A zinc-based metal-organic framework material, its preparation method and application

Abstract

This application relates to the field of carbon dioxide capture and catalytic conversion technology, and in particular to a zinc-based metal-organic framework material, its preparation method, and its application. The zinc-based metal-organic framework material has the formula: Zn₂(X)₂L; where X represents 3-amino-1,2,4-triazole that has lost one proton, and L represents the fumarate ion; the zinc-based metal-organic framework material has a columnar three-dimensional porous network structure; the pore size of the zinc-based metal-organic framework material is 0.2 nm to 0.3 nm, and the porosity is 20% to 25%. This zinc-based metal-organic framework material exhibits significantly better adsorption selectivity for CO₂ than other volatile organic compounds, achieving effective separation of C₂H₄ / CO₂ and C₂H₂ / CO₂, and enabling the electrocatalytic reduction of CO₂ to CO, which is beneficial for its widespread application in the field of CO₂ capture and catalytic conversion.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of carbon dioxide capture and catalytic conversion, in particular to a zinc-based metal-organic framework material and a preparation method and application thereof. BACKGROUND

[0002] Ethylene (C2H2) and ethylene (C2H4) are two important industrial raw materials, which are used to manufacture various organic chemicals, including vinyl chloride, acrylic acid, 1,4-butanediol, and plastic such as polyethylene and polyvinyl chloride. In industry, ethylene is mainly produced by thermal cracking of hydrocarbons, and acetylene is mainly produced by cracking or burning of natural gas, in which carbon dioxide (CO2) is usually co-present. Purification of C2H2 or C2H4 from CO2 has important industrial significance for obtaining high-purity, high-value-added organic chemicals. Due to similar physicochemical properties, the separation of C2H4 / CO2 and C2H2 / CO2 is still a key problem to be solved, but current industrial separation technologies such as solvent extraction or cryogenic rectification are high-energy-consuming and environmentally unfriendly.

[0003] In recent years, porous material adsorption separation has attracted more and more attention due to its energy saving, environmental protection and product purity. As an emerging porous material, metal-organic framework (MOF) material has a wide application prospect in gas adsorption separation due to its diversity in composition, adjustable pore structure and functional pore surface. However, traditional MOF materials still have difficulty in realizing effective separation of C2H4 / CO2 and C2H2 / CO2. SUMMARY

[0004] Therefore, it is necessary to provide a zinc-based metal-organic framework material and a preparation method and application thereof to solve the problem that traditional MOF materials are difficult to realize effective separation of C2H4 / CO2 and C2H2 / CO2.

[0005] The above-mentioned purpose of the application is realized by the following technical solutions:

[0006] In a first aspect, the application provides a zinc-based metal-organic framework material, which has an expression formula: Zn2(X)2L.

[0007] X represents 3-amino-1,2,4-triazole losing one proton, and L represents fumarate ion.

[0008] The zinc-based metal-organic framework material has a columnar layered three-dimensional porous network structure.

[0009] The pore size of the zinc-based metal-organic framework material is 0.2 nm-0.3 nm, and the porosity is 20%-25%.

[0010] In some embodiments, the zinc-based metal-organic framework material belongs to the monoclinic crystal system with space group . C 2 / c .

[0011] In some embodiments, the cell parameters of the zinc-based metal-organic framework material are: a = 23.39Å, b = 8.34Å, c = 9.11Å, α = 90°, β = 116.36°, gamma = 90°, cell volume is 1592.65 Å 3 .

[0012] In some embodiments, at 298 K, the zinc-based metal-organic framework material has an adsorption capacity of ≥0.95 mmol / g for CO2 and an adsorption capacity of ≤0.55 mmol / g for volatile organic compounds, wherein the volatile organic compounds include one or more of C2H2, C2H4, C2H6, C3H6, and C3H8.

[0013] A second aspect of this application provides a method for preparing a zinc-based metal-organic framework material, comprising the following steps:

[0014] Methanol and water are mixed to obtain a mixed solvent;

[0015] The reactants containing 3-amino-1,2,4-triazole, zinc salt and fumaric acid are dissolved in the mixed solvent and subjected to a solvothermal reaction to obtain the zinc-based metal-organic framework material.

[0016] In some embodiments, the zinc salt includes one or more of zinc nitrate, zinc chloride, zinc sulfate, zinc carbonate, zinc acetate, zinc oxalate, and zinc acetylacetonate.

[0017] In some embodiments, the molar ratio of the 3-amino-1,2,4-triazole, the zinc element in the zinc salt, and the fumaric acid is (0.8~1.2):1:0.5.

[0018] In some embodiments, the volume ratio of methanol to water is 1:(1.5~2.5).

