An amide-based metal-organic framework material, its preparation method and application

Abstract

This invention provides an amide-based metal-organic framework material, its preparation method, and its application. The preparation method includes: uniformly mixing 3-amino-1,2,4-triazole powder, ester substances, an alkaline catalyst, and an organic solvent to obtain a first mixed solution; subjecting the first mixed solution to a modification reaction; centrifuging, washing, and drying the product after the modification reaction to obtain a modified ligand containing amide bonds; dissolving a zinc salt or copper salt and the modified ligand containing amide bonds in a solution composed of phosphoric acid, ammonia, methanol, and water, and ensuring complete dissolution to obtain a second mixed solution; subjecting the second mixed solution to a hydrothermal reaction; and centrifuging, washing, and drying the product after the hydrothermal reaction to obtain the amide-based metal-organic framework material. The material of this invention exhibits reduced water absorption, making it suitable as an adsorbent for separating ethylene / ethane gases, which can improve adsorption efficiency and significantly reduce industrial energy consumption.

Description

Technical Field

[0001] This invention relates to an amide-based metal-organic framework material, its preparation method, and its application, belonging to the field of materials technology, particularly the field of adsorbent materials technology. Background Technology

[0002] Metal-organic frameworks (MOFs) are novel multifunctional materials composed of organic ligands and metal ions. They have wide applications in gas separation, storage, and transportation, with particularly promising prospects in gas separation. Taking ethylene / ethane separation as an example, ethylene (C2H4), as one of the world's most important chemical raw materials, is widely used in many fields. Ethylene is mainly produced through the cracking of petroleum vapors, and in this process, a small amount of ethane impurities are inevitably generated, necessitating ethylene / ethane separation. For substances like ethylene and ethane, whose relative volatility and boiling points are similar, cryogenic separation processes require at least 150 trays, resulting in high energy consumption, which can account for more than 75% of the ethylene production cost. Therefore, it is necessary to explore adsorption separation processes with lower energy consumption for ethylene / ethane separation, and the key to adsorption separation processes lies in the selection of adsorbents. MOF adsorbents possess advantages such as high specific surface area and tunable structure, thus exhibiting excellent adsorption performance. For example, the MOF material ZnAtzPO4 has a pillared three-dimensional structure with high-density phosphate and amino groups distributed inside the pores, which can efficiently capture ethylene. The pore cross-section exhibits a periodic expansion-contraction change, with the narrowest pore diameter being [missing information]. It can effectively limit ethane diffusion and has excellent selectivity in the separation of ethylene / ethane.

[0003] In practical applications of MOF adsorbents, the actual adsorption performance of ethylene / ethane often decreases due to water absorption by the material. For example, Xian et al. studied that the adsorption capacity and CO2 / CH4 selectivity of MIL-101(Cr) significantly decreased in the presence of water vapor. Specifically, when the relative humidity of the feed stream increased from 0% to 50%, the CO2 adsorption capacity and CO2 / CH4 selectivity of MIL-101(Cr) decreased by 44% and 18%, respectively (Xian, SK; Peng, JJ; Zhang, ZJ; Xia, QB; Wang, HH; Li, Z. Highly enhanced and weakened adsorption properties of two MOFs by water vapor for separation of CO2 / CH4 and CO2 / N2 binary mixtures. Chem Eng J 2015, 270, 385-392, doi:10.1016 / j.cej.2015.02.041.). Paul M. Schoenecker et al. found that water vapor has a significant impact on the adsorption performance of MOFs, especially for MOFs containing Zn-COOH (such as DMOF-1; DMOF-1-NH2; UMCM-1). At 90% relative humidity, water vapor completely loses its crystallinity, severely reducing its adsorption performance. (Schoenecker, PM; Carson, CG; Jasuja, H.; Flemming, CJJ; Walton, K. Effect of Water Adsorption on Retention of Structure and Surface Area of ​​Metal-Organic Frameworks. Ind Eng Chem Res 2012, 51, 6513-6519, doi:10.1021 / ie202325p.). To address this issue, the art typically involves high-temperature drying activation of the adsorbent under vacuum conditions to remove moisture and other impurities from the material's pores. However, this adds an activation step to the adsorption process, making it more complex and significantly increasing industrial energy consumption.

[0004] Therefore, providing a novel amide-based metal-organic framework material, its preparation method, and its application has become a pressing technical problem to be solved in this field. Summary of the Invention

[0005] To address the aforementioned shortcomings and deficiencies, the present invention aims to provide an amide-based metal-organic framework material, its preparation method, and its applications. This invention improves the water resistance of novel MOFs when used as adsorbents by introducing amide bonds, thereby reducing material activation time and overcoming the high energy consumption caused by activation in industrial applications.

