A copper metal-organic framework material, and a preparation method and application thereof

Abstract

The application provides a copper metal-organic framework material and a preparation method and application thereof. The preparation raw material of the copper metal-organic framework material comprises a copper salt and an organic ligand; and the organic ligand is a benzenedicarboxylic acid derivative modified by an amino group and / or a nitro group. The amino group and / or the nitro group are used as basic sites to modify the organic ligand, so that the prepared copper metal-organic framework material has a larger specific surface area, rich porosity and more CO2 adsorption sites, and the CO2 adsorption capacity is effectively improved. Meanwhile, electrostatic interaction or hydrogen bond interaction occurs between the above-mentioned basic sites and CO2, and the affinity of the copper metal-organic framework material and CO2 is enhanced.

Description

Technical Field

[0001] This invention belongs to the field of organic materials technology, specifically relating to a copper-organic framework material, its preparation method, and its application. Background Technology

[0002] To date, over 85% of global energy demand is supported by the burning of fossil fuels, and over 60% of global warming is caused by CO2. Therefore, CO2 capture is one of the effective methods to mitigate the greenhouse effect.

[0003] Common methods for capturing CO2 are classified into three categories: absorption, adsorption, and membrane technology. Among these, amine washing in absorption methods can achieve a CO2 removal rate of 98%, but it requires a large amount of alkaline absorbent and causes severe corrosion to the equipment, making it unsuitable for long-term CO2 capture. Adsorption methods commonly use adsorbents such as zeolites, activated carbon, or metal oxide molecular sieves. These adsorbents bind to CO2 only through weak physical adsorption, resulting in low adsorption capacity and a tendency for adsorption performance to decline. Furthermore, due to weak interactions within their structures, they are prone to structural collapse and exhibit poor selectivity during adsorption, further limiting their widespread application.

[0004] Metal-organic frameworks (MOFs), porous crystalline adsorbents formed by the coordination and combination of metal clusters and organic ligands, can form a honeycomb-like porous structure after linkage. These small channels give them characteristics such as high specific surface area, tunable pore size, and large adsorption capacity, thus they have been widely used in gas storage and separation. In recent years, researchers have found that the affinity of MOF materials disclosed in existing technologies for CO2 is relatively poor. To address this issue, CN113663649A discloses a method for preparing a low-temperature CO2 capture adsorbent, which introduces diamine into the pores of Mg2(dobpdc) through in-situ synthesis. Although the introduction of diamine can greatly protect the metal center and improve its stability to a certain extent, the introduction of diamine also blocks some pores. Moreover, most of the diamine is impregnated on the surface of the MOF material, and the structure is more prone to collapse when the temperature is increased. Furthermore, the internal pores cannot be effectively utilized, resulting in limited improvement in CO2 adsorption capacity.

[0005] Therefore, there is an urgent need in this field to develop a CO2 adsorbent material that not only has high adsorption capacity and adsorption efficiency, but also good structural stability. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide a copper metal-organic framework material, its preparation method, and its applications. This invention modifies organic ligands using amino and / or nitro groups as basic sites, resulting in a copper metal-organic framework material with a large specific surface area, abundant porosity, and more CO2 adsorption sites, effectively improving the CO2 adsorption capacity. Simultaneously, electrostatic interactions or hydrogen bonding occur between these basic sites and CO2, enhancing the affinity of the copper metal-organic framework material for CO2.

[0007] To achieve this objective, the present invention employs the following technical solution:

[0008] In a first aspect, the present invention provides a copper metal-organic framework material, wherein the raw materials for preparing the copper metal-organic framework material include copper salts and organic ligands;

[0009] The organic ligand is a phthalic acid derivative modified with amino and / or nitro groups.

[0010] This invention modifies organic ligands using amino and / or nitro groups as basic sites. The amino and / or nitro groups are inserted into the benzene ring of the organic ligand at the ortho position of the pyrimidine or pyridine ring. The nitrogen atom contained therein can form a strong interaction with CO2, and the H atom in -NH2 can also form an intermolecular hydrogen bond with the O atom in CO2. -NO2 can also form a strong electrostatic interaction with CO2. The above two strong interactions have a synergistic effect, further enhancing the affinity between CO2 and the framework. Compared with unmodified copper metal-organic framework materials, it has more basic sites and stronger interaction forces, thereby increasing its Qst with CO2, enabling it to efficiently capture large amounts of CO2 as an adsorbent.