[0019] In some embodiments, the reactants further contain a base regulator, which includes one or more of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, and potassium bicarbonate.

[0020] In some embodiments, the molar ratio of the zinc salt to the alkali regulator is 1:(0.1~1.5).

[0021] In some embodiments, the temperature of the solvothermal reaction is 70 ℃~90 ℃ and the time is 48 h~72 h.

[0022] In a third aspect, this application provides the application of a zinc-based metal-organic framework material prepared by the method described above, or a zinc-based metal-organic framework material prepared by the method described above, in carbon dioxide capture and catalytic conversion.

[0023] This application has at least the following beneficial effects:

[0024] This application provides a hybrid columnar zinc-based metal-organic framework material (Zn-MOF material) whose catalytic performance can be tuned by adjusting its two-dimensional layered ligand X and pillared ligand L. The two-dimensional layered ligand X is selected from 3-amino-1,2,4-triazole that has lost one proton. The ligand has a -NH2 side group, which is a highly electron-donating group. This relaxes the Zn-O bond, helping to expose more Zn sites and thus improving catalytic performance. The pillared ligand L is selected from the fumarate ion, which has a longer chain length and greater rigidity. By modulating the connection mode of the two ligands, the Zn-MOF material forms a new topology and crystal phase structure, exhibiting a pore structure and active site microenvironment that are drastically different from traditional Zn-MOFs. This Zn-MOF material has a pore size of 0.25 nm–0.28 nm and a porosity of 20.6%–22.9%. Its CO2 adsorption selectivity is significantly superior to other volatile organic compounds, enabling effective separation of C2H4 / CO2 and C2H2 / CO2, which is beneficial for its widespread application in CO2 capture and catalytic conversion. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this application and to more completely understand this application and its beneficial effects, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 PXRD patterns of the products from Examples 1-7;

[0027] Figure 2 Comparison diagrams of two-dimensional layers, three-dimensional framework, and topology of Zn-atz-fma(rob) and Zn-atz-fma(pcu);

[0028] Figure 3The PXRD images of the product of Example 1 after soaking in different solvents for 24 h are shown.

[0029] Figure 4 The VT-PXRD pattern of the product of Example 1;

[0030] Figure 5 FESEM image of the product of Example 1;

[0031] Figure 6 The image shows the adsorption-desorption isotherms of the product from Example 1. Detailed Implementation

[0032] To facilitate understanding of this application, the following detailed description is provided in conjunction with specific embodiments. However, this application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this application.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application.

[0034] In this application, "and / or" means any and all combinations of one or more of the related listed items. "At least one" means one or more, such as one, two, or more. "Multiple" or "several" means at least two, such as two, three, etc., and "multi-layered" means at least two layers, such as two, three, etc., unless otherwise expressly and specifically defined. In the description of this application, "several" means at least one, such as one, two, etc., unless otherwise expressly and specifically defined.

[0035] When a numerical range is disclosed in this application, the range is considered continuous and includes the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Furthermore, when the range refers to an integer, it includes every integer between the minimum and maximum values ​​of the range. Additionally, when multiple ranges are provided to describe a feature or characteristic, the ranges may be merged. In other words, unless otherwise specified, all ranges disclosed in this application should be understood to include any and all subranges to which they are included.

[0036] Unless otherwise specified, all steps in this application may be performed sequentially or randomly. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the method may also include step (c), indicating that step (c) may be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0037] In this application, "above" or "below" includes the number itself. For example, "below 1" includes 1.

[0038] Unless otherwise specified, the temperature parameters in this application are permitted to be either constant-temperature treatment or variations within a certain temperature range. It should be understood that the constant-temperature treatment allows temperature fluctuations within the precision range of the instrument control, such as ±5℃, ±4℃, ±3℃, ±2℃, or ±1℃.

[0039] In this application, room temperature refers to indoor temperature, normal temperature, or general temperature. Generally, room temperature can be any of the following temperature ranges: 23℃±2℃, 25℃±5℃, or 20℃±5℃.

[0040] Terminology

[0041] Unless otherwise stated or in case of conflict, the terms or phrases used in this application shall have the following meanings:

[0042] PXRD: Powder X-ray Diffraction.

[0043] SC-XRD: Single-Crystal X-ray Diffraction

[0044] VT-PXRD: Variable-Temperature Powder X-ray Diffraction.

[0045] FESEM: Field Emission Scanning Electron Microscope.

[0046] VOC: Volatile Organic Compounds (VOC).

[0047] The following provides a detailed description of the Zn-MOF provided in this application, its preparation method, and its applications.