[0006] To achieve the above objectives, on the one hand, the present invention provides a method for preparing an amide-based metal-organic framework material, wherein the preparation method includes:

[0007] Step (1) Modification of organic ligands: 3-amino-1,2,4-triazole powder, esters, alkaline catalyst and organic solvent are mixed evenly to obtain a first mixed solution. The first mixed solution is subjected to a modification reaction. After the modification reaction is completed, the product is centrifuged, washed and dried to obtain a modified ligand containing amide bonds.

[0008] Step (2) Preparation of amide-based metal-organic framework materials: Dissolve zinc salt or copper salt and modified ligand containing amide bonds in a solution composed of phosphoric acid, ammonia, methanol and water and allow it to fully dissolve to obtain a second mixed solution. Allow the second mixed solution to undergo a hydrothermal reaction. After the hydrothermal reaction is completed, centrifuge, wash and dry the product to obtain amide-based metal-organic framework materials.

[0009] As a specific embodiment of the preparation method described above in this invention, in step (1), esters, alkaline catalysts and organic solvents are added to 3-amino-1,2,4-triazole powder and mixed evenly to obtain a first mixed solution.

[0010] In step (1) of the preparation method described above, the uniform mixing can be achieved by magnetic stirring or manual stirring until the solid material is completely dissolved.

[0011] The present invention does not specify the amount of alkaline catalyst and organic solvent in step (1) of the preparation method described above, and can make reasonable adjustments as needed.

[0012] In one specific embodiment of the preparation method described above in this invention, in step (1), the mass ratio of 3-amino-1,2,4-triazole powder to the ester is 1:3 to 1:8. In some embodiments of this invention, the mass ratio of 3-amino-1,2,4-triazole powder to the ester can be, for example, 1:3, 1:3.5, 1:4, 1:4.5, 1:5, 1:6, 1:7, and 1:8.

[0013] As a specific embodiment of the preparation method described above in this invention, in step (1), the ester substance includes ethyl acetate, etc.

[0014] This invention does not specify the exact substances of the alkaline catalyst and the organic solvent used in step (1) of the preparation method described above. Existing conventional alkaline catalysts and organic solvents can be selected as needed. For example, in some embodiments of this invention, the alkaline catalyst may be sodium methoxide or the organic solvent may be N,N-dimethylformamide and / or methanol or the like.

[0015] In one specific embodiment of the preparation method described above in this invention, in step (1), the temperature of the modification reaction is 100-150°C, and the time is 12-24 hours. In some embodiments of this invention, the temperature of the modification reaction may be, for example, 100°C, 110°C, 120°C, 130°C, 140°C, and 150°C, and the time of the modification reaction may be, for example, 12 hours, 13 hours, 14 hours, 15 hours, 16 hours, 17 hours, 18 hours, 19 hours, 20 hours, 21 hours, 22 hours, 23 hours, and 24 hours.

[0016] In one specific embodiment of the preparation method described above in this invention, the heating rate of the modification reaction process in step (1) is 5-7.5℃ / min. In some embodiments of this invention, the heating rate of the modification reaction process may be, for example, 5℃ / min, 5.5℃ / min, 6℃ / min, 6.5℃ / min, 7℃ / min, and 7.5℃ / min.

[0017] In one specific embodiment of the preparation method described above, in step (1), the washing is performed using deionized water. This invention does not specify the number of washes and can adjust them as needed. Furthermore, this invention does not specify the drying operation and conditions in step (1) of the preparation method described above, and can also adjust them as needed, as long as the drying objective is achieved.

[0018] The present invention does not specify the specific composition and amount of the solution made of phosphoric acid, ammonia, methanol and water used in step (2) of the preparation method described above, and can make reasonable adjustments as needed.

[0019] The complete dissolution in step (2) of the preparation method described above can be achieved by stirring the system with a magnetic stirrer. Furthermore, this invention does not specify particular requirements for the rotation speed or stirring time of the magnetic stirrer, and these can be adjusted as needed. For example, in some embodiments of this invention, the rotation speed can be 500 r / min, and the stirring time can be 30 min.

[0020] In one specific embodiment of the preparation method described above in this invention, in step (2), the mass ratio of the zinc salt or copper salt (calculated as metal) to the modified ligand containing the amide bond is 1:1 to 1:5. In some embodiments of this invention, the mass ratio of the zinc salt or copper salt (calculated as metal) to the modified ligand containing the amide bond can be, for example, 1:1, 1:1.5, 1:2, 1:2.5, 1:3, 1:3.4, 1:3.5, 1:4, 1:4.5, and 1:5, etc.

