A copper nanoparticle-modified metal-organic framework catalyst and its preparation method
By preparing a copper nanoparticle-modified metal-organic framework catalyst Cu-NPs@Zn-MOF, the problems of noble metal participation and solvent requirements in the prior art were solved, and the cycloaddition reaction of CO2 with propyne amine substrates was achieved under mild conditions with high yield and good catalyst stability.
Patent Information
- Application Number
- CN202610537383.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-04-22
- Publication Date
- 2026-05-26
AI Technical Summary
Existing catalysts require the participation of precious metals, are not mild enough, have low catalytic efficiency, and require organic solvents and base additives in the cycloaddition reaction of carbon dioxide with propyne amine substrates, resulting in high cost and a lack of environmental friendliness.
Oxazolidinone was prepared by catalyzing the cycloaddition reaction of CO2 with propyneamine substrates at room temperature using a copper nanoparticle-modified metal-organic framework catalyst Cu-NPs@Zn-MOF in a solvent-free and alkali-free manner.
It achieved efficient catalytic cycloaddition reaction of CO2 with propyne amine substrates under mild conditions, with a yield of over 80%. The catalyst maintained 91% catalytic efficiency after 10 cycles, reducing production costs.
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Figure CN122076525A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the fields of materials chemistry and chemical engineering, specifically relating to a nano-copper modified metal-organic framework catalyst and its preparation method. Background Technology
[0002] The continued global consumption of fossil fuels has led to a significant increase in carbon dioxide emissions, causing serious climate and environmental problems. Oxazolidinones, produced by the cyclization addition reaction of carbon dioxide with propyne amine substrates, are important intermediates with wide applications in the pharmaceutical field, and this reaction is also a promising carbon dioxide conversion pathway. However, the thermodynamic stability and kinetic inertness of carbon dioxide require harsh conditions for this reaction, such as high temperature, pressure, and organic solvents. Therefore, achieving the capture and catalytic conversion of carbon dioxide to oxazolidinones under mild and green conditions is particularly important for contributing to the "dual carbon" goals and sustainable development.
[0003] Metal-organic frameworks (MOFs) are widely used in gas separation and catalysis due to their advantages such as open metal active sites, high specific surface area, tunable pore size, and good adsorption capacity. Regarding the enhancement of catalytic activity for carbon dioxide, literature reports typically utilize noble metal-modified MOFs (such as silver and palladium) to achieve the cycloaddition reaction of carbon dioxide with propyneamine substrates under mild conditions. However, the involvement of noble metals in the preparation of these catalytic materials increases conversion costs. A few studies have reported that monovalent copper-based MOFs have achieved the above reaction under mild conditions, but monovalent copper is prone to deterioration in air, which may reduce the efficiency of the catalyst. Overall, these catalysts often face problems such as insufficiently mild reaction conditions, low catalytic efficiency, and the need for organic solvents, especially the use of alkaline additives.
[0004] Therefore, there is an urgent need to develop a metal-organic framework catalyst that is simple to prepare, inexpensive, stable, green, and efficient, and to use it for the cycloaddition reaction of CO2 with propyneamine substrates. Summary of the Invention
[0005] In view of the above shortcomings, the purpose of this invention is to provide a method for preparing a copper nanoparticle-modified metal-organic framework catalyst and its application, so as to solve the problems in the prior art of catalyzing the cycloaddition reaction of CO2 with propyneamine substrates, which requires the participation of noble metals, the conditions are not mild enough, the catalytic efficiency is low, and the additives such as organic solvents and bases are required.
[0006] To achieve the above-mentioned technical effects, the present invention adopts the following technical solution:
[0007] This invention first discloses a method for preparing a copper nanoparticle-modified metal-organic framework catalyst, comprising the following steps:
[0008] (1) 1.12 g of 3,6-bis(1H-imidazol-1-yl)o-phenylenediamine, 1.23 g of 1,10-phenanthroline-5,6-dione and 2.00 g of potassium carbonate were reacted in 100 mL of anhydrous methanol at 70 °C for 18 hours to prepare ligand A.
[0009] (2) Dissolve 2.5g of 1,8-naphthalenedicarboxylic anhydride and 2.7g of 5-aminoisophthalic acid in 40mL of anhydrous N,N-dimethylformamide (DMF) and react at 120℃ for 12 hours to prepare ligand B.