[0048] MOF materials originate from the self-assembly of organic ligands and inorganic nodes. Despite some gas molecules having nearly identical molecular sizes and physical properties, MOF materials demonstrate great potential for separating these two gas molecules through structural framework modulation. Many MOF materials have been used for the storage of C2H2 and the separation of C2H4 / CO2 or C2H2 / CO2. However, almost all reported MOF adsorbents exhibit a trade-off between high adsorption capacity and high adsorption selectivity. For example, MOF materials with high open metal site density, such as the MOF-74 series, have high C2H2 storage capacity, but their adsorption and separation selectivity for C2H4 / CO2 and C2H2 / CO2 is low. Therefore, it is necessary to develop MOF materials with high adsorption selectivity to achieve efficient separation of C2H4 / CO2 and C2H2 / CO2.

[0049] Based on this, in a first aspect, this application provides a zinc-based metal-organic framework material (Zn-MOF material) to improve the adsorption selectivity of Zn-MOF material in order to achieve effective separation of C2H4 / CO2 and C2H2 / CO2.

[0050] In some embodiments, the expression for Zn-MOF material is: Zn2(X)2L;

[0051] Where X represents 3-amino-1,2,4-triazole that has lost one proton, and L represents fumarate ion;

[0052] Zn-MOF materials have a columnar layered three-dimensional porous network structure;

[0053] The Zn-MOF material has a pore size of 0.2 nm to 0.3 nm and a porosity of 20% to 25%.

[0054] This application provides a mixed-structure columnar Zn-MOF material whose adsorption selectivity can be tuned by adjusting its two-dimensional layered ligand X and pillared ligand L. The two-dimensional layered ligand X is selected from 3-amino-1,2,4-triazole that has lost one proton. The ligand has a -NH2 side group, which is a highly electron-donating group. This relaxes the Zn-O bond, helping to expose more Zn sites and thus improving adsorption activity. The pillar-supporting ligand L is selected from the fumarate ion, which has a longer chain and greater rigidity. By regulating the connection mode of the two ligands, the Zn-MOF material forms distinctly different pore structures and active site microenvironments. The Zn-MOF material has a pore size of 0.25 nm–0.28 nm and a porosity of 20.6%–22.9%. Its adsorption selectivity for CO2 is significantly better than that for volatile organic compounds (VOCs), enabling effective separation of C2H4 / CO2 and C2H2 / CO2, which is beneficial for its widespread application in CO2 capture and catalytic conversion.

[0055] As an example, the pore size of Zn-MOF materials includes, but is not limited to, 0.2 nm, 0.21 nm, 0.22 nm, 0.23 nm, 0.24 nm, 0.25 nm, 0.26 nm, 0.27 nm, 0.28 nm, 0.29 nm or 0.3 nm, preferably 0.25 nm to 0.28 nm.

[0056] As an example, the porosity of the Zn-MOF material includes, but is not limited to, 20%, 20.5%, 21%, 21.5%, 22%, 22.5%, 23%, 23.5%, 24%, 24.5% or 25%, preferably 20.6% to 22.9%.

[0057] In some embodiments, the Zn-MOF material belongs to the monoclinic crystal system with space group . C 2 / c .

[0058] In some embodiments, the unit cell parameters of the Zn-MOF material are: a = 23.39Å, b = 8.34Å, c = 9.11Å, α =90°, β = 116.36°, gamma = 90°, cell volume is 1592.65 Å 3 .

[0059] In some embodiments, at 298 K, the adsorption capacity of the Zn-MOF material for CO2 is ≥0.95 mmol / g, including but not limited to 0.95 mmol / g, 0.96 mmol / g, 0.97 mmol / g, 0.98 mmol / g, 0.99 mmol / g, 1 mmol / g, 1.02 mmol / g, 1.05 mmol / g, 1.08 mmol / g or 1.1 mmol / g, preferably 0.95 mmol / g to 1.05 mmol / g.

[0060] In some embodiments, at 298 K, the Zn-MOF material adsorbs ≤0.55 mmol / g of VOCs, including one or more of acetylene (C2H2), ethylene (C2H4), ethane (C2H6), propylene (C3H6), and propane (C3H8).

[0061] As examples, the adsorption capacities of Zn-MOF materials for VOCs include, but are not limited to, 0.55 mmol / g, 0.5 mmol / g, 0.45 mmol / g, 0.4 mmol / g, 0.35 mmol / g, 0.3 mmol / g, 0.25 mmol / g, 0.2 mmol / g, 0.15 mmol / g, 0.1 mmol / g, 0.05 mmol / g, 0.02 mmol / g, or 0.01 mmol / g. In some specific examples, the adsorption capacities of Zn-MOF materials for acetylene are 0.5 mmol / g to 0.55 mmol / g, and for ethylene, ethane, propylene, and propane are 0.01 mmol / g to 0.06 mmol / g.

