Copper-based metal organic framework material as well as preparation method and application thereof
By preparing a copper-based metal-organic framework material [Cu2(TPPE)(μ2-H2O)2], the problem of ammonia capture at low concentrations was solved, and efficient and stable ammonia adsorption was achieved under low pressure.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- WUYI UNIV
- Filing Date
- 2026-02-11
- Publication Date
- 2026-05-12
AI Technical Summary
Capturing ammonia molecules at low concentrations remains a critical issue with existing technologies, and traditional materials are ineffective at capturing ammonia under low pressure and are easily corroded by ammonia.
A copper-based metal-organic framework material [Cu2(TPPE)(μ2-H2O)2] was developed, which exhibits excellent stability and the ability to capture trace amounts of ammonia under low pressure. The material was prepared by a solvothermal reaction.
It maintains stability under strong alkaline conditions and achieves the capture of trace amounts of ammonia under low pressure, thereby improving the adsorption efficiency of low-concentration ammonia.
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Figure CN122011413A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to metals The field of organic framework materials technology, particularly a copper-based metal-organic framework material, its preparation method, and its applications. Background Technology
[0002] Since the Haber-Bosch process was industrially applied in 1908, ammonia has become one of the most widely used inorganic chemicals, with an annual production exceeding 200 million tons. Ammonia is crucial in industries such as petrochemicals, metal manufacturing, papermaking, textiles, and agriculture. However, despite its economic advantages, nitrogen emissions pose significant environmental and health risks. Ammonia is a widely used inorganic chemical, but its strong irritant and corrosive properties have led it to be listed as a hazardous chemical. Especially in environments where low concentrations of ammonia (5-50 ppm) are not easily detected by the sense of smell, it can cause potential hazards such as olfactory fatigue, respiratory damage, and loss of consciousness. The national standard for ammonia detection is 20 mg / m³. 3 Prolonged exposure to ammonia can lead to respiratory damage, loss of consciousness, and even cardiopulmonary dysfunction. For many years, researchers have been dedicated to exploring suitable materials for ammonia adsorption, such as traditional porous materials like activated carbon, mesoporous silica, and zeolites, as well as emerging adsorbents like metal-organic frameworks, hydrogen-bonded organic frameworks, covalent organic frameworks, and porous polymers. Porous materials have received widespread attention in recent years due to their applications in the physical and chemical adsorption of ammonia.
[0003] Although high-concentration ammonia adsorption technology has been well developed, capturing ammonia molecules at low concentrations remains a key challenge. Compared to the currently studied high-concentration ammonia adsorption, it is necessary to develop materials that can capture trace amounts of ammonia at lower pressures, i.e., with stronger interaction forces with ammonia, while also being unaffected by ammonia corrosion. Summary of the Invention
[0004] The present invention aims to at least solve one of the technical problems existing in the prior art. To this end, the first aspect of the present invention proposes a copper-based metal-organic framework material, which has excellent stability and can achieve trace capture of ammonia gas under low pressure.
[0005] A second aspect of the present invention also provides a method for preparing a copper-based metal-organic framework material.
[0006] A third aspect of the present invention also provides an adsorbent.
[0007] The fourth aspect of the present invention also provides an application of a copper-based metal-organic framework material.
[0008] According to a first aspect of the present invention, a copper-based metal-organic framework material is provided, wherein the molecular formula of the copper-based metal-organic framework material is [Cu2(TPPE)( μ 2-H2O)2];TPPE 4- The term represents deprotonated 1,1,2,2-tetrakis(4-(1H-pyrazol-4-yl)phenyl)ethylene; in the copper-based metal-organic framework material, each asymmetric unit comprises one Cu. 2+ Ions, 1 / 2 completely deprotonated TPPE 4- ligand and 1 bridge μ 2-H2O molecule.
[0009] According to a preferred embodiment of the present invention, the crystal structure of the copper-based metal-organic framework material belongs to the monoclinic crystal system. P 2 / m Space group; crystallographic data are as follows: a = 11.9568(3) Å; b = 16.2011(3) Å; c = 14.1530(4) Å; α = 90°; β = 106.510(3)°; γ = 90°; V = 2628.59(12) Å 3 Z = 2.