[0010] (3) The solute is a mixture of ligand A, ligand B and Zn(NO3)2·6H2O. The solvent is added to dissolve the mixture in a polytetrafluoroethylene hydrothermal reactor. The resulting mixture is placed in an oven for reaction and then slowly cooled to room temperature (25℃) to obtain zinc metal-organic framework (Zn-MOF).
[0011] (4) Zn-MOF was then dispersed in water, and Cu(CH3COO)2·H2O and hydrazine hydrate were added sequentially to react and prepare a nano-copper modified metal-organic framework catalyst Cu-NPs@Zn-MOF that can catalyze the cycloaddition of CO2 with propyne amine substrates.
[0012] Furthermore, in step (3), the mass ratio of ligand A, ligand B and Zn(NO3)2·6H2O is 4.5:10.4:14.8.
[0013] Furthermore, the molar ratio of ligand A, ligand B and Zn(NO3)2·6H2O in step (3) is 2:1:4.
[0014] Furthermore, the solvent in step (3) is a mixed solution of acetonitrile and pure water in a volume ratio of 2:12.
[0015] Furthermore, the mass-volume ratio of solute to solvent in step (3) is 29.7 mg:14 mL.
[0016] Furthermore, the reaction conditions in the oven described in step (3) are: temperature 160℃, reaction time 48h.
[0017] Furthermore, in step (4), the mass ratio of Zn-MOF, Cu(CH3COO)2.H2O, and hydrazine hydrate is 96:57:210.
[0018] Furthermore, in step (4), the mass-to-volume ratio of Zn-MOF to water is 96 mg:30 mL.
[0019] Furthermore, the reaction conditions in step (4) are: 80℃ for 2 hours.
[0020] The present invention also discloses a nano-copper modified metal-organic framework catalyst prepared according to any of the above preparation methods.
[0021] This invention also discloses the application of the above-mentioned copper nanoparticle-modified metal-organic framework catalyst in the cycloaddition of CO2 with propyneamine substrates to prepare oxazolidinone.
[0022] Furthermore, the application includes: adding a propyne amine substrate to a reactor, introducing CO2, adding a metal-organic framework catalyst, and carrying out catalytic conversion at room temperature, without solvents or alkali additives, for a reaction time of 15 h, with a yield of over 80%.
[0023] Furthermore, the catalytic yield of the metal-organic framework catalyst is not less than 91% after being recycled 10 times.
[0024] The beneficial effects of this invention are:
[0025] 1. This invention provides a method for preparing a copper nanoparticle-modified metal-organic framework catalyst. The preparation method is simple, and the prepared Cu-NPs@Zn-MOF has good thermal stability.
[0026] 2. The Cu-NPs@Zn-MOF prepared by this invention exhibits good / excellent catalytic efficiency for different propyne amine substrates under the conditions of room temperature, reaction time of 15 h, no solvent, and no alkali additive, with a yield of over 80%, and good catalytic applicability.
[0027] 3. The Cu-NPs@Zn-MOF prepared by this invention has good catalytic stability. After 10 cycles, the catalytic yield can still reach 91%, reducing production costs. Attached Figure Description
[0028] The invention will now be further described with reference to the accompanying drawings.
[0029] Figure 1 This is a schematic diagram of the structure of ligand A and ligand B in Embodiment 1 of the present invention;
[0030] Figure 2 This is a schematic diagram of the coordination environment of Zn-MOF in Embodiment 1 of the present invention;
[0031] Figure 3 This is a schematic diagram of the two-dimensional structure of Zn-MOF in Embodiment 1 of the present invention;
[0032] Figure 4 This is a scanning electron microscope image of Cu-NPs@Zn-MO in Embodiment 1 of the present invention;
[0033] Figure 5This is the powder diffraction pattern of Cu-NPs@Zn-MO in Example 1 of this invention;
[0034] Figure 6 This is the X-ray photoelectron spectrum of Cu-NPs@Zn-MO in Example 1 of this invention;
[0035] Figure 7 This is the thermogravimetric curve of Cu-NPs@Zn-MOF in Embodiment 2 of the present invention;
[0036] Figure 8 This is a schematic diagram of the N2 isotherm of Cu-NPs@Zn-MOF in Embodiment 3 of the present invention;
[0037] Figure 9 This is a graph showing the relationship between the amount of alkali used and the catalytic CO2 carboxylation-cyclization efficiency in Example 4 of the present invention;
[0038] Figure 10 This is a graph showing the relationship between different amounts of the catalyst Cu-NPs@Zn-MOF and the catalytic efficiency of CO2 carboxylation and cyclization in Example 4 of this invention.