[0021] As a specific embodiment of the preparation method described above in this invention, in step (2), the zinc salt includes one or a combination of several of the following: basic zinc carbonate, zinc sulfate, and zinc nitrate;

[0022] The copper salt includes one or a combination of several of the following: basic copper carbonate, copper sulfate, and copper nitrate.

[0023] In one specific embodiment of the preparation method described above in this invention, in step (2), the temperature of the hydrothermal reaction is 150-180°C, and the time is 36-48 hours. In some embodiments of this invention, the temperature of the hydrothermal reaction may be, for example, 150°C, 155°C, 160°C, 165°C, 170°C, 175°C, and 180°C, and the time of the hydrothermal reaction may be, for example, 36 hours, 37 hours, 38 hours, 39 hours, 40 hours, 41 hours, 42 hours, 43 hours, 44 hours, 45 hours, 46 hours, 47 hours, and 48 hours.

[0024] In one specific embodiment of the preparation method described above in this invention, the heating rate of the hydrothermal reaction process in step (2) is 7-9 °C / min. In some embodiments of this invention, the heating rate of the hydrothermal reaction process may be, for example, 7 °C / min, 7.5 °C / min, 8 °C / min, 8.5 °C / min, and 9 °C / min.

[0025] In one specific embodiment of the preparation method described above, in step (2), the washing is performed sequentially with deionized water and methanol. This invention does not specify the number of times the washing is performed with deionized water and methanol; these can be adjusted as needed. Furthermore, this invention does not specify the drying operation and conditions in step (2) of the preparation method described above; these can also be adjusted as needed, as long as the drying objective is achieved.

[0026] On the other hand, the present invention also provides an amide-based metal-organic framework material, which is prepared by the above-described method for preparing amide-based metal-organic framework materials.

[0027] In another aspect, the present invention also provides the application of the above-described amide-based metal-organic framework materials as adsorbent materials in the separation of ethylene / ethane gas.

[0028] Compared with the prior art, the beneficial technical effects that the technical solution of the present invention can achieve include at least the following:

[0029] The preparation method provided by the present invention first modifies the organic ligand 3-amino-1,2,4-triazole to form amide bonds in the organic ligand to obtain a modified ligand containing amide bonds. Then, the modified ligand containing amide bonds is synthesized by hydrothermal synthesis to form an amide-based metal-organic framework material with metal ions.

[0030] The preparation method provided by this invention is simple to operate, and the resulting amide-based metal-organic framework material has a smaller pore size, which improves the material's water resistance (i.e., reduces the material's water absorption), thereby overcoming the disadvantage of existing MOF materials being relatively hygroscopic. Using the amide-based metal-organic framework material of this invention as an adsorbent for separating ethylene / ethane gases can increase the actual adsorption effect during the adsorption process, avoid the problem of decreased adsorption performance due to water absorption, and reduce the material's activation time, significantly reducing industrial energy consumption. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 The PXRD patterns are of the amide-based metal-organic framework material provided in Example 1 of the present invention and the metal-organic framework material provided in Comparative Example 1.

[0033] Figure 2a The above are PXRD images of the modified ligands (C4H6N4O) containing amide bonds provided in Examples 1-4 of this invention.

[0034] Figure 2b The PXRD patterns are of the amide-based metal-organic framework materials provided in Examples 1-4 of this invention.

[0035] Figure 3a Thermogravimetric analysis (TGA) diagrams of the amide-based metal-organic framework material sample provided in Example 1 of the present invention and the metal-organic framework material sample provided in Comparative Example 1 under dry conditions.

[0036] Figure 3b The thermogravimetric analysis (TGA) comparison of the amide-based metal-organic framework material sample provided in Example 1 of the present invention and the metal-organic framework material sample provided in Comparative Example 1 after pre-wetting for 48 hours at a relative humidity of 75%.

[0037] Figure 4 The infrared spectra of the 3-amino-1,2,4-triazole powder (C2H4N4) used in Example 1 of this invention and the modified ligand containing amide bonds (C4H6N4O) obtained in step (1) are shown.

[0038] Figure 5 The thermogravimetric analysis diagram of the amide-based metal-organic framework material provided in Example 1 of the present invention and the pre-wetted sample obtained after pre-wetting the material for 48 hours at a relative humidity of 75% is shown in Test Example 4.

