Metal-organic framework material, preparation method therefor, and use thereof

Abstract

Provided are a metal-organic framework material, a preparation method therefor, and a use thereof. The metal-organic framework material comprises a two-dimensional layer formed by coordination of a metal element and a first organic ligand, and a pillar structure formed by coordination of a metal element and a second organic ligand, wherein the two-dimensional layer is connected to the pillar structure to form a three-dimensional layer-pillar framework structure, and the three-dimensional layer-pillar framework structure is doubly interpenetrated to form a first pore channel and a second pore channel; the area of the first pore channel is (I); and the area of the second pore channel is (II). The provided metal-organic framework material has two pore channels having different areas. When the metal-organic framework is used for adsorbing carbon dioxide from a mixed gas containing carbon dioxide and nitrogen, both a relatively high adsorption capacity and a relatively high selectivity for carbon dioxide can be achieved simultaneously, thereby achieving efficient capture of carbon dioxide.

Description

Metal-organic framework materials, their preparation methods and applications

[0001] This application claims priority to Chinese Patent Application No. 202411588611.2, filed on November 8, 2024, entitled “A metal-organic framework material and its preparation method and application”, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application belongs to the field of adsorption separation technology, and in particular relates to a metal-organic framework material, its preparation method and application. Background Technology

[0003] With the development of science and technology and the improvement of living standards, human demand for fossil fuels is increasing, leading to a serious energy crisis and environmental pollution. One of the main manifestations of environmental pollution is the greenhouse effect. Since the Industrial Revolution, the amount of heat-absorbing greenhouse gases such as carbon dioxide emitted into the atmosphere by humans has increased year by year, intensifying the atmospheric greenhouse effect and triggering a series of serious problems such as global warming, attracting worldwide attention. Therefore, mitigating and solving the greenhouse effect is urgent. Carbon dioxide released into the air mainly comes from the exhaust of fuel-powered engines, and its main components are 75% nitrogen, 10-15% carbon dioxide, 7% water vapor, and small amounts of oxidizing and corrosive gases. Therefore, the efficient selective adsorption and separation of carbon dioxide and nitrogen is the main evaluation criterion for carbon dioxide adsorbents.

[0004] The paper "Exquisitely Constructing a Robust MOF with Dual Pore Sizes for Efficient CO2 Capture" discloses the use of a dual-pore metal-organic framework material to adsorb carbon dioxide from a mixed gas containing carbon dioxide and nitrogen, with pore sizes of [missing information]. and The pore size is small, and correspondingly, the adsorption capacity and adsorption selectivity for carbon dioxide are low.

[0005] The literature *Tuning CO2 Selective Adsorption over N2 and CH4 in UiO-67 Analogues through Ligand Functionalizatio* discloses the preparation of the metal-organic framework material BUT-10 and its application in carbon dioxide / nitrogen separation. This material has a CO2 adsorption capacity as high as 100 mg / g, but its selectivity is only 18%.

[0006] The paper "Optimized Pore Nanospace through the Construction of a Cagelike Metal-Organic Framework for CO2 / N2 Separation" discloses the preparation of the metal-organic framework material FJUT-4 and its application in carbon dioxide / nitrogen separation. The material has a CO2 selectivity of 69, but an adsorption capacity of only 44 mg / g.

[0007] In summary, existing adsorption materials often struggle to achieve both high adsorption capacity and high selectivity when adsorbing carbon dioxide from a mixture of carbon dioxide and nitrogen, which limits their practical applications.

[0008] Application content

[0009] The main objective of this application is to provide a metal-organic framework material that can achieve high adsorption capacity and high selectivity for carbon dioxide when used to adsorb carbon dioxide from a mixed gas containing carbon dioxide and nitrogen.

[0010] This application also provides a method for preparing a metal-organic framework material, which can prepare the above-mentioned metal-organic framework material, and the process is simple and low in cost.

[0011] This application also provides an adsorption column. Since the adsorption column includes the aforementioned metal-organic framework material, when the adsorption column is used to adsorb and separate a mixed gas containing carbon dioxide and nitrogen, it can achieve a high adsorption capacity and high selectivity for carbon dioxide.

[0012] This application also provides a fixed bed, which, since it includes the aforementioned metal-organic framework material or adsorption column, can achieve a high adsorption capacity and high selectivity for carbon dioxide when used for adsorption and separation of a mixed gas containing carbon dioxide and nitrogen.

[0013] This application also provides a method for adsorption and separation of carbon dioxide and nitrogen. Since the method uses the aforementioned metal-organic framework material, adsorption column, or fixed bed to adsorb the mixed gas containing carbon dioxide and nitrogen, the adsorption and separation method can achieve a high adsorption capacity and high selectivity for carbon dioxide.

[0014] In a first aspect, this application provides a metal-organic framework material, the metal-organic framework material comprising a two-dimensional layer formed by coordination of a metal element and a first organic ligand, a column structure formed by coordination of a metal element and a second organic ligand, the two-dimensional layer and the column structure being connected to form a three-dimensional layer-column framework structure, the three-dimensional layer-column framework structure being doubly intersected to form a first channel and a second channel.

[0015] The area of ​​the first channel is

[0016] The area of ​​the second channel is

[0017] In the metal-organic framework material described above, the first channel and the second channel are staggered in a first direction, and the length of the first channel in the first direction is less than the length of the second channel in the first direction.

[0018] In the metal-organic framework material described above, the length of the first channel in the first direction is... The length of the second channel in the first direction is

[0019] In the metal-organic framework material described above, the first organic ligand includes a carboxylic acid ligand; the second organic ligand includes an amide ligand.

[0020] The metal-organic framework material as described above, wherein the three-dimensional layer-pillar framework structure includes a first material column distributed along a first direction and a second material column distributed along a second direction, wherein the first material column includes the first organic ligand and the second material column includes the second organic ligand, wherein the first pore and the second pore of the metal-organic framework material are defined by the first material column and the second material column; wherein the connection between the first material column and the second material column includes the metal element.

[0021] In the metal-organic framework materials described above, the carboxylic acid ligands include compounds represented by Formula 1:

[0022] Wherein, R1 and R2 are each independently selected from hydrogen, substituted or unsubstituted C1-C8 straight-chain or branched alkyl groups, substituted or unsubstituted C1-C8 straight-chain or branched alkoxy groups, hydroxyl groups, amino groups, mercapto groups, halogen groups, cyano groups and their derivatives.