[0039] Figure 11 This is a graph showing the relationship between different reaction times and the catalytic CO2 carboxylation-cyclization efficiency in Example 4 of this invention;
[0040] Figure 12 This is a graph showing the relationship between different cycle numbers of the catalyst Cu-NPs@Zn-MOF and the catalytic CO2 carboxylation and cyclization efficiency in Example 18 of this invention. Detailed Implementation
[0041] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.
[0042] Example 1
[0043] A method for preparing Cu-NPs@Zn-MOF includes the following steps:
[0044] A mixture of 3,6-bis(1H-imidazol-1-yl)o-phenylenediamine (3.3 g, 12.4 mmol) and 1,10-phenanthroline-5,6-dione (3.7 g, 16.8 mmol) was added to 100 mL of CH3OH, followed by 2 g of K2CO3. The reaction was carried out at 90 °C for 18 h under a nitrogen atmosphere. The mixture was filtered while hot, and the residue was washed with hot water at 90 °C and methanol to obtain ligand A.
[0045] Ligand B was prepared by dissolving 2.5 g of 1,8-naphthalenedicarboxylic anhydride and 2.7 g of 5-aminoisophthalic acid in 40 mL of dry DMF and reacting at 120 °C for 12 hours.
[0046] Ligand A (10.4 mg), ligand B (4.5 mg), and Zn(NO3)2·6H2O (14.8 mg) were added to a 25 mL polytetrafluoroethylene reactor. The solutes were dissolved and dispersed using a mixture of 2 mL acetonitrile and 12 mL pure water as solvents. The reactor was placed in an oven and reacted at 160 °C for 48 h. The mixture was then slowly cooled to room temperature to obtain a zinc metal-organic framework (Zn-MOF).
[0047] 95.66 mg of Zn-MOF was dispersed in 30 mL of deionized water, and 3 mL of Cu(CH3COO)2·H2O aqueous solution was added dropwise with stirring. Then, 150 μL of hydrazine hydrate was added to the reaction mixture. The reaction was carried out at 80 °C for 2 h. After cooling the mixture to room temperature, unreacted hydrazine hydrate was thoroughly washed with water and methanol to remove it, and the mixture was dried under vacuum at 80 °C for 12 h to obtain Cu-NPs@Zn-MOF.
[0048] Schematic diagrams of ligand A and ligand B are shown below. Figure 1 As shown in the diagram. A schematic diagram of the coordination environment of Zn-MOF is shown below. Figure 2 As shown, the two-dimensional structure diagram is as follows: Figure 3 As shown, this zinc metal-organic framework belongs to the monoclinic crystal system, with the space group symbol P21 / c. Each asymmetric unit of the zinc metal-organic framework contains one Zn atom. 2+ There is one ligand A and one ligand B. The four coordinating atoms of Zn1 (N2, N8, N9, O3, O6) come from two ligand A molecules and one ligand B molecule, respectively.
[0049] The prepared Cu-NPs@Zn-MOF was analyzed by scanning electron microscopy (SEM). The SEM images are shown below. Figure 4 As shown, Cu-NPs@Zn-MOF has a rod-like shape, with copper nanoparticles attached to its surface and interior.
[0050] Powder diffraction (PXRD) analysis was performed on the prepared Cu-NPs@Zn-MOF. The PXRD pattern is shown below. Figure 5 As shown, this illustrates the preservation of the material's framework structure and the successful modification with nano-copper particles.
[0051] X-ray photoelectron spectroscopy (XPS) analysis was performed on the prepared Cu-NPs@Zn-MOF. The XPS plot is shown below. Figure 6 As shown, this demonstrates the successful modification of copper nanoparticles.
[0052] Example 2
[0053] Thermal stability testing of Cu-NPs@Zn-MOF
[0054] Thermogravimetric analysis was performed on the Cu-NPs@Zn-MOF prepared in Example 1 under an argon atmosphere, as follows: Figure 7 As shown, the weight loss of Cu-MOF between 30℃ and 220℃ is 7.37% (theoretical value 6.7%, corresponding to 4 free water molecules). When the temperature exceeds 350℃, significant weight loss begins to occur, indicating that the crystal structure begins to collapse. Experimental results demonstrate that Cu-MOF possesses good thermal stability.
[0055] Example 3
[0056] N2 isothermal adsorption performance test of Cu-NPs@Zn-MOF
[0057] Isothermal performance tests were conducted on N2 at room temperature and 100 kPa, revealing a maximum adsorption capacity of 27.51 cm³. 3 / g, the BET calculated value is 7.0722 m² / g, such as Figure 8 As shown.