[0011] In addition, on the one hand, the stable Kagome crystal structure in metal-organic framework materials provides a large specific surface area and abundant porosity; on the other hand, the presence of N atoms in amino and nitro groups provides more CO2 adsorption sites, effectively improving the CO2 adsorption capacity.

[0012] Preferably, the copper salt includes any one or a combination of at least two of CuSO4·5H2O, Cu(NO3)2·3H2O, or CuCl2·2H2O.

[0013] Preferably, the organic ligand comprises any one or a combination of at least two of the following: 5-[3-amino-4-(pyrimidin-5-yl)benzamide] isophthalic acid, 5-[3-nitro-4-(pyrimidin-5-yl)benzamide] isophthalic acid, 5-[3-amino-4-(pyrimidin-5-yl)benzamide] isophthalic acid, 5-[3-nitro-4-(pyrimidin-5-yl)benzamide] isophthalic acid, 5-[2-amino-4-(pyrimidin-5-yl)benzamide] isophthalic acid, or 5-[2-nitro-4-(pyrimidin-5-yl)benzamide] isophthalic acid.

[0014] In this invention, by selecting the above-mentioned types of organic ligands, the polarity and optical properties of copper metal-organic framework materials are improved, the interaction between the frameworks is enhanced, and thus their thermal stability is enhanced. The introduction of basic groups also enhances the CO2 adsorption capacity of copper metal-organic framework materials.

[0015] Preferably, when both nitro-modified organic ligands and amino-modified organic ligands are introduced simultaneously, the mass percentage of the amino-modified organic ligand is 0% to 100%, preferably 50% to 75%, and can be, for example, 0%, 10%, 20%, 30%, 40%, 50%, 52%, 55%, 58%, 60%, 62%, 65%, 68%, 70%, 72%, 75%, 80%, 90%, 100%, etc.

[0016] In this invention, by adjusting the mass percentage of amino-modified organic ligands, the adsorption capacity of the material is improved to a certain extent. If the content is too low, the pore size of MOFs will be unstable, reducing the specificity of the material. Conversely, if the content is too high, it will cause blockage of MOF pores, weakening the bond strength between metal ions and ligands and reducing their stability.

[0017] In a second aspect, the present invention provides a method for preparing the copper metal-organic framework material according to the first aspect, the method comprising the following steps:

[0018] The copper metal-organic framework material is obtained by mixing copper salt, organic ligand, acid solution and solvent and then performing a hydrothermal reaction.

[0019] In this invention, the preparation method provided is a one-step synthesis method, which has a short synthesis time and a simple preparation process, and is expected to be able to efficiently capture CO2.

[0020] Preferably, the copper salt includes any one or a combination of at least two of CuSO4·5H2O, Cu(NO3)2·3H2O, or CuCl2·2H2O.

[0021] Preferably, the amount of copper salt used is 200-250 mg, for example, it can be 200 mg, 205 mg, 208 mg, 210 mg, 212 mg, 215 mg, 218 mg, 220 mg, 222 mg, 225 mg, 228 mg, 230 mg, 232 mg, 235 mg, 238 mg, 240 mg, 242 mg, 245 mg, 248 mg, 250 mg, etc.

[0022] In this invention, high-quality copper metal-organic framework materials are obtained by controlling the amount of copper salt. If the amount is too low, the reaction yield of the copper metal-organic framework material will decrease, and the generated copper metal-organic framework material crystals will be small or form an amorphous state. If the amount is too high, the synthesis reaction will be violent, the generated crystal size will be too large, and the structural stability of the copper metal-organic framework material will be poor.

[0023] Preferably, the organic ligand comprises any one or a combination of at least two of the following: 5-[3-amino-4-(pyrimidin-5-yl)benzamide] isophthalic acid, 5-[3-nitro-4-(pyrimidin-5-yl)benzamide] isophthalic acid, 5-[3-amino-4-(pyrimidin-5-yl)benzamide] isophthalic acid, 5-[3-nitro-4-(pyrimidin-5-yl)benzamide] isophthalic acid, 5-[2-amino-4-(pyrimidin-5-yl)benzamide] isophthalic acid, or 5-[2-nitro-4-(pyrimidin-5-yl)benzamide] isophthalic acid.

