Fluorine ion doped copper-based MOF composite material as well as preparation method and application thereof

Abstract

The invention relates to the technical field of crystalline porous materials, in particular to a fluorine ion doped copper-based MOF composite material and a preparation method and application thereof.The preparation method comprises the steps that 2, 3, 4-trifluorophenol, formaldehyde and CM MOF are subjected to a gas-phase polymerization reaction in a gas-phase polymerization reactor at the temperature of 70-100 DEG C under normal pressure, and F3 / CM MOF is obtained after the reaction is conducted for 10-20 h. According to the fluorine ion doped copper-based MOF composite material, the unique cubic structure mode and the pore structure of CM MOF are utilized, Cu sites and fluorine ions are organically combined, an F3 / CM MOF material is prepared, protection and fluorination effects on the open metal Cu sites can be achieved through introduction of F ions, the structural stability of the CM MOF is promoted, and adsorption of ethylene oxide gas is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of crystalline porous materials, and in particular to a fluorine ion-doped copper-based MOF composite material and a preparation method and application thereof. Background Art

[0002] VOCs refer to volatile organic compounds. Outdoor sources include industrial waste gases from fuel combustion and transportation, automobile exhaust, and photochemical pollution. Indoor sources include coal and natural gas combustion, smoking, cooking, and other sources. Building and decorative materials, furniture, and household appliances also generate VOCs. In recent years, VOCs have attracted widespread attention due to their toxicity, irritation, and carcinogenicity. VOC treatment technologies primarily include thermal destruction, pressure swing adsorption separation, purification, adsorption, and oxidation treatment. Ethylene oxide is an organic compound widely used in the pharmaceutical and printing and dyeing industries. In the chemical industry, it serves as a starting agent for cleaning agents. It is miscible with water in all proportions and is also soluble in organic solvents such as alcohol, ether, and carbon disulfide. Ethylene oxide is a toxic carcinogen and highly toxic to humans, causing central nervous system depression, respiratory distress, and pulmonary edema. Key methods for treating ethylene oxide include direct combustion, atmospheric pressure catalytic water treatment, specialized ethylene oxide exhaust emission equipment, and catalytic adsorption. Catalytic adsorption, with its advantages of high efficiency and selectivity, has attracted widespread attention. The catalysts commonly used in the catalytic adsorption method include transition metal oxides, ceramic fiber catalysts, activated carbon-based catalysts, metal-based catalysts, etc. Among them, metal-based catalysts have the advantages of high catalytic activity, reusability, and wide application.

[0003] Metal-organic frameworks (MOFs) are a new type of crystalline porous functional material. They are composed of metal ions or metal clusters and organic ligands, forming a porous network structure based on coordination bonds. MOFs have a periodic three-dimensional structure and are studied across multiple disciplines, including crystal engineering, topology, organic chemistry, inorganic chemistry, coordination chemistry, and materials chemistry. After decades of development, they have been widely used in fields such as adsorption separation, gas storage, drug release, and catalysis. Copper-based MOFs can be prepared using a variety of ligands and different synthetic methods, exhibiting structural tunability and catalytic stability. The paper [AC Massibility control of Cu sites to enhance the adsorption capacity of ultra-low-concentration methyl mercaptan] reports a copper-based metal-organic framework (MOF) that was used to adsorb low-concentration methyl mercaptan by adjusting the pore size and number of unsaturated sites, ultimately achieving an optimal removal capacity of 160.3 mg / g. Chinese patent CN113413878A prepared amino-copper-based MOF adsorbents and new MOFs grafted with amino groups. It was found that after grafting with amino groups, the adsorption rate of 1000ppm H2S reached more than 99%. The literature [Molecular sieve screening based on low-concentration octafluoropropane gas adsorption, MOFs preparation and adsorption performance research] synthesized the cobalt-doped metal organic framework material CoxCr-MIL-101 by hydrothermal method, in which Co 0.2 The adsorption equilibrium capacity of Cr-MIL-101 sample for C3F8 at 25℃ and 180Pa is 0.077mmol / g.

[0004] Although there are many studies on the use of MOFs for catalytic adsorption of organic gases, there are few reports on the catalytic adsorption and separation of ethylene oxide using MOFs, and the recyclability of current materials used for the adsorption and separation of ethylene oxide is low. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a fluorine ion-doped copper-based MOF composite material and its preparation method and application. The fluorine ion-doped copper-based MOF composite material can adsorb and separate low-concentration ethylene oxide and has good regeneration performance.

