Pillared metal organic framework material, preparation method thereof and adsorbent

Abstract

The invention relates to a pillared metal organic framework material, a preparation method thereof and an adsorbent. The molecular formula of the pillared metal organic framework material is C6H6N8O5Zn2, ZnOX-zinc oxalate dihydrate Zn (C2O4). 2H2O serving as a metal salt source and ATZ-3-amino-1, 2, 4-triazole serving as an organic ligand react in a hydrothermal environment to generate a compound Zn-OX-ATZ, and the Zn-OX-ATZ is a crystalline state material. According to the method, the Zn-OX-ATZ is synthesized for the first time in a kilogram level, and the compound is utilized to selectively capture carbon dioxide from the flue gas under working conditions so as to achieve the capability of further purifying the flue gas, so that the method is expected to replace an organic amine-solution carbon dioxide absorption process with high energy consumption at present, and has great application potential in industrial application of flue gas purification.

Description

Technical Field

[0001] The present invention relates to the technical field of metal-organic frameworks, and in particular to a pillar-layered metal-organic framework material, a preparation method thereof, and an adsorbent. Background Art

[0002] At present, the carbon dioxide capture process in flue gas mainly relies on an organic amine solvent system. The principle of this process is that carbon dioxide reacts with the amine solution to form unstable salts, and after heating, carbon dioxide is released again. This process can effectively remove carbon dioxide, but there are obvious deficiencies in the absorption of carbon dioxide by organic amines. The main reasons are that the regeneration energy consumption is very high, and the decomposition of amines may occur during the regeneration process, resulting in the release of toxic substances. Therefore, it is very necessary to develop a more energy-saving, efficient and safe method for capturing carbon dioxide from flue gas.

[0003] Although some MOFs have been reported to be used to selectively adsorb carbon dioxide from flue gas, most MOF materials usually have greatly reduced adsorption capacity and selectivity for carbon dioxide under humid conditions due to the competitive effect of water and carbon dioxide, and moisture often causes some MOFs with high carbon dioxide selective adsorption performance to degrade. This situation has led to the inability of most MOFs to achieve efficient capture of carbon dioxide in flue gas under actual working conditions (such as 318K, 30 - 70% RH). Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a pillar-layered metal-organic framework material, which is used as an adsorbent to achieve efficient capture of carbon dioxide in flue gas.

[0005] To solve the above technical problems, the present invention adopts the following technical solutions: A pillar-layered metal-organic framework material, with the molecular formula C 6 H 6 N 8 O 5 Zn 2 , which is formed by reacting zinc oxalate dihydrate Zn(C 2 O 4 )·2H 2 O as a metal salt source and 3-amino-1,2,4-triazole (ATZ) as an organic ligand in a hydrothermal environment to form a compound Zn-OX-ATZ, and the Zn-OX-ATZ is a crystalline material.

[0006] Furthermore, in the molecular structure of the compound Zn-OX-ATZ, the structural unit includes Zn 2+ , ATZ, and C 2 O 42- ; wherein, Zn 2+ combines with N atoms from three different ATZs to form a planar layer, and different planar layers are connected through C 2 O 4 2- . Among them, the four oxygen atoms of C 2 O 4 2- are respectively connected to Zn 2+ ions of two different layers.

[0007] Furthermore, the crystal structure of the compound Zn-OX-ATZ has one-dimensional pores; the BET specific surface area of the Zn-OX-ATZ is 303.3 cm 2 / g; the pore volume of the Zn-OX-ATZ is 0.15 cm 3 / g; the pore size distribution of the Zn-OX-ATZ is concentrated in

[0008] Furthermore, the interior of the pores has -NH 2 groups, which can generate stronger interaction with carbon dioxide, thereby realizing the capture of carbon dioxide from flue gas.

[0009] Furthermore, the crystallographic parameters of the compound Zn-OX-ATZ are as follows:

[0010] The present invention provides a preparation method for preparing the pillar-supported metal-organic framework material described in the above embodiments, including the following steps: Step S1, prepare a reaction system: Disperse zinc oxalate dihydrate Zn(C 2 O 4 )·2H 2 O and 3-amino-1,2,4-triazole in a solvent to form a homogeneous mixture; Step S2, carry out a synthesis reaction under a hydrothermal environment to obtain a product containing Zn-OX-ATZ; Step S3, separate and purify the product containing Zn-OX-ATZ to obtain a crystalline material of Zn-OX-ATZ.