[0023] In the metal-organic framework materials described above, the amide ligands include N,N'-(1,4-phenylene)diisonicotinamide.

[0024] The metal-organic framework material as described above, wherein the metal element includes at least one selected from copper, zinc, magnesium, iron, manganese, cobalt, and nickel.

[0025] Secondly, this application provides a method for preparing the metal-organic framework material as described above, comprising the following steps: performing a solvothermal reaction on a raw material system including amide ligands, carboxylic acid ligands and metal elements to obtain the metal-organic framework material.

[0026] In the preparation method described above, the temperature of the solvothermal reaction is 50℃-200℃;

[0027] And / or, the solvothermal reaction time is 4h-96h;

[0028] And / or, the molar ratio of the metal element to the carboxylic acid ligand is 1:(0.1-5);

[0029] And / or, the molar ratio of the metal element to the amide ligand is 1:(0.1-5).

[0030] Thirdly, this application provides an application of the metal-organic framework material as described above in an adsorption column.

[0031] Fourthly, this application provides an application of the metal-organic framework material described above in a fixed bed.

[0032] Fifthly, this application provides an application of the metal-organic framework material described above in the adsorption and separation of carbon dioxide and nitrogen.

[0033] The metal-organic framework material provided in this application has two channels with different areas. The smaller first channel can improve the selectivity for carbon dioxide, and the larger second channel can improve the adsorption capacity for carbon dioxide. Therefore, when the metal-organic framework material is used to adsorb carbon dioxide in a mixed gas containing carbon dioxide and nitrogen, it can achieve a high adsorption capacity and high selectivity for carbon dioxide. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the accompanying drawings used in the description of the embodiments of this application or related technologies are briefly introduced below. Obviously, the drawings described below are merely some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 is a schematic diagram of the crystal structure of the metal-organic framework material of Embodiment 1 of this application;

[0036] Figure 2 is a comparison of X-ray diffraction data of the metal-organic framework material of Example 1 of this application and the simulated metal-organic framework material;

[0037] Figure 3 is a comparison of X-ray diffraction data of the metal-organic framework material and the simulated metal-organic framework material in Example 2 of this application;

[0038] Figure 4 is a comparison of X-ray diffraction data of the newly synthesized metal-organic framework material in Example 1 of this application, the metal-organic framework material exposed to 75% moisture for one day, and the metal-organic framework material soaked in water for one day.

[0039] Figure 5 is a comparison of X-ray diffraction data of the newly synthesized metal-organic framework material in Example 2 of this application, the metal-organic framework material exposed to 75% moisture for one day, and the metal-organic framework material soaked in water for one day.

[0040] Figure 6 is a thermal decomposition curve of the metal-organic framework material of Example 1 of this application;

[0041] Figure 7 is a thermal decomposition curve of the metal-organic framework material of Example 2 of this application;

[0042] Figure 8 is an adsorption isotherm curve of the metal-organic framework material of Example 1 of this application at 273K for a mixed gas including carbon dioxide and nitrogen.

[0043] Figure 9 is an adsorption isotherm curve of the metal-organic framework material of Example 1 of this application at 298K for a mixed gas including carbon dioxide and nitrogen.

[0044] Figure 10 is a cyclic penetration curve of the metal-organic framework material of Example 1 of this application under dry conditions at 273K for a mixed gas including carbon dioxide and nitrogen.

[0045] Figure 11 is a cyclic penetration curve of the metal-organic framework material of Example 1 of this application under dry conditions at 298K for a mixed gas including carbon dioxide and nitrogen.

[0046] Figure 12 is a cyclic penetration curve of the metal-organic framework material of Example 1 of this application at 298K and 75%RH for a mixed gas including carbon dioxide and nitrogen.

[0047] Figure 13 is a cycle penetration curve of the metal-organic framework material of Example 1 of this application after being regenerated 5 times under dry conditions at 298K, through a mixed gas including carbon dioxide and nitrogen.

[0048] Explanation of reference numerals in the attached figures: 1-First channel; 2-Second channel; 3-First channel row; 4-Second channel row; 5-Carboxylic acid ligand; 6-Amide ligand; 7-Metal node; 8-First material row; 9-Second material row. Detailed Implementation

[0049] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the embodiments of this application. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0050] In the industrial and environmental fields, carbon dioxide capture and separation is an important research topic, particularly in reducing greenhouse gas emissions and addressing climate change. Traditional carbon dioxide capture technologies, such as chemical absorption and physical adsorption, often suffer from high energy consumption, low selectivity, and material corrosion. Therefore, developing efficient and low-cost carbon dioxide capture materials has become a research hotspot. Metal-organic frameworks (MOFs) have attracted widespread attention due to their unique structure and excellent performance. MOFs are a class of porous materials composed of metal ions or clusters and organic ligands through coordination bonds. They possess high specific surface area, tunable pore size, and the ability to be chemically functionalized, making them ideal candidate materials for gas adsorption and separation. In the separation of carbon dioxide and nitrogen mixtures, improving the adsorption capacity and selectivity for carbon dioxide is a key challenge. The differences in molecular size and polarity between carbon dioxide and nitrogen provide possibilities for selective separation. By designing channels with different sizes and shapes, dual-pore MOF materials can achieve a sieving effect on gas molecules, thereby improving the adsorption capacity and selectivity for carbon dioxide. This dual-pore structure not only enhances the physical adsorption of carbon dioxide but also improves the chemical adsorption capacity by adjusting the chemical environment of the channels. Furthermore, the structural diversity and tunability of MOF materials allow for further performance optimization through post-synthetic modifications, such as introducing functionalized groups to enhance their interaction with carbon dioxide. These characteristics make dual-pore MOF materials a promising candidate for applications in gas separation, particularly carbon dioxide capture.

[0051] Based on this, in a first aspect, this application provides a metal-organic framework material, comprising a two-dimensional layer formed by the coordination of a metal element and a first organic ligand, and a columnar structure formed by the coordination of the metal element and a second organic ligand. The two-dimensional layer and the columnar structure are connected to form a three-dimensional layer-column framework structure, and the three-dimensional layer-column framework structure is doubly interwoven to form a first channel and a second channel; wherein, the area of ​​the first channel is... The area of ​​the second channel is

[0052] The metal-organic framework material provided in this application includes two channels with different areas. When used to adsorb carbon dioxide from a mixed gas containing carbon dioxide and nitrogen, it can achieve a high adsorption capacity and high selectivity for carbon dioxide.

