Two-dimensional bio-based MOF nano material as well as preparation method and application thereof
By preparing two-dimensional bio-based MOF nanomaterials and using TBAB as an auxiliary agent to synergistically catalyze the reaction of CO2 with epoxy substrates, the problem of poor stability of existing MOF catalysts under high temperature, high pressure and acid-base conditions was solved, and efficient catalytic conversion of CO2 into cyclic carbonates was achieved under mild conditions.
Patent Information
- Application Number
- CN202511006491.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-22
- Publication Date
- 2025-11-11
AI Technical Summary
Existing MOF catalysts require high temperature and high pressure conditions to catalyze the conversion of CO2 into cyclic carbonates, and their stability is poor under water or acid-base conditions, which limits their application range.
A method for preparing two-dimensional bio-based MOF nanomaterials was adopted, using L-carnosine as a ligand to prepare MOF nanomaterials with specific structures through a solvothermal reaction, and then co-catalyzing the reaction of CO2 with an epoxy substrate with TBAB as an auxiliary agent to generate cyclic carbonates.
High catalytic activity and stability are achieved under mild conditions, with selectivity and yield of cyclic carbonates reaching 99% and 92%-97%, respectively, and good biocompatibility and environmental friendliness.
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Figure CN120923802A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to MOF nanomaterials, specifically to a two-dimensional bio-based MOF nanomaterial, its preparation method, and its applications. Background Technology
[0002] Rapid industrialization has led to the massive combustion of fossil fuels, causing a surge in atmospheric carbon dioxide (CO2) levels and triggering a series of ecological and environmental problems. CO2 emission reduction and utilization have become urgent (Chemical Engineering Journal, 2025, 505, 158951). There are two main ways to reduce atmospheric CO2 levels: carbon capture and storage (CCS) and carbon capture and utilization (CCU). CCU technology is an effective method for carbon utilization, converting CO2 into high-value-added chemicals, promoting the recycling of carbon resources and economic development, which aligns closely with the principles of sustainable and green chemistry (Fuel, 2023, 332, 125972). CO2 is a thermodynamically stable molecule, requiring high energy to activate its C=O bonds, which means that the catalytic conversion of CO2 often faces harsh reaction conditions. Therefore, developing novel and efficient catalytic systems to achieve CO2 conversion under mild conditions is crucial (Journal of Energy Chemistry, 2025, 105, 54-56).
[0003] In recent years, metal-organic frameworks (MOFs) have proven to be effective adsorbents for CO2 capture and have been widely studied as highly efficient catalysts for the conversion of CO2 to cyclic carbonates (Chemical Engineering Journal, 2025, 506, 160371). MOFs can improve CO2 conversion efficiency by optimizing the structure and performance of catalysts through tuning the properties of Lewis acid centers and organic linking ligands. Despite the great potential of MOFs in CO2 catalytic conversion, several challenges remain, typically requiring high temperature or high pressure conditions for CO2 conversion. Furthermore, some MOFs exhibit poor stability under aqueous or acidic / alkaline conditions, limiting their application scope.
[0004] Therefore, developing green and economical MOF catalysts with high catalytic activity and stability under mild conditions (low temperature and normal pressure) remains a challenge. Summary of the Invention
[0005] The technical problem to be solved by the present invention is to provide a method for preparing two-dimensional bio-based MOF nanomaterials. The MOF nanomaterials with specific structures obtained by the method can be used as catalysts in the reaction of catalyzing the conversion of CO2 into cyclic carbonates. They can exhibit high catalytic activity under mild reaction conditions, as well as high stability and high conversion rate.
[0006] The technical solution adopted by this invention to solve its technical problem is a method for preparing two-dimensional bio-based MOF nanomaterials, comprising the following steps:
[0007] L-carnosine was dissolved in deionized water, and concentrated ammonia and DMF solution were added and sonicated to mix evenly. Then, a soluble metal salt solution was added dropwise, and after thorough mixing, a solvothermal reaction was carried out. After the reaction was completed, the solid and liquid were separated and dried to obtain the two-dimensional bio-based MOF nanomaterial.