[0011] Preferably, in the step S1: the solvent is water; the molar ratio of zinc oxalate dihydrate to 3-amino-1,2,4-triazole is 1:3 to 6; the ratio of zinc oxalate dihydrate to the solvent is to add 3 to 8 mL of the solvent per 1 mmol of zinc oxalate dihydrate; in the step S2: the reaction temperature under the hydrothermal environment is 150 - 190 °C.

[0012] The preparation method further includes step S4 of activating the Zn-OX-ATZ crystalline material obtained in step S3 to obtain an adsorbent material; preferably, the activation temperature is 120-180°C.

[0013] The present invention provides an adsorbent, which is a pillared metal-organic framework material described in the above embodiments as an adsorbent for capturing carbon dioxide.

[0014] In some embodiments, the adsorbent is used to selectively capture carbon dioxide from flue gas by a physical adsorption method to purify the flue gas; the adsorption temperature of the physical adsorption method is 0-60°C, and the adsorption pressure is 0-3 bar; the desorption temperature is 50-180°C, and the desorption pressure is 0.01-1.0 bar; the physical adsorption method uses an adsorption column.

[0015] The beneficial effects of the present invention are: The metal-organic framework material (MOF) Zn-OX-ATZ of the present invention, used as an adsorption material, has low cost and high stability, and can efficiently capture carbon dioxide from flue gas by an adsorption separation method (even under operating conditions of 318±50K, 30-70% RH) to reduce carbon dioxide emissions and contribute to the realization of the "dual carbon" goal. Description of the Drawings

[0016] Figure 1 It is the coordination diagram of different building units of the pillared metal-organic framework material Zn-OX-ATZ of the embodiment of the present invention, wherein (a) shows the coordination environment of Zn-OX-ATZ, and (b) shows the structural schematic diagram of Zn-OX-ATZ.

[0017] Figure 2 It is the X-ray diffraction pattern of the Zn-OX-ATZ materials obtained in Examples 1 to 3 of the present invention.

[0018] Figure 3 It is the CO of the Zn-OX-ATZ material obtained in Example 1 of the present invention 2 195K adsorption and desorption isotherm and pore size distribution diagram.

[0019] Figure 4 It is the adsorption isotherm of carbon dioxide and nitrogen of the Zn-OX-ATZ material obtained in Example 1 of the present invention under the conditions of 298 and 318K.

[0020] Figure 5 It is the selectivity diagram of carbon dioxide / nitrogen of the Zn-OX-ATZ material obtained in Example 1 of the present invention at 298K and 318K.

[0021] Figure 6This is the dynamic breakthrough curve and cyclic dynamic breakthrough curve of the adsorption methods in Application Example 1 and Application Example 2 of the present invention. Among them, Figure (a) shows the dynamic breakthrough curves of the adsorption methods in Application Example 1 and Application Example 2 under the conditions of 318K and dry or 70% RH, and Figure (b) shows the cyclic dynamic breakthrough curve of the adsorption method in Application Example 2 under the conditions of 318K and 70% RH.

[0022] Figure 7 This is the dynamic breakthrough curve of the simulated industrial flue gas under dry or 70% RH at 318K for the adsorption method in Application Example 3 of the present invention. Detailed implementation manners

[0023] The exemplary embodiments of the present application will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present application are shown in the drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present application and to fully convey the scope of the present application to those skilled in the art.

[0024] It should be understood that the terms used herein are only for the purpose of describing specific exemplary embodiments and are not intended to be limiting. Unless otherwise clearly specified in the context, the singular forms "a", "an", and "the" as used herein may also include the plural forms. The terms "comprising", "including", "containing", and "having" are inclusive and thus specify the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring them to be performed in the specific order described or illustrated, unless the execution order is explicitly stated. It should also be understood that additional or alternative steps may be used.

[0025] Unless otherwise specified, the experimental methods described in the following examples are all conventional methods; unless otherwise specified, the reagents and materials can all be obtained from commercial channels.

