Composite catalyst and method for its preparation

Abstract

This invention relates to the field of nanoparticle functional composite material preparation technology, and provides a composite catalyst and its preparation method. Using a molecularly imprinted polymer (MIP) with catalytic activity as a support, zirconium-based MOF nanoparticles are combined through in-situ doping to prepare a MIP / MOF composite catalyst. This effectively integrates two highly active catalytic materials to obtain a highly efficient MIP / MOF hybrid system, achieving synergistic promotion and complementarity in catalytic efficiency between the polymer matrix and MOF. Simultaneously, it overcomes the limitations of MOF materials, such as difficulty in processing and molding, and inconvenience for independent application. Functional alkaline components are introduced into the MIP network system through copolymerization and crosslinking, endowing the polymer matrix with pH self-buffering properties, creating a suitable reaction microenvironment for the MIP / MOF composite catalytic system, and ultimately achieving rapid and efficient degradation of organophosphate poisoning agents in a near-realistic environment using the composite artificial enzyme catalyst material.

Description

Technical Field

[0001] This invention relates to the field of nanoparticle functional composite material preparation technology, and in particular to a composite catalyst and its preparation method. Background Technology

[0002] Organophosphate nerve agents are among the most lethal poisons known today. As inhibitors of acetylcholinesterase, excessive accumulation in the human body can cause severe dysfunction of the central and peripheral cholinergic nervous systems, leading to paralysis and death by asphyxiation. Therefore, it is urgent to develop efficient purification processes and detoxification and protective materials for organophosphate nerve agents.

[0003] Natural catalysts such as organophosphodiesterases, including phosphotriesterases, exhibit highly efficient degradation activity under environmental conditions. However, the difficulty in extracting natural enzymes and their instability hinder their large-scale development and use. Therefore, developing environmentally stable artificial catalysts inspired by phosphodiesterases has become a hot topic in the field in recent years. In recent years, metal-organic frameworks (MOFs) and molecularly imprinted polymers have become the most widely used catalyst materials in the degradation of organophosphodiester poisons due to their highly efficient organophosphodiester catalytic activity and flexible functional designability.

[0004] Based on actual reaction conditions, current molecularly imprinted polymer / MOF catalysts exhibit a strong dependence on alkaline media to achieve high catalytic efficiency, thus limiting their practical application. Furthermore, the powdered physical form of MOF materials is difficult to process and recycle, hindering direct application. Therefore, it is necessary to seek polymer materials with strong mechanical properties as support carriers. Summary of the Invention

[0005] This invention aims to at least solve one of the technical problems existing in related technologies. Given that molecularly imprinted polymers (MIPs) possess the characteristic of precisely controllable active sites and main chain structure, this invention directly introduces basic functional molecules into MIPs through copolymerization and crosslinking, while simultaneously introducing dispersed zirconium-based MOF nanoparticles into the MIP matrix phase. This process prepares a composite catalyst that integrates physical processability, self-buffering, and rapid mass transfer, providing a feasible solution for achieving broad-spectrum catalysis of organophosphate nerve agents by artificial catalysts and their practical application.

[0006] This invention provides a method for preparing a composite catalyst, comprising the following steps:

[0007] S1: Preparation of functional monomer molecules;

[0008] S2: The functional monomer molecule, metal ion and template molecule are placed in a mixed solution of acetonitrile and methanol and stirred to obtain a molecularly imprinted pre-assembled complex.

[0009] S3: Vinyl functionalization treatment of zirconium-based MOFs to obtain vinyl functionalized MOFs;

[0010] S4: The molecularly imprinted pre-assembled complex, acrylic monomer, crosslinking agent and potassium persulfate are placed in an organic solvent and stirred to obtain a first mixed solution. The vinyl functionalized MOF is added to the first mixed solution and ultrasonically dispersed to obtain a first mixed dispersion.