[0010] According to a preferred embodiment of the present invention, in the copper-based metal-organic framework material, Cu 2+ There are three coordination modes. The occupancy rates of Cu1, Cu2, and Cu3 are 0.25, 0.5, and 0.25, respectively. Both Cu1 and Cu2 are hexacoordinated with four TPPE groups. 4- The N atom of the ligand and two atoms with a occupancy of 0.5 μ 2-H2O molecules form an octahedral configuration; Cu3 and 4 different TPPEs 4- The N atom on the ligand forms a planar quadrilateral configuration.
[0011] The copper-based metal-organic framework material according to embodiments of the present invention has at least the following beneficial effects: This invention constructs a novel metal-organic framework material with bridging water molecules. This copper-based metal-organic framework material exhibits excellent stability even in strongly alkaline environments. Furthermore, due to the large pores in the material structure and the hydration mechanism of bridging water molecules within the framework, it can achieve trace capture of ammonia gas under low pressure.
[0012] According to a second aspect of the present invention, a method for preparing a copper-based metal-organic framework material as described in the first aspect of the present invention is provided, comprising the following steps: A mixture is prepared by mixing copper salt, 1,1,2,2-tetrakis(4-(1H-pyrazole-4-yl)phenyl)ethylene, solvent and water; the mixture is then subjected to a solvothermal reaction to obtain the final product.
[0013] According to a preferred embodiment of the present invention, the molar ratio of 1,1,2,2-tetrakis(4-(1H-pyrazol-4-yl)phenyl)ethylene to the copper salt is (2 ~ 3.3):1.
[0014] According to a preferred embodiment of the present invention, the temperature of the solvothermal reaction is 90 to 150°C.
[0015] According to a preferred embodiment of the present invention, the temperature of the solvothermal reaction is 120~150°C.
[0016] According to a preferred embodiment of the present invention, the solvothermal reaction time is 12 to 24 hours.
[0017] According to a preferred embodiment of the present invention, the copper salt comprises copper nitrate.
[0018] According to a preferred embodiment of the present invention, the copper nitrate comprises Cu(NO3)2·3H2O and / or Cu(NO3)2·4H2O.
[0019] According to a preferred embodiment of the present invention, the solvent comprises N , N -Dimethylformamide, H2O, MeOH and HCOOH.
[0020] The role of HCOOH is to adjust the pH of the solvent system, inhibit excessively rapid crystal nucleation, and reduce defects.
[0021] A third aspect of the present invention provides an adsorbent comprising the copper-based metal-organic framework material described in the first aspect of the present invention. Therefore, this adsorbent exhibits excellent stability even under strongly alkaline conditions and achieves trace adsorption of ammonia gas at low pressure.
[0022] The fourth aspect of the present invention provides the application of the copper-based metal-organic framework material described above, or the adsorbent described in the third aspect, in the adsorption of ammonia.
[0023] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. Attached Figure Description
[0024] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a crystal structure diagram of the copper-based metal-organic framework material of Embodiment 1 of the present invention; Figure 2 This is the powder diffraction pattern of the copper-based metal-organic framework material of Example 1 of the present invention; Figure 3 These are powder diffraction patterns of the copper-based metal-organic framework material of Example 1 of the present invention after being immersed in different solvents; Figure 4 This is the powder diffraction pattern of the copper-based metal-organic framework material of Example 1 of the present invention after treatment with boiling water, concentrated ammonia and saturated sodium hydroxide solution; Figure 5 This is a thermogravimetric curve of the copper-based metal-organic framework material of Embodiment 1 of the present invention; Figure 6 This is a photograph of the copper-based metal-organic framework material of Embodiment 1 of the present invention after thermal activation treatment; Figure 7 These are the powder diffraction patterns of the copper-based metal-organic framework material and the material after thermal activation treatment in Embodiment 1 of the present invention; Figure 8 These are powder diffraction patterns of the copper-based metal-organic framework material of Example 1 of the present invention at different temperatures; Figure 9 This is a crystal structure diagram of the material after thermal activation treatment; Figure 10 It is the powder diffraction pattern of the material after thermal activation treatment; Figure 11 It is a powder diffraction pattern of a material that has undergone thermal activation treatment and has been treated with boiling water, concentrated ammonia, and saturated sodium hydroxide solution. Figure 12 It is a thermogravimetric curve of the material after thermal activation treatment; Figure 13 This is the N2 adsorption isotherm diagram at 77K for the copper-based metal-organic framework material and the material after thermal activation treatment in Embodiment 1 of the present invention.