[0006] The present invention solves the above technical problems through the following technical means:

[0007] The first aspect of the present application provides a method for preparing a fluoride ion-doped copper-based MOF composite material. The preparation method comprises the following steps: subjecting 2,3,4-trifluorophenol, formaldehyde and CM MOF to a gas phase polymerization reaction at a temperature of 70 to 100°C and normal pressure in a gas phase polymerization reactor, and reacting for 10 to 20 hours to obtain F3 / CM MOF.

[0008] Preferably, the mass ratio of 2,3,4-trifluorophenol, formaldehyde and CM MOF is (1-2):(1-2):(1-2).

[0009] Preferably, the mass ratio of 2,3,4-trifluorophenol, formaldehyde and CM MOF is 2:1:2.

[0010] Preferably, the raw materials for preparing the CM MOF include CuCl2, 1H-pyrazole-4-carboxylic acid, N,N-dimethylformamide and acetic acid, and the mass ratio of CuCl2, 1H-pyrazole-4-carboxylic acid, N,N-dimethylformamide and acetic acid is (8-20): (8-20): 1:1.

[0011] Preferably, the preparation method of the CM MOF is as follows:

[0012] CuCl2, 1H-pyrazole-4-carboxylic acid, N,N-dimethylformamide, and acetic acid were weighed separately; CuCl2 and 1H-pyrazole-4-carboxylic acid (L1H4) were added to a headspace injection vial, N,N-dimethylformamide was added to dissolve, and ultrasonic treatment was performed, followed by addition of acetic acid, mixing evenly, and reacting at a temperature of 100-150°C for 3-5 days. The obtained reaction product was washed and dried to obtain CM MOF.

[0013] Preferably, the mass ratio of CuCl2 to 1H-pyrazole-4-carboxylic acid, N,N-dimethylformamide and acetic acid is 10:10:1:1.

[0014] Preferably, the reaction product is washed with DMF and methanol for 3 to 5 times respectively, and dried in an oven at 40 to 80° C. for 10 to 20 hours.

[0015] The second aspect of the present application provides a fluoride ion-doped copper-based MOF composite material, which is prepared using the preparation method described in the first aspect.

[0016] The third aspect of the present application provides the use of the fluorine ion-doped copper-based MOF composite material described in the second aspect in an ethylene oxide gas adsorption material.

[0017] The fluoride ion-doped copper-based MOF composite material of the present invention utilizes the unique cubic structural mode and pore structure of CM MOF to organically combine fluoride ions at Cu sites to prepare F3 / CM MOF material. The introduction of F ions can achieve protection and fluorination of open metal Cu sites, promote the structural stability of CM MOF, and realize the adsorption of ethylene oxide gas.

[0018] The fluoride-ion-doped copper-based MOF composite material of the present invention has strong structural stability, can achieve adsorption of low-concentration (8 ppm) ethylene oxide gas, with an adsorption capacity of up to 152 mg / g, and exhibits good regeneration performance. The fluoride-ion-doped copper-based MOF composite material of the present invention can be used to prepare ethylene oxide gas adsorption materials for adsorbing low-concentration ethylene oxide gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is the thermogravimetric diagram of the composite material prepared in Example 4;

[0020] Figure 2 The adsorption kinetics curves of ethylene oxide by the composite materials prepared in Examples 1-4 and Comparative Example 1 are as follows;

[0021] Figure 3 1 is a graph showing the adsorption cycle performance of the composite materials prepared in Example 2, Example 4 and Comparative Example 1 for ethylene oxide. DETAILED DESCRIPTION

[0022] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0023] In the specification and claims herein, the terms "first" and "second" are used to distinguish different objects, rather than to describe a specific order of objects. In the description of the embodiments of this application, unless otherwise specified, the meaning of "plurality" refers to two or more. For example, "multiple processing units" refers to two or more processing units, etc., and "multiple components" refers to two or more components, etc.

[0024] In the embodiments of this application, words such as "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of this application should not be interpreted as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0025] The fluoride ion-doped copper-based MOF composite material of the present application utilizes the unique cubic structural pattern and pore structure of CM MOF to organically combine fluoride ions at the Cu site to prepare F3 / CM MOF material. The introduction of F ions can achieve protection and fluorination of the open metal Cu site, promote the structural stability of CM MOF, and realize the adsorption of ethylene oxide gas.