[0011] S5: In an inert gas atmosphere, the first mixed dispersion is heated to obtain a composite catalyst;

[0012] The structural formula of the functional monomer molecule is as follows:

[0013] Wherein, R1 is an alkyl or alkyl alcohol; R2 is vinylbenzyl or allyl; R3 represents one of imidazole, pyridine, ortho-methyl, meta-methyl, para-methyl, amino-substituted pyridine derivatives, oxime or amylopyridine; R4 is one of hydroxyl, oxime or amylopyridine; and R5 is one of hydroxyl, oxime or amylopyridine.

[0014] According to the method for preparing a composite catalyst provided by the present invention, step S1 includes the following steps:

[0015] S11: Will Ethyl trifluoroacetate was placed in dichloromethane and stirred to obtain a second mixed solution. The second mixed solution was extracted, dried, and then evaporated to dryness to obtain the first compound.

[0016] Wherein, R1 is an alkyl group or an alkyl alcohol;

[0017] S12: Will R2-Cl and anhydrous potassium carbonate were placed in acetonitrile and refluxed at 60°C for 10–24 h to obtain a third mixed solution. This third mixed solution was filtered to obtain a filtrate, which was then evaporated to dryness and purified to obtain the final product.

[0018]

[0019] S13: Will NaOH is placed in a methanol solution and stirred to obtain a fourth mixed solution. The fourth mixed solution is then extracted and evaporated to dryness to obtain...

[0020]

[0021] S14: Will The mixture was placed in methanol and stirred to obtain a fifth mixed solution. This fifth mixed solution was then purified to obtain...

[0022]

[0023] Wherein, X is an aldehyde or cyano group, and R4' is one of a hydroxyl, aldehyde, or cyano group;

[0024] S15: Will and The mixture was placed in acetonitrile and stirred at 40–60 °C to obtain a sixth mixed solution. NaOH was added dropwise to the sixth mixed solution, and the mixture was refluxed and heated to obtain a seventh mixed solution. The seventh mixed solution was purified to obtain...

[0025] Wherein, Y is one of imidazole, pyridine, ortho-methyl substituted pyridine derivative, meta-methyl substituted pyridine derivative, para-methyl substituted pyridine derivative, or amino substituted pyridine derivative;

[0026] R3' is one of an aldehyde group, a cyanoimidazole group, a pyridine group, a pyridine derivative with ortho-methyl substituted group, a pyridine derivative with meta-methyl substituted group, a pyridine derivative with para-methyl substituted group, or a pyridine derivative with amino substituted group.

[0027] S16: Will The solution is mixed with an aqueous solution of hydroxylamine to obtain an eighth mixed solution. The eighth mixed solution is then placed in ethanol and refluxed to obtain a ninth mixed solution. The ninth mixed solution is then purified to obtain the functional monomer molecule.

[0028] According to the method for preparing a composite catalyst provided by the present invention, step S3 includes the following steps:

[0029] S31: Disperse the zirconium-based MOF in dichloromethane to obtain a second mixed dispersion;

[0030] S32: Triethylamine is added to the second mixed dispersion to obtain a third mixed dispersion;

[0031] S33: Under an inert gas atmosphere, methacryloyl chloride is dropped into the third mixed dispersion and stirred to obtain a vinyl-functionalized MOF.

[0032] According to a method for preparing a composite catalyst provided by the present invention, the metal ion includes one of Zn(II), Ag(I), Cu(II), Co(II), Ni(II), La(II) or Cd(II).

[0033] According to a method for preparing a composite catalyst provided by the present invention, the zirconium-based MOF includes one of UiO-66, MOF-808, Nu-1000, UiO-66-NH2, MOF-808-NH2 or Nu-1000-NH2.

[0034] According to a method for preparing a composite catalyst provided by the present invention, the template molecule includes one of parathion, paraoxon, trichlorfon, chlorpyrifos, diazinon, stiotronidazole, diethyl (4-nitrobenzyl) phosphate or bis(4-nitrophenyl) phosphate.

[0035] According to the method for preparing a composite catalyst provided by the present invention, the acrylic monomer is sodium acrylate or sodium methacrylate.