[0025] Figure 14 This is an isotherm diagram of ammonia adsorption at 298 K and 1 bar for the copper-based metal-organic framework material and the material after thermal activation treatment in Embodiment 1 of the present invention.
[0026] Figure 15 This is an isotherm diagram of ammonia adsorption at 298 K and 0.001 bar for the copper-based metal-organic framework material and the material after thermal activation treatment in Embodiment 1 of the present invention.
[0027] Figure 16This is a bar chart showing the ammonia adsorption capacity of the copper-based metal-organic framework material and the material after thermal activation treatment in Example 1 of the present invention under conditions of 1 bar and 0.001 bar, respectively. Detailed Implementation
[0028] The following are specific embodiments of the present invention, and the technical solutions of the present invention will be further described in conjunction with the embodiments, but the present invention is not limited to these embodiments.
[0029] Unless otherwise specified, the reagents, methods and equipment used in this invention are all conventional reagents, methods and equipment in this technical field.
[0030] In some embodiments of the present invention, a copper-based metal-organic framework material is provided, wherein the molecular formula of the copper-based metal-organic framework material is [Cu2(TPPE)( μ 2-H2O)2];TPPE 4- The term represents deprotonated 1,1,2,2-tetrakis(4-(1H-pyrazol-4-yl)phenyl)ethylene; in the copper-based metal-organic framework material, each asymmetric unit comprises one Cu. 2+ Ions (the occupancy rates of Cu1, Cu2, and Cu3 were 0.25, 0.5, and 0.25, respectively), 1 / 2 completely deprotonated TPPE 4- Ligands and two bridges with an occupancy of 0.5 μ 2-H2O molecule.
[0031] It is understood that the present invention develops a novel copper-based metal-organic framework material that exhibits excellent stability under strong alkaline conditions and achieves trace ammonia capture under low pressure.
[0032] In some embodiments of the present invention, the crystal structure of the copper-based metal-organic framework material belongs to the monoclinic crystal system. P 2 / m Space group; crystallographic data are as follows: a = 11.9568(3) Å; b = 16.2011(3) Å; c = 14.1530(4) Å; α = 90°; β = 106.510(3)°; γ = 90°; V = 2628.59(12) Å 3 Z = 2.
[0033] In some embodiments of the present invention, Cu in the copper-based metal-organic framework material 2+There are three coordination modes, with occupancy rates of Cu1, Cu2, and Cu3 of 0.25, 0.5, and 0.25, respectively. Both Cu1 and Cu2 are hexacoordinated with four TPPE groups. 4- The N atom of the ligand and two atoms with a occupancy of 0.5 μ 2-H2O molecules form an octahedral configuration, Cu3 and 4 different TPPEs 4- The N atom on the ligand forms a planar quadrilateral configuration.
[0034] In some embodiments of the present invention, a method for preparing a copper-based metal-organic framework material as described in the first aspect of the present invention is provided, comprising the following steps: A mixture is prepared by mixing copper salt, 1,1,2,2-tetrakis(4-(1H-pyrazole-4-yl)phenyl)ethylene, solvent and water; the mixture is then subjected to a solvothermal reaction to obtain the final product.
[0035] In some embodiments of the present invention, the molar ratio of 1,1,2,2-tetrakis(4-(1H-pyrazol-4-yl)phenyl)ethylene to the copper salt is (2 ~ 3.3):1. For example, it includes subranges of 2:1, 2.1:1, 2.2:1, 2.3:1, 2.4:1, 2.5:1, 2.6:1, 2.7:1, 2.8:1, 2.9:1, 3.0:1, 3.1:1, 3.2:1, 3.3:1, or any two of the above ratios.