[0062] As shown in Table 1, the kinetic diameter of CO2 is 0.33 nm, the kinetic diameter of C2H2 is comparable to that of CO2, and the kinetic diameters of the other VOC gases are all above 0.4 nm. Given that the pore size of Zn-MOF materials is 0.25 nm to 0.28 nm, its small pore size is more conducive to the adsorption of small molecule gases.

[0063] Table 1. Dynamic diameter of gas

[0064]

[0065] In a second aspect, this application provides a method for preparing Zn-MOF materials, which is used to prepare Zn-MOF materials as described above.

[0066] In some embodiments, the preparation method of Zn-MOF materials includes the following steps:

[0067] S11: Mix methanol and water to obtain a mixed solvent;

[0068] S12: Dissolve the reactants containing 3-amino-1,2,4-triazole, zinc salt and fumaric acid in a mixed solvent and carry out a solvothermal reaction to obtain Zn-MOF material.

[0069] In traditional solvothermal reactions, substances containing... N , N The mixed solvent of dimethylformamide (DMF) was used, but the adsorption selectivity of the prepared Zn-MOF material was not ideal, making it difficult to achieve effective separation of C2H4 / CO2 and C2H2 / CO2.

[0070] The applicant discovered through research that even if the two-dimensional layered ligand X and the pillared ligand L are the same, the topological structure and crystal phase structure of MOF materials may be completely different. This is because the solvent in the solvothermal reaction plays a dual role in the synthesis of MOF materials: (1) as a structure directing agent, the solvent molecules play a dynamic regulatory role in the entire process from the construction of basic structural units to the formation of the final three-dimensional framework through strong interactions with metal nodes and organic ligands (such as coordination bonds, hydrogen bonds, etc.); (2) although the solvent molecules only have weak interactions with the framework components, by filling the pore space and providing sufficient support, the solvent molecules can act as a template agent to induce the framework to grow around it.

[0071] Based on this, the applicant conducted an in-depth investigation into the effect of solvent template effect on the adsorption selectivity of Zn-MOF materials, and found that by using different solvents as template agents, Zn-MOF materials with the same framework structure composition but different topological structures and crystal phase structures can be synthesized, which in turn has a significant impact on their adsorption selectivity.

[0072] Specifically, when using macromolecular organic solvents such as DMF as template agents, the prepared Zn-MOF materials have relatively large pores and lack a clear selectivity for gas molecules with different kinetic diameters, resulting in low adsorption selectivity for CO2. To avoid the negative impact of macromolecular organic solvents, the applicant used methanol and water as small-molecule solvents and controlled their volume ratio to synthesize a small-pore Zn-MOF material capable of selectively adsorbing CO2, thereby achieving effective separation of C2H4 / CO2 and C2H2 / CO2.

[0073] In some embodiments, the volume ratio of methanol to water is 1:(1.5~2.5), including but not limited to 1:1.5, 1:1.6, 1:1.7, 1:1.8, 1:1.9, 1:2, 1:2.1, 1:2.2, 1:2.3, 1:2.4 or 1:2.5, preferably 1:2.

[0074] In some embodiments, zinc salts include zinc nitrate (Zn(NO3)2), zinc chloride (ZnCl2), zinc sulfate (ZnSO4), zinc carbonate (ZnCO3), zinc acetate (Zn(CH3COO3)2), zinc oxalate (ZnC2O4), and zinc acetylacetonate (C). 10 H 14 One or more of ZnO4.

[0075] Understandably, zinc salts are salt compounds containing zinc. They can be simple salts or complex salts, such as basic zinc carbonate (2ZnCO3·3Zn(OH)2). The above zinc salts may or may not contain water of crystallization, such as zinc nitrate hexahydrate (Zn(NO3)2·6H2O).

[0076] In some embodiments, the molar volume ratio of zinc element in the zinc salt to the mixed solvent is 1 / 7 mol / L to 1 / 5 mol / L, including but not limited to 1 / 7 mol / L, 1 / 6.5 mol / L, 1 / 6 mol / L, 1 / 5.5 mol / L or 1 / 5 mol / L, preferably 1 / 6 mol / L.

[0077] In some embodiments, the molar ratio of 3-amino-1,2,4-triazole, zinc in the zinc salt, and fumaric acid is (0.8~1.2):1:0.5, including but not limited to 0.8:1:0.5, 0.9:1:0.5, 1:1:0.5, 1.1:1:0.5, or 1.2:1:0.5, preferably 1:1:0.5.