[0058] Example 4
[0059] Effect of different alkali dosages on the efficiency of CO2 carboxylation and cyclization catalyzed by Cu-NPs@Zn-MOF
[0060] The effect of the amount of DBU as a base promoter on the efficiency of CO2 carboxylation and cyclization was investigated. The amounts of DBU were 0, 0.05 mmol, 0.1 mmol, 0.15 mmol, and 0.2 mmol, respectively. The catalytic conditions were 1 mmol benzyl-2-propynylamine, 1 atm CO2, 2 mol% Cu-MOF, and the reaction was carried out at room temperature for 15 hours. After the reaction was completed, the conversion of the reactants was determined by 1H NMR spectroscopy.
[0061] Figure 9 The graph shows the relationship between the catalytic efficiency of Cu-NPs@Zn-MOF prepared in Example 1 and the amount of DBU used for CO2 carboxylation and cyclization. It can be seen from the graph that when the DBU amount is 0, the CO2 carboxylation and cyclization reaction still reaches 92%, indicating that the catalyst itself plays a promoting role in the CO2 carboxylation and cyclization reaction. As the DBU amount gradually increases, the product yield does not increase significantly. Considering the greenness of the reaction, DBU is not used in the reaction.
[0062] Example 5
[0063] Effect of Cu-NPs@Zn-MOF dosage on the catalytic efficiency of CO carboxylation cyclization
[0064] The effect of Cu-NPs@Zn-MOF dosage on the catalytic efficiency of CO2 carboxylation and cyclization was investigated. The dosages of Cu-NPs@Zn-MOF were 0%, 1 mol%, 2 mol%, 3 mol%, and 4 mol%. The catalytic conditions were 1 mmol benzyl-2-propynylamine, 1 atm CO2, and 15 hours at room temperature. The yield of the reactants was determined by proton nuclear magnetic resonance spectroscopy after the reaction was completed.
[0065] Figure 10 The graph shows the relationship between the amount of Cu-NPs@Zn-MOF prepared in Example 1 and the catalytic efficiency of CO2 carboxylation and cyclization. As can be seen from the graph, the yield of the product oxazolidinone increases sharply from 0 to 1 mol% and then remains stable. Specifically, when the Cu-MOF amount is 1 mol%, the oxazolidinone yield reaches 92%. Further increases in the amount of Cu-NPs@Zn-MOF do not lead to a further increase in yield.
[0066] Example 6
[0067] Effect of different reaction times on the efficiency of CO2 carboxylation and cyclization catalyzed by Cu-NPs@Zn-MOF
[0068] Figure 11 To investigate the effect of reaction time on the efficiency of Cu-NPs@Zn-MOF-catalyzed CO2 cycloaddition, the catalytic conditions were 1 mmol benzyl-2-propynylamine, 1 atm CO2, and 1 mol% Cu-NPs@Zn-MOF. The reaction was carried out at room temperature, and the reaction was stopped at 12, 15, 18, and 24 h. The product conversion was determined by 1H NMR spectroscopy. The graph shows that as the reaction time increased from 12 h to 15 h, the yield of the oxazolidinone product reached a maximum of 97% and then remained stable. Further increasing the reaction time did not lead to a further increase in yield.
[0069] Examples 7-17
[0070] Application of a nano-copper modified metal-organic framework catalyst in the catalytic production of oxazolidinone from CO2.
[0071] As shown in Examples 4-6, the optimal reaction conditions for the cycloaddition reaction of CO2 catalyzed by Cu-NPs@Zn-MOF prepared in Example 1 are as follows: 1 mmol of benzyl-2-propynylamine is added to the reactor, 1 atm of CO2 and 1 mol% of Cu-NPs@Zn-MOF prepared in Example 1 are introduced, and the reaction is carried out at room temperature for 15 hours. The final product conversion rate reaches 97%, indicating that under these conditions, Cu-NPs@Zn-MOF exhibits excellent catalytic performance in the CO2 carboxylation and cyclization reaction, with mild catalytic conditions and high catalytic yield.
[0072] The Cu-NPs@Zn-MOF prepared in Example 1 was used to catalyze the cycloaddition reactions of different propyneamines and CO2.