[0024] Preferably, the amount of the organic ligand is 50-60 mg, for example, 50 mg, 51 mg, 52 mg, 53 mg, 54 mg, 55 mg, 56 mg, 57 mg, 58 mg, 59 mg, 60 mg, etc.

[0025] In this invention, the morphology of copper metal-organic framework materials is controlled by adjusting the amount of organic ligands. If the amount is too low, there will be virtually no crystallization of copper metal-organic framework materials, while if the amount is too high, the distance between metal ions will increase, affecting the formation of the framework structure.

[0026] Preferably, the molar ratio of the organic ligand to the copper salt is 1:(2-4), more preferably 1:(3-4), and for example, it can be 1:2, 1:2.2, 1:2.5, 1:2.8, 1:3, 1:3.2, 1:3.5, 1:3.8, 1:4, etc.

[0027] In this invention, by controlling the molar ratio of organic ligands to copper salts, copper metal-organic framework materials with stable structure and properties are obtained. If the molar ratio is too low, the cell parameters of the copper metal-organic framework material will change. Low concentration of metal salts may lead to an overly loose crystal structure, while high concentration may lead to an overly large cell volume, which will reduce the stability of the copper metal-organic framework material.

[0028] Preferably, the acid solution includes a hydrochloric acid solution.

[0029] Preferably, the concentration of the hydrochloric acid solution is 2 to 4 mol / L, for example, it can be 2 mol / L, 2.2 mol / L, 2.5 mol / L, 2.8 mol / L, 3 mol / L, 3.2 mol / L, 3.5 mol / L, 3.8 mol / L, 4 mol / L, etc.

[0030] Preferably, the amount of hydrochloric acid used is 0.4 to 0.8 mL, more preferably 0.4 to 0.6 mL, for example, 0.4 mL, 0.42 mL, 0.45 mL, 0.48 mL, 0.5 mL, 0.52 mL, 0.55 mL, 0.58 mL, 0.6 mL, 0.65 mL, 0.7 mL, 0.75 mL, 0.8 mL, etc.

[0031] Preferably, the solvent includes any one or a combination of at least two of N,N-dimethylformamide, acetonitrile, or ethanol.

[0032] Preferably, the amount of solvent used is 20-30 mL, for example, 20 mL, 22 mL, 25 mL, 28 mL, 30 mL, etc.

[0033] Preferably, the mixing is performed under ultrasound.

[0034] Preferably, the ultrasound duration is 2 to 10 minutes, more preferably 5 to 10 minutes, for example, 2 minutes, 3 minutes, 4 minutes, 5 minutes, 6 minutes, 7 minutes, 8 minutes, 9 minutes, 10 minutes, etc.

[0035] Preferably, the temperature of the hydrothermal reaction is 80-120℃, more preferably 80-100℃, for example, 80℃, 82℃, 85℃, 88℃, 90℃, 92℃, 95℃, 98℃, 100℃, 105℃, 110℃, 115℃, 120℃, etc.

[0036] Preferably, the hydrothermal reaction time is 18 to 48 hours, more preferably 18 to 24 hours, for example, 18 hours, 20 hours, 22 hours, 24 hours, 28 hours, 30 hours, 32 hours, 36 hours, 38 hours, 40 hours, 42 hours, 48 ​​hours, etc.

[0037] Preferably, the hydrothermal reaction is followed by centrifugation, filtration, washing, and drying.

[0038] Preferably, the centrifugation speed is 3000-10000 r / min, more preferably 6000-8000 r / min, for example, it can be 3000 r / min, 5000 r / min, 6000 r / min, 7000 r / min, 8000 r / min, 9000 r / min, 10000 r / min, etc.

[0039] Preferably, the centrifugation time is 5 to 20 minutes, more preferably 10 to 15 minutes, for example, 5 minutes, 8 minutes, 10 minutes, 12 minutes, 15 minutes, 18 minutes, 20 minutes, etc.

[0040] Preferably, the washing solvent used for filtration includes at least one of DMF, acetone, methanol, or ethanol.

[0041] Preferably, the filter is washed 1 to 4 times, more preferably 2 to 3 times, for example, 1 time, 2 times, 3 times, 4 times, etc.

[0042] Preferably, the drying temperature is room temperature and the time is 1 to 6 hours, more preferably 3 to 6 hours, for example, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, etc.