[0078] In some embodiments, the reactants further contain a base regulator, which includes one or more of sodium hydroxide (NaOH), potassium hydroxide (KOH), sodium carbonate (Na2CO3), potassium carbonate (K2CO3), sodium bicarbonate (NaHCO3), and potassium bicarbonate (KHCO3), preferably NaOH or KOH.

[0079] Adding an appropriate amount of alkali regulator can increase the pH in the solvothermal reaction, promoting the reaction towards the formation of Zn-MOF materials, thereby significantly improving the yield and enabling the production to increase from the milligram level to the gram level, thus achieving large-scale commercial production.

[0080] In some embodiments, the molar ratio of zinc element to alkali regulator in zinc salt is 1:(0.1~1.5), including but not limited to 1:0.1, 1:0.2, 1:0.3, 1:0.4, 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9, 1:1, 1:1.1, 1:1.2, 1:1.3, 1:1.4 or 1:1.5, preferably 1:(0.5~1.5), and more preferably 1:(1~1.5).

[0081] In some embodiments, the method for dissolving the reactants in the mixed solvent is ultrasonication.

[0082] In some embodiments, the temperature of the solvothermal reaction is 70 °C to 90 °C, and the time is 48 h to 72 h. As examples, the temperature of the solvothermal reaction includes, but is not limited to, 70 °C, 72 °C, 74 °C, 76 °C, 78 °C, 80 °C, 82 °C, 84 °C, 86 °C, 88 °C, or 90 °C; and the time of the solvothermal reaction includes, but is not limited to, 48 h, 52 h, 56 h, 60 h, 64 h, 68 h, or 72 h.

[0083] In the solvothermal reaction of this application, the yield of Zn-MOF material decreases significantly with increasing temperature. However, by conducting the solvothermal reaction within a temperature range of 70℃ to 90℃, and in synergy with a base regulator, the yield of Zn-MOF material can be increased to over 20%. Furthermore, the low-temperature conditions can significantly reduce reaction energy consumption and lower the requirements for the reaction apparatus, thereby saving on material preparation costs and facilitating further scale-up synthesis.

[0084] In some embodiments, the solvothermal reaction is carried out under stirring conditions.

[0085] In traditional techniques, the solvothermal reaction for synthesizing Zn-MOF materials typically requires a closed reactor under high temperature and pressure, which makes stirring difficult, resulting in insufficient contact between different components and uneven local concentrations, thus significantly reducing the reaction rate and yield. In contrast, the solvothermal reaction in this application occurs at a lower temperature, eliminating the need for high-temperature, high-pressure, and closed conditions, and allowing for thorough stirring during the reaction, thereby significantly improving both the reaction rate and yield.

[0086] In some embodiments, after the solvothermal reaction, a step of washing the resulting product is further included. The washing solvent includes, but is not limited to, water, methanol, or ethanol, and the washing method may be washing with the solvent 1 to 5 times, or washing with the solvent for 1 hour to 72 hours.

[0087] In some specific embodiments, the preparation method of Zn-MOF material includes the following steps: mixing 3-amino-1,2,4-triazole, zinc salt, fumaric acid and base regulator in a molar ratio of (0.8~1.2):1:0.5:(0.1~1.5) to obtain reactants; mixing methanol and water in a volume ratio of 1:(1.5~2.5) to obtain a mixed solvent; adding reactants to the mixed solvent according to a molar volume ratio of zinc element in zinc salt to mixed solvent of 1 / 7 mol / L~1 / 5 mol / L, sonicating until completely dissolved, and then placing it on a heating platform at 70 ℃~90℃ for a solvothermal reaction for 48 h~72 h; washing the obtained product with solvent for 48 h~72 h to obtain Zn-MOF material.

[0088] In a third aspect, this application provides the application of the Zn-MOF material prepared by the method described above, or the Zn-MOF material prepared by the method described above, in CO2 capture and catalytic conversion.

[0089] In some embodiments, under a CO2 atmosphere, constant-potential electrolysis experiments were conducted, and the Faraday efficiency of the Zn-MOF material in catalyzing the reduction of CO2 to carbon monoxide (CO) reached 46%–68%. to It exhibits high selectivity for CO products within the potential window, and no other reduction products were detected throughout the test.

[0090] The following description is further illustrated with specific embodiments and comparative examples. Unless otherwise specified, the raw materials involved in the following specific embodiments and comparative examples are all commercially available. Unless otherwise specified, the instruments used are all commercially available. Unless otherwise specified, the processes involved are conventionally selected by those skilled in the art.