[0026] The preparation method of the fluoride ion-doped copper-based MOF composite material of the present application is as follows:

[0027] (1) Preparation of CM MOF

[0028] Weigh CuCl2, 1H-pyrazole-4-carboxylic acid, N,N-dimethylformamide, and acetic acid separately; add CuCl2 and 1H-pyrazole-4-carboxylic acid (L1H4) into a headspace injection vial, add N,N-dimethylformamide to dissolve, and ultrasonicate, then add acetic acid, mix well, and react at a temperature of 100-150°C for 3-5 days. The obtained reaction product is washed with DMF and methanol 3-5 times each, and dried in an oven at 40-80°C for 10-20 hours to obtain CM MOF. In this step, the mass ratio of CuCl2 to 1H-pyrazole-4-carboxylic acid, N,N-dimethylformamide, and acetic acid is (8-20): (8-20): 1:1

[0029] (2) Preparation of F3 / CM MOF materials

[0030] 2,3,4-trifluorophenol, formaldehyde, and CM MOF are subjected to a gas-phase polymerization reaction in a gas-phase polymerization reactor at a temperature of 70-100°C and normal pressure for 10-20 hours to obtain F3 / CM MOF. The mass ratio of 2,3,4-trifluorophenol, formaldehyde, and CM MOF is (1-2):(1-2):(1-2).

[0031] In order to better understand the above technical solution, the above technical solution will be described in detail below with reference to the accompanying drawings and specific implementation methods.

[0032] Example 1

[0033] The preparation method of the fluorine ion-doped copper-based MOF composite material of this embodiment is as follows:

[0034] (1) Preparation of CM MOF

[0035] CuCl2, L1H4, DMF, and acetic acid were weighed according to the mass ratio of 10:20:1:1, and CuCl2 and 1H-pyrazole-4-carboxylic acid (L1H4) were added to a headspace injection bottle, dissolved in DMF, and ultrasonically treated for 5 minutes. Acetic acid was added and mixed evenly. The mixture was placed in a 120°C oven for reaction for 5 days, washed with DMF and methanol 5 times respectively, and dried in a 50°C oven for 12 hours to obtain CM MOF.

[0036] (2) Preparation of F3 / CM MOF materials

[0037] 2,3,4-trifluorophenol, formaldehyde and CM MOF were weighed according to a mass ratio of 1:2:2, and added into a gas phase polymerization reactor. The gas phase polymerization reaction was carried out at a temperature of 90°C and the reaction was carried out at normal pressure for 12 hours to obtain F3 / CM MOF.

[0038] Example 2

[0039] The preparation method of the fluorine ion-doped copper-based MOF composite material of this embodiment is as follows:

[0040] (1) Preparation of CM MOF

[0041] CuCl2, L1H4, DMF, and acetic acid were weighed according to the mass ratio of 10:10:1:1, and CuCl2 and 1H-pyrazole-4-carboxylic acid (L1H4) were added to a headspace injection bottle, dissolved in DMF, and ultrasonically treated for 5 minutes. Acetic acid was added and mixed evenly. The mixture was placed in a 120°C oven to react for 5 days, washed with DMF and methanol 5 times respectively, and dried in a 50°C oven for 12 hours to obtain CM MOF.

[0042] (2) Preparation of F3 / CM MOF materials

[0043] 2,3,4-trifluorophenol, formaldehyde and CM MOF were weighed in a mass ratio of 1:1:1, respectively, and added into a gas phase polymerization reactor. The gas phase polymerization reaction was carried out at a temperature of 90°C and the reaction was carried out at normal pressure for 12 hours to obtain F3 / CM MOF.

[0044] Example 3

[0045] The preparation method of the fluorine ion-doped copper-based MOF composite material of this embodiment is as follows:

[0046] (1) Preparation of CM MOF

[0047] CuCl2, L1H4, DMF, and acetic acid were weighed according to the mass ratio of 10:10:1:1, and CuCl2 and 1H-pyrazole-4-carboxylic acid (L1H4) were added to a headspace injection bottle, dissolved in DMF, and ultrasonically treated for 5 minutes. Acetic acid was added and mixed evenly. The mixture was placed in a 120°C oven to react for 5 days, washed with DMF and methanol 5 times respectively, and dried in a 50°C oven for 12 hours to obtain CM MOF.

[0048] (2) Preparation of F3 / CM MOF materials

[0049] 2,3,4-trifluorophenol, formaldehyde and CM MOF were weighed in a mass ratio of 2:1:1, respectively, and added into a gas phase polymerization reactor. The gas phase polymerization reaction was carried out at a temperature of 90°C and the reaction was carried out at normal pressure for 12 hours to obtain F3 / CM MOF.