[0036] According to a method for preparing a composite catalyst provided by the present invention, the crosslinking agent is one of N,N-methylenebisacrylamide, divinylbenzene, ethylene glycol dimethacrylate, trimethoxypropane trimethacrylate, or pentaerythritol acrylate.

[0037] According to a method for preparing a composite catalyst provided by the present invention, the organic solvent is a mixed solution of methanol, acetonitrile, dichloromethane, N,N-dimethylformamide and dimethyl sulfoxide; or the organic solvent is a mixed solution of methanol, acetonitrile, N,N-dimethylformamide, dimethyl sulfoxide and water.

[0038] The present invention also provides a composite catalyst prepared by the method described above, wherein the composite catalyst is used to degrade organophosphate poisons.

[0039] The above-described one or more technical solutions in the embodiments of the present invention have at least one of the following technical effects:

[0040] This invention provides a composite catalyst and its preparation method. Using a molecularly imprinted polymer (MIM) with catalytic activity as a support, zirconium-based MOF nanoparticles, which also possess high-efficiency catalytic capabilities against organophosphate poisons, are combined through in-situ doping. This effectively integrates two highly active catalytic materials to obtain a highly efficient MIM / MOF composite catalyst. This achieves synergistic promotion and complementarity in catalytic efficiency between the polymer matrix and the MOF material. Simultaneously, it overcomes the limitations of MOF materials, which are difficult to process and shape for independent application. Functional alkaline components are introduced into the MIM network system through copolymerization and crosslinking, endowing the MIM matrix with pH self-buffering properties and creating a suitable reaction microenvironment for the MIM / MOF composite catalytic system. Ultimately, this enables the composite artificial enzyme catalyst material to rapidly and efficiently degrade organophosphate poisons in near-realistic environments.

[0041] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0043] Figure 1 This is a SEM image of the internal structure morphology of MIP / UiO-66-NH2 provided by the present invention.

[0044] Figure 2 The infrared spectra of MIP-(PAAO-AAs), MIP / UiO-66-NH2-0.25, MIP / UiO-66-NH2-0.5 and MIP / UiO-66-NH2-0.75 provided by this invention are shown.

[0045] Figure 3 The kinetic curves of the catalytic hydrolysis reaction of MIP / UiO-66-NH2-0.25, MIP / UiO-66-NH2-0.5, MIP / UiO-66-NH2-0.75, UiO-66-NH2 and MIP-(PAAO-AAs) in pure water liquid medium provided by the present invention are shown.

[0046] Figure 4 The kinetic curves of the solid-state catalytic hydrolysis reaction of methyl paraoxon with MIP / UiO-66-NH2-0.25, MIP / UiO-66-NH2-0.5, MIP / UiO-66-NH2-0.75, UiO-66-NH2 and MIP-(PAAO-AAs) provided by this invention in a high humidity air environment are shown. Detailed Implementation

[0047] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention. The following embodiments are used to illustrate this invention but should not be used to limit the scope of this invention.

[0048] Furthermore, the terms “first,” “second,” and “third” are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0049] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0050] The following is combined Figures 1 to 4 This invention describes a composite catalyst, its preparation method, and its applications.

[0051] This invention provides a method for preparing a composite catalyst, comprising the following steps.

[0052] S1: Preparation of functional monomer molecules.

[0053] S2: The functional monomer molecule, metal ion and template molecule are placed in a mixed solution of acetonitrile and methanol and stirred to obtain a molecularly imprinted pre-assembled complex.

[0054] The molar ratio of functional monomer molecules to metal ions is 1:0.5 to 2:0.25; the molar ratio of metal ions to template molecules is 2:0.25 to 2:1.

[0055] Among them, molecularly imprinted pre-assembled complexes are assemblies of functional monomer molecules, metal ions and template molecules, which can form catalytic active sites.

[0056] S3: Vinyl functionalization treatment of zirconium-based MOFs to obtain vinyl functionalized MOFs.

