Alkaline material modified metal organic framework material as well as preparation method and application thereof
The MOF material modified by alkaline material prepared by solvent-assisted ligand incorporation method solves the problem of low efficiency of MOF material degrading nerve agents in pure water environments, achieves rapid hydrolysis and efficient degradation, and promotes practical application.
Patent Information
- Application Number
- CN202510612731.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-13
- Publication Date
- 2025-08-01
AI Technical Summary
Existing MOF materials require high alkalinity and high volatile NEM buffers when catalyzing the degradation of nerve agents, which limits their use in practical applications and has low degradation efficiency in pure water environments.
Solvent-assisted ligand incorporation method (SALI) was used to bind the basic material L-Histidine to the Zr active center of MOF through covalent bonding to prepare a metal organic framework material modified with alkaline material. By adjusting the pH value of the microporous environment, the regeneration of the active site is achieved in pure water, and the binding of toxic products and active sites is avoided.
Rapid hydrolysis of nerve agents (half-life less than 30 seconds, complete degradation time within 10 minutes) is achieved in a pure water environment, which is close to the catalytic efficiency when adding NEM buffer, which promotes the possibility of MOF materials in actual protection applications.
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Figure CN120399259A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a metal-organic framework material modified with an alkaline material, a preparation method thereof and an application thereof, and belongs to the technical field of metal-organic framework materials. Background Art
[0002] Nerve agents such as sarin (GB), soman (GD) and VX, as well as blister agents such as sulfur mustard (HD), are the most representative toxic chemical agents. They are highly toxic and can cause serious harm or even fatal consequences to the human body in a short time. In order to address the serious threats they pose globally, the research on materials for the adsorption, separation and degradation of toxic chemical reagents has become crucial. Existing adsorption and degradation materials mainly include bleaching agents, metal oxides, biocatalysts and polyoxometalates, etc. However, due to poor stability, strong reaction conditions or slow degradation ability, these materials usually face application limitations.
[0003] Metal-organic frameworks (MOFs) are crystalline hybrid materials composed of metal nodes and polydentate organic ligands, and have advantages such as high porosity, large specific surface area and abundant active sites, and are widely used in catalysis, adsorption and separation. Among them, Zr-based MOFs contain metal clusters with a structure of Zr(IV)-OH-Zr(IV), which is similar to the Zn(II)-OH-Zn(II) active site in phosphotriesterase (PTE). Zr-MOF has become the best-performing catalyst for the rapid degradation of nerve agents and mimics.
[0004] It is worth noting that most studies have investigated the degradation of nerve agent / mimics catalyzed by MOF in N-ethylmorpholine (NEM) buffer. NEM is an important base for regulating the pH value during the catalytic process and regenerating the active Zr sites in MOF. Although the alkaline reaction medium has a relatively fast hydrolysis-assisted ability, due to its high alkalinity and high volatility, it makes NEM difficult to be applied to personal protective equipment and the destruction of stockpiled nerve agents, which limits the practical application of MOF materials. Summary of the Invention
[0005] To solve the contradiction between the necessity of the presence of a base and the limited practical application of alkaline buffers, the present invention provides a metal-organic framework material modified with an alkaline material, a preparation method thereof and an application thereof, and realizes the efficient hydrolysis of an organophosphorus nerve agent mimic in a pure water environment.
[0006] In order to achieve the above object, a preparation method of a metal-organic framework material modified with an alkaline material adopted by the present invention includes the following steps:
[0007] S1. Prepare MOF-808;
[0008] S2. Disperse MOF-808 in DMF containing L-Histidine, then place the mixture in a round-bottom flask, react for a period of time at a certain temperature, centrifuge to obtain a solid, wash it with DMF and MeOH respectively, and finally dry it under vacuum to obtain the metal-organic framework material modified with the basic material.
[0009] As an improvement, the specific steps of S1 include: adding zirconium oxychloride octahydrate and trimesic acid to a mixed solution of FA and DMF, putting it into a reaction kettle, putting on a metal shell, reacting in an oven, after cooling to room temperature, washing it with DMF and acetone respectively for multiple times, and activating it in a vacuum drying oven to obtain MOF-808.
[0010] As an improvement, the mass ratio of zirconium oxychloride octahydrate to trimesic acid is (9 - 10):(2 - 3); the volume ratio of FA to DMF is 1:1; react at 110 °C in the oven for 24 h; activate in a vacuum drying oven at 120 °C for 12 h.