[0091] Example 1

[0092] 84 mg (1.0 mmol) of 3-amino-1,2,4-triazole, 297 mg (1.0 mmol) of zinc nitrate (ZnNO3·6H2O), 58 mg (0.5 mmol) of fumaric acid, and 60 mg (1.5 mmol) of sodium hydroxide were mixed in a molar ratio of 1:1:0.5:1.5 to obtain the reactant. 2 mL of methanol and 4 mL of water were mixed in a volume ratio of 1:2 in a 20 mL glass sample bottle to obtain the mixed solvent. The reactant was added to the mixed solvent, sonicated until completely dissolved, and then reacted on a heating stage at 70 °C for 2 days to obtain colorless parallelepiped bulk crystals. After the reaction was completed, the mixture was filtered, washed three times with methanol, and dried in air. The resulting product was denoted as Zn-atz-fma(rob).

[0093] Examples 2-7

[0094] The difference between Examples 2-7 and Example 1 lies in the amount of NaOH added, as detailed below:

[0095] Example 2: The molar amount of NaOH was 1.1 mmol;

[0096] Example 3: The molar amount of NaOH was 0.9 mmol;

[0097] Example 4: The molar amount of NaOH was 0.7 mmol;

[0098] Example 5: The molar amount of NaOH was 0.5 mmol;

[0099] Example 6: The molar amount of NaOH was 0.3 mmol;

[0100] Example 7: The molar amount of NaOH was 0 mmol;

[0101] Example 8

[0102] 0.84 g of 3-amino-1,2,4-triazole, 2.97 g of zinc nitrate (ZnNO3·6H2O), 0.84 g of fumaric acid, and 0.60 g of sodium hydroxide were mixed in a molar ratio of 1:1:0.5:1.5 to obtain the reactant. 20 mL of methanol and 40 mL of water were mixed in a volume ratio of 1:2 in a 100 mL round-bottom flask to obtain the mixed solvent. The reactant was added to the mixed solvent, sonicated until completely dissolved, and then stirred and refluxed at 90 °C for 2 days. After the reaction was completed, the mixture was filtered, washed three times with methanol, and then dried in air to obtain the Zn-MOF material.

[0103] Comparative Example 1

[0104] 0.042 g of 3-amino-1,2,4-triazole, 0.149 g of zinc nitrate (ZnNO3·6H2O), and 0.029 g of fumaric acid were mixed in a molar ratio of 1:1:0.5 to obtain the reactant. 5 mL of DMF, 4 mL of MeOH, and 2 mL of H2O were mixed in a volume ratio of 5:4:2 in a 20 mL glass sample bottle to obtain the mixed solvent. The reactant was added to the mixed solvent, sonicated until completely dissolved, and then reacted on a heating stage at 70 ℃ for 3 days to obtain colorless cubic block crystals. After the reaction was completed, the mixture was filtered, washed three times with methanol, and dried in air. The obtained product was denoted as Zn-atz-fma(pcu).

[0105] Test Examples

[0106] 1. Yield and yield:

[0107] The mass of the Zn-MOF materials obtained in each example was weighed using an analytical balance, and the yield of the Zn-MOF materials was calculated based on ZnNO3·6H2O. The results are shown in Table 2. Table 2 shows that the yield of Zn-MOF material in Example 1 was 155.4 mg, with a yield of 75.6%. The comparison of Examples 1-7 shows that the yield of Zn-MOF material increased significantly with the increase of the amount of alkali regulator. The yield of Example 8 was 1.4324 g, achieving an improvement from milligram to gram levels, indicating that its preparation method has excellent scalability.

[0108] Table 2. Yield and Production Rate of Zn-MOF Materials

[0109]

[0110] 2. Phase characterization:

[0111] The products synthesized in Examples 1-7 were subjected to PXRD analysis using a Rigaku MiniFlex 600 X-ray powder diffractometer. The results are shown in the figure. Figure 1 .in, Figure 1 The simulated PXRD curves of the Zn-MOF material were obtained through modeling. Figure 1 As can be seen, the products of Examples 1-7 are in high agreement with the simulated curves, with each major diffraction peak clearly visible and without obvious impurities. The diffraction peaks are sharp and the baseline is stable, demonstrating a significant advantage in maintaining the integrity of the material structure. Therefore, compared to the traditional solvothermal method, the preparation method provided in this application not only significantly improves the synthesis efficiency of Zn-MOF materials, but also ensures that the obtained products maintain excellent crystallinity, laying an important foundation for the large-scale preparation and practical application of Zn-MOF materials.

[0112] 3. Structural characterization:

[0113] The Zn-atz-fma(rob) product of Example 1 was subjected to SC-XRD analysis using a Rigaku Xtalab Pro MM007HF DW single-crystal X-ray diffractometer. The obtained single-crystal data were analyzed using an Olex spectrometer. 2 The software's embedded ShelXT was used for structure analysis, and the ShelXL program was used to refine the structure, obtaining its crystallographic data and crystal structure diagram. The results are shown in Table 3 and... Figure 2 .