[0039] Figure 6 The thermogravimetric analysis (TGA) diagram for Test Example 5 shows the existing Mg-gallate material and the pre-wetted sample obtained after pre-wetting the material for 48 hours at a relative humidity of 75%.

[0040] Figure 7 Thermogravimetric analysis of the unmodified metal-organic framework material provided in Comparative Example 1 of the present invention and the pre-wetted sample obtained after pre-wetting the material for 48 hours at a relative humidity of 75% is shown in Test Example 6. Detailed Implementation

[0041] It should be noted that the term "comprising" and any variations thereof in the specification, claims, and accompanying drawings of this invention are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or devices.

[0042] The "range" disclosed in this invention is given in the form of a lower limit and an upper limit. It can be one or more lower limits and one or more upper limits, respectively. A given range is defined by selecting a lower limit and an upper limit. The selected lower and upper limits define the boundaries of the particular range. All ranges defined in this way are composable, meaning that any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for specific parameters, it is also expected that ranges of 60-110 and 80-120 are also expected. Furthermore, if the listed minimum range values ​​are 1 and 2, and the listed maximum range values ​​are 3, 4, and 5, then the following ranges are all expected: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5.

[0043] In this invention, unless otherwise specified, the numerical range "ab" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0-5" indicates that all real numbers between "0-5" have been listed in this invention, and "0-5" is simply a shortened representation of these numerical combinations.

[0044] In this invention, unless otherwise specified, all embodiments and preferred embodiments mentioned in this invention can be combined with each other to form new technical solutions.

[0045] In this invention, unless otherwise specified, all technical features and preferred features mentioned in this invention can be combined with each other to form new technical solutions.

[0046] In this invention, unless otherwise specified, all steps mentioned herein may be performed sequentially or randomly, but are preferably performed sequentially. For example, if the method includes steps (a) and (b), it means that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, if the method may also include step (c), it means that step (c) may be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0047] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. The embodiments described below are some, but not all, embodiments of this invention, and are only used to illustrate the invention, and should not be considered as limiting the scope of the invention. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0048] Example 1

[0049] This embodiment provides an amide-based metal-organic framework material, which is prepared by a method including the following specific steps:

[0050] Step (1) Modification of organic ligands:

[0051] Step 1): Weigh 0.83g of 3-amino-1,2,4-triazole powder (C2H4N4), 5.28g of ethyl acetate, and 0.162g of sodium methoxide catalyst, and dissolve them in 10ml of N,N-dimethylformamide (DMF), wherein the mass ratio of 3-amino-1,2,4-triazole powder to ethyl acetate is approximately 1:6.4;

[0052] Step 2): Stir the system with magnetic stirring until completely dissolved, with a stirring speed of 500 r / min, to obtain a uniformly mixed first solution;

[0053] Step 3): Add the first mixed solution to a 100ml reaction vessel with a polytetrafluoroethylene liner, heat it to 150℃ at a heating rate of 5℃ / min, and react at 150℃ for 24h.

[0054] Step 4): After the reaction is complete, the product is centrifuged, washed twice with deionized water, and finally dried at 100℃ for 12h to obtain the modified ligand containing amide bonds (C4H6N4O).

[0055] The structural formulas of the 3-amino-1,2,4-triazole powder and the modified ligand containing amide bonds are as follows: (Formula 1) and (Formula 2).

[0056] As shown in Equation 2).

[0057]

[0058] Step (2) Preparation of amide-based metal-organic framework materials:

[0059] Step ①: Weigh 0.4g of basic zinc carbonate (Zn5C2O) 12 H6) and 0.8 g of amide-containing modified ligands;

[0060] Step 2: Weigh 0.093g of phosphoric acid, 5.3ml of deionized water, 2.67ml of methanol and 0.102ml of ammonia water and mix them together, stirring thoroughly to obtain a clear solution;

[0061] Step ③: Add the basic zinc carbonate and the modified ligand containing the amide bond from Step ① to the clear solution from Step ②, and stir with a magnetic stirrer at a speed of 500 r / min for 30 min to fully dissolve them to obtain a second mixed solution. Place the second mixed solution in a 100 ml reaction vessel with a polytetrafluoroethylene liner, heat it to 180 °C at a heating rate of 9 °C / min, and react at 180 °C for 48 h.

[0062] Step 4: After the reaction is complete, the product is centrifuged and washed twice each with deionized water and methanol.

[0063] Step 5: Finally, the product is placed in an oven and dried at 100°C for 6 hours to obtain the amide-based metal-organic framework material, which is a white powder.