[0053] In this application, the metallic element and the first organic ligand coordinate to form a two-dimensional layer, and the metallic element and the second organic ligand coordinate to form a column structure, connecting the different two-dimensional layers. That is, the two-dimensional layers are connected by the column structure to form a three-dimensional layer-column frame structure. The three-dimensional layer-column frame structure interpenetrates to form the first channel and the second channel.

[0054] This application does not limit the specific types of metal elements, first organic ligands, and second organic ligands, as long as it can achieve the formation of a two-dimensional layer through coordination between the metal element and the first organic ligand, the formation of a column structure through coordination between the metal element and the second organic ligand, the connection between the two-dimensional layer and the column structure to form a three-dimensional layer-column frame structure, and the double interpenetration of the three-dimensional layer-column frame structure to form the first channel and the second channel.

[0055] In the metal-organic framework (MOF) material provided in this application, the areas of the first and second channels refer to the cross-sectional areas of the channels, which are substantially perpendicular to the channel direction of the MOF material. The first channel has a smaller area, with a size closer to that of a carbon dioxide molecule, while the nitrogen molecule is slightly larger, allowing for kinetic selective separation of carbon dioxide / nitrogen molecules based on size. Furthermore, the organic ligands and metal nodes in the MOF material enhance the selective adsorption of carbon dioxide through polar interactions and chemical functionalization. The polar and linear molecular structure of carbon dioxide makes it easier for it to interact with the active sites of the MOF material. Additionally, the second channel in the MOF material has a larger area, which helps increase the adsorption capacity for carbon dioxide, allowing it to accommodate more carbon dioxide molecules. Through the synergistic effect of the first and second channels in the MOF material, a high adsorption capacity and high selectivity for carbon dioxide can be achieved.

[0056] For example, the area of ​​the first channel can be Or the range consisting of any two of them. The area of ​​the second channel can be or a range consisting of any two of them.

[0057] The metal-organic framework material provided in this application has two channels with different areas. When used to adsorb carbon dioxide from a mixed gas containing carbon dioxide and nitrogen, it can achieve a high adsorption capacity and high selectivity for carbon dioxide.

[0058] The width of the first channel in this application is That is, the length of the first channel in the first direction (x direction) is For example, it can be... or a range consisting of any two of them. The length of the first channel is... That is, the length of the first channel in the second direction (y direction) is For example, it can be... Or a range consisting of any two of them. The width of the second channel is That is, the length of the second channel in the second direction (y direction) is For example, it can be... Or a range consisting of any two of them. The length of the second channel is... That is, the length of the second channel in the first direction (x direction) is For example, it can be... or a range consisting of any two of them.

[0059] In some embodiments of this application, the number ratio of the first channel and the second channel can be substantially equivalent, that is, the number ratio can be substantially 1:1.

[0060] In some embodiments, in the metal-organic framework material, the first channel and the second channel are staggered in a first direction, and the length of the first channel in the first direction is less than the length of the second channel in the first direction.

[0061] Typically, metal-organic framework materials contain multiple first channels and multiple second channels. The ratio of first to second channels provided in this application falls within the aforementioned range. This ratio allows for a synergistic balance between the adsorption capacity and selectivity for carbon dioxide. It fully utilizes both the high selectivity of the smaller first channels for carbon dioxide and the high adsorption capacity of the larger second channels. In other words, an appropriate ratio ensures that the metal-organic framework material has sufficient selectivity for carbon dioxide without sacrificing its adsorption capacity.

[0062] As shown in Figure 1, in a metal-organic framework (MOF) material, the first and second channels are staggered along a first direction (x-direction in Figure 1), and the length D1 of the first channel in the first direction is less than the length D2 of the second channel in the first direction. Specifically, the MOF material includes a first channel column and a second channel column. The first channel column includes multiple first channels distributed along a second direction (y-direction in Figure 1), and the second channel column includes multiple second channels distributed along the second direction (y-direction in Figure 1). The first and second channel columns are staggered along the first direction; that is, the MOF material includes multiple first channel columns and multiple second channel columns distributed along the first direction. In these first channel columns, there is a second channel column between every two adjacent first channel columns, and each pair of adjacent second channel columns is separated by a first channel column. The first and second directions intersect, but can be substantially perpendicular. Specifically, the first direction can intersect with the thickness direction of the metal-organic framework material, and the two can be basically perpendicular; the second direction can intersect with the thickness direction of the metal-organic framework material, and the two can be basically perpendicular.

[0063] In this application, the first and second channels are staggered in the first direction, forming complex gas transport paths and enhancing the diffusion and transport efficiency of gas molecules. This structure helps to increase the transport rate of carbon dioxide molecules in the metal-organic framework material, thereby improving adsorption efficiency. The staggered arrangement of channels also provides diverse adsorption sites, allowing the metal-organic framework material to more effectively utilize its internal space to adsorb carbon dioxide molecules. In addition, the staggered design helps maintain the structural stability of the metal-organic framework material, preventing structural collapse or degradation of mechanical properties due to improper channel arrangement.

[0064] In addition, by designing first and second channels of different lengths in the first direction, the first channel with a smaller D1 is more suitable for selectively separating carbon dioxide and nitrogen, while the second channel with a larger D2 helps to improve the adsorption capacity for carbon dioxide.

[0065] Specifically, the length of the first channel in the first direction is For example, it can be... or a range consisting of any two of them. The length of the second channel in the first direction is... For example, it can be... or a range consisting of any two of them.

[0066] In this application, the length of the first channel in the first direction is relatively small, making it suitable for the selective adsorption of small carbon dioxide molecules (carbon dioxide molecular dynamic diameter is...). This effectively prevents larger nitrogen molecules from entering the pores, thereby further improving the selectivity for carbon dioxide.

[0067] Meanwhile, the second channel has a longer length in the first direction, which provides enough space to increase the adsorption capacity for carbon dioxide and can accommodate more carbon dioxide molecules, thereby further improving the adsorption capacity for carbon dioxide.

[0068] In some embodiments of this application, the first organic ligand includes a carboxylic acid ligand; the second organic ligand includes an amide ligand.

[0069] It should be noted that the metal elements in metal-organic framework materials exist in the form of metal cations, and the second organic ligands include amide ligands, that is, organic ligands containing amide groups.

