraction, the microstructure of which is schematically shown in FIG. 1, the frame had a reo topology, two types of cavities were present in the frame, and the inner diameter of the small cavity (yellow)

Inner diameter (pink) of large cavity>

Wherein Zr is ₆ Clusters belonging to the 8-linkage, i.e. one Zr ₆ The clusters are linked with 8 2,5 thiophene dicarboxylic acids.

The X-ray diffraction Pattern (PXRD) of the obtained DUT-67 was tested, and the result is shown in FIG. 2, and the diffraction peak in the PXRD pattern of the DUT-67 obtained by the method is narrow and sharp, well matched with the powder pattern of single crystal simulation, and proved to have good crystallinity and be pure phase. Wherein, the powder pattern of the single crystal simulation is obtained by converting corresponding single crystal data based on Mercury software.

To test the specific surface area of the obtained DUT-67, the pore size and pore volume thereof were analyzed, and the DUT-67 was subjected to a 77K nitrogen isothermal adsorption test, the test result is shown in FIG. 3, and the BET specific surface area is 1178.23m ² .g ^-1 The aperture is

And

in order to test the hydrothermal stability and physical and chemical stability of the obtained DUT-67, the synthesized fresh sample is soaked in hot water at 85 ℃, hydrochloric acid at 12M and hydrochloric acid at 6M and aqueous solution of NaOH at 1M for 24 hours respectively, soaked in seawater for one month, and then PXRD data of the soaked sample is tested, and the result is shown in figure 4, the PXRD pattern of the DUT-67 after being soaked in hot water, acid, alkali solution or seawater can still be well matched with the pattern of the freshly synthesized DUT-67, which shows that the DUT-67 still maintains good structural integrity after being soaked in various solutions, and has excellent hydrothermal stability and acid-base stability.

To determine the thermal stability of DUT-67 in air, thermal stability tests were performed. Thermogravimetric analysis (TGA) was performed first and samples were run at 10℃for a period of min ^-1 As a result of the heating to 800 c at a rate of about 250 c, the DUT-67 sample obtained by this method showed a first plateau at about 250 c, indicating that the sample lost almost all of the solvent in the cell, i.e., the structure of the sample began to collapse after 250 c. At the same time, the invention also carries out temperature-changing X-ray powder diffraction test, and the obtained DUT-67 sample is respectively processed at 5 ℃ for min ^-1 The temperature was gradually increased to 100deg.C, 120deg.C, 140deg.C, 160deg.C, 180deg.C, 220deg.C, 260deg.C, 280 deg.C and 300deg.C, and maintained at these temperatures for 10 minutes to obtain PXRD data at these temperatures, which were consistent with the TGA data as shown in FIG. 5b, and the PXRD of the DUT-67 treated at different temperatures was still well matched with the freshly synthesized diffraction pattern of DUT-67 (25deg.C), demonstrating that the resulting DUT-67 had good thermal stability and still maintained the stability of the frame at a high temperature of 250deg.C.

To characterize DUT-76 at 273 and 298K for the principal component of air (N ₂ 、O ₂ 、CO ₂ )、SO ₂ The single component adsorption performance of R22 and R134a, the single component adsorption isotherms of these gases at two temperatures were tested, and as shown in FIG. 6, DUT-67 had lower or no adsorption performance on the main component of air, but no adsorption performance on SO ₂ R22 and R134a all showed excellent adsorption performance, indicating DUT-67 has good adsorption to Air/SO ₂ And Air/R22/R134a, and the desorption curves and adsorption curves of adsorption isotherms of all gases in the graph are synchronously changed and coincide, which indicates that the adsorption process is physical adsorption and the adsorption is reversible.

To further determine DUT-67 pair Air/SO ₂ CO in Air/R22/R134a mixed system ₂ (adsorption is most competitive) with SO in a mixed system ₂ Selectivity of separation of R22 and R134a, SO at different molar ratios was calculated by theory of ideal adsorption solution (Ideal Adsorbed Solution Theory, IAST) ₂ /CO ₂ 、R22/CO ₂ And R134a/CO ₂ The results are shown in FIG. 7 and FIG. 8, and the results show that IAST selectivity of three two-component gases is all>20, demonstrates that DUT-67 can separate and trap SO from flue gas and air with high selectivity ₂ R22 and R134a.