[0026] The endpoints and any values of the endpoint values disclosed in the present invention are not limited to the exact ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, between the endpoint values of each range, between the endpoint values of each range and individual point values, and between individual point values, they can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein.

[0027] The present invention relates to a metal-organic framework material Zn-OX-ATZ, molecular formula: C 6H 6 N 8 O 5 Zn 2 , is a layered pillared microporous material, used as an adsorption material, with low cost and high stability. By means of adsorption separation (even under the working conditions of 318±50K, 30-70%RH), it can efficiently capture carbon dioxide from flue gas (such as CO 2 / N 2 =15 / 85 v / v) to reduce carbon dioxide emissions and contribute to the realization of the "dual carbon" goal.

[0028] Specifically, the present invention uses low-cost zinc oxalate dihydrate (Zn(C 2 O 4 )·2H 2 O, abbreviated as ZnOX) and 3-amino-1,2,4-triazole (abbreviated as ATZ) as raw materials to synthesize the pillared ultra-microporous material - Zn-OX-ATZ. The reaction principle is as follows: Zinc oxalate dihydrate dissolves into Zn 2+ and C 2 O 4 2- under high-temperature hydrothermal conditions, while ATZ will remove the H atom on the triazole to form an anion; driven by molecular thermodynamics and anion / cation electrostatic interaction, a three-dimensional pillared structure is self-assembled; among them, Zn 2+ combines with three N atoms from different ATZs to form a planar layer, and then different planar layers are connected through C 2 O 4 2- . Among them, the four oxygen atoms of C 2 O 4 2- are respectively connected to Zn 2+ ions of two different layers, and the three components cooperate to form a layered pillared ultra-microporous metal-organic framework material MOF (Zn-OX-ATZ) with one-dimensional channels.

[0029] Referring to Figure 1 , for the Zn-OX-ATZ material synthesized in the embodiment of the present invention (crystals with larger sizes can be selected), X-ray single crystal diffraction (SC-XRD) analysis is carried out to determine the crystal structure of Zn-OX-ATZ. The specific molecular coordination mode is as shown in figure (a) in Figure 1 . Zn 2+ (yellow) is coordinated with three N atoms from different ATZs and with the O atom from C 2 O 4 2- ; C 2 O 4 2-O (red) coordinates with different Zn 2+ coordinates, while ATZ coordinates with three different Zn through three N atoms (blue 2+ coordinates. The coordination of the above structural units together constructs the three-dimensional structure of Zn-OX-ATZ. As shown in Figure 1 (b) in, it can be seen that the crystal has obvious one-dimensional pores.

[0030] Using Zn-OX-ATZ as an adsorption material, the adsorption test was carried out with carbon dioxide at 195K, and the pore structure of Zn-OX-ATZ was measured. Its BET specific surface area is about 303.3 cm 2 / g, the pore volume is about 0.15 cm 3 / g, and the pore size distribution is concentrated around . This Zn-OX-ATZ material can not only provide a suitable pore size for the adsorption of carbon dioxide molecules, but also has rich -NH 2 groups inside the pores, which can generate stronger interactions with carbon dioxide, thus realizing the complete capture of carbon dioxide from flue gas and further achieving the ability to purify flue gas in one step.

[0031] Table 1 The Zn-OX-ATZ compound synthesized in the examples of the present invention has the following crystallographic parameters as shown in Table 1: Table 1 Crystallographic parameters of Zn-OX-ATZ

[0032] The layered pillared metal-organic framework material Zn-OX-ATZ of the present invention is a metal-organic framework material formed by reacting zinc oxalate dihydrate (Zn(C 2 O 4 )·2H 2 O) as a metal salt source and 3-amino-1,2,4-triazole (ATZ) as an organic ligand under hydrothermal conditions. The preparation method of the Zn-OX-ATZ material includes the following steps: Step S1, prepare the reactant system, disperse a certain proportion of zinc oxalate dihydrate (Zn(C 2 O 4 )·2H 2 O), 3-amino-1,2,4-triazole in a certain amount of solvent to form a homogeneous mixture, and then transfer the mixture to a stainless steel reaction kettle lined with Teflon; Step S2, carry out the synthesis reaction under hydrothermal conditions to obtain the product sample of Zn-OX-ATZ. Specifically, put the reaction kettle into an oven and react at a predetermined reaction temperature for a certain time; Step S3: Separation and purification. For example, a white powder is obtained by filtering the product sample. Washing can be carried out (but is not limited to) multiple times with ethanol and water to remove unreacted salts and ligands in the sample, and Zn-OX-ATZ crystals are obtained. Step S4: Activating the crystals. The crystals are activated in a vacuum at a predetermined activation temperature for a predetermined duration to remove water in the crystal pores, and then an activated Zn-OX-ATZ crystal sample is obtained.