[0043] Thirdly, the present invention provides an adsorbent material comprising the copper metal-organic framework material according to the first aspect.

[0044] Fourthly, the present invention provides a CO2 capture agent comprising the adsorbent material according to the third aspect.

[0045] In this invention, the CO2 capture agent provided by this invention captures CO2 under normal temperature and pressure conditions.

[0046] Compared with the prior art, the present invention has the following beneficial effects:

[0047] This invention provides a copper-organic framework material, which inherently possesses a large specific surface area, tunable structure, and modifiable pores. The organic ligands introduce nitrogen-containing groups, increasing adsorption sites and enhancing the affinity between the copper-organic framework and CO2. Furthermore, the copper-organic framework material exhibits excellent CO2 adsorption performance (9.8 mmol / g), good adsorption-desorption curve agreement, and good cyclic adsorption performance, making it widely applicable in carbon capture.

[0048] The preparation method provided by this invention adopts a one-step synthesis method, which has mild reaction conditions, simple operation and short reaction time. Attached Figure Description

[0049] Figure 1 XRD patterns of the copper metal-organic framework materials provided in Examples 1, 2, 3 and Comparative Example 1;

[0050] Figure 2 SEM images of the copper metal-organic framework materials provided in Examples 1, 2, 3 and Comparative Example 1;

[0051] Figure 3 Infrared spectra of the copper metal-organic framework materials provided in Examples 1, 2, 3 and Comparative Example 1;

[0052] Figure 4 Thermogravimetric curves of the copper metal-organic framework materials provided in Examples 1, 2, 3 and Comparative Example 1;

[0053] Figure 5 Nitrogen adsorption-desorption curves of the copper metal-organic framework materials provided in Examples 1, 2, 3 and Comparative Example 1 at 77 K;

[0054] Figure 6 CO2 adsorption-desorption curves of the copper metal-organic framework materials provided in Examples 1, 2, 3 and Comparative Example 1 at 298 K and 1 bar. Detailed Implementation

[0055] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be considered as specific limitations thereof.

[0056] Example 1

[0057] This embodiment provides a copper metal-organic framework material (Cu-MOFs), the raw materials for preparing the copper metal-organic framework material include Cu(NO3)2·3H2O and an organic ligand; the organic ligand is 5-[3-amino-4-(pyrimidin-5-yl)benzamide]isophthalic acid.

[0058] This embodiment also provides a method for preparing the above-mentioned copper metal-organic framework material, which includes the following steps:

[0059] 0.3 mmol of 5-[3-amino-4-(pyrimidin-5-yl)benzamide]isophthalic acid and 0.9 mmol of Cu(NO3)2·3H2O were dissolved in 30 mL of N,N-dimethylformamide solution and sonicated in an ultrasonic reactor for 8 min until the solution was clear and transparent. Then, 0.5 mL of 2 mol / L hydrochloric acid was added to the mixed solution to turn the solution emerald green. The mixed solution was transferred to a 50 mL reaction vessel liner and reacted in an 80 °C drying oven for 18 h. After cooling to room temperature, the resulting solution was subjected to solid separation at 8000 r / min for 15 min. The obtained amino-modified adsorbent was filtered and washed with filter paper (washed sequentially with N,N-dimethylformamide and acetone, once with N,N-dimethylformamide and twice with acetone) to remove unreacted salts or ligands, resulting in blue-green regular hexagonal plate-like crystals. After drying at room temperature for 4 h, the copper metal-organic framework material was obtained.

[0060] from Figure 1 It can be seen that amino-modified Cu-MOFs exhibit obvious diffraction peaks near 2θ = 5.5° / 5.85° / 6.65° and 2θ = 9.16° / 9.54°, which is basically consistent with the characteristic diffraction peak positions and peak shapes of Cu-MOFs reported in previous literature. Some new small peaks also appear in the figure, which may be due to the introduction of amino groups, but will not affect the crystal structure of amino-modified Cu-MOFs.

[0061] Figure 2 This indicates that it exhibits a regular hexagonal morphology with a size of 30 μm. Figure 3 This indicates that at 1650cm -1 and 3400cm -1 It exhibits characteristic peaks corresponding to -OH and C=O groups. Figure 4 The results from the TG curve show that the adsorbent experiences significant mass loss at around 280℃, which may be due to the breakage of the coordination bonds between the ligands and the metal in Cu-MOFs, leading to the collapse of the adsorbent structure. Figure 5 The observation of small hysteresis loops indicates the presence of micropores in the structure, with a specific surface area reaching 1194.7 cm². 3 / g, pore volume 0.44cm 3 / g, belongs to the category of micro-mesoporous adsorbents with a large specific surface area and a pore size of approximately 0.53nm.