[0057] S4: The molecularly imprinted pre-assembled complex, acrylic monomer, crosslinking agent and potassium persulfate are placed in an organic solvent and stirred to obtain a first mixed solution. The vinyl functionalized MOF is added to the first mixed solution and ultrasonically dispersed to obtain a first mixed dispersion.

[0058] The molar ratio of the molecularly imprinted pre-assembled complex to the acrylic monomer is 1:0.25 to 4:1.

[0059] Furthermore, the molar ratio of the molecularly imprinted pre-assembled complex to the crosslinking agent is 1:0.1 to 10:1.

[0060] Furthermore, the mass ratio of the molecularly imprinted pre-assembled complex to the vinyl-functionalized MOF is 1:0.1 to 4:1.

[0061] S5: In an inert gas atmosphere, the first mixed dispersion is heated to obtain a composite catalyst.

[0062] In this process, the first mixed dispersion is heated to 6–200°C in an inert gas atmosphere and reacted for 4–48 hours to obtain a composite catalyst.

[0063] Furthermore, composite catalysts refer to composite catalysts of molecularly imprinted polymers (MIPs) and MOFs.

[0064] The structural formula of the functional monomer molecule is as follows:

[0065] Wherein, R1 is an alkyl or alkyl alcohol; R2 is vinylbenzyl or allyl; R3 represents one of imidazole, pyridine, ortho-methyl, meta-methyl, para-methyl, amino-substituted pyridine derivatives, oxime or amylopyridine; R4 is one of hydroxyl, oxime or amylopyridine; and R5 is one of hydroxyl, oxime or amylopyridine.

[0066] According to the method for preparing a composite catalyst provided by the present invention, step S1 includes the following steps.

[0067] S11: Will Ethyl trifluoroacetate was placed in dichloromethane and stirred to obtain a second mixed solution. The second mixed solution was extracted, dried, and then evaporated to dryness to obtain the first compound.

[0068] R1 is an alkyl group or an alkyl alcohol.

[0069] S12: Will R2-Cl and anhydrous potassium carbonate were placed in acetonitrile and refluxed at 60°C for 10–24 h to obtain a third mixed solution. This third mixed solution was filtered to obtain a filtrate, which was then evaporated to dryness and purified to obtain the final product. The reaction equation is shown below:

[0070]

[0071] S13: Will NaOH is placed in a methanol solution and stirred to obtain a fourth mixed solution. The fourth mixed solution is then extracted and evaporated to dryness to obtain...

[0072]

[0073] S14: Will The mixture was placed in methanol and stirred to obtain a fifth mixed solution. This fifth mixed solution was then purified to obtain...

[0074]

[0075] Wherein, X is an aldehyde or cyano group, and R4' is one of a hydroxyl, aldehyde, or cyano group;

[0076] The reaction equation is shown below:

[0077]

[0078] in, It can also be replaced with

[0079] S15: Will and The mixture was placed in acetonitrile and stirred at 40–60 °C to obtain a sixth mixed solution. NaOH was added dropwise to the sixth mixed solution, and the mixture was refluxed and heated to obtain a seventh mixed solution. The seventh mixed solution was purified to obtain...

[0080] Wherein, Y is one of imidazole, pyridine, ortho-methyl substituted pyridine derivative, meta-methyl substituted pyridine derivative, para-methyl substituted pyridine derivative, or amino substituted pyridine derivative;

[0081] R3' is one of an aldehyde group, a cyanoimidazole group, a pyridine group, a pyridine derivative with ortho-methyl substituted group, a pyridine derivative with meta-methyl substituted group, a pyridine derivative with para-methyl substituted group, or a pyridine derivative with amino substituted group.

[0082] The reaction equation is shown below:

[0083]

[0084] in, It can also be replaced with

[0085] S16: Will The solution is mixed with an aqueous solution of hydroxylamine to obtain an eighth mixed solution. The eighth mixed solution is placed in ethanol and heated under reflux to obtain a ninth mixed solution. The ninth mixed solution is purified to obtain the functional monomer molecule.