[0033] Preferably, in step S1, the solvent is water.

[0034] Preferably, in step S1, the molar ratio of zinc oxalate dihydrate to 3-amino-1,2,4-triazole is 1:3 - 6, and a more preferred ratio is 1:4.5.

[0035] Preferably, in step S1, the ratio of zinc oxalate dihydrate to water is that 3 - 8 mL of water needs to be added for every 1 mmol of zinc oxalate dihydrate. More preferably, the amount of water added for every 1 mmol of zinc oxalate dihydrate is 5 mL.

[0036] In step S1, the raw material reactants can be uniformly dispersed in the solvent by ultrasonic dispersion or stirring.

[0037] Preferably, in step S2, the reaction temperature is 150 - 190 °C, and more preferably, the reaction temperature is 180 °C.

[0038] Preferably, in step S4, the activation temperature of the crystalline material is 120 - 180 °C, and the activation duration can be 12 hours; more preferably, the activation temperature is 150 °C.

[0039] The Zn-OX-ATZ metal-organic framework material (MOFs) of the present invention is used as an adsorbent, which has selective adsorption of carbon dioxide to purify flue gas.

[0040] Verified by experiments, when a binary mixed gas of carbon dioxide and nitrogen flows through the synthesized Zn-OX-ATZ adsorbent, the adsorbent will selectively adsorb carbon dioxide in the mixed gas, that is, it can purify flue gas.

[0041] The adsorption process can adopt one or a combination of adsorption methods such as pressure swing adsorption with a fixed bed, temperature swing adsorption, or low-pressure adsorption and desorption.

[0042] The specific process of the adsorption process is as follows: At a set adsorption temperature and pressure, the mixed gas enters a fixed bed filled with Zn-OX-ATZ adsorbent at a set flow rate. Nitrogen preferentially penetrates the bed layer, and carbon dioxide is enriched in the adsorption bed layer. After carbon dioxide penetrates, the bed layer is regenerated by desorption for the next cycle.

[0043] In some embodiments, the adsorption temperature is 0 - 60 °C, the adsorption pressure is 0 - 3 bar, the desorption temperature is 50 - 180 °C, and the desorption pressure is 0.01 - 1.0 bar.

[0044] Example 1: In this example, the metal-organic framework material (MOF) Zn-OX-ATZ was synthesized. The specific preparation method was as follows: Zn(C 2 O 4 )·2H 2 O (0.1 mmol) and 3-amino-1,2,4-triazole (0.45 mmol) were ultrasonically dispersed in water (5 mL). Then the mixture was transferred to a Teflon-lined autoclave and placed in an oven at 180 °C for reaction for 2 days. The product was obtained by filtration and then washed five times with ethanol and water to remove the unreacted salts and ligands in the sample, obtaining the crystals of Zn-OX-ATZ. After vacuum drying at 150 °C for 5 hours, the activated Zn-OX-ATZ was obtained and could be used as an adsorbent.

[0045] For the Zn-OX-ATZ material obtained in this Example 1, the CO 2 adsorption and desorption tests were carried out at 195 K. The adsorption and desorption isotherms and pore size distribution diagrams are as shown in Figure 3 . As can be seen from the figure, the Zn-OX-ATZ material is a microporous material, and its pore size is concentrated at 0.40 nm.

[0046] For the Zn-OX-ATZ material obtained in this Example 1, adsorption experiments on carbon dioxide and nitrogen were carried out at 298 K and 318 K. The adsorption isotherms are as shown in Figure 4 . As can be seen from Figure 4 , the Zn-OX-ATZ material showed rapid low-pressure adsorption of carbon dioxide and very little adsorption of nitrogen, proving the preferential adsorption of carbon dioxide by this material.