[0050] Example 4

[0051] The preparation method of the fluorine ion-doped copper-based MOF composite material of this embodiment is as follows:

[0052] (1) Preparation of CM MOF

[0053] CuCl2, L1H4, DMF, and acetic acid were weighed according to the mass ratio of 10:10:1:1, and CuCl2 and 1H-pyrazole-4-carboxylic acid (L1H4) were added to a headspace injection bottle, dissolved in DMF, and ultrasonically treated for 5 minutes. Acetic acid was added and mixed evenly. The mixture was placed in a 120°C oven to react for 5 days, washed with DMF and methanol 5 times respectively, and dried in a 50°C oven for 12 hours to obtain CM MOF.

[0054] (2) Preparation of F3 / CM MOF materials

[0055] 2,3,4-trifluorophenol, formaldehyde and CM MOF were weighed according to a mass ratio of 2:1:2, and added into a gas phase polymerization reactor. The gas phase polymerization reaction was carried out at a temperature of 90°C and the reaction was carried out at normal pressure for 12 hours to obtain F3 / CM MOF.

[0056] Example 5

[0057] The preparation method of the fluorine ion-doped copper-based MOF composite material of this embodiment is as follows:

[0058] (1) Preparation of CM MOF

[0059] CuCl2, L1H4, DMF, and acetic acid were weighed according to the mass ratio of 8:8:1:1, and CuCl2 and 1H-pyrazole-4-carboxylic acid (L1H4) were added to a headspace injection bottle, dissolved in DMF, and ultrasonically treated for 2 minutes. Acetic acid was added and mixed evenly. The mixture was placed in a 100°C oven to react for 3 days, washed with DMF and methanol three times respectively, and dried in a 40°C oven for 20 hours to obtain CM MOF.

[0060] (2) Preparation of F3 / CM MOF materials

[0061] 2,3,4-trifluorophenol, formaldehyde and CM MOF were weighed according to a mass ratio of 1.5:1:1.5, respectively, and added into a gas phase polymerization reactor. The gas phase polymerization reaction was carried out at a temperature of 70°C and the reaction was carried out at normal pressure for 10 hours to obtain F3 / CM MOF.

[0062] Example 6

[0063] The preparation method of the fluorine ion-doped copper-based MOF composite material of this embodiment is as follows:

[0064] (1) Preparation of CM MOF

[0065] CuCl2, L1H4, DMF, and acetic acid were weighed according to the mass ratio of 20:20:1:1, and CuCl2 and 1H-pyrazole-4-carboxylic acid (L1H4) were added to a headspace injection bottle, dissolved in DMF, and ultrasonically treated for 4 minutes. Acetic acid was added and mixed evenly. The mixture was placed in a 150°C oven for reaction for 3 days, washed with DMF and methanol four times respectively, and dried in an 80°C oven for 10 hours to obtain CM MOF.

[0066] (2) Preparation of F3 / CM MOF materials

[0067] 2,3,4-trifluorophenol, formaldehyde and CM MOF were weighed according to a mass ratio of 1:2:1, and added into a gas phase polymerization reactor. The gas phase polymerization reaction was carried out at a temperature of 100°C and at normal pressure for 20 hours to obtain F3 / CM MOF.

[0068] Comparative Example 1

[0069] The composite material of this comparative example differs from that of Example 4 in that fluoride ions are not loaded, that is, the CMMOF in Example 4.

[0070] The composite materials prepared in Examples 1-4 and Comparative Example 1 were tested for ethylene oxide adsorption performance, as follows:

[0071] The composite materials prepared in Examples 1-4 and Comparative Example 1 were used as samples for ethylene oxide gas adsorption tests: ethylene oxide gas adsorption tests were performed on each composite material using a UTEST static adsorption device, controlling the test flow rate (15 L / min), test resistance (<70 Pa), and test concentration (8 ppm). The test results are shown in Table 1. Figure 1 This is the thermogravimetric diagram of the composite material prepared in Example 4. Figure 2 The adsorption kinetics curves of ethylene oxide by the composite materials prepared in Examples 1-4 and Comparative Example 1 are as follows: Figure 3 1 is a graph showing the adsorption cycle performance of the composite materials prepared in Example 2, Example 4 and Comparative Example 1 for ethylene oxide.