[0036] In some embodiments of the present invention, the temperature of the solvothermal reaction is 90~150°C. For example, it includes 90°C, 95°C, 100°C, 105°C, 110°C, 115°C, 120°C, 125°C, 130°C, 135°C, 140°C, 145°C, 150°C, or any sub-range of any two of the above values.
[0037] In some embodiments of the present invention, the temperature of the solvothermal reaction is 120~150°C. For example, it includes 120°C, 125°C, 130°C, 135°C, 140°C, 145°C, 150°C, or any sub-range consisting of any two of the above values.
[0038] In some embodiments of the present invention, the solvothermal reaction time is 12 to 24 hours. For example, it includes 12 hours, 13 hours, 14 hours, 15 hours, 16 hours, 17 hours, 18 hours, 19 hours, 20 hours, 21 hours, 22 hours, 23 hours, 24 hours, or any subrange consisting of two of the above ratios.
[0039] In some embodiments of the present invention, the copper salt comprises copper nitrate.
[0040] In some embodiments of the present invention, the copper nitrate comprises Cu(NO3)2·3H2O and / or Cu(NO3)2·4H2O.
[0041] In some embodiments of the present invention, the solvent includes N , N -Dimethylformamide, H2O, MeOH and HCOOH.
[0042] In some embodiments of the present invention, an adsorbent is provided, comprising the copper-based metal-organic framework material described in the first aspect of the present invention. Therefore, this adsorbent exhibits excellent stability even under strongly alkaline conditions and achieves trace adsorption of ammonia gas at low pressure.
[0043] In some embodiments of the present invention, the application of the copper-based metal-organic framework material described above, or the adsorbent described in the third aspect, in the adsorption of ammonia is provided.
[0044] Example 1 This example provides a copper-based metal-organic framework material, the preparation steps of which are as follows: Add 0.03 mmol of Cu(NO3)2·3H2O or Cu(NO3)2·4H2O and 0.015 mmol of H4TPPE to a 20 mL glass bottle, followed by 5 mL of... N,N - Dimethylformamide, sonicated for 30 minutes; Add 5 mL of methanol, 1 mL of pure water, and 200 mL of sodium hydroxide to the above-mentioned ultrasonicated solution. μ The solution containing L-formic acid was sonicated for 30 minutes. The ultrasonically mixed solution was heated to 120 °C and reacted for 24 hours, with the reaction proceeding at 5 °C h. 1 After cooling to room temperature, small dark brown crystalline materials were obtained.
[0045] Example 2 This example provides a copper-based metal-organic framework material, the preparation steps of which are as follows: Add 0.03 mmol of Cu(NO3)2·3H2O or Cu(NO3)2·4H2O and 0.015 mmol of H4TPPE to a 100 mL glass bottle, followed by 15 mL of... N,N - Dimethylformamide, sonicated for 30 minutes; Add 15 mL of methanol, 3 mL of pure water, and 600 mL of sodium hydroxide to the above-mentioned ultrasonicated solution. μ The solution containing L-formic acid was sonicated for 30 minutes. The ultrasonically mixed solution was heated to 120 °C and reacted for 24 hours, with a reaction time of 5 °C / h. 1 After cooling to room temperature, small dark brown powder material was obtained.
[0046] Example 3 This example provides a copper-based metal-organic framework material, the preparation steps of which are as follows: Add 0.12 mmol of Cu(NO3)2·3H2O or Cu(NO3)2·4H2O and 0.06 mmol of H4TPPE to a 500 mL glass bottle, followed by 15 mL of... N,N - Dimethylformamide, sonicated for 30 minutes; Add 15 mL of methanol, 3 mL of pure water, and 600 mL of sodium hydroxide to the above-mentioned ultrasonicated solution. μ The solution containing L-formic acid was sonicated for 30 minutes. The ultrasonically mixed solution was heated to 120 °C and reacted for 2 hours, with a reaction time of 5 °C / h. 1 After cooling to room temperature, a large quantity of powder material was obtained.