[0114] Table 3 shows that Zn-atz-fma(rob) crystallizes in the monoclinic crystal system. C 2 / c Space group, cell parameters a = 23.39Å, b = 8.34Å, c = 9.11Å, α = 90°, β = 116.36°, gamma = 90°, cell volume is 1592.65 Å 3 The independent unit of Zn-atz-fma(rob) has one Zn 2+ ,one ligand and half Ligands. Zn(II) adopts a tetrahedral configuration with four-coordinated atoms, each originating from one of the three ligands. N atom and a O atoms.

[0115] like Figure 2 As shown, in Zn-atz-fma(rob), Zn(Ⅱ) and This forms a dual-core unit, which shares... The ligands extend within a two-dimensional plane, forming a twisted square lattice layered structure. Then, through... As a linear pillared ligand, its carboxyl oxygen atoms at both ends are respectively bonded to Zn in the adjacent two-dimensional layer. 2+ Coordination, through a staggered stacking pattern, precisely connects two-dimensional layers to ultimately form a stable structure with a three-dimensional framework.

[0116] Simplifying the crystal structure diagrams of Zn-atz-fma(pcu) and Zn-atz-fma(rob) to their topological structure diagrams reveals that in Zn-atz-fma(pcu), Zn(II) and... Ligand linkages form a two-dimensional SQL layer, with pillared ligands bridging along a direction perpendicular to the two-dimensional layer; in Zn-atz-fma(rob), although Zn(II) and The ligand linkages also form a two-dimensional SQL layer, but the interlacing connections between the pillared ligands cause a certain degree of distortion in its layered structure. Therefore, the product Zn-atz-fma(rob) from Example 1 is significantly different from Zn-atz-fma(pcu) in terms of its two-dimensional layer, three-dimensional framework, and topology, resulting in a clear difference in adsorption selectivity and catalytic performance.

[0117] Table 3. Crystallographic data of the product of Example 1

[0118]

[0119] 4. Solvent stability:

[0120] Zn-atz-fma(rob) was immersed in different solvents for 24 h and then subjected to PXRD tests. The results are shown below. Figure 3 .Depend on Figure 3 It can be seen that the Zn-MOF material prepared in Example 1 is resistant to water (H2O), methanol (MeOH), ethanol (EtOH), and isopropanol (…). i It retains its crystalline state after being soaked in PrOH for 24 hours, exhibiting excellent solvent stability.

[0121] 5. Thermal stability:

[0122] Zn-atz-fma(rob) was subjected to VT-PXRD analysis using a Rigaku Ultima IV X-ray powder diffractometer at a heating rate of 10 °C / min. The results are shown in [Figure number missing]. Figure 4 .Depend on Figure 4 It can be seen that Zn-atz-fma(rob) has good thermal stability and can maintain good crystallinity even when heated to 400 ℃.

[0123] 6. Morphological characteristics:

[0124] The product of Example 1 was analyzed by FESEM using a Zeiss Gemini 300 field emission scanning electron microscope equipped with an energy dispersive spectrometer. The results are shown in [Figure number missing]. Figure 5 .Depend on Figure 5 It can be seen that the product particles of Example 1 are uniform. Based on its single crystal structure and crystallographic data, the pore size of the product of Example 1 is 0.25 nm to 0.28 nm, and the porosity is 20.6% to 22.9%.

[0125] 7. Adsorption performance:

[0126] The product of Example 1 was vacuum activated at 120 °C for 24 h, and then adsorption-desorption isotherm tests were performed. The results are shown in [Figure 1]. Figure 6 And Table 4. From Figure 6 As shown in Table 4, the highest CO2 adsorption capacity of the Zn-MOF material at 195 K is 4.90 mmol / g, and its CO2 adsorption capacity decreases with increasing temperature. At 298 K, the highest CO2 adsorption capacity of the Zn-MOF material is 0.96 mmol / g, while the adsorption capacity for C2H2 is very low, and almost no adsorption is observed for C2H4, C2H6, C3H6, and C3H8. The CO2 adsorption capacity is significantly better than that for C2H2. This indicates that the Zn-MOF material exhibits excellent adsorption selectivity for CO2 and can effectively separate volatile organic compounds such as CO2 and C2H2.

[0127] Table 4. Adsorption properties of the product from Example 1

[0128]

[0129] The ratio of the highest adsorption capacity for CO2 to the highest adsorption capacity for C2H2 at 298 K was denoted as S1, and the ratio of the highest adsorption capacity for CO2 to the highest adsorption capacity for C2H4 at 298 K was denoted as S2. This was used to measure the difference in adsorption selectivity between Zn-atz-fma(rob) and Zn-atz-fma(pcu). The results are shown in Table 5. Table 5 shows that both S1 and S2 for Zn-atz-fma(rob) are significantly better than those for Zn-atz-fma(pcu), indicating that the product Zn-atz-fma(pcu) from Example 1 can selectively adsorb CO2, which is beneficial for achieving effective separation of C2H4 / CO2 and C2H2 / CO2.