[0070] Specifically, the first organic ligand, namely carboxylic acid ligands, can form strong coordination bonds with metal cations, providing a stable framework structure. Furthermore, carboxylic acid ligands can enhance their interaction with carbon dioxide molecules through hydrogen bonding and electrostatic interactions. The second organic ligand, namely amide ligands, possesses polarity and hydrogen bond donor / acceptor properties, enabling them to form stable hydrogen-bonded complexes with carbon dioxide molecules, thus contributing to improved selective adsorption of carbon dioxide.

[0071] In this application, the first and second organic ligands have strong binding ability to metal cations, avoiding open metal sites, thus giving the metal-organic framework material high thermodynamic and chemical stability, especially strong moisture resistance. It can achieve efficient and stable separation of carbon dioxide and nitrogen under high humidity conditions, and has significant application potential.

[0072] Metal-organic framework materials include multiple metal nodes, each metal node (or core) includes at least one metal element (e.g., 1 to 2 metal elements), and the metal elements in each pair of adjacent metal nodes are coordinated and connected by organic ligands, thereby defining the pores (i.e., the first pore and the second pore) of the metal-organic framework material.

[0073] In some embodiments of this application, the three-dimensional layer-column frame structure includes a first material column distributed along a first direction and a second material column distributed along a second direction. The first material column includes a first organic ligand, and the second material column includes a second organic ligand. The first material column and the second material column define a first channel and a second channel of the metal-organic framework material. The connection between the first material column and the second material column includes a metal element.

[0074] The metal-organic framework material of this application includes a plurality of first material columns distributed along a first direction and a plurality of second material columns distributed along a second direction. The first and second material columns define channels within the metal-organic framework material. Specifically, the first material columns may be located between the first channels (first channel columns) and the second channels (second channel columns). The second material columns are located between the first channels (first channel columns) or between the second channels (second channel columns). The connection points between the first and second material columns, i.e., the metal nodes, include metal elements.

[0075] The combination of the first and second organic ligands utilizes their different chemical properties. The carboxylic acid group in the first organic ligand enhances the adsorption of carbon dioxide molecules through electrostatic interactions and hydrogen bonding, while the amide group in the second organic ligand further improves the selectivity for carbon dioxide molecules through its polarity and hydrogen bonding donor / acceptor properties. This synergistic effect contributes to improved selective adsorption of carbon dioxide. Connecting different material groups with metal elements forms a stable framework structure. This connection method not only provides good mechanical strength but also ensures the stability of metal-organic framework materials under various application conditions.

[0076] In some embodiments, carboxylic acid ligands include compounds represented by Formula 1:

[0077] R1 and R2 are each independently selected from hydrogen, substituted or unsubstituted C1-C8 (e.g., a range consisting of C1, C2, C3, C4, C5, C6, C7, C8, or any two thereof) straight-chain or branched alkyl, amino, hydroxyl, halogen, cyano, and their derivatives. By selecting different substituents, the pore environment and chemical functionalization sites of the metal-organic framework material can be optimized, thereby improving the selective adsorption of carbon dioxide.

[0078] In some embodiments, the amide ligand includes N,N'-(1,4-phenylene)diisonicotinamide. The amide group possesses polarity and hydrogen bond donor / acceptor properties, enabling it to form stable hydrogen-bonded complexes with carbon dioxide, further enhancing the selective adsorption of carbon dioxide.

[0079] In some embodiments, the metal element includes at least one selected from copper, zinc, magnesium, iron, manganese, cobalt, and nickel. This metal element has suitable coordination ability and spatial configuration, and can coordinate with ligands (amide ligands and carboxylic acid ligands) in a suitable manner, so that the metal-organic framework material has a suitable pore structure and pore size. Furthermore, the metal element can have a high affinity for carbon dioxide, thereby improving the adsorption performance and adsorption capacity of the metal-organic framework material for carbon dioxide. In addition, the metal element can also enhance the thermal stability and chemical stability of the metal-organic framework material.

[0080] In some embodiments of this application, the thermal decomposition temperature of the metal-organic framework material is not lower than 300°C, and the material has good thermal stability.

[0081] Thermogravimetric analysis (TGA) curves of the metal-organic framework materials provided in this application show that the thermal decomposition temperature is not lower than 300℃, and the metal-organic framework materials exhibit high thermal stability before 300℃. In the TGA curves, the material exhibits slight weight loss between 30-290℃, mainly due to solvent evaporation.

[0082] Secondly, this application provides a method for preparing the metal-organic framework material as described above, comprising the following steps: performing a solvothermal reaction on a raw material system including amide ligands, carboxylic acid ligands and metal elements to obtain the metal-organic framework material.

[0083] It is understood that in this application, the raw materials for preparing metal-organic framework materials include amide ligands, carboxylic acid ligands, and compounds containing metal elements, and the solvent for solvothermal reaction may include at least one of N,N-dimethylformamide, N,N-dimethylacetamide, and methanol.

[0084] Specifically, a certain proportion of amide ligands, carboxylic acid ligands, and compounds containing metal elements can be dissolved in a solvent to obtain a reaction solution. Ultrasonic dissolution can be used to ensure that the raw materials are fully dissolved in the solvent. Then, the reaction solution is transferred to a stainless steel reactor lined with polytetrafluoroethylene. After sealing the reactor, it is placed in an oven for a solvothermal reaction. After the reaction is completed, the reactor is washed, filtered, and dried to obtain a metal-organic framework material.

[0085] The method for preparing metal-organic framework materials in this application uses amide ligands, carboxylic acid ligands, and compounds containing metal elements as raw materials, and obtains the above-mentioned metal-organic framework materials through a solvothermal reaction. This method is simple, easy to implement, and low in cost.

[0086] In some embodiments of this application, the temperature of the solvothermal reaction is 50°C-200°C, for example, it can be a range of 50°C, 80°C, 100°C, 120°C, 150°C, 180°C, 200°C or any two of them, and further can be 100°C-150°C.

[0087] In some embodiments, the solvothermal reaction time is 4h-96h, for example, it can be a range of 4h, 10h, 20h, 30h, 40h, 50h, 60h, 70h, 80h, 90h, 96h or any two of these, and more specifically, it can be 12h-48h.

[0088] In some embodiments, the molar ratio of the metal element to the carboxylic acid ligand is 1:(0.1-5), for example, it can be a range of 1:0.1, 1:0.5, 1:1, 1:2, 1:3, 1:4, 1:5 or any two of them, and more specifically 1:(0.5-1.5).