[0064] Example 2

[0065] This embodiment provides an amide-based metal-organic framework material, which is prepared by a method including the following specific steps:

[0066] Step (1) Modification of organic ligands:

[0067] Step 1): Weigh 0.83g of 3-amino-1,2,4-triazole powder (C2H4N4), 5.28g of ethyl acetate, and 0.162g of sodium methoxide catalyst, and dissolve them in 10ml of N,N-dimethylformamide (DMF), wherein the mass ratio of 3-amino-1,2,4-triazole powder to ethyl acetate is approximately 1:6.4;

[0068] Step 2): Stir the system with magnetic stirring until completely dissolved, with a stirring speed of 500 r / min, to obtain a uniformly mixed first solution;

[0069] Step 3): Add the first mixed solution to a 100ml reaction vessel with a polytetrafluoroethylene liner, heat it to 100℃ at a heating rate of 5℃ / min, and react at 100℃ for 24h.

[0070] Step 4): After the reaction is complete, the product is centrifuged, washed twice with deionized water, and finally dried at 100℃ for 12h to obtain the modified ligand containing amide bonds (C4H6N4O).

[0071] The structural formulas of the 3-amino-1,2,4-triazole powder and the modified ligand containing amide bonds are as follows: (Formula 1) and (Formula 2).

[0072] As shown in Equation 2).

[0073]

[0074] Step (2) The preparation process of the amide-based metal-organic framework material is the same as in Example 1.

[0075] Example 3

[0076] This embodiment provides an amide-based metal-organic framework material, which is prepared by a method including the following specific steps:

[0077] Step (1) The modification process of the organic ligand is the same as in Example 1.

[0078] Step (2) Preparation of amide-based metal-organic framework materials:

[0079] Step ①: Weigh 0.4g of basic zinc carbonate (Zn5C2O) 12 H6) and 0.8 g of amide-containing modified ligands;

[0080] Step 2: Weigh 0.093g of phosphoric acid, 5.3ml of deionized water, 2.67ml of methanol and 0.102ml of ammonia water and mix them together, stirring thoroughly to obtain a clear solution;

[0081] Step ③: Add the basic zinc carbonate and the modified ligand containing the amide bond from Step ① to the clear solution from Step ②, and stir with a magnetic stirrer at a speed of 500 r / min for 30 min to fully dissolve them to obtain a second mixed solution. Place the second mixed solution in a 100 ml reaction vessel with a polytetrafluoroethylene liner, heat it to 150 °C at a heating rate of 9 °C / min, and react at 150 °C for 48 h.

[0082] Step 4: After the reaction is complete, the product is centrifuged and washed twice each with deionized water and methanol.

[0083] Step 5: Finally, the product is placed in an oven and dried at 100°C for 6 hours to obtain the amide-based metal-organic framework material, which is a white powder.

[0084] Example 4

[0085] This embodiment provides an amide-based metal-organic framework material, which is prepared by a method including the following specific steps:

[0086] Step (1) The modification process of the organic ligand is the same as in Example 1.

[0087] Step (2) Preparation of amide-based metal-organic framework materials:

[0088] Step ①: Weigh 0.4g of basic copper carbonate (Cu2(OH)2CO3) and 0.8g of modified ligand containing amide bonds;

[0089] Step 2: Weigh 0.093g of phosphoric acid, 5.3ml of deionized water, 2.67ml of methanol and 0.102ml of ammonia water and mix them together, stirring thoroughly to obtain a clear solution;

[0090] Step ③: Add the basic copper carbonate and the modified ligand containing the amide bond from Step ① to the clear solution from Step ②, and stir with a magnetic stirrer at a speed of 500 r / min for 30 min to fully dissolve them to obtain a second mixed solution. Place the second mixed solution in a 100 ml reaction vessel with a polytetrafluoroethylene liner, heat it to 150 °C at a heating rate of 9 °C / min, and react at 150 °C for 48 h.

[0091] Step 4: After the reaction is complete, the product is centrifuged and washed twice each with deionized water and methanol.

[0092] Step 5: Finally, the product is placed in an oven and dried at 100°C for 6 hours to obtain the amide-based metal-organic framework material, which is a white powder.

[0093] Comparative Example 1

[0094] This comparative example provides a metal-organic framework material, which differs from Example 1 in that the organic ligands are not modified. Its preparation method includes the following specific steps:

[0095] Step ①: Weigh 0.4g of basic zinc carbonate (Zn5C2O) 12 H6) and 0.8 g of 3-amino-1,2,4-triazole powder (C2H4N4);

[0096] Step 2: Weigh 0.093g of phosphoric acid, 5.3ml of deionized water, 2.67ml of methanol and 0.102ml of ammonia water and mix them together, stirring thoroughly to obtain a clear solution;

[0097] Step ③: Add the basic zinc carbonate and 3-amino-1,2,4-triazole powder from Step ① to the clear solution from Step ②, and stir with a magnetic stirrer at 500 r / min for 30 min to fully dissolve them to obtain a second mixed solution. Place the second mixed solution in a 100 ml reaction vessel with a polytetrafluoroethylene liner, heat it to 180 °C at a heating rate of 9 °C / min, and react at 180 °C for 48 h.