[0008] The structural formula of L-carnosine is as follows:
[0009] In some embodiments, the molar ratio of the soluble metal salt to L-carnosine is 0.8-1.2.
[0010] In some embodiments, the soluble metal salt is a soluble salt of manganese, iron, cerium, or cobalt. Specifically, the soluble metal salt includes, but is not limited to, nitrates, chlorides, and acetates of manganese, iron, cerium, and cobalt.
[0011] In some embodiments, the concentration of the concentrated ammonia solution is 25-29 wt%.
[0012] In some embodiments, the temperature of the solvothermal reaction is 80-120°C.
[0013] In some embodiments, the rate of addition of the soluble metal salt is 10-20 ml / min.
[0014] The present invention also provides MOF nanomaterials obtained by the preparation method of any of the above embodiments.
[0015] This invention also provides the application of the above-mentioned MOF nanomaterials as catalysts in the catalytic reaction of CO2 with epoxy substrates to synthesize cyclic carbonates.
[0016] In some embodiments, the MOF nanomaterial is used as a catalyst in the catalytic reaction of CO2 with an epoxy substrate to synthesize cyclic carbonates as follows:
[0017] The MOF nanomaterials were mixed with TBAB (tetrabutylammonium bromide) as an additive, and then added to a reaction system of carbon dioxide and epoxy substrate to generate cyclic carbonates.
[0018] In some embodiments, the mass ratio of the MOF nanomaterial to TBAB in the application method is 1:4; the mass ratio of the MOF nanomaterial to the epoxy substrate is 1:30.
[0019] In some embodiments, the reaction temperature is 60-80°C and the CO2 pressure is 0.1-0.5 MPa.
[0020] In some implementations, the reaction time is 12-24 hours.
[0021] Compared with the prior art, the beneficial effects of the present invention are as follows:
[0022] This invention uses L-carnosine with a specific structure as a ligand to prepare MOF nanomaterials under specific process conditions. The MOF nanomaterials prepared by the method of this invention have the characteristics of low toxicity, good biocompatibility, environmental friendliness and low cost, which are in line with the concept of "green chemistry". Moreover, the preparation method is simple, easy to operate and highly controllable.
[0023] The obtained MOF nanomaterials were used as catalysts in the reaction of CO2 with epoxy substrates to synthesize cyclic carbonates. Due to their specific ligand structures, MOF nanomaterials have numerous readily accessible active sites, which enhances their ability to catalyze the conversion of larger substrate molecules. This allows the reaction to proceed under mild, solvent-free conditions with excellent conversion efficiency and selectivity. The synergistic effect of the MOF nanomaterials with TBAB co-catalysts efficiently catalyzes the conversion of CO2 and larger epoxy substrates to produce cyclic carbonates, achieving excellent conversion rates, selectivity, and reusability under mild, solvent-free conditions. The selectivity and yield of cyclic carbonates can reach as high as 99% and 92%-97%, respectively, demonstrating excellent catalytic conversion performance and promising practical applications. Attached Figure Description
[0024] Figure 1 The infrared spectrum of the M-Car MOF nanomaterial prepared in Example 1 of this invention;
[0025] Figure 2 This is a transmission electron microscope image of the Co-Car MOF two-dimensional nanomaterial prepared in Example 1 of this invention;
[0026] Figure 3 This is a graph showing the effect of reaction temperature on the conversion of CO2 by the Co-Car MOF two-dimensional nanomaterials obtained in Example 1 of this invention;
[0027] Figure 4 This is a graph showing the catalyst dosage for CO2 conversion using the Co-Car MOF two-dimensional nanomaterials obtained in Example 1 of this invention;
[0028] Figure 5 This is a graph showing the amount of co-catalyst used to convert CO2 using the Co-Car MOF two-dimensional nanomaterials obtained in Example 1 of this invention;
[0029] Figure 6This is a graph showing the effect of reaction time on the conversion of CO2 by the Co-Car MOF two-dimensional nanomaterial obtained in Example 1 of this invention. Detailed Implementation
[0030] The present invention will be further described below with reference to specific embodiments.