[0011] As an improvement, the mass ratio of MOF-808 to L-Histidine in step S2 is (100 - 110):(40 - 50).
[0012] As an improvement, the reaction temperature in step S2 is 70 - 90 °C, and the reaction time is 40 - 50 h.
[0013] In the second aspect of the present invention, there is also provided a metal-organic framework material modified with a basic material, which is prepared by using the described preparation method.
[0014] In the third aspect of the present invention, there is also provided an application of the metal-organic framework material modified with the basic material in the catalytic degradation of dimethyl-4-nitrophenyl phosphate in a pure water system.
[0015] As an improvement, mix the metal-organic framework material modified with the basic material and dimethyl-4-nitrophenyl phosphate in an aqueous solution, and stir it.
[0016] As an improvement, the pure aqueous solution is composed of D2O and H2O mixed according to a volume ratio of 1:9.
[0017] As an improvement, the mass-volume ratio of the metal-organic framework material modified with the basic material, dimethyl-4-nitrophenyl phosphate and the pure aqueous solution is (5 - 10) mg:(5 - 7) mg:1 mL.
[0018] The mechanism of the present invention is:
[0019] After the alkaline material-modified metal-organic framework material of the present invention reacts with DMNP (dimethyl-4-nitrophenyl phosphate), the zirconium clusters in Zr-MOF (such as the Zr6 node in MOF-808) have a phosphotriesterase active site structure (such as Zr–OH–Zr), and its Lewis acidic site (Zr 4+ ) can bind to the phosphorus atom in the organophosphorus agent mimic DMNP, activate the electrophilicity of the phosphorus center through electron transfer, promote the cleavage of the phosphorus-oxygen bond (P-O bond), destroy the structure of DMNP, and convert it from a macromolecular toxic compound into a small molecule non-toxic compound, achieving the purpose of degrading DMNP.
[0020] Since the Zr active site on the MOF captures and hydrolyzes the nerve agent, its degradation product DMP will stably bind to the Zr active site, poisoning the MOF material and restricting the catalytic activity of the MOF material. The alkaline buffer solution can compete with its product (DMP) for the active site, realizing the regeneration of the Zr active site, avoiding the poisoning of the MOF material, and ensuring the catalytic activity of the MOF material. However, the commonly used NEM alkaline buffer solution has high volatility and toxicity, which is not conducive to practical applications. The present invention uses the Solvent-Assisted Ligand Incorporation (SALI) method to covalently bind L-His with a carboxyl functional group in the alkaline material to the Zr active center of the MOF. In a pure water environment, the modified alkaline material adjusts the pH of the microporous environment of the MOF, promoting the deprotonation of the active site without adding additional alkaline buffer solutions such as NEM, avoiding the binding of the hydrolysis product (DMP) of the nerve agent to the active site, and avoiding the poisoning of the MOF material.
[0021] The alkaline material-modified metal-organic framework material of the present invention can rapidly hydrolyze DMNP in a pure water environment (half-life less than 30 seconds and completely degrade DMNP within 10 minutes), approaching the catalytic efficiency of the MOF material in an environment with alkaline buffer solutions such as NEM, greatly promoting the possibility of the MOF material in practical protection applications.
[0022] Compared with the prior art, the beneficial effects of the present invention are:
[0023] (1) The alkaline material-modified metal-organic framework material is prepared by a two-step reaction, with simple synthesis and relatively high yield.
[0024] (2) The alkaline material-modified metal-organic framework material does not require additional addition of alkaline substances, has the advantages of large degradation amount and rapid response in a pure water system, and can completely degrade DMNP within 10 min when reacting with a DMNP solution. Description of the Drawings
[0025] The present invention will be further described below in conjunction with the accompanying drawings.