[0098] Step 4: After the reaction is complete, the product is centrifuged and washed twice each with deionized water and methanol.

[0099] Step 5: Finally, place the product in an oven and dry it at 100℃ for 6 hours to obtain a metal-organic framework material, which is a white powder.

[0100] Test Example 1

[0101] This test example performs PXRD analysis on the amide-containing modified ligand (C4H6N4O) provided in Examples 1-4 of this invention, the amide-based metal-organic framework material provided in Examples 1-4 of this invention, and the metal-organic framework material provided in Comparative Example 1. The obtained PXRD patterns are shown below. Figure 1 and Figures 2a-2b As shown, where, Figure 1 The images show the PXRD patterns of the amide-based metal-organic framework material provided in Example 1 and the metal-organic framework material provided in Comparative Example 1. Figure 2aPXRD patterns of the amide-containing modified ligands (C4H6N4O) provided in Examples 1-4 of this invention and Figure 2b The PXRD patterns are of the amide-based metal-organic framework materials provided in Examples 1-4 of this invention.

[0102] from Figure 1 As can be seen from the above, the amide-based metal-organic framework material provided in Example 1 of the present invention and the metal-organic framework material provided in Comparative Example 1 do not have diffraction peaks with consistent positions. This indicates that Example 1 of the present invention obtained a novel amide-based metal-organic framework material through the above preparation method.

[0103] like Figure 2a and Figure 2b As shown, the XRD diffraction peaks of the modified ligands (C4H6N4O) containing amide bonds provided in Examples 1-4 of this invention are consistent, and the XRD diffraction peak positions of the finally synthesized amide-based metal-organic framework materials are also consistent, proving that the modification of organic ligands can be achieved at temperatures of 100℃ and 150℃, and that the successful preparation of amide-based metal-organic framework materials can be achieved by using zinc salts or copper salts in the embodiments of this invention.

[0104] like Figure 2a and Figure 2b As shown, the XRD diffraction peaks of the modified ligands (C4H6N4O) containing amide bonds provided in Examples 1-4 of this invention are consistent, and the XRD diffraction peak positions of the finally synthesized amide-based metal-organic framework materials are also consistent, proving that the preparation of amide-based metal-organic framework materials can be achieved at temperatures of 150℃ and 180℃, and that the successful preparation of amide-based metal-organic framework materials can be achieved by using zinc salt or copper salt in the embodiments of this invention.

[0105] Test Example 2

[0106] In this test example, a portion of the amide-based metal-organic framework material sample provided in Example 1 of this invention and a portion of the metal-organic framework material sample provided in Example 1 were taken, and the thermogravimetric analysis (TGA) of the dried samples was tested respectively. Then, another portion of the amide-based metal-organic framework material sample and another portion of the metal-organic framework material sample were placed under a relative humidity of 75% (RH=75%) for 48 hours, and the TGA was tested again. The resulting TGA comparison charts are shown below. Figure 3a and Figure 3b As shown, where, Figure 3a This is a thermogravimetric analysis (TGA) comparison of the amide-based metal-organic framework material sample provided in Example 1 of the present invention and the metal-organic framework material sample provided in Comparative Example 1 under dry conditions. Figure 3bThe thermogravimetric analysis (TGA) comparison of the amide-based metal-organic framework material sample provided in Example 1 of the present invention and the metal-organic framework material sample provided in Comparative Example 1 after pre-wetting for 48 hours at a relative humidity of 75%.

[0107] from Figure 3a As can be seen, the first dehydration stage of the dried amide-based metal-organic framework material provided in Example 1 of the present invention is basically the same as that of the dried metal-organic framework material provided in Comparative Example 1. However, from... Figure 3b It can be seen that when the two samples were placed in an environment with a relative humidity of 75% (RH=75%) and kept there for 48 hours, and then the thermogravimetric analysis was performed again, the metal-organic framework material provided in Comparative Example 1 showed a significantly greater weight decrease in the first dehydration stage. This indicates that the metal-organic framework material provided in Comparative Example 1 experienced a greater weight decrease due to greater water absorption. In contrast, the amide-based metal-organic framework material sample provided in Example 1 of this invention showed less weight reduction in this stage after being placed in an environment with RH=75% and kept there for 48 hours, further demonstrating that the water resistance of the amide-based metal-organic framework material provided in Example 1 of this invention is superior to that of the metal-organic framework material provided in Comparative Example 1.