[0089] In some embodiments, the molar ratio of the metal element to the amide ligand is 1:(0.1-5), for example, it can be a range of 1:0.1, 1:0.5, 1:1, 1:2, 1:3, 1:4, 1:5 or any two of them, and more specifically, it can be 1:(0.5-1.5).

[0090] This application limits the temperature and time of the solvothermal reaction to a suitable range, which allows the reaction to proceed under appropriate kinetic conditions, facilitating the formation of metal-organic framework materials with dual channels of varying areas. Limiting the molar ratio between raw materials to a suitable range avoids situations where there is an excess or deficiency of raw materials, which helps reduce the formation of byproducts and improve the purity of the products. As a result, the prepared metal-organic framework materials exhibit high adsorption selectivity and high adsorption capacity for carbon dioxide. In addition, it can also save costs and improve economic efficiency.

[0091] This application limits the temperature, time, and molar ratio of the raw materials in the solvothermal reaction, which is beneficial for preparing metal-organic framework materials with dual channels of different areas. Moreover, the metal-organic framework materials have high adsorption selectivity and high adsorption capacity for carbon dioxide.

[0092] Thirdly, this application provides an application of the metal-organic framework material as described above in an adsorption column.

[0093] The adsorption column in this application includes the metal-organic framework material described above or the metal-organic framework material prepared according to the above preparation method. Specifically, the metal-organic framework material can be packed into an adsorption column of a certain length, for example, 5 cm, and a mixed gas including carbon dioxide and nitrogen can be passed into the adsorption column for adsorption and separation. This adsorption column can achieve a high adsorption capacity and high selectivity for carbon dioxide.

[0094] Fourthly, this application provides an application of the metal-organic framework material described above in a fixed bed.

[0095] The fixed bed in this application includes the above-mentioned metal-organic framework material, or the metal-organic framework material prepared according to the above-mentioned preparation method, or the above-mentioned adsorption column. Specifically, the above-mentioned metal-organic framework material can be loaded into an adsorption column of a certain length, for example, 5 cm, and the adsorption column can be fixed in the fixed bed. A mixed gas including carbon dioxide and nitrogen is introduced into the fixed bed for adsorption and separation. The fixed bed can achieve a high adsorption capacity and high selectivity for carbon dioxide.

[0096] Fifthly, this application provides an application of the metal-organic framework material described above in the adsorption and separation of carbon dioxide and nitrogen.

[0097] In this method for carbon dioxide / nitrogen adsorption separation, a metal-organic framework (MOF) material, an adsorption column, or a fixed bed is used to adsorb a mixed gas containing carbon dioxide and nitrogen. Carbon dioxide is captured within the MOF material, adsorption column, or fixed bed, while nitrogen is allowed to pass through as much as possible, thus achieving separation of carbon dioxide and nitrogen. The volume ratio of carbon dioxide to nitrogen in the mixed gas can be 15:85, and the adsorption separation temperature can be 0-25℃, achieving high adsorption capacity and high selectivity for carbon dioxide. The MOF material of this application can effectively distinguish between carbon dioxide and nitrogen molecules, thus showing broad application prospects in industrial gas purification, air separation, and carbon capture.

[0098] The technical solution of this application will be further described below with reference to specific embodiments.

[0099] Raw material source: Sinopharm Reagent.

[0100] Equipment: Bruker D8 PHASER X-ray diffractometer; TGA-55 thermogravimetric analyzer; BSD-VVS multi-station gravimetric dynamic vapor adsorption analyzer; gas phase penetration analyzer.

[0101] Example 1

[0102] The preparation method of the metal-organic framework material in this embodiment includes the following steps:

[0103] 0.5 mmol N,N'-(1,4-phenylene)diisocyanamide, 0.5 mmol 1,6-naphthalenedicarboxylic acid, and 0.5 mmol Co(NO3)2·6H2O were dissolved in 20 mL N,N-dimethylformamide and subjected to ultrasonic treatment to obtain a reaction precursor solution. The molar ratio of cobalt to 1,6-naphthalenedicarboxylic acid was 1:1, denoted as ratio 1; the molar ratio of cobalt to N,N'-(1,4-phenylene)diisocyanamide was 1:1, denoted as ratio 2. Subsequently, the reaction precursor solution was transferred to a stainless steel reactor lined with polytetrafluoroethylene. The stainless steel reactor was sealed and placed in an oven for a solvothermal reaction at 120 °C for 48 h. The metal-organic framework material was obtained by filtration. As shown in Figure 1, in a metal-organic framework (MOF) material, a metal element (Co) and a first organic ligand (1,6-naphthalenedicarboxylic acid ligand) coordinate to form a two-dimensional layer, and the metal element (Co) and a second organic ligand (N,N'-(1,4-phenylene)diisonicotinamide ligand) coordinate to form a columnar structure. The two-dimensional layer and the columnar structure connect to form a three-dimensional layer-column framework structure, and the three-dimensional layer-column framework structure double-interpenetrates to form a first channel and a second channel. Specifically, the MOF material has a first material column distributed along a first direction (x-direction) and a second material column distributed along a second direction (y-direction). The first material column is a 1,6-naphthalenedicarboxylic acid ligand, and the second material column is an N,N'-(1,4-phenylene)diisonicotinamide ligand. The first and second material columns define the first and second channels of the MOF material; the connection between the first and second material columns is a Co element. The metal-organic framework material contains a first channel and a second channel, which are staggered in a first direction (x-direction). The length D1 of the first channel in the first direction (x-direction) is... The length D2 of the second channel in the first direction (x direction) is The ratio of the number of first channels to the number of second channels is 1:1, and the area of ​​the first channel is... The area of ​​the second channel is

[0104] Example 2

[0105] The preparation method of the metal-organic framework material in Example 2 is basically the same as that in Example 1, except that 0.5 mmol N,N'-(1,4-phenylene)diisonicotinamide, 0.5 mmol 1,6-naphthalenedicarboxylic acid and 0.5 mmol Cu(NO3)2·3H2O are dissolved in 20 mL N,N-dimethylacetamide.

[0106] Example 3

[0107] The preparation method of the metal-organic framework material in Example 3 is basically the same as that in Example 1, except that 0.5 mmol N,N'-(1,4-phenylene)diisonicotinamide, 0.5 mmol 1,6-naphthalenedicarboxylic acid and 0.5 mmol Mn(NO3)2·6H2O are dissolved in a mixed solvent of 10 mL N,N-dimethylacetamide and 5 mL methanol.