[0062] Example 2

[0063] This embodiment provides a copper metal-organic framework material (Cu-MOFs), the raw materials for preparing the copper metal-organic framework material include Cu(NO3)2·3H2O and an organic ligand; the organic ligand is 5-[3-nitro-4-(pyrimidin-5-yl)benzamide]isophthalic acid.

[0064] This embodiment also provides a method for preparing the above-mentioned copper metal-organic framework material, which includes the following steps:

[0065] 0.3 mmol of 5-[3-nitro-4-(pyrimidin-5-yl)benzamide]isophthalic acid and 0.9 mmol of Cu(NO3)2·3H2O were dissolved in 30 mL of N,N-dimethylformamide solution and sonicated in an ultrasonic reactor for 8 min until the solution was clear and transparent. Then, 0.5 mL of 2 mol / L hydrochloric acid was added to the mixed solution to turn the solution emerald green. The mixed solution was transferred to a 50 mL reaction vessel liner and reacted in an 80 °C drying oven for 18 h. After cooling to room temperature, the resulting solution was subjected to solid separation at 8000 r / min for 15 min. The obtained amino-modified adsorbent was filtered and washed with filter paper (washed sequentially with N,N-dimethylformamide and acetone, once with N,N-dimethylformamide and twice with acetone) to remove unreacted salts or ligands, resulting in blue-green regular hexagonal plate-like crystals. After drying at room temperature for 4 h, the copper metal-organic framework material was obtained.

[0066] Example 3

[0067] This embodiment provides a copper metal-organic framework material (Cu-MOFs), the raw materials for preparing the copper metal-organic framework material include Cu(NO3)2·3H2O and organic ligands; the organic ligands are 5-[3-nitro-4-(pyrimidin-5-yl)benzamide]isophthalic acid and 5-[3-amino-4-(pyrimidin-5-yl)benzamide]isophthalic acid.

[0068] This embodiment also provides a method for preparing the above-mentioned copper metal-organic framework material, which includes the following steps:

[0069] 0.3 mmol of 5-[3-nitro-4-(pyrimidin-5-yl)benzamide]isophthalic acid and 5-[3-amino-4-(pyrimidin-5-yl)benzamide]isophthalic acid (molar ratio 1:3) and 0.9 mmol of Cu(NO3)2·3H2O were dissolved in 30 mL of N,N-dimethylformamide solution and sonicated in an ultrasonic reactor for 8 min until the solution became clear and transparent. Then, 0.5 mL of 2 mol / L hydrochloric acid was added to the mixed solution to make the solution turn green. The green mixed solution was transferred into a 50 mL reaction vessel liner and reacted in an 80 °C drying oven for 18 h. After cooling to room temperature, the resulting solution was separated into solids at 8000 r / min for 15 min. The obtained amino-modified adsorbent was filtered and washed with filter paper (rinsed sequentially with N,N-dimethylformamide and acetone, once with N,N-dimethylformamide and twice with acetone) to remove unreacted salts or ligands, yielding blue-green regular hexagonal plate-like crystals. After drying at room temperature for 4 h, the copper metal-organic framework material was obtained.

[0070] Example 4

[0071] The difference between this embodiment and Example 3 is that 0.3 mmol of 5-[3-nitro-4-(pyrimidin-5-yl)benzamide]isophthalic acid and 5-[3-amino-4-(pyrimidin-5-yl)benzamide]isophthalic acid (molar ratio of 1:1) and 0.9 mmol of Cu(NO3)2·3H2O were dissolved in 30 mL of N,N-dimethylformamide solution. All other aspects were the same as in Example 3.

[0072] Example 5

[0073] The difference between this embodiment and Example 1 is that the molar ratio of 5-[3-amino-4-(pyrimidin-5-yl)benzamide]isophthalic acid to Cu(NO3)2·3H2O is 1:1, while all other aspects are the same as in Example 1.

[0074] Example 6

[0075] The difference between this embodiment and Example 1 is that the molar ratio of 5-[3-amino-4-(pyrimidin-5-yl)benzamide]isophthalic acid to Cu(NO3)2·3H2O is 1:8, while all other aspects are the same as in Example 1.