[0130] Table 5. Adsorption selectivity of Zn-atz-fma(rob) and Zn-atz-fma(pcu)

[0131]

[0132] 8. Electrocatalytic CO2RR performance test:

[0133] Constant potential electrolysis experiments were conducted on Zn-atz-fma(rob) and Zn-atz-fma(pcu) using a membrane electrode assembly (MEA) type two-electrode electrolytic cell. During the test, high-purity CO2 gas (flow rate 20 sccm, purity 99.999%) was continuously introduced into the cathode chamber, while 1.0 M KOH electrolyte was circulated into the anode chamber (flow rate 10 mL / min). The test duration was 64 min, and the reaction products (CO and H2) were analyzed by gas chromatography. The results are shown in Table 6. Table 6 shows that Zn-atz-fma(rob) at... ~ The current density at the potential is generally higher than that of Zn-atz-fma(pcu). At the specified potential, Zn-atz-fma(rob) achieves a Faraday efficiency of 68% for CO, demonstrating high selectivity for CO products.

[0134] Table 6. Current density at different potentials

[0135]

[0136] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0137] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of protection of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these modifications and improvements all fall within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the appended claims.

Claims

1. A zinc-based metal-organic framework material, characterized in that, An expression of which is: Zn2(X)2L; Wherein, X represents 3-amino-1, 2, 4-triazole losing a proton, and L represents fumarate ion; The zinc-based metal organic framework material has a columnar layer three-dimensional porous network structure. The pore size of the zinc-based metal organic framework material is 0.2 nm~0.3 nm, and the porosity is 20%~25%. The zinc-based metal organic framework material belongs to a monoclinic system, and a space group is C 2 / c ; At 298 K, the adsorption amount of the zinc-based metal organic framework material for CO2 is ≥0.95 mmol / g, and the adsorption amount of the volatile organic compound is ≤0.55 mmol / g, wherein the volatile organic compound includes one or more of C2H2, C2H4, C2H6, C3H6 and C3H8. The preparation method of the zinc-based metal organic framework material comprises the following steps: Mixing methanol and water to obtain a mixed solvent; Dissolving reactants containing 3-amino-1, 2, 4-triazole, zinc salt and fumaric acid in the mixed solvent to perform a solvothermal reaction to obtain the zinc-based metal organic framework material.

2. The zinc-based metal-organic framework material of claim 1, wherein, The unit cell parameters of the zinc-based metal organic framework material are a = 23.39 Å, b = 8.34 Å, c = 9.11 Å, α = 90°, β = 116.36°, γ = 90°, and the unit cell volume is 1592.65 Å 3 .

3. The zinc-based metal-organic framework material of claim 1, wherein, The adsorption amount of the zinc-based metal organic framework material for C2H2 is 0.5 mmol / g~0.55 mmol / g, and the adsorption amount for C2H4, C2H6, C3H6 and C3H8 is all 0.01 mmol / g~0.06 mmol / g.

4. The zinc-based metal-organic framework material of any one of claims 1-3, wherein, The volume ratio of the methanol to the water is 1:(1.5~2.5).

5. The zinc-based metal-organic framework material of claim 4, wherein, The method for dissolving the reactants in the mixed solvent is ultrasonic method.

6. The zinc-based metal-organic framework material of claim 4, wherein, One or more of the following conditions are met: (1) The zinc salt includes one or more of zinc nitrate, zinc chloride, zinc sulfate, zinc carbonate, zinc acetate, zinc oxalate and zinc acetylacetone; (2) The molar ratio of the 3-amino-1, 2, 4-triazole, the zinc element in the zinc salt and the fumaric acid is (0.8~1.2):1:0.

5.

7. The zinc-based metal-organic framework material of claim 4, wherein, The reactants also contain an alkali regulator, and the alkali regulator includes one or more of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate and potassium bicarbonate.

8. The zinc-based metal-organic framework material of claim 7, wherein, The molar ratio of the zinc salt to the alkali regulator is 1:(0.1~1.5).

9. The zinc-based metal-organic framework material of any one of claims 5-8, wherein, The temperature of the solvothermal reaction is 70 ℃~90 ℃, and the time is 48 h~72 h.

10. The zinc-based metal organic framework material according to any one of claims 1~9 in carbon dioxide capture and catalytic conversion.

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