[0108] Example 4

[0109] The preparation method of the metal-organic framework material in Example 4 is basically the same as that in Example 1, except that 0.5 mmol N,N'-(1,4-phenylene)diisonicotinamide, 0.5 mmol 1,6-naphthalenedicarboxylic acid and 0.5 mmol Ni(NO3)2·6H2O are dissolved in 20 mL N,N-dimethylformamide.

[0110] Example 5

[0111] The preparation method of the metal-organic framework material in Example 5 is basically the same as that in Example 1, except that 0.5 mmol N,N'-(1,4-phenylene)diisonicotinamide, 0.5 mmol 1,6-naphthalenedicarboxylic acid and 0.5 mmol Zn(NO3)2·6H2O are dissolved in 20 mL N,N-dimethylformamide.

[0112] Example 6

[0113] The preparation method of the metal-organic framework material in Example 6 is basically the same as that in Example 1, except that 0.5 mmol N,N'-(1,4-phenylene)diisonicotinamide, 0.5 mmol 1,6-naphthalenedicarboxylic acid and 0.5 mmol Mg(NO3)2·6H2O are dissolved in 20 mL N,N-dimethylformamide.

[0114] Example 7

[0115] The preparation method of the metal-organic framework material in Example 7 is basically the same as that in Example 1, except that 0.5 mmol N,N'-(1,4-phenylene)diisonicotinamide, 0.5 mmol 1,6-naphthalenedicarboxylic acid and 0.5 mmol Fe(NO3)3·9H2O are dissolved in 20 mL N,N-dimethylformamide.

[0116] Example 8

[0117] The preparation method of the metal-organic framework material in Example 8 is basically the same as that in Example 1, except that 0.5 mmol N,N'-(1,4-phenylene)diisocyanamide, 0.5 mmol 1,5-dimethylnaphthalene-2,6-dicarboxylic acid and 0.5 mmol Co(NO3)2·6H2O are dissolved in 20 mL N,N-dimethylformamide.

[0118] Example 9

[0119] The preparation method of the metal-organic framework material in Example 9 is basically the same as that in Example 1, except that 0.5 mmol N,N'-(1,4-phenylene)diisocyanamide, 0.5 mmol 1,5-dihydroxynaphthalene-2,6-dicarboxylic acid and 0.5 mmol Co(NO3)2·6H2O are dissolved in 20 mL N,N-dimethylformamide.

[0120] Example 10

[0121] The preparation method of the metal-organic framework material in Example 10 is basically the same as that in Example 1, except that 0.5 mmol N,N'-(1,4-phenylene)diisonicotinamide, 0.5 mmol 1,5-diaminonaphthalene-2,6-dicarboxylic acid and 0.5 mmol Co(NO3)2·6H2O are dissolved in 20 mL N,N-dimethylformamide.

[0122] Example 11

[0123] The preparation method of the metal-organic framework material in Example 11 is basically the same as that in Example 1, except that 0.5 mmol N,N'-(1,4-phenylene)diisocyanamide, 0.5 mmol 1,5-dibromonaphthalene-2,6-dicarboxylic acid and 0.5 mmol Co(NO3)2·6H2O are dissolved in 20 mL N,N-dimethylformamide.

[0124] Example 12

[0125] The preparation method of the metal-organic framework material in Example 12 is basically the same as that in Example 1, except that the reaction temperature of the solvothermal reaction is 50°C.

[0126] Example 13

[0127] The preparation method of the metal-organic framework material in Example 13 is basically the same as that in Example 1, except that the reaction temperature of the solvothermal reaction is 200°C.

[0128] Example 14

[0129] The preparation method of the metal-organic framework material in Example 14 is basically the same as that in Example 1, except that 0.05 mmol N,N'-(1,4-phenylene)diisonicotinamide, 0.05 mmol 1,6-naphthalenedicarboxylic acid and 0.5 mmol Co(NO3)2·6H2O are dissolved in 20 mL N,N-dimethylformamide.

[0130] Example 15

[0131] The preparation method of the metal-organic framework material in Example 15 is basically the same as that in Example 1, except that 2.5 mmol of N,N'-(1,4-phenylene)diisonicotinamide, 2.5 mmol of 1,6-naphthalenedicarboxylic acid and 0.5 mmol of Co(NO3)2·6H2O are dissolved in 20 mL of N,N-dimethylformamide.

[0132] Example 16

[0133] The preparation method of the metal-organic framework material in Example 16 is basically the same as that in Example 1, except that the reaction time of the solvothermal reaction is 12 hours.

[0134] Example 17

[0135] The preparation method of the metal-organic framework material in Example 17 is basically the same as that in Example 1, except that the reaction time of the solvothermal reaction is 96 hours.

[0136] Comparative Example 1

[0137] The preparation method of the metal-organic framework material in this comparative example includes the following steps:

[0138] 0.5 mmol N,N'-(1,4-phenylene)diisocyanamide, 0.5 mmol 1,4-phthalic acid, and 0.5 mmol Co(NO3)2·6H2O were dissolved in 20 mL of N,N-dimethylformamide and subjected to ultrasonic treatment to obtain the reaction precursor solution. The molar ratio of cobalt to 1,4-phthalic acid was 1:1, denoted as ratio 1; the molar ratio of cobalt to N,N'-(1,4-phenylene)diisocyanamide was 1:1, denoted as ratio 2. Subsequently, the reaction precursor solution was transferred to a stainless steel reactor lined with polytetrafluoroethylene (PTFE). The reactor was sealed and placed in an oven for a solvothermal reaction at 120 °C for 48 h. The target product was obtained by filtration. Specific results are shown in Table 1.

[0139] Comparative Example 2

[0140] The preparation method of the metal-organic framework material in this comparative example includes the following steps:

[0141] 0.3 mmol of 4,4'-biphenyl dicarboxylic acid, 0.3 mmol of ZrCl4, and 3 mL of acetic acid solution were dissolved in 17 mL of N,N-dimethylformamide to obtain the reaction precursor, wherein the molar ratio of 4,4'-biphenyl dicarboxylic acid to zirconium was 1:1. The reaction precursor was then sealed in a glass bottle and heated at 120 °C for 10 h. The resulting yellow crystals were collected, washed with N,N-dimethylformamide and acetone, and then dried in air to obtain the target product. Specific results are shown in Table 1.