[0026] Figure 1 It is the scanning electron microscope spectrum of the MOF-808 metal framework material prepared in Example 1;
[0027] Figure 2 It is the scanning electron microscope spectrum of the MOF-808-[His]3 metal framework material prepared in Example 1;
[0028] Figure 3 It is the XRD spectrum of the MOF-808 and MOF-808-[His]3 metal framework materials prepared in Example 1;
[0029] Figure 4 It is the FTIR spectrum of the MOF-808 and MOF-808-[His]3 metal framework materials prepared in Example 1;
[0030] Figure 5 It is the BET spectrum of the MOF-808 and MOF-808-[His]3 metal framework materials prepared in Example 1;
[0031] Figure 6 It is of dimethyl-4-nitrophenyl phosphate prepared in Example 4 1 1H NMR spectrum;
[0032] Figure 7 It is of dimethyl-4-nitrophenyl phosphate prepared in Example 4 13 13C NMR spectrum;
[0033] Figure 8 It is the hydrolysis mechanism diagram of DMNP in Example 4;
[0034] Figure 9 It is the UV-vis spectrum of MOF-808-[His]3 hydrolyzing DMNP (25 μmol) in pure water environment in Example 4;
[0035] Figure 10 It is of MOF-808 and MOF-808-[His]3 hydrolyzing DMNP (25 μmol) in pure water environment 31 31P NMR spectrum;
[0036] Figure 11 It is the 31P NMR spectrum of MOF-808-[His]3 hydrolyzing DMNP (25 μmol) repeated three times in pure water environment 31 31P NMR spectrum. Detailed implementation manners
[0037] Next, in combination with the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.
[0038] Example 1
[0039] A preparation method of a metal-organic framework material modified with an alkaline material, comprising the following steps:
[0040] S1. Add zirconium oxychloride octahydrate (970 mg, 3 mmol) and trimesic acid (210 mg, 1 mmol) to a mixed solution of formic acid and N,N-dimethylformamide (FA and DMF volume ratio = 1:1), place it in a 100 mL polytetrafluoroethylene bottle, put on a metal shell, react at 110 °C in an oven for 24 h, after cooling to room temperature, wash it with DMF and acetone respectively for multiple times, and activate it in a vacuum drying oven at 120 °C for 12 h to obtain MOF-808;
[0041] S2. Disperse 106 mg (0.07 mmol) of MOF-808 in 8 mL of DMF containing 0.035 M L-Histidine (L-histidine, 44.4 mg), then place the mixture in a round-bottom flask, react the mixture at a constant temperature of 80 °C for 48 h, then obtain a solid by centrifugation (10000 × g, 5 min), wash it with DMF and MeOH three times respectively, and finally dry it in vacuum at 80 °C to prepare MOF-808-[His]3, that is, the metal-organic framework material modified with the alkaline material.
[0042] The MOF-808 and MOF-808-[His]3 prepared in Example 1 were respectively analyzed by scanning electron microscopy spectra, XRD spectra, FTIR spectra and BET spectra. Among them, the scanning electron microscopy spectra are as Figure 1 、 Figure 2 shown. The SEM images show that the synthesized MOFs are all octahedral in shape, the sizes of most MOF materials are about 300-500 nm, and the microcrystalline shape of the MOF does not change significantly after L-His modification, indicating that the MOF-808-[His]3 synthesized by the SALI method has good structural stability.
[0043] The XRD spectra are as Figure 3As shown in the figure, the diffraction peaks at 2θ = 8.30°, 8.69°, 9.92° and 10.93° are related to the (311), (222), (400) and (331) planes, respectively. The synthesized MOF-808 shows high structural crystallinity and verifies the phase purity and unchanged crystal structure of MOF-808 after amino acid incorporation.
[0044] FTIR spectrum such as Figure 4 As shown in the analysis, in the spectrum of MOF-808-[His]3, at 1159 cm -1 and 850cm –1 A new peak corresponding to the C–N stretching vibration of the imidazole group and the out-of-plane bending vibration peak of NH were observed at 3263 cm –1 and 3143 cm –1 A doublet of −NH2 stretching vibration was observed at 147 nm. The above results clearly indicate that L-histidine was successfully modified in MOF-808.
[0045] BET spectrum such as Figure 5 As shown in the figure, the analysis shows that the N2 adsorption / desorption isotherms of the two metal framework materials are both type I, which is a typical feature of microporous materials. After the introduction of L-His, the BET surface area of MOF-808 material increased from 1463 m 2 g -1 Reduced to 685 m 2 g -1 , further confirming the successful combination of L-histidine and MOF-808.
[0046] Example 2
[0047] A method for preparing a metal-organic framework material modified with an alkaline material comprises the following steps:
[0048] S1. Zirconium oxychloride octahydrate (950 mg) and trimesic acid (205 mg) were added to a mixed solution of formic acid and N,N-dimethylformamide (FA:DMF volume ratio = 1:1) in a 100 mL polytetrafluoroethylene bottle, covered with a metal shell, and reacted in an oven at 110°C for 24 h. After cooling to room temperature, the mixture was washed with DMF and acetone several times, respectively, and activated in a vacuum drying oven at 120°C for 12 h to obtain MOF-808.