[0031] 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 invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.
[0032] Unless otherwise specified, the reagents and materials used in the following examples were obtained through ordinary commercial channels or prepared by common conventional methods.
[0033] Example 1
[0034] The preparation method of M-Car MOF nanomaterials in this embodiment is as follows:
[0035] Taking Co-Car MOF as an example, L-Car (L-carnosine) ligand (0.64 mmol, 144.8 mg) was dissolved in 8 mL of deionized water, and then 80 μL of concentrated ammonia and 12 mL of DMF solution were added. The mixture was sonicated to make it homogeneous and a mixed solution was obtained.
[0036] Co(NO3)2·6H2O (0.64 mmol, 190.4 mg) was dissolved in 4 mL of deionized water to obtain a metal solution. The metal solution was slowly added dropwise (10 mL / min) to the above mixed solution. After mixing and sonicating, the mixture was placed in an oven and reacted at 100 °C for 48 h. After the reaction was completed, the mixture was washed, centrifuged, and dried to obtain a purple-red solid powder (Co-Car nanomaterial).
[0037] Mn-Car, Fe-Car, and Ce-Car nanomaterials were prepared using MnCl2·6H2O, FeCl3·6H2O, and Ce(NO3)3·6H2O, respectively, according to the same method.
[0038] Infrared spectroscopy was performed on the M-Car MOFs of this embodiment, and the results are as follows: Figure 1 As shown, 1660cm is clearly visible. -1 and 1407cm -1 The peaks at the left and right are characteristic of the asymmetric vibration of the carboxyl group in L-carnosine, and are associated with metal ions (Co). 2+ Mn 2+ Fe 3+ Ce 3+After coordination, the characteristic absorption peak of the carboxyl group red-shifts to 1635 cm⁻¹. -1 and 1384cm -1 Left and right sides. 3250cm -1 The distinct absorption peak at 1100 cm⁻¹ is attributed to the asymmetric stretching vibration of the amino group in L-carnosine. After coordination with the metal, the stretching vibration peak belonging to NH disappears. Meanwhile, the peak at 1100 cm⁻¹... -1 The stretching vibration of CN shifted to 1078 cm. -1 This indicates that amino groups may coordinate with metals.
[0039] Transmission electron microscopy was performed on the M-Car MOFs of this embodiment. Taking Car-Co MOFs as an example, the results are as follows: Figure 2 As shown.
[0040] The following is an application experiment of M-Car MOFs as a catalyst in this embodiment: The M-Car MOFs were mixed with TBAB co-catalyst to synergistically catalyze the conversion of CO2 with an epoxy substrate to produce cyclic carbonates; the specific method is as follows:
[0041] 4 mg of M-Car MOF catalyst, 16 mg of TBAB (tetrabutylammonium bromide) and 1 mmol of styrene oxide were added to a 10 mL side-mounted flask and the mixture was heated to 80 °C under the action of 1 atm (0.101 MPa) CO2 for 12 h.
[0042] In this study, Co-Car MOF was used as the catalyst, and the effects of different temperatures, catalyst dosage, TBAB dosage, and reaction time on the reaction were investigated. When one of the conditions (such as reaction temperature) was used as a variable, the other reaction conditions (such as catalyst dosage, co-catalyst dosage, and reaction time) remained unchanged.
[0043] The effect of temperature on the reaction: experimental results are as follows Figure 3 As shown;
[0044] The effect of catalyst dosage on the reaction: Experimental results are as follows Figure 4 As shown;
[0045] The effect of co-catalyst dosage on the reaction: Experimental results are as follows Figure 5 As shown;
[0046] The effect of reaction time on the reaction: Experimental results are as follows Figure 6 As shown.
[0047] In summary, the optimal process conditions for M-Car MOFs as catalysts to catalyze the reaction of CO2 with styrene oxidation to cyclic carbonates are as follows:
[0048] 4 mg of M-Car MOF catalyst, 16 mg of TBAB (tetrabutylammonium bromide) and 1 mmol of styrene oxide were added to a 10 mL side-mounted flask and the mixture was heated to 80 °C under 1 atm CO2 and reacted for 12 h.