[0108] Test Example 3

[0109] In this test example, infrared spectroscopy analysis was performed on the 3-amino-1,2,4-triazole powder (C2H4N4) used in Example 1 of this invention and the amide-containing modified ligand (C4H6N4O) obtained in step (1). The obtained infrared spectra are shown below. Figure 4 As shown. Among them, 3-amino-1,2,4-triazole powder (C2H4N4) is a primary amine, which... Figure 4 3400-3500cm -1 Two absorption peaks appear nearby, representing symmetric and antisymmetric stretching vibrations, respectively. If an amide bond is formed, the primary amine will change into a secondary amine. Figure 4 3400-3500cm -1 The two absorption peaks at that point become a single absorption peak, and compared with the positions of other characteristic peaks of the amide bond, such as the C=O stretching vibration peak, which are all in the 1680-1650 cm⁻¹ range. -1 Within this range, the NH bending vibration peaks are all between 1570 and 1515 cm⁻¹. -1 Within this range, the CN stretching vibration peaks are all between 1310 and 1200 cm⁻¹. -1 Within the scope, it can also be proven that the modified ligand (C4H6N4O) containing amide bonds obtained in step (1) of Example 1 of the present invention does indeed contain amide bonds.

[0110] Test Example 4

[0111] This test example demonstrates the water resistance of the amide-based metal-organic framework material provided in Example 1 of this invention through thermogravimetric analysis, including the following specific steps:

[0112] Step (a): The amide-based metal-organic framework material obtained after drying in step ⑤ of Example 1 was immediately subjected to thermogravimetric analysis. The thermogravimetric analysis results are shown in [the table below]. Figure 5 Curve 1 in the middle;

[0113] Step (b): Take 0.1g of the amide-based metal-organic framework material obtained after drying in step ⑤ of Example 1 and place it in an environment with a relative humidity of 75% (RH=75%) for 48h to obtain a pre-humidified sample;

[0114] Step (c): Remove the pre-humidified sample and immediately perform thermogravimetric analysis. The thermogravimetric analysis results are shown in [the table below]. Figure 5 Curve 2 in the diagram.

[0115] from Figure 5 As can be seen, in the first water loss stage, the weight of the pre-wetted sample obtained after pre-wetting for 48 hours under a relative humidity of 75% decreased slightly, but it was basically the same as the weight loss of the amide-based metal-organic framework material sample obtained after drying in step ⑤ of Example 1. The water content increased from 2% to 2.3%, which was only 0.3%. This indicates that the amide-based metal-organic framework material provided in Example 1 of the present invention has good water resistance.

[0116] Test Example 5

[0117] This test example demonstrates the water resistance of Mg-gallate through thermogravimetric analysis, including the following specific steps:

[0118] Mg-gallate synthesis: In a beaker, MgCl2 (50 mmol) and gallic acid (100 mmol) were mixed into 250 ml of KOH aqueous solution (0.4 M) and stirred for 5 min. After mixing evenly, the top of the beaker was covered with tin foil and then placed in a constant temperature drying oven and heated at 393 K for 24 h. After the reaction was completed, the mixture was cooled, the product was collected and washed twice with water and ethanol respectively for later use.

[0119] Water resistance test:

[0120] Step (a): Thermogravimetric analysis was immediately performed on the Mg-gallate product obtained after drying during the synthesis process. The results of the thermogravimetric analysis are shown in [the table below]. Figure 6 Curve 3 in the middle;

[0121] Step (b): Take 0.1 g of the Mg-gallate product obtained after drying during the synthesis process and place it in an environment with a relative humidity of 75% (RH=75%) for 48 h to obtain a pre-humidified sample;

[0122] Step (c): Remove the pre-humidified sample and immediately perform thermogravimetric analysis. The thermogravimetric analysis results are shown in [the table below]. Figure 6 Curve 4 in the diagram.

[0123] from Figure 6 As can be seen, in the first water loss stage, the pre-wetted sample obtained after 48 hours of pre-wetting at a relative humidity of 75% showed a greater weight decrease, with the water content increasing from 4% to 7%, a 3% increase. This indicates that Mg-gallate materials readily absorb water. (Comparison) Figure 5 and Figure 6 It can be seen that the water resistance of Mg-gallate material is worse than that of the amide-based metal-organic framework material provided in Example 1 of this invention, which further proves that the novel amide-based MOF provided in this invention has excellent water resistance.