[0072] name <![CDATA[BET(m 2 / g)]]> Air volume (L / min) Adsorption capacity (mg / g) Example 1 542 15 121 Example 2 651 15 137 Example 3 543 15 132 Example 4 832 15 152 Comparative Example 1 465 15 86

[0073] Table 1

[0074] Figure 1 The data show that the F3 / CM MOF material prepared in Example 4 begins to decompose at 240°C and has good thermal stability. Figure 2 The data show that the F3 / CM MOF material prepared in Example 4 has the best adsorption effect on ethylene oxide and the largest adsorption capacity, reaching adsorption saturation in about 120 minutes. In addition, the adsorption performance of the F3 / CM MOF material is higher than that of the CMMOF in the comparative example, indicating that the binding of fluoride ions helps to improve the adsorption performance. Figure 2 The data show that after five cycles of adsorption, the adsorption capacity of ethylene oxide by the F3 / CM MOF material prepared in Example 4 decreased from 152 mg / g in the first cycle to 120 mg / g, maintaining a relatively stable ethylene oxide adsorption capacity. However, the CM MOF material of the comparative example showed a significant decrease in adsorption capacity in the second cycle, indicating that the regeneration performance of the F3 / CM MOF material is better than that of the CM MOF material, and that the doping of fluoride ions is beneficial to improving the regeneration performance of the adsorption material.

[0075] In summary, the fluoride-ion-doped copper-based MOF composite material of the present invention has strong structural stability, can achieve low-concentration (8 ppm) adsorption of ethylene oxide gas, and exhibits good regeneration performance. The fluoride-ion-doped copper-based MOF composite material of the present invention can be used to prepare ethylene oxide gas adsorption materials for adsorbing low-concentration ethylene oxide gas.

[0076] The above embodiments are intended only to illustrate the technical solutions of the present invention and are not intended to limit the scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art will appreciate that the technical solutions of the present invention may be modified or replaced with equivalents without departing from the spirit and scope of the technical solutions of the present invention, and such modifications or equivalents shall be encompassed by the claims of the present invention. Any techniques, shapes, and structures not described in detail herein are well known.

Claims

1. A method for preparing a fluoride ion-doped copper-based MOF composite material, characterized in that: The preparation method comprises the following steps: placing 2,3,4-trifluorophenol, formaldehyde and CM MOF in a gas phase polymerization reactor at a temperature of 70-100° C. and normal pressure to carry out a gas phase polymerization reaction, and reacting for 10-20 hours to obtain F3 / CM MOF.

2. The method for preparing a fluorine ion-doped copper-based MOF composite material according to claim 1, wherein: The mass ratio of the 2,3,4-trifluorophenol, formaldehyde and CM MOF is (1-2): (1-2): (1-2).

3. The method for preparing a fluorine ion-doped copper-based MOF composite material according to claim 2, wherein: The mass ratio of 2,3,4-trifluorophenol, formaldehyde and CM MOF is 2:1:

2.

4. The method for preparing a fluorine ion-doped copper-based MOF composite material according to claim 1, wherein: The raw materials for preparing the CM MOF include CuCl2, 1H-pyrazole-4-carboxylic acid, N,N-dimethylformamide and acetic acid, and the mass ratio of CuCl2, 1H-pyrazole-4-carboxylic acid, N,N-dimethylformamide and acetic acid is (8-20): (8-20): 1:

1.

5. The method for preparing a fluorine ion-doped copper-based MOF composite material according to claim 4, characterized in that: The preparation method of the CM MOF is as follows: Weigh CuCl2, 1H-pyrazole-4-carboxylic acid, N,N-dimethylformamide, and acetic acid respectively; CuCl2 and 1H-pyrazole-4-carboxylic acid (L1H4) were added to a headspace injection bottle, dissolved with N,N-dimethylformamide, and ultrasonically treated. Acetic acid was then added and mixed evenly. The mixture was reacted at a temperature of 100-150°C for 3-5 days. The obtained reaction product was washed and dried to obtain CM MOF.

6. The method for preparing a fluorine ion-doped copper-based MOF composite material according to claim 5, characterized in that: The mass ratio of the CuCl2 to 1H-pyrazole-4-carboxylic acid, N,N-dimethylformamide and acetic acid is 10:10:1:

1.

7. The method for preparing a fluorine ion-doped copper-based MOF composite material according to claim 5, characterized in that: The reaction product was washed with DMF and methanol for 3 to 5 times respectively, and dried in an oven at 40 to 80° C. for 10 to 20 hours.

8. Fluoride ion-doped copper-based MOF composite material, characterized in that: The composite material is prepared by the preparation method according to any one of claims 1 to 7.

9. Use of the fluoride ion-doped copper-based MOF composite material according to claim 8 in an ethylene oxide gas adsorption material.

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