[0049] S2. Disperse 110 mg of MOF-808 in 8.5 mL of DMF containing L-His (46 mg), then place the mixture in a round-bottom flask. The mixture is reacted at a constant temperature of 85 °C for 50 h. After that, the solid is obtained by centrifugation (10000 × g, 5 min), and washed three times with DMF and MeOH respectively, and finally dried under vacuum at 80 °C to prepare MOF-808-[His]3, that is, the metal-organic framework material modified with the basic material.
[0050] Example 3
[0051] A preparation method of a metal-organic framework material modified with a basic material, comprising the following steps:
[0052] S1. Add zirconium oxychloride octahydrate (930 mg) and trimesic acid (205 mg) to a mixed solution of formic acid and N,N-dimethylformamide (volume ratio of FA and DMF = 1:1), place it in a 100 mL polytetrafluoroethylene bottle, put on a metal shell, and react at 110 °C in an oven for 24 h. After cooling to room temperature, wash it multiple times with DMF and acetone respectively, and activate it in a vacuum drying oven at 120 °C for 12 h to obtain MOF-808;
[0053] S2. Disperse 100 mg of MOF-808 in 7 mL of DMF containing L-His (42 mg), then place the mixture in a round-bottom flask. The mixture is reacted at a constant temperature of 75 °C for 50 h. After that, the solid is obtained by centrifugation (10000 × g, 5 min), and washed three times with DMF and MeOH respectively, and finally dried under vacuum at 80 °C to prepare MOF-808-[His]3, that is, the metal-organic framework material modified with the basic material.
[0054] Example 4
[0055] MOF-808-[His]3 hydrolysis of DMNP experiment:
[0056] First, synthesize DMNP according to the literature method. The method is as follows:
[0057] In a stirred solution of tetrahydrofuran (THF) (20 mL), p-nitrophenol (8.5 mmol), triethylamine (1.8 mL), tetrahydrofuran (10 mL), dimethyl chlorophosphate (2.65 mL, 12.75 mmol), and tetrahydrofuran (10 mL) were added, and the reaction was carried out in an ice-water bath; after the solution was stirred for 2 hours, NaHCO3 (10 mL) was added to quench the reaction, and the mixture was extracted with dichloromethane (CH2Cl2) (3×20 mL). The organic layers were combined, dried over magnesium sulfate (MgSO4), and filtered; the filtrate was concentrated to obtain the corresponding crude product, which was purified by silica gel column chromatography and verified by 1 1H and 13 13C NMR of the product, as Figure 6 and Figure 7 shown, proving that the product obtained was DMNP;
[0058] Then, MOF-808-[His]3 (7 mg) synthesized in Example 1 and DMNP (6.2 mg, 25 μmol) were added to 1 mL of pure aqueous solution (volume ratio of D2O to H2O was 1:9), stirred for 10 min, and the supernatant was taken to detect the ultraviolet absorption. As Figure 9 shown, in a pure water environment of D2O:H2O = 1:9, DMNP (25 μmol) had an ultraviolet absorption peak at 273 nm. After adding MOF-808-[His]3, the ultraviolet absorption peak at 273 nm disappeared, and a new peak attributed to 4-NP (degradation product) appeared at 400 nm.
[0059] To further monitor the reaction process, 0.9 mL of the reaction solution was taken by centrifugation after the reaction, and its reaction process was monitored by 31 31P NMR. As Figure 10 shown, in a pure water environment with a volume ratio of D2O to H2O of 1:9, the characteristic peak δ of DMNP was at -4.29 ppm. After adding MOF-808-[His]3, the characteristic peak δ of DMNP at -4.29 ppm disappeared, and a new peak of DMP (hydrolysis product) appeared at δ = 2.88 ppm.
[0060] Combined with the ultraviolet spectrum ( Figure 9 ), and Figure 10 the NMR spectrum ( Figure 8 ) of the hydrolysis of DMNP by MOF-808-[His]3, MOF-808-[His]3 achieved complete degradation of DMNP in a pure water environment. Moreover, the principle of the hydrolysis of DMNP by MOF-808-[His]3 is as
[0061] Example 5
[0062] Repeated experiments:
[0063] To exclude the contingency of experiments through multiple experiments, the synthesized MOF-808-[His]3 (7 mg) and DMNP (6.2 mg, 25 μmol) in Example 1 were added to 1 mL of pure aqueous solution (the volume ratio of D2O to H2O was 1:9), stirred for 10 min, and after the reaction, 0.9 mL of the reaction solution was taken by centrifugation. Through 31 31P NMR to monitor the reaction process. The results are as Figure 11 shown. The results of three repeated experiments all proved that in a pure water environment with a volume ratio of D2O to H2O of 1:9, the characteristic peak δ of DMNP was at -4.29 ppm. After adding MOF-808-[His]3, the characteristic peak δ of DMNP disappeared at -4.29 ppm, and a new peak of DMP (hydrolysis product) appeared at δ = 2.88 ppm.