[0049] The M-Car MOF nanomaterials prepared in this embodiment were used as catalysts to catalyze the reaction of CO2 with styrene oxide to form cyclic carbonates. The reaction results are shown in Table 1.
[0050] Table 1. Catalytic effect of M-Car MOFs on the reaction of CO2 with styrene oxide to form cyclic carbonates.
[0051]
[0052] As shown in Table 1, all four carnosine-based MOFs can achieve efficient CO2 cycloaddition of sterically hindered epoxy substrates (styrene oxide) under mild conditions, with selectivity and yield reaching 99% and 71%-92%, respectively. Among them, the Co-Car MOF catalyst showed the best performance, with selectivity and yield of 99% and 92%, respectively.
[0053] Example 2
[0054] 4 mg of Co-Car MOF catalyst, 16 mg of TBAB (tetrabutylammonium bromide) and 1 mmol of different epoxy substrates were added to a 10 mL side-mounted flask and reacted for 12 h at 1 atm CO2 and 80 °C. The reaction results are shown in Table 2.
[0055] Table 2. Catalytic effect of Co-Car on the reaction of CO2 with different epoxides on cyclic carbonates.
[0056]
[0057]
[0058] As shown in Table 2, the Co-Car two-dimensional bio-based MOF catalytic system can achieve efficient CO2 cycloaddition of low-sterically hindered and high-sterically hindered epoxide substrates under mild conditions (60-80℃, 1 atm CO2), with yields of 96%-97% and 84%-96%, respectively. Even cyclohexane oxide, a sterically hindered internal epoxide, achieved a yield of 37%. This demonstrates that the MOF nanomaterials of this invention exhibit excellent catalytic performance in the reaction of CO2 with cyclic carbonates containing epoxides.
[0059] 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.
[0060] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the contents of the claims.
Claims
1. A method for preparing two-dimensional bio-based MOF nanomaterials, characterized in that, Includes the following steps: L-carnosine was dissolved in deionized water, and concentrated ammonia and DMF solution were added and sonicated to mix evenly. Then, a soluble metal salt solution was added dropwise, and after thorough mixing, a solvothermal reaction was carried out. After the reaction was completed, the solid and liquid were separated and dried to obtain the two-dimensional bio-based MOF nanomaterial. The structural formula of L-carnosine is as follows:
2. The method for preparing two-dimensional bio-based MOF nanomaterials according to claim 1, characterized in that, The molar ratio of the soluble metal salt to L-carnosine is 0.8-1.
2.
3. The method for preparing two-dimensional bio-based MOF nanomaterials according to claim 1 or 2, characterized in that, The soluble metal salt is a soluble salt of manganese, iron, cerium, or cobalt.
4. The method for preparing two-dimensional bio-based MOF nanomaterials according to claim 1 or 2, characterized in that, The temperature for the solvothermal reaction is 80-120℃.
5. The method for preparing two-dimensional bio-based MOF nanomaterials according to claim 1 or 2, characterized in that, The rate of adding soluble metal salts is 10-20 ml / min.
6. MOF nanomaterials prepared by the preparation method according to any one of claims 1-5.
7. The application of the MOF nanomaterial as described in claim 6 as a catalyst in the catalytic reaction of CO2 with epoxy substrates to synthesize cyclic carbonates.
8. The application according to claim 7, characterized in that, The MOF nanomaterials were mixed with TBAB additives and then added to a system in which carbon dioxide and epoxy substrates reacted to generate cyclic carbonates.
9. The application according to claim 8, characterized in that, The mass ratio of the MOF nanomaterial to TBAB is 1:4; the mass ratio of the MOF nanomaterial to the epoxy substrate is 1:
30.
10. The application according to claim 8, characterized in that, The reaction temperature is 60-80℃, the CO2 pressure is 0.1-0.5MPa, and the reaction time is 12-24h.