[0142] Comparative Example 3

[0143] The preparation method of the metal-organic framework material in this comparative example includes the following steps:

[0144] 0.3 mmol NiSO4·7H2O and 0.2 mmol 1,3,5-benzenetricarboxylic acid ester were added to a mixed solvent of 5 mL N,N-dimethylformamide and 2 mL methanol. Then, 150 μL of HF (hydrofluoric acid, 50% wt) aqueous solution was added, and the mixture was sonicated for 1 h. Finally, the mixture was sealed, heated to 120 °C, and held at that temperature for 72 h. The resulting green crystals were collected and washed with N,N-dimethylformamide to obtain the target product. The specific results are shown in Table 1.

[0145] Experimental example:

[0146] 1. X-ray diffraction test: X-ray powder diffraction tests were performed on the materials prepared in Examples 1 and 2 of this application, as well as the materials prepared in Examples 1 and 2 after being exposed to 75% humidity for one day and immersed in water for one day, respectively, using a Bruker D8 QUEST X-ray single crystal diffractometer. Cu Kα rays were used at room temperature. Diffraction data were collected as a radiation source. Indexing and data integration were performed using APEX4 (Differential Vector Method). Absorption correction was performed using a multi-scan method implemented in SADABS. The spatial group was determined using XPREP implemented in APEX4. The structure was solved using SHELXL-2014 (Direct Method), and the anisotropic shifts included in the APEX4 package were refined using SHELXL-2014 (Full Matrix Least Squares on F2). Hydrogen atoms on carbon and nitrogen were calculated at ideal positions, with isotropic placement parameters set to 1.2 × Ueq of the attached atoms, yielding the three-dimensional atomic space coordinates of the adsorbent material.

[0147] 2. Pore size and pore area: Based on the three-dimensional spatial structure of the material obtained by X-ray diffraction testing, the parallel cross-section of the pore was established using Mercury (Mercury 4.0: From Visualization to Analysis, Design and Prediction. J. Appl. Crystallogr. 2020, 53, 226–235) crystal structure visualization software, and the length and width of the pore were measured using the Measure distances tool. The corresponding pore area was obtained by multiplying the two dimensions.

[0148] 3. Thermogravimetric analysis: The thermal stability of the materials prepared in Example 1 and Example 2 was tested by thermogravimetric analysis using a TGA-55 thermogravimetric analyzer.

[0149] 4. Adsorption isotherm test: The material prepared in Example 1 was placed in a quartz crucible of a BSD-VVS multi-station gravimetric dynamic vapor adsorption apparatus. The material was first activated under vacuum at 100℃. Then, the samples were placed in environments of 273K and 298K, with partial pressure points set at 0.1-1 bar and a step size of 0.1 bar. Single-component gas static adsorption tests were performed using carbon dioxide or nitrogen (99.999% purity), and adsorption isotherms were obtained. The adsorption capacity can be obtained from the adsorption isotherms.

[0150] 5. Cyclic Breakthrough Curve Test: The material prepared in Example 1 was packed into a 5 cm fixed-bed adsorption column. A mixture of dry carbon dioxide and nitrogen (volume ratio 15:85) with a humidity of 75% RH was introduced into the adsorption column at 273 K or 298 K to conduct a fixed-bed breakthrough experiment. The CO2-enriched adsorption column was purged with inert helium for several minutes to regenerate the column.

[0151] 6. Adsorption Selectivity: The composition ratio of carbon dioxide and nitrogen in the simulated flue gas (15:85) was used to calculate the separation selectivity of the materials prepared in the examples and comparative examples for carbon dioxide in a mixed gas containing carbon dioxide and nitrogen at 273 K using the ideal adsorption solution theory (IAST theory).

[0152] Figure 1 is a schematic diagram of the crystal structure of the metal-organic framework material of Embodiment 1 of this application;

[0153] As can be seen from Figure 1, the first and second channels in the metal-organic framework material of Embodiment 1 of this application are staggered in the first direction.

[0154] Figure 2 is a comparison of X-ray diffraction data of the metal-organic framework material of Example 1 of this application and the simulated metal-organic framework material;

[0155] As can be seen from Figure 2, the X-ray diffraction data of the metal-organic framework material in Example 1 of this application are basically consistent with those of the simulated metal-organic framework material.

[0156] Figure 3 is a comparison of X-ray diffraction data of the metal-organic framework material and the simulated metal-organic framework material in Example 2 of this application;

[0157] As can be seen from Figure 3, the X-ray diffraction data of the metal-organic framework material in Example 2 of this application are basically consistent with those of the simulated metal-organic framework material.

[0158] Figure 4 is a comparison of X-ray diffraction data of the newly synthesized metal-organic framework material in Example 1 of this application, the metal-organic framework material exposed to 75% moisture for one day, and the metal-organic framework material soaked in water for one day.

[0159] As can be seen from Figure 4, the X-ray diffraction data of the newly synthesized metal-organic framework material in Example 1 of this application, the metal-organic framework material exposed to 75% moisture for one day, and the metal-organic framework material soaked in water for one day are basically the same.

[0160] Figure 5 is a comparison of X-ray diffraction data of the newly synthesized metal-organic framework material in Example 2 of this application, the metal-organic framework material exposed to 75% moisture for one day, and the metal-organic framework material soaked in water for one day.

[0161] As can be seen from Figure 5, the X-ray diffraction data of the newly synthesized metal-organic framework material in Example 2 of this application, the metal-organic framework material exposed to 75% moisture for one day, and the metal-organic framework material soaked in water for one day are basically the same.

[0162] Figure 6 is a thermal decomposition curve of the metal-organic framework material of Example 1 of this application;

[0163] As can be seen from Figure 6, the thermal decomposition temperature of the metal-organic framework material in Example 1 of this application is about 370°C.

[0164] Figure 7 is a thermal decomposition curve of the metal-organic framework material of Example 2 of this application;

[0165] As can be seen from Figure 7, the thermal decomposition temperature of the metal-organic framework material in Example 2 of this application is about 310°C.

[0166] Figure 8 is an adsorption isotherm curve of the metal-organic framework material of Example 1 of this application at 273K for a mixed gas including carbon dioxide and nitrogen.

[0167] As can be seen from Figure 8, the metal-organic framework material of Example 1 of this application has a high adsorption capacity for carbon dioxide in a mixed gas including carbon dioxide and nitrogen at 273K.