[0124] Test Example 6

[0125] This test example demonstrates the water resistance of the metal-organic framework material provided in Comparative Example 1 using thermogravimetric analysis, including the following specific steps:

[0126] Step (a): Thermogravimetric analysis was immediately performed on the metal-organic framework material obtained after drying in step ⑤ of Comparative Example 1. The thermogravimetric analysis results are shown in [Figure 1]. Figure 7 Curve 5 in the middle;

[0127] Step (b): Take 0.1g of the metal-organic framework material obtained after drying in step ⑤ of Comparative Example 1 and place it in an environment with a relative humidity of 75% (RH=75%) for 48h to obtain a pre-humidified sample;

[0128] Step (c): Remove the pre-humidified sample and immediately perform thermogravimetric analysis. The thermogravimetric analysis results are shown in [the table below]. Figure 7 Curve 6 in the diagram.

[0129] from Figure 7 As can be seen, after placing the metal-organic framework material provided in Comparative Example 1, i.e., the MOF synthesized using unmodified ligands, in an environment of RH = 75% for 48 hours, its water content decreased significantly in the first dehydration stage, indicating that this metal-organic framework material absorbs a large amount of water. Compared to... Figure 5The water absorption of the MOF synthesized using the unmodified ligand in Comparative Example 1 is significantly higher than that of the amide MOF synthesized using the modified organic ligand in Example 1 of this invention. This also indirectly proves that the amide MOF synthesized using the modified organic ligand in the examples of this invention has better water resistance.

[0130] The above description is merely a specific embodiment of the present invention and should not be construed as limiting the scope of the invention. Therefore, any substitution of equivalent components or equivalent changes and modifications made within the scope of protection of this patent should still fall within the scope of this patent. Furthermore, the technical features, technical features and technical inventions, and technical inventions in this invention can be freely combined and used.

Claims

1. A method for preparing an amide-based metal-organic framework material, wherein, The preparation method includes: Step (1) Modification of organic ligands: 3-amino-1,2,4-triazole powder, esters, alkaline catalyst and organic solvent are mixed evenly to obtain a first mixed solution. The first mixed solution is subjected to a modification reaction. After the modification reaction is completed, the product is centrifuged, washed and dried to obtain a modified ligand containing amide bonds. Step (2) Preparation of amide-based metal-organic framework materials: Dissolve zinc salt or copper salt and modified ligand containing amide bonds in a solution composed of phosphoric acid, ammonia, methanol and water and allow it to fully dissolve to obtain a second mixed solution. Allow the second mixed solution to undergo a hydrothermal reaction. After the hydrothermal reaction is completed, centrifuge, wash and dry the product to obtain amide-based metal-organic framework materials.

2. The preparation method according to claim 1, wherein, In step (1), esters, alkaline catalysts and organic solvents are added to 3-amino-1,2,4-triazole powder and mixed evenly to obtain a first mixed solution.

3. The preparation method according to claim 1, wherein, In step (1), the mass ratio of 3-amino-1,2,4-triazole powder to ester substances is 1:3-1:

8.

4. The preparation method according to any one of claims 1-3, wherein, In step (1), the esters include ethyl acetate.

5. The preparation method according to any one of claims 1-3, wherein, In step (1), the temperature of the modification reaction is 100-150℃ and the time is 12-24h.

6. The preparation method according to claim 5, wherein, In step (1), the heating rate of the modification reaction process is 5-7.5℃ / min.

7. The preparation method according to claim 1, wherein, In step (2), the mass ratio of zinc or copper salt (calculated as metal) to modified ligand containing amide bond is 1:1 to 1:

5.

8. The preparation method according to claim 1 or 7, wherein, In step (2), the zinc salt includes one or a combination of zinc carbonate, zinc sulfate and zinc nitrate; The copper salt includes one or a combination of basic copper carbonate, copper sulfate, and copper nitrate.

9. The preparation method according to claim 1 or 7, wherein, In step (2), the temperature of the hydrothermal reaction is 150-180℃ and the time is 36-48h.

10. The preparation method according to claim 9, wherein, In step (2), the heating rate of the hydrothermal reaction process is 7-9℃ / min.

11. An amide-based metal-organic framework material, which is prepared by the preparation method of the amide-based metal-organic framework material according to any one of claims 1-10.

12. The application of the amide-based metal-organic framework material of claim 11 as an adsorbent material in the separation of ethylene / ethane gas.

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