[0047] For the Zn-OX-ATZ material obtained in this Example 1, adsorption experiments on carbon dioxide / nitrogen (15 / 85, V / V) were carried out at 298 K and 318 K. The selectivity diagram for carbon dioxide / nitrogen is referred to Figure 5 . As can be seen from Figure 5 , both of them exceeded 1000 for carbon dioxide / nitrogen at 1 bar, proving that the Zn-OX-ATZ adsorbent has excellent selectivity for carbon dioxide / nitrogen.

[0048] Example 2: In this example, the metal-organic framework material (MOF) Zn-OX-ATZ was synthesized. The specific preparation method was as follows: Zn(C 2 O 4 )·2H 2O (0.1 mmol), 3-amino-1,2,4-triazole (0.45 mmol) were ultrasonically dispersed in water (5 mL). Then the mixture was transferred to a Teflon-lined autoclave and placed in an oven at 150 °C for 3 days. The product was obtained by filtration and then washed five times with ethanol and water to remove the unreacted salts and ligands in the sample, obtaining the crystalline material of Zn-OX-ATZ. It was vacuum dried at 120 °C for 5 hours to obtain the activated Zn-OX-ATZ, which can be used as an adsorbent.

[0049] Example 3: In this example, the metal-organic framework material (MOF) Zn-OX-ATZ was synthesized. The specific preparation method was as follows: 1 kg of zinc oxalate dihydrate and 5 kg of 3-amino-1,2,4-triazole were added to a large self-generated pressure autoclave (with a volume of 30 L) containing 15 L of water. After electric stirring for 50 minutes, the heating program was started and the reaction was carried out in an oven at 180 °C for 3 days. A white powder was obtained by centrifugation, and then centrifugally washed 3 times with water and ethanol to remove the unreacted salts and ligands in the sample, obtaining the crystalline material of Zn-OX-ATZ. Then it was vacuum dried at 180 °C for 5 hours to obtain the activated Zn-OX-ATZ, which can be used as an adsorbent.

[0050] In this example, the Zn-OX-ATZ compound was synthesized on a kilogram scale with stable production and stable product quality.

[0051] Refer to Figure 2 , which is the X-ray diffraction pattern of the Zn-OX-ATZ materials obtained in Examples 1 to 3. It can be seen from Figure 2 that the powder X-ray diffraction of the samples synthesized on different scales is highly consistent with the simulated pattern, proving that the synthesized samples have high purity and the products are stable after scale-up.

[0052] Application Example 1 In this application example, the Zn-OX-ATZ material was used as an adsorbent for adsorption (and desorption) tests to verify the efficient capture of carbon dioxide by the Zn-OX-ATZ material. The operating conditions for the adsorption test can be selected as the dry condition at 318 K. Specifically, the Zn-OX-ATZ material obtained in Example 1 above was loaded into an adsorption column (inner diameter 5 mm, volume 2 ml). At a back pressure of 45 °C and 1 bar, a two-component gas of carbon dioxide / nitrogen (volume ratio 15 / 85) was passed through the adsorption column at a flow rate of 4.0 mL / min. High-purity nitrogen (>99.9%) was detected at the tail end of the adsorption column. When the carbon dioxide completely penetrated, the test was stopped. Under the condition of 150 °C, the adsorption column was purged with helium for cyclic regeneration; or it was desorbed and regenerated with a vacuum pump at room temperature with a vacuum degree of 0.05 bar.

[0053] As can be seen from this embodiment, Zn-OX-ATZ of the present invention can selectively capture carbon dioxide in flue gas as an adsorbent.

[0054] Application Example 2 In this application example, the Zn-OX-ATZ material was used as an adsorbent for adsorption (and desorption) tests to verify the efficient capture of carbon dioxide by the Zn-OX-ATZ material. The operating conditions for the adsorption (and desorption) tests can be selected to be at 318 K and a humidity of 70% RH. Specifically, the Zn-OX-ATZ material obtained in the first embodiment above was loaded into an adsorption column (inner diameter 5 mm, volume 2 ml), and at a back pressure of 45 °C and 1 bar, a two-component gas of carbon dioxide / nitrogen (volume ratio 15 / 85) was passed through a steam generator at a flow rate of 4.0 mL / min. At this time, the humidity of the mixed gas was 70% RH, and then it passed through the adsorption column. High-purity nitrogen (>99.9%) was detected at the end of the adsorption column. When the carbon dioxide was completely penetrated, the test was stopped, and the adsorption column was purged with helium at 150 °C to achieve cyclic regeneration. Or at room temperature, it was desorbed and regenerated with a vacuum pump, and the vacuum degree was 0.05 bar.