[0047] Performance testing The copper-based metal-organic framework material of Example 1 of this invention was subjected to single-crystal X-ray diffraction, and the results are as follows: Figure 1 As shown, where, Figure 1 In this context, 'a' represents an asymmetric unit structure. Figure 1 In this context, 'b' represents the value of Cu. 2+ With TPPE 4- The N atom of the pyrazole group of the ligand and μ A one-dimensional chain composed of 2-H2O, Figure 1 In this context, 'c' represents the combination of a one-dimensional chain and TPPE. 4- Three-dimensional structures formed by ligand linkages; Figure 1 In the diagram, 'd' represents the three-dimensional structure of a copper-based metal-organic framework. From... Figure 1 It can be seen that the structure crystallizes in the monoclinic crystal system. P 2 / m The space group, whose asymmetric unit contains one Cu 2+ Ions (three coordination modes, with occupancy rates of Cu1, Cu2, and Cu3 of 0.25, 0.5, and 0.25, respectively), and 1 / 2 completely deprotonated TPPE 4- The ligand and two bridges with an occupancy of 0.5 μ 2-H₂O molecule. Cu in the structure. 2+ There are three coordination modes. Both Cu1 and Cu2 are hexacoordinated with four TPPE groups. 4- The N atom of the ligand and 1 μ The 2-H₂O molecule forms an octahedral configuration. It is worth noting that these two... μ Due to the Jahn-Teller effect, the axial H2O molecule is connected to Cu via a longer Cu-O bond in the axial position. 2+ Ions [Cu-O bond (2.4 Å, 2.8 Å)]. Cu3 with 4 different TPPEs 4- The nitrogen atoms on the ligands form a planar quadrilateral configuration. Among them, Cu... 2+ The ion and the N atom on the pyrazole group and μ 2-H₂O molecules interconnect to form infinitely long one-dimensional chains. These one-dimensional chains are linked by TPPE. 4- Ligand linkages further form a three-dimensional framework of two rhomboid channels. Neglecting solvent molecules, the porosity is 50.3%. The pore size, measured along the crystallographic c-axis, is 7.1 × 10.8 Å. 2 (Including the van der Waals radius).
[0048] Furthermore, powder data for copper-based metal-organic frameworks (Cu-MOF materials) were simulated using Mercury software and single-crystal analysis results. The synthesized samples were then ground, pressed into tablets, and tested using a powder diffractometer. The purity and uniformity of the samples were assessed by comparing the powder diffraction patterns (PXRD). The results are as follows: Figure 2 As shown, the powder diffraction pattern of the Cu-MOF material highly matches the diffraction peaks simulated by single-crystal data, indicating that the compound has good crystallinity and high purity. The sample soaked in dichloromethane showed the formation of new peaks in its powder diffraction pattern due to sample preparation methods.
[0049] Furthermore, the solvent stability of the copper-based metal-organic framework material of Example 1 of the present invention was tested. The powder X-ray diffraction patterns of the copper-based metal-organic framework material after immersion in benzene, dichloromethane, toluene, acetonitrile, and diethyl ether were also tested, and the results are as follows: Figure 3 As shown, this Cu-MOF exhibits good stability in different organic solvents. The observed shift in the corresponding sample powder suggests that the structure may possess a certain degree of flexibility and adapt to different guest molecules. Furthermore, the powder X-ray diffraction patterns of the copper-based metal-organic framework material from Example 1 after immersion in boiling water, 25% concentrated ammonia, and 20 M sodium hydroxide solution are shown in the figures. Figure 4 As shown, the copper-based metal-organic framework material in Example 1 can still maintain a good peak shape, indicating that Cu-MOF has excellent stability in solvents and strong alkaline environments.
[0050] Furthermore, the copper-based metal-organic framework material of Example 1 of the present invention was subjected to thermogravimetric analysis, and its thermogravimetric curve is shown in the figure below. Figure 5As shown, the thermogravimetric data indicate that Cu-MOF does not have a significant weight loss plateau, which may be because as the temperature increases, high-boiling-point DMF molecules and H2O molecules in the pores gradually detach.