[0076] Example 7

[0077] The difference between this embodiment and Example 1 is that 5-[3-amino-4-(pyrimidin-5-yl)benzamide]isophthalic acid is replaced with 5-[3-amino-4-(pyridin-5-yl)benzamide]isophthalic acid, while all other aspects are the same as in Example 1.

[0078] Example 8

[0079] The difference between this embodiment and Example 3 is that 0.3 mmol of 5-[3-nitro-4-(pyrimidin-5-yl)benzamide]isophthalic acid and 5-[3-amino-4-(pyrimidin-5-yl)benzamide]isophthalic acid (molar ratio of 1:5) and 0.9 mmol of Cu(NO3)2·3H2O were dissolved in 30 mL of N,N-dimethylformamide solution. All other aspects were the same as in Example 3.

[0080] Example 9

[0081] The difference between this embodiment and Example 3 is that 0.3 mmol of 5-[3-nitro-4-(pyrimidin-5-yl)benzamide]isophthalic acid and 5-[3-amino-4-(pyrimidin-5-yl)benzamide]isophthalic acid (molar ratio of 3:1) and 0.9 mmol of Cu(NO3)2·3H2O were dissolved in 30 mL of N,N-dimethylformamide solution. All other aspects were the same as in Example 3.

[0082] Comparative Example 1

[0083] The difference between this comparative example and Example 1 is that 5-[3-amino-4-(pyrimidin-5-yl)benzamide]isophthalic acid is replaced with 5-[4-(pyrimidin-5-yl)benzamide]isophthalic acid, while all other aspects are the same as in Example 1.

[0084] Comparative Example 2

[0085] The difference between this comparative example and Example 1 is that 5-[3-amino-4-(pyrimidin-5-yl)benzamide]isophthalic acid is replaced with 2,5-dihydroxyterephthalic acid, while all other aspects are the same as in Example 1.

[0086] Test conditions

[0087] The copper metal-organic framework materials provided in Examples 1 to 9 and Comparative Examples 1 to 2 were tested using the following methods:

[0088] (1) X-ray diffraction pattern: The test range is from 3° to 40°, and the scanning speed is 5° / min;

[0089] (2) Thermogravimetric test: Under N2 atmosphere, the copper metal-organic framework material was heated from 40℃ to 900℃ at a heating rate of 10° / min;

[0090] (3) Nitrogen adsorption-desorption test: The N2 adsorption-desorption isotherm was measured at 77K. Before the test, the pores were degassed and activated at 120℃ for 24h to remove residual solvent molecules.

[0091] (4) CO2 adsorption performance determination: 40 mg of modified adsorbent material was placed in a sample tube and degassed at 120 °C for 24 h to obtain activated adsorbent material. Then, its CO2 adsorption capacity was measured at 25 °C and 1 bar.

[0092] The test results are shown in Table 1:

[0093] Table 1

[0094]

[0095]

[0096] As can be seen from Table 1, such as Figure 6 As shown, comparing the adsorption capacity of Cu-MOFs with and without amino-modified ligands reveals that the introduction of amino groups results in a greater CO2 adsorption capacity. The maximum adsorption capacity (7.1 mmol / g) is achieved when both amino and nitro-modified ligands are introduced in a 1:3 ratio. This is because the electrostatic interaction of the nitro groups enhances the stability of the MOF framework, and the introduction of nitro ligands increases the pore size of the MOFs. The strong electron-donating effect of nitro groups increases the electron cloud density at the metal centers, altering the geometry of the MOF material and increasing its pore size. Since MOFs bind to CO2 through interaction forces, excessively large pore sizes reduce the affinity between CO2 and the framework, hindering CO2 adsorption. The introduction of amino groups provides new basic adsorption sites, enhancing the interaction between the framework and gas molecules. The synergistic effect of these two interactions maximizes the adsorption capacity. Decreasing or increasing the proportion of amino-modified ligands both decrease the adsorption capacity of Cu-MOFs. At the same time, increasing or decreasing the ratio of metal salt to organic ligand also showed a certain decrease in the adsorption capacity. The increase of copper salt or organic ligand led to poor crystal stability, thereby reducing the CO2 adsorption capacity of the adsorbent.