[0055] As can be seen from this embodiment, Zn-OX-ATZ of the present invention can still selectively capture carbon dioxide in flue gas as an adsorbent under the operating conditions of 318 K and 70% RH.

[0056] Refer to Figure 6 , where Figure (a) shows the dynamic breakthrough curve and cyclic dynamic breakthrough curve of the first and second application examples above; Figure (a) shows the dynamic breakthrough curve of the first and second application examples above under the operating conditions of 318 K, dry or 70% RH; Figure (b) shows the cyclic dynamic breakthrough curve of the second application example under the operating conditions of 318 K and 70% RH. As Figure 6 can be seen, nitrogen breaks through the adsorption column prior to carbon dioxide, the retention time of carbon dioxide in the adsorption column exceeds 1 hour, and its performance remains stable during multiple cycles, confirming that Zn-OX-ATZ can be used as an adsorbent to achieve efficient capture of carbon dioxide in flue gas.

[0057] Application Example 3 In the embodiment of this application, the Zn-OX-ATZ material is used as an adsorbent to implement the adsorption process, and the high-efficiency capture of carbon dioxide by the Zn-OX-ATZ material is verified. The Zn-OX-ATZ material obtained in the above Example 3 is used as an adsorbent, and adsorption and desorption operations are carried out on dry gas at 318K and simulated industrial flue gas at 70% RH. Specifically, the Zn-OX-ATZ material obtained in Example 3 is loaded into an adsorption column (inner diameter 70mm, volume 1L). At a back pressure of 45°C and 1 bar, the simulated flue gas, the gas composition of which is shown in Table 2, is passed through a steam generator at a flow rate of 1L / min. At this time, the humidity of the mixed gas is 70% RH, and then it passes through the adsorption column. The concentration of carbon dioxide is detected at the end of the adsorption column. When the concentration of carbon dioxide detected at the end of the adsorption column reaches the inlet concentration, the gas supply is stopped. Under the condition of 180°C, the adsorption column is purged with nitrogen to realize the cyclic regeneration of the sample. When carrying out the adsorption and desorption operation under the working conditions of dry gas at 318K, the test gas does not need to pass through the steam generator, and other operations are the same or similar. The adsorption and desorption operations at 318K and 70% RH are respectively carried out on various simulated flue gases shown in Table 2.

[0058] Table 2 Gas composition parameters of simulated industrial flue gas

[0059] In this embodiment, using Zn-OX-ATZ as an adsorbent can selectively capture carbon dioxide in flue gas, and this adsorbent can perform carbon dioxide capture tests on kilogram-scale samples of simulated flue gas under the working conditions of 318K and 70% RH.

[0060] Referring to Figure 7 , in Application Example 3, the dynamic breakthrough curves of dry gas at 318K and simulated industrial flue gas at 70% RH. From Figure 7 it can be seen that under the conditions of dry gas and high humidity (70% RH), the Zn-OX-ATZ material can completely separate carbon dioxide and nitrogen in the simulated industrial flue gas at 318K, which proves that this material can be applied to the capture of carbon dioxide in flue gas under actual industrial conditions.

[0061] The present invention synthesizes Zn-OX-ATZ and uses this compound to selectively capture carbon dioxide from flue gas to achieve the ability to purify flue gas in one step, and is expected to replace the current high-energy-consuming organic amine-solution carbon dioxide absorption process, having great application potential in the industrial application of flue gas purification.

[0062] In other embodiments, the Zn-OX-ATZ of the present invention is used as an adsorbent for efficiently capturing carbon dioxide and can also be used to separate or treat other carbon dioxide-containing mixed gases other than flue gas. The adsorption method can refer to Application Example 1 and Application Example 2 above and will not be elaborated here.