[0051] Furthermore, the copper-based metal-organic framework material of Example 1 of this invention was subjected to thermal activation treatment at 150°C under vacuum for 2 hours. The color change of the sample before and after activation is as follows: Figure 6 As shown, it can be visually observed that the color of the sample after heat activation treatment changes from dark brown to yellowish-brown.
[0052] Furthermore, powder diffraction tests were performed on the copper-based metal-organic framework material of Example 1 of the present invention and the material after thermal activation, and the results are as follows: Figure 7 As shown, the diffraction of the thermally activated material powder changed significantly, preliminarily indicating that a phase transition had occurred.
[0053] Furthermore, powder X-ray diffraction of the copper-based metal-organic framework material of Example 1 at different temperatures was tested, and the resulting spectra are as follows: Figure 8 As shown, this further verifies that the sample underwent a structural transformation.
[0054] Furthermore, the thermally activated material was subjected to single-crystal X-ray diffraction (SCXRD), and its crystal structure was as follows: Figure 9 As shown, where, Figure 9 In this context, 'a' represents an asymmetric element. Figure 9 In this context, 'b' represents the value of Cu. 2+ With TPPE 4- A one-dimensional chain composed of the N atoms of the pyrazole group of the ligand; Figure 9 In this context, 'c' represents the combination of a one-dimensional chain and TPPE. 4- Three-dimensional structures formed by ligand linkages; Figure 9 In this context, d represents a three-dimensional structure.
[0055] It belongs to the orthorhombic crystal system. Pbam The space group, whose asymmetric unit contains one Cu 2+ Ions and 1 / 2 of completely deprotonated TPPE 4- Ligands, Cu in the structure 2+ The ions are tetracoordinated with four TPPEs 4- The nitrogen atoms on the ligands form a planar quadrilateral configuration. It is worth noting that, comparing the structures before and after activation, it was found that removing the surface of the framework... μ 2 - The H2O water molecules were obtained, and the three-dimensional rhombic channels with a porosity of 50.3% (calculated after removing guest molecules) shrank to one-dimensional channels with a porosity of 43.0%, achieving a single-crystal transformation. The pore size, measured along the crystallographic b-axis, is 16.5 × 9.7 Å. 2 (Including the van der Waals radius).
[0056] Furthermore, the powder X-ray diffraction pattern of the thermally activated material was tested, and the results are as follows: Figure 10 As shown, the powder diffraction pattern of the activated material highly matches the diffraction peaks simulated by single-crystal data, indicating that it also has good crystallinity and high purity.
[0057] Furthermore, after treating the thermally activated material with boiling water, concentrated ammonia, and saturated sodium hydroxide solution, the powder X-ray diffraction pattern was tested, and the results are as follows. Figure 11 As shown, the activated Cu-MOF also exhibits excellent chemical stability.
[0058] Furthermore, the thermally activated material was subjected to thermogravimetric analysis (TGA), and its TGA curve is shown in the figure. Figure 12 The thermogravimetric curve data also showed no obvious weight loss plateau.
[0059] Furthermore, the N2 adsorption isotherms at 77 K were tested for Cu-MOF after ethanol and boiling water exchange, as well as for thermal activation treatment. The N2 adsorption isotherms at 77 K are as follows: Figure 13 As shown, this demonstrates that both materials possess microporous characteristics. It exhibits a type I isotherm in the initial low-pressure range ( P / P The presence of significant adsorption within the 0<0.01 cm⁻¹ region indicates that these particles possess microporous characteristics. The saturated nitrogen adsorption capacity is 327.68 cm⁻¹. 3 g -1 (Aperture: 0.5069 cm) 3 g -1 ) and 291.37 cm 3 g -1 (Aperture: 0.4508 cm) 3 g -1 The theoretical adsorption capacity of 332.04 cm⁻¹ was calculated using the crystal structure. 3 g -1 (Kong capacity 0.5138 cm) 3 g -1 ) and 308.31 cm 3 g -1 (Diameter 0.4770 cm) 3 g -1 The results are largely consistent. Comprehensive data analysis shows that both are porous. Comparative experimental data indicates that the exchange phase adsorbs more N2 than the activated phase, which aligns with the corresponding pore structure characteristics of both.