[0073] The structural formulas and final conversion rates of the substrates and products in Examples 7-17 and the comparative examples are shown in Table 1;
[0074] Table 1
[0075]
[0076] The conversion rate is determined by 1 H NMR analysis showed that, as shown in Table 1, the catalyst exhibited strong catalytic efficiency for all propargylamine substrates, with yields ranging from 80% to 97% for different substrates, indicating that its catalytic performance has good general applicability.
[0077] Example 18
[0078] Cu-MOF cyclic catalytic performance test
[0079] The carboxylation cyclization reaction of CO2 with benzyl-2-propynylamine was carried out using Cu-NPs@Zn-MOF prepared in Example 1 as a catalyst. The stability and recycling characteristics of Cu-NPs@Zn-MOF were investigated. In the cyclic catalysis process, after one catalytic cyclization reaction, Cu-NPs@Zn-MOF was centrifuged, washed with ethanol, vacuum dried, and then subjected to the next round of catalytic cyclization reaction. This process was repeated 10 times. The results are as follows: Figure 12 As shown. By Figure 12 It can be seen that the yield decreases slightly with the increase of Cu-NPs@Zn-MOF catalysis cycles. This may be due to the adhesion of solvents and compounds to the metal-organic framework channels or continuous long-term stirring, which leads to a slight reduction in the Cu-NPs attached to Cu-NPs@Zn-MOF. However, the crystal still maintains a good stable structure, and the catalytic efficiency can still reach 91% after 10 cycles, indicating that the nano-copper modified metal-organic framework catalyst prepared in this invention also has excellent cyclic catalytic ability.
[0080] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.
[0081] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.
Claims
1. A method for preparing a copper nanoparticle-modified metal-organic framework catalyst, comprising: (1) 1.12 g of 3,6-bis(1H-imidazol-1-yl)o-phenylenediamine, 1.23 g of 1,10-phenanthroline-5,6-dione and 2.00 g of potassium carbonate were reacted in 100 mL of anhydrous methanol at 70 °C for 18 hours to prepare ligand A; (2) Dissolve 2.5g of 1,8-naphthalenedicarboxylic anhydride and 2.7g of 5-aminoisophthalic acid in 40mL of anhydrous N,N-dimethylformamide and react at 120℃ for 12 hours to prepare ligand B; (3) The solute is a mixture of ligand A, ligand B and Zn(NO3)2·6H2O. The solvent is added to dissolve the mixture in a polytetrafluoroethylene hydrothermal reactor. The resulting mixture is placed in an oven for reaction and then slowly cooled to room temperature to obtain zinc metal-organic framework Zn-MOF. (4) Subsequently, the metal-organic framework Zn-MOF was dispersed in water, and Cu(CH3COO)2·H2O and hydrazine hydrate were added in sequence to react and prepare a nano-copper modified metal-organic framework catalyst Cu-NPs@Zn-MOF.
2. The preparation method according to claim 1, wherein: In step (3), the mass ratio of ligand A, ligand B, and Zn(NO3)2·6H2O is 4.5:10.4:14.
8. The molar ratio of ligand A, ligand B and Zn(NO3)2·6H2O is 2:1:
4.
3. The preparation method according to claim 1, wherein: The solvent in step (3) is a mixed solution of acetonitrile and pure water in a volume ratio of 2:12; The mass-to-volume ratio of the solute to the solvent is 29.7 mg:14 mL.
4. The preparation method according to claim 1, wherein: The reaction conditions in the oven in step (3) are: temperature 160℃, reaction time 48h.
5. The preparation method according to claim 1, wherein: The mass ratio of Zn-MOF, Cu(CH3COO)2.H2O, and hydrazine hydrate in step (4) is 96:57:210; The mass-to-volume ratio of Zn-MOF to water is 96 mg:30 mL.
6. The preparation method according to claim 1, wherein: The reaction conditions described in step (4) are: 80℃ for 2 hours.
7. A nano-copper modified metal-organic framework catalyst prepared by any one of the preparation methods according to claims 1 to 6.
8. The application of a nano-copper modified metal-organic framework catalyst according to claim 7 in the catalytic cycloaddition of CO2 with propyneamine substrates to prepare oxazolidinone.
9. The application according to claim 8, comprising: A propyne amine substrate was added to the reactor, CO2 was introduced, and a metal-organic framework catalyst was added. The catalytic conversion was carried out at room temperature, without solvents or alkali additives, for 15 h, with a yield of over 80%.
10. The application according to claim 8 or 9, wherein: The metal-organic framework catalyst, after being recycled 10 times, has a catalytic yield of no less than 91%.