[0063] In other embodiments, the metal-organic framework material (MOF) Zn-OX-ATZ of the present invention is used as an adsorption material, which has low cost and high stability. By means of adsorption separation, carbon dioxide can be efficiently captured from flue gas or other mixed gases to reduce carbon dioxide emissions. Using the Zn-OX-ATZ adsorption material of the present invention, flue gas or other mixed gases are separated or treated by means of adsorption separation (for example, using the adsorption columns and adsorption and desorption conditions in Application Example 1 and Application Example 2 above). Under the actual working conditions of 318±50K and 0-70% RH, carbon dioxide can still be efficiently captured from flue gas or other mixed gases.

[0064] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The protection scope of the present invention is defined by the appended claims and their equivalent scope.

Claims

1. A pillared metal organic framework material, whose molecular formula is C6H6N8O5Zn2, is prepared by reacting ZnOX-zinc oxalate dihydrate Zn(C2O4)·2H2O as a metal salt source and ATZ-3-amino-1,2,4-triazole as an organic ligand under a hydrothermal environment to generate a compound Zn-OX-ATZ, wherein the Zn-OX-ATZ is a crystalline material.

2. The pillared metal organic framework material according to claim 1, characterized in that: In the molecular structure of the compound Zn-OX-ATZ, the structural unit includes Zn 2+ , ATZ and C2O4 2- Among them, Zn 2+ Combined with three N atoms from different ATZ to form a planar layer, different planar layers are connected by C2O4 2- Make a connection where C2O4 2- The four oxygen atoms are respectively bonded to two different layers of Zn 2+ Ions connected.

3. The pillared metal organic framework material according to claim 2, characterized in that: The molecular coordination mode of the compound Zn-OX-ATZ is: The structural units of the compound Zn-OX-ATZ are coordinated to jointly construct a three-dimensional structure of Zn-OX-ATZ, and the three-dimensional structure is:

4. The pillared metal organic framework material according to any one of claims 1 to 3, characterized in that: The crystal structure of the compound Zn-OX-ATZ has a one-dimensional pore; the BET specific surface area of ​​Zn-OX-ATZ is 303.3 cm 2 / g; the pore volume of the Zn-OX-ATZ is 0.15cm 3 / g; the pore size distribution of the Zn-OX-ATZ is concentrated in The -NH2 groups inside the pores can produce a stronger interaction force with carbon dioxide, thereby achieving the capture of carbon dioxide from flue gas.

5. The pillared metal organic framework material according to claim 4, characterized in that: The crystallographic parameters of the compound Zn-OX-ATZ are:

6. A method for preparing a pillared metal organic framework material, comprising the following steps: Step S1, preparing a reaction system: dispersing zinc oxalate dihydrate Zn(C2O4)·2H2O and 3-amino-1,2,4-triazole in a solvent to form a uniform mixture; Step S2, performing a synthesis reaction under a hydrothermal environment to obtain a product containing Zn-OX-ATZ; Step S3, separating and purifying the product containing Zn-OX-ATZ to obtain a Zn-OX-ATZ crystalline material; The Zn-OX-ATZ is the pillared metal organic framework material according to any one of claims 1 to 5.

7. The preparation method according to claim 6, characterized in that: In step S1: The solvent is water; The molar ratio of zinc oxalate dihydrate to 3-amino-1,2,4-triazole is 1:3-6; The ratio of zinc oxalate dihydrate to the solvent is 3 to 8 mL of the solvent per 1 mmol of zinc oxalate dihydrate; In the step S2: the reaction temperature in the hydrothermal environment is 150-190°C.

8. The preparation method according to claim 6, characterized in that: The preparation method further comprises: Step S4, activating the Zn-OX-ATZ crystalline material obtained in step S3 to obtain an adsorbent material; The activation temperature is 120-180°C.

9. An adsorbent made of the pillared metal organic framework material according to any one of claims 1 to 5, used for capturing carbon dioxide.

10. The adsorbent according to claim 9, characterized in that: The adsorbent is used to selectively capture carbon dioxide from flue gas through a physical adsorption method to achieve flue gas purification; the adsorption temperature of the physical adsorption method is 0-60°C, the adsorption pressure is 0-3bar; the desorption temperature is 50-180°C, and the desorption pressure is 0.01-1.0bar; the physical adsorption method uses an adsorption column.

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