[0060] Furthermore, the copper-based metal-organic framework material of Example 1 of the present invention and the material after thermal activation were subjected to ammonia adsorption tests, and the results are as follows: Figure 14As shown, the copper-based metal-organic framework material in Example 1 achieved a saturated ammonia adsorption capacity of 180.32 cm⁻² at 298 K. 3 g -1 After thermal activation treatment, the removal µ The material with the 2-H₂O site achieved a saturated ammonia adsorption capacity of 129.16 cm⁻¹ at 298 K. 3 g -1 .
[0061] Furthermore, the adsorption capacity of the copper-based metal-organic framework material and the thermally activated material of Example 1 of the present invention for ammonia was tested at a low pressure of 0.001 bar. The results of the NH3 adsorption isotherm curves at 0.001 bar and 298 K are as follows: Figure 15 As shown, the ammonia adsorption capacity of the copper-based metal-organic framework material in Example 1 reaches 33.65 cm⁻¹. 3 g -1 Comparative data analysis showed that the saturated ammonia adsorption capacity at 298 K increased by approximately 1.4 times, and the saturated ammonia adsorption capacity at a low pressure of 0.001 bar increased by approximately 5.8 times. Comprehensive analysis indicates that... µ Cu-MOFs with 2-H2O sites can achieve trace NH3 capture (bar chart as shown). Figure 16 (As shown).
[0062] The present invention has been described in detail above with reference to the embodiments of the present invention. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.
Claims
1. A copper-based metal-organic framework material, characterized in that, The molecular formula of the copper-based metal-organic framework material is [Cu2(TPPE)( μ 2-H2O)2];TPPE 4- The term represents deprotonated 1,1,2,2-tetrakis(4-(1H-pyrazol-4-yl)phenyl)ethylene; in the copper-based metal-organic framework material, each asymmetric unit comprises one Cu. 2+ Ions, 1 / 2 completely deprotonated TPPE 4- ligand and 1 bridge μ 2-H2O molecule.
2. The copper-based metal-organic framework material according to claim 1, characterized in that, The crystal structure of the copper-based metal-organic framework material belongs to the monoclinic crystal system. P 2 / m Space group; crystallographic data are as follows: a = 11.9568(3) Å; b = 16.2011(3) Å; c = 14.1530(4) Å; α = 90°; β = 106.510(3)°; γ = 90°; V = 2628.59(12)Å 3 Z = 2.
3. The copper-based metal-organic framework material according to claim 1 or 2, characterized in that, In the copper-based metal-organic framework material, Cu 2+ There are three coordination modes, with occupancy rates of Cu1, Cu2, and Cu3 of 0.25, 0.5, and 0.25, respectively; Cu1 and Cu2 are both hexacoordinated with four TPPEs. 4- The N atom of the ligand and two atoms with a occupancy of 0.5 μ 2-H2O molecules form an octahedral configuration, Cu3 and 4 different TPPEs 4- The N atom on the ligand forms a planar quadrilateral configuration.
4. A method for preparing a copper-based metal-organic framework material as described in any one of claims 1 to 3, characterized in that, Includes the following steps: A mixture is prepared by mixing copper salt, 1,1,2,2-tetrakis(4-(1H-pyrazole-4-yl)phenyl)ethylene, solvent and water; the mixture is then subjected to a solvothermal reaction to obtain the final product.
5. The preparation method according to claim 4, characterized in that, The molar ratio of the 1,1,2,2-tetrakis(4-(1H-pyrazol-4-yl)phenyl)ethylene to the copper salt is (2 ~ 3.3):
1.
6. The preparation method according to claim 4, characterized in that, The temperature of the solvothermal reaction is 90℃~150℃.
7. The preparation method according to claim 4, characterized in that, The solvothermal reaction takes 12 h to 24 h.
8. The preparation method according to claim 4, characterized in that, The copper salt includes copper nitrate.
9. An adsorbent, characterized in that, Including the copper-based metal-organic framework material as described in any one of claims 1 to 3.
10. The application of the copper-based metal-organic framework material according to any one of claims 1 to 3, or the adsorbent according to claim 9, in the adsorption of ammonia.