To simulate an actual industrial separation process, dynamic penetration experiments were employed to evaluate DUT-67 for simulated flue gas Air/SO ₂ Mixed gas (N) ₂ ：O ₂ ：CO ₂ ：SO ₂ =81.8: 15:3:0.2 SO in (x) ₂ Is effective in the separation. 1.0g of activated DUT-67 sample was packed into a packed column as a fixed bed of an adsorption column followed by 40mL.min ^-1 Is introduced into the packed column, the result is shown in FIG. 9, since DUT-67 is for N ₂ ,O ₂ ,CO ₂ Is low in adsorption affinity, and the three gases rapidly penetrate through the packed column SO ₂ Has strong interaction with the framework of the DUT-67, can be absorbed in the pore canal by the DUT-67 in a large amount, and starts to pass out of the filling column after 96 minutes, and SO in the mixed gas flowing through the column before 96 minutes ₂ Are all completely trapped on the packed column, proving that DUT-67 can realize the function of N ₂ ：O ₂ ：CO ₂ ：SO ₂ (81.8:15:3:0.2) SO in the gas mixture ₂ High-efficiency and high-selectivity separation and trapping of the catalyst.

In order to explore the separation effect under the working condition temperature in actual industrial production, an Air/SO is used ₂ (N ₂ ：O ₂ ：CO ₂ ：SO ₂ =81.8: 15:3:0.2 Mixed gas, gas flow rate 40mL min ^-1 Separation curves were tested for 273K (simulating winter temperature) and 303K (simulating summer temperature), respectively, and the results are shown in FIG. 10, where temperature versus SO ₂ Has obvious influence on the separation effect of DUT-67 on SO at 273K ₂ 2.11 times the capture of about 298K, 2.46 times 303K, indicating that low temperatures favor SO ₂ Is trapped, and the separation effect is reduced at high temperatures.

DUT-67 vs SO in the presence of steam was studied to approximate actual commercial production conditions ₂ Influence of trapping Effect Using Air/SO ₂ (N ₂ ：O ₂ ：CO ₂ ：SO ₂ (81.8:15:3:0.2)) and gas flow rate of 40ml.min ^-1 The separation effect at 50% humidity was tested, and as shown in FIG. 11, SO was found after increasing the humidity ₂ Is only 1.21 minutes earlier than the exit point without humidity effect, indicating that water vapor traps SO for DUT-67 ₂ The effect of the method is very little, and the material has good steam interference resistance.

To test material recycling performance, at 298K, air/SO was used ₂ (N ₂ ：O ₂ ：CO ₂ ：SO ₂ =81.8: 15:3:0.2 Mixed gas, gas flow rate 40mL min ^-1 Cycle tested 3 times SO ₂ The result of trapping is shown in FIG. 12, and the result shows SO ₂ The time points of penetrating out the filling column are consistent, the curve coincidence is also good, and the material has good stability and recycling performance.

To evaluate the separation performance of the material for low concentrations of R22 and R134a in the atmosphere, a mixture of Air/R22/R134a (80:10:10; 98:1:1) was first used, 10mL. Min ^-1 Under 298K, the trapping performance of DUT-67 on R22 and R134a in air was tested, and as shown in FIGS. 13 and 14, the DUT-67 material can completely trap R22 and R134a from air onto a packed column, thereby realizing air purification and selective recovery of R22 and R134a.

The fluorochloroalkane in the atmosphere is partially dissolved into the surface water of the ocean, the surface seawater is usually collected during environmental monitoring, and then the dissolved fluorochloroalkane in the seawater is enriched by adopting a sweeping and trapping mode. Since the solubility of fluorochloroalkanes in seawater is very low, to explore whether the material can be used to capture very low concentrations of R22 and R134a taken from the seawater purge, an Air/R22/R134a (99.6:0.02:0.02) mixture was used at 50mL min ^-1 The trapping effect of the sample on R22 and R134a in the mixed gas is tested, and the result is shown in figure 15, and the sample is found to still trap R22 and R134a in the air which only contains 0.02% on the column, which proves that the material can be used for sweeping, condensing and trapping to detect the fluorochloroalkane in the seawaterAnd the adsorbent is efficiently trapped.