[0097] The applicant declares that the present invention is illustrated by the above embodiments, but the present invention is not limited to the above process steps, that is, it does not mean that the present invention must rely on the above process steps to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions of the raw materials used in the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A copper-organic framework material, characterized in that, The raw materials for preparing the copper metal-organic framework material include copper salts and organic ligands; The copper salt includes any one or a combination of at least two of CuSO4·5H2O, Cu(NO3)2·3H2O or CuCl2·2H2O; The organic ligand comprises a combination of at least two of the following: 5-[3-amino-4-(pyrimidin-5-yl)benzamide] isophthalic acid, 5-[3-nitro-4-(pyrimidin-5-yl)benzamide] isophthalic acid, 5-[3-amino-4-(pyrimidin-5-yl)benzamide] isophthalic acid, 5-[3-nitro-4-(pyrimidin-5-yl)benzamide] isophthalic acid, 5-[2-amino-4-(pyrimidin-5-yl)benzamide] isophthalic acid, and 5-[2-nitro-4-(pyrimidin-5-yl)benzamide] isophthalic acid, wherein the nitro-modified organic ligand and the amino-modified organic ligand are introduced simultaneously, and the mass percentage of the amino-modified organic ligand is 50% to 75%. The molar ratio of the organic ligand to the copper salt is 1:(2~4).

2. A method for preparing the copper metal-organic framework material according to claim 1, characterized in that, The method includes the following steps: The copper metal-organic framework material is obtained by mixing copper salt, organic ligand, acid solution and solvent and then performing a hydrothermal reaction.

3. The method according to claim 2, characterized in that, The copper salt includes any one or a combination of at least two of CuSO4·5H2O, Cu(NO3)2·3H2O or CuCl2·2H2O; The amount of copper salt used is 200-250 mg; The organic ligand comprises a combination of at least two of the following: 5-[3-amino-4-(pyrimidin-5-yl)benzamide] isophthalic acid, 5-[3-nitro-4-(pyrimidin-5-yl)benzamide] isophthalic acid, 5-[3-amino-4-(pyrimidin-5-yl)benzamide] isophthalic acid, 5-[3-nitro-4-(pyrimidin-5-yl)benzamide] isophthalic acid, 5-[2-amino-4-(pyrimidin-5-yl)benzamide] isophthalic acid; The amount of the organic ligand used is 50-60 mg; The molar ratio of the organic ligand to the copper salt is 1:(2~4).

4. The method according to claim 3, characterized in that, The molar ratio of the organic ligand to the copper salt is 1:(3~4).

5. The method according to claim 2, characterized in that, The acid solution includes hydrochloric acid solution; The concentration of the hydrochloric acid solution is 2~4 mol / L; The amount of hydrochloric acid used is 0.4~0.8 mL.

6. The method according to claim 5, characterized in that, The amount of hydrochloric acid used is 0.4~0.6 mL.

7. The method according to claim 2, characterized in that, The solvent includes any one or a combination of at least two of N,N-dimethylformamide, acetonitrile, or ethanol. The amount of solvent used is 20-30 mL.

8. The method according to claim 2, characterized in that, The mixing is performed under ultrasound; The ultrasound duration is 2-10 minutes; The temperature of the hydrothermal reaction is 80~120℃; The hydrothermal reaction time is 18-48 hours.

9. The method according to claim 8, characterized in that, The ultrasound session lasted 5-10 minutes. The temperature of the hydrothermal reaction is 80~100℃; The hydrothermal reaction takes 18-24 hours.

10. The method according to claim 2, characterized in that, The hydrothermal reaction is followed by centrifugation, filtration, washing and drying processes in sequence. The centrifuge speed is 3000~10000 r / min; The centrifugation time is 5-20 minutes; The washing solvent for filtration includes at least one of DMF, acetone, methanol, or ethanol; The filter is washed 1 to 4 times; The drying temperature is room temperature, and the time is 1 to 6 hours.

11. The method according to claim 10, characterized in that, The centrifuge speed is 6000~8000 r / min; The centrifugation time is 10-15 minutes; The filter is washed 2 to 3 times; The drying time is 3 to 6 hours.

12. An adsorbent material, characterized in that, The adsorbent material includes the copper-organic framework material according to claim 1.

13. A CO2 scavenger, characterized in that, The CO2 capture agent includes the adsorbent material according to claim 12.

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