[0064] Comparative Example 1
[0065] The synthesized MOF-808 (5 mg) and DMNP (6.2 mg, 25 μmol) in Example 1 were added to 1 mL of pure aqueous solution (the volume ratio of D2O to H2O was 1:9), and stirred for 1 h. Only 31P NMR spectrum of MOF-808 was used to monitor the hydrolysis of DMNP (6.2 mg, 25 μmol). 31 31P NMR spectrum monitoring.
[0066] In a pure water environment with a volume ratio of D2O to H2O of 1:9, the characteristic peak δ of DMNP (25 μmol) was at -4.29 ppm. After adding MOF-808 (5 mg), the absorption peak of the characteristic peak δ of DMNP at -4.29 ppm decreased, and a new peak of DMP (hydrolysis product) appeared at δ = 2.88. The results are as Figure 10 shown, indicating that pure MOF-808 does not have the ability to completely hydrolyze DMNP.
[0067] It should be noted that the above technical content of the present invention is only for explaining and clarifying the technical essence of the present invention so that those skilled in the art can understand it. Therefore, the above technical content is not used to limit the scope of the substantial protection of the present invention. The scope of the substantial protection of the present invention shall be subject to what is described in the claims. Those skilled in the art should know that any modifications, equivalent replacements, and improvements made based on the substantial spirit of the present invention shall be within the scope of the substantial protection of the present invention.
Claims
1. A preparation method of an alkaline material-modified metal-organic framework material, characterized in that, It includes the following steps: S1. Prepare MOF-808; S2. Disperse MOF-808 in DMF containing L-Histidine, then place the mixture in a round-bottom flask, react for a period of time at a certain temperature, centrifuge to obtain a solid, wash it with DMF and MeOH respectively, and finally dry it under vacuum to obtain the metal-organic framework material modified with the basic material.
2. The preparation method of a metal-organic framework material modified with an alkaline material according to claim 1, characterized in that, The specific steps of S1 include: Add zirconium oxychloride octahydrate and trimesic acid to the mixed solution of FA and DMF, put it into a reaction kettle, put on a metal shell, react in an oven, after cooling to room temperature, wash it with DMF and acetone respectively for multiple times, and activate it in a vacuum drying oven to obtain MOF-808.
3. The preparation method of a metal-organic framework material modified with an alkaline material according to claim 2, characterized in that, The mass ratio of zirconium oxychloride octahydrate to trimesic acid is (9-10):(2-3); the volume ratio of FA to DMF is 1:1; react at 110 °C in the oven for 24 h; activate it in a vacuum drying oven at 120 °C for 12 h.
4. The preparation method of a metal-organic framework material modified with an alkaline material according to claim 1, characterized in that, In step S2, the mass ratio of MOF-808 to L-Histidine is (100-110):(40-50).
5. The preparation method of a metal-organic framework material modified with an alkaline material according to claim 1, characterized in that, In step S2, the reaction temperature is 70-90 °C and the reaction time is 40-50 h.
6. An alkaline material-modified metal-organic framework material, characterized in that, It is prepared by using the preparation method according to any one of claims 1-5.
7. Application of the metal-organic framework material modified with the basic material according to claim 6 in catalytic degradation of dimethyl-4-nitrophenyl phosphate in a pure water system.
8. The application according to claim 7, characterized in that Mix the metal-organic framework material modified with the basic material and dimethyl-4-nitrophenyl phosphate in an aqueous solution and stir.
9. The application according to claim 8, wherein The pure aqueous solution is composed of D2O and H2O mixed according to a volume ratio of 1:
9.
10. The application according to claim 7 or 8, characterized in that, The mass-volume ratio of the metal-organic framework material modified with the basic material, dimethyl-4-nitrophenyl phosphate and the pure aqueous solution is (5-10) mg:(5-7) mg:1 mL.