For testing the recycling performance of the materials, a mixture of Air/R22/R134a (80:10:10) was used at 10mL min ^-1 The DUT-67 was tested for cycle trapping performance for R22 and R134a in air at 298K. The six cycles are shown in FIG. 16, and the exit points of R22 and R134a in each cycle are basically consistent, which shows that the material has good recycling performance.

To investigate the effect of the presence of water vapor on DUT-67 capturing R22 and R134a, a mixture of Air/R22/R134a (80:10:10) was used at 10mL min ^-1 The DUT-67 was tested for the trapping of R22 and R134a in 50% humidity air at 298K, and the results are shown in fig. 17, where the penetration time points of R22 and R134a were only slightly advanced compared to the dry state (fig. 13), demonstrating that the material has very high resistance to moisture vapor interference.

In order to prove the feasibility of large-scale synthesis of the series of materials, the synthesis scale of the DUT-67 is enlarged, the result is shown in figure 18, 1.2kg of DUT-67 is synthesized at one time by adopting a 40L industrial reaction kettle, the obtained product is subjected to PXRD characterization, and the result is shown in figure 19, the PXRD spectrum of the obtained DUT-67 can be well matched with the single crystal data simulation spectrum of the DUT-67, so that the product of large-scale synthesis has high purity and good crystallinity.

The crystal structure, physicochemical properties, and selective trapping and separation gas properties of the DUTs-67 prepared in examples 2-7 are substantially identical to those of the DUT-67 prepared in example 1.

The above examples are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above examples, and any other changes, modifications, substitutions, combinations, and simplifications that do not depart from the spirit and principle of the present invention should be made in the equivalent manner, and the embodiments are included in the protection scope of the present invention.

Claims

1. The preparation method of the microporous zirconium-based metal organic framework material is characterized by comprising the following steps of: fully mixing a polar organic solvent with formic acid, adding zirconium salt and thiophene dicarboxylic acid organic ligand, fully mixing, heating at 80-150 ℃ for complete reaction, and carrying out post-treatment to obtain the catalyst;

wherein the polar organic solvent is N, N-dimethylacetamide or N, N-dimethylformamide;

the volume ratio of the polar organic solvent to the formic acid is 2:0.5 to 2;

2. The method of claim 1, wherein the microporous zirconium-based metal organic framework material has the molecular formula Zr ₆ O ₈ (OH) ₈ X ₄ ；

Wherein X is a thiophene dicarboxylic acid organic ligand.

3. The preparation method according to claim 1, wherein the zirconium salt is ZrOCl ₂ 、ZrCl ₄ 、ZrO(NO ₃ ) ₂ Any one of the following.

4. The process according to claim 1, wherein the organic ligand of thiophene dicarboxylic acid is 2, 5-thiophene dicarboxylic acid.

5. The preparation method according to claim 1, wherein the mixing ratio of the total volume of the polar organic solvent and formic acid to the total mass of zirconium salt and thiophene dicarboxylic acid organic ligand is 6.5mL: 60-450 mg.

6. The process according to claim 1, wherein the reaction is completed for a period of 12 to 150 hours.

7. The method of claim 1, wherein the post-treatment further comprises suction filtration, washing, soaking, and drying.

8. The method according to claim 7, wherein the drying is performed after drying at room temperature.

9. The use of the microporous zirconium-based metal organic framework material prepared by the preparation method of any one of claims 1to 8 in haloalkane gas and sulfur dioxide adsorption and separation.

10. The use according to claim 9, wherein the haloalkane gas comprises difluoromethane, 1, 2-tetrafluoroethane, sulfur hexafluoride, carbon tetrafluoride, hexafluoroethane, fluorotrichloromethane, hexafluoroethane, tetrafluoromethane, octafluoropropane, dichlorodifluoromethane, chlorotrifluoromethane, pentafluoroethane, trifluoromethane.