[0168] Figure 9 is an adsorption isotherm curve of the metal-organic framework material of Example 1 of this application at 298K for a mixed gas including carbon dioxide and nitrogen.

[0169] As can be seen from Figure 9, the metal-organic framework material of Example 1 of this application has a high adsorption capacity for carbon dioxide in a mixed gas including carbon dioxide and nitrogen at 298K.

[0170] Figure 10 is a cyclic penetration curve of the metal-organic framework material of Example 1 of this application under dry conditions at 273K for a mixed gas including carbon dioxide and nitrogen.

[0171] As can be seen from Figure 10, the metal-organic framework material of Example 1 of this application adsorbs and separates a mixed gas including carbon dioxide and nitrogen under dry conditions at 273K. Since the interaction between nitrogen and metal-organic framework material is weak, nitrogen flows out of the fixed bed almost immediately, while carbon dioxide begins to penetrate after 30 minutes. At this time, the adsorption column reaches equilibrium and stops adsorption.

[0172] Figure 11 is a cyclic penetration curve of the metal-organic framework material of Example 1 of this application under dry conditions at 298K for a mixed gas including carbon dioxide and nitrogen.

[0173] As can be seen from Figure 11, the metal-organic framework material of Example 1 of this application adsorbs and separates a mixed gas including carbon dioxide and nitrogen under dry conditions at 298K. Since the interaction between nitrogen and metal-organic framework material is weak, nitrogen flows out of the fixed bed almost immediately, while carbon dioxide begins to penetrate after 15 minutes. At this time, the adsorption column reaches equilibrium and stops adsorption.

[0174] Figure 12 is a cyclic penetration curve of the metal-organic framework material of Example 1 of this application at 298K and 75%RH for a mixed gas including carbon dioxide and nitrogen.

[0175] As can be seen from Figure 12, the metal-organic framework material of Example 1 of this application adsorbs and separates a mixed gas including carbon dioxide and nitrogen at 298K and 75%RH. Since the interaction between nitrogen and metal-organic framework material is weak, nitrogen flows out of the fixed bed almost immediately, while carbon dioxide begins to penetrate after 15 minutes. At this time, the adsorption column reaches equilibrium and stops adsorption.

[0176] Figure 13 is a cycle penetration curve of the metal-organic framework material of Example 1 of this application after being regenerated 5 times under dry conditions at 298K, through a mixed gas including carbon dioxide and nitrogen.

[0177] As shown in Figure 13, the metal-organic framework material of Example 1 of this application adsorbs and separates a mixed gas including carbon dioxide and nitrogen under dry conditions at 298K. Since the interaction between nitrogen and metal-organic framework material is weak, nitrogen flows out of the fixed bed almost immediately, while carbon dioxide begins to penetrate after 15 minutes. At this time, the adsorption column reaches equilibrium and stops adsorption. The adsorption column enriched with carbon dioxide is purged with inert gas helium for several minutes to regenerate the adsorption column. This cycle is repeated 5 times to maintain the material's penetration performance and allow for recycling.

[0178] Table 1

[0179] As shown in Table 1, compared with the comparative example, the metal-organic framework material provided in this application has two channels with different areas. When used to adsorb carbon dioxide in a mixed gas containing carbon dioxide and nitrogen, it can achieve a higher adsorption capacity and higher selectivity for carbon dioxide.

[0180] As can be seen from the comparison between Example 1 and Comparative Examples 1-3, the metal-organic framework material provided in this application can achieve a high adsorption capacity and high selectivity for carbon dioxide when used to adsorb carbon dioxide from a mixed gas containing carbon dioxide and nitrogen.

[0181] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A metal-organic framework material, characterized in that, The metal-organic framework material includes a two-dimensional layer formed by the coordination of a metal element and a first organic ligand, and a column structure formed by the coordination of a metal element and a second organic ligand. The two-dimensional layer and the column structure are connected to form a three-dimensional layer-column framework structure. The three-dimensional layer-column framework structure is double-intersected to form a first channel and a second channel. The area of ​​the first channel is The area of ​​the second channel is 2. The metal-organic framework material according to claim 1, characterized in that, In the metal-organic framework material, the first channel and the second channel are staggered in a first direction, and the length of the first channel in the first direction is less than the length of the second channel in the first direction.

3. The metal-organic framework material according to claim 2, characterized in that, The length of the first channel in the first direction is The length of the second channel in the first direction is 4. The metal-organic framework material according to any one of claims 1-3, characterized in that, The first organic ligand includes carboxylic acid ligands; the second organic ligand includes amide ligands.

5. The metal-organic framework material according to claim 1, characterized in that, The three-dimensional layer-column frame structure includes a first material column distributed along a first direction and a second material column distributed along a second direction. The first material column includes the first organic ligand, and the second material column includes the second organic ligand. The first and second material columns define the first and second channels of the metal-organic framework material. The connection between the first and second material columns includes the metal element.

6. The metal-organic framework material according to claim 4, characterized in that, The carboxylic acid ligands include compounds represented by Formula 1: R1 and R2 are each independently selected from hydrogen, substituted or unsubstituted C1-C8 straight-chain or branched alkyl groups, substituted or unsubstituted C1-C8 straight-chain or branched alkoxy groups, amino groups, hydroxy groups, mercapto groups, halogen groups, cyano groups and their derivatives.

7. The metal-organic framework material according to claim 4, characterized in that, The amide ligands include N,N'-(1,4-phenylene)diisonicotinamide.

8. The metal-organic framework material according to claim 1, characterized in that, The metallic element includes at least one of copper, zinc, magnesium, iron, manganese, cobalt, and nickel.

9. A method for preparing a metal-organic framework material according to any one of claims 1-8, characterized in that, Includes the following steps: The metal-organic framework material is obtained by solvothermal reaction of a raw material system including amide ligands, carboxylic acid ligands and metal elements.

10. The preparation method according to claim 9, characterized in that, The temperature of the solvothermal reaction is 50℃-200℃; And / or, the solvothermal reaction time is 4h-96h; And / or, the molar ratio of the metal element to the carboxylic acid ligand is 1:(0.1-5); And / or, the molar ratio of the metal element to the amide ligand is 1:(0.1-5).

11. The application of a metal-organic framework material according to any one of claims 1-8 in an adsorption column.

12. The use of a metal-organic framework material according to any one of claims 1-8 in a fixed bed.

13. The application of a metal-organic framework material according to any one of claims 1-8 in carbon dioxide / nitrogen adsorption and separation.

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