[0086] The reaction equation is shown below:

[0087]

[0088] According to the method for preparing a composite catalyst provided by the present invention, step S3 includes the following steps:

[0089] S31: Disperse the zirconium-based MOF in dichloromethane to obtain a second mixed dispersion;

[0090] S32: Triethylamine is added to the second mixed dispersion to obtain a third mixed dispersion;

[0091] S33: Under an inert gas atmosphere, methacryloyl chloride is dropped into the third mixed dispersion and stirred to obtain a vinyl-functionalized MOF.

[0092] According to a method for preparing a composite catalyst provided by the present invention, the metal ion includes one of Zn(II), Ag(I), Cu(II), Co(II), Ni(II), La(II) or Cd(II).

[0093] According to a method for preparing a composite catalyst provided by the present invention, the zirconium-based MOF includes one of UiO-66, MOF-808, Nu-1000, UiO-66-NH2, MOF-808-NH2 or Nu-1000-NH2.

[0094] According to a method for preparing a composite catalyst provided by the present invention, the template molecule includes one of parathion, paraoxon, trichlorfon, chlorpyrifos, diazinon, stiotronidazole, diethyl (4-nitrobenzyl) phosphate or bis(4-nitrophenyl) phosphate.

[0095] According to the method for preparing a composite catalyst provided by the present invention, the acrylic monomer is sodium acrylate or sodium methacrylate.

[0096] Among them, acrylic monomers mainly play a role in forming molecularly imprinted polymers through copolymerization and crosslinking. Since acrylic monomers are strong hydrophilic basic functional monomers with self-buffering properties, the introduction of acrylic monomer functional components can realize auxiliary properties such as self-buffering and hydrophilic hygroscopic properties of molecularly imprinted polymers, thereby effectively improving the catalytic activity of composite catalysts.

[0097] According to a method for preparing a composite catalyst provided by the present invention, the crosslinking agent is one of N,N-methylenebisacrylamide, divinylbenzene, ethylene glycol dimethacrylate, trimethoxypropane trimethacrylate, or pentaerythritol acrylate.

[0098] According to a method for preparing a composite catalyst provided by the present invention, the organic solvent is a mixed solution of methanol, acetonitrile, dichloromethane, N,N-dimethylformamide and dimethyl sulfoxide; or the organic solvent is a mixed solution of methanol, acetonitrile, N,N-dimethylformamide, dimethyl sulfoxide and water.

[0099] The present invention also provides a composite catalyst prepared by the method described above, wherein the composite catalyst is used to degrade organophosphate poisons.

[0100] Among them, a molecularly imprinted polymer with catalytic activity is used as a support, and zirconium-based MOF nanoparticles are combined with it through in-situ doping. The zirconium-based MOF nanoparticles also have the high-efficiency catalytic ability of organophosphate poisoning agents. A molecularly imprinted polymer / MOF composite catalyst is prepared, which effectively integrates two highly active catalytic materials to obtain a highly efficient MIP / MOF hybrid system. This achieves synergistic promotion and complementarity between the polymer matrix and MOF in terms of catalytic efficiency, overcomes the limitation of performance decay in practical application conversion, and has good processability and mechanical stability while maintaining high catalytic performance. This realizes the development and preparation of a new type of high-efficiency and practical phosphatase-like material.

[0101] The preparation method of the composite catalyst provided by the present invention is described below according to Examples 1-5:

[0102] Example 1

[0103] N-methylethylenediamine and ethyl trifluoroacetate were placed in dichloromethane and reacted with stirring at room temperature for 24 hours to obtain a second mixed solution. This second mixed solution was washed with saturated brine, dried overnight with anhydrous MgSO4, and then filtered through the MgSO4. The filtrate was collected and evaporated to dryness to obtain the final product.

[0104] Furthermore, 4-Vinylbenzyl chloride and anhydrous potassium carbonate were placed in acetonitrile and refluxed at 60°C for 24 hours to obtain a third mixed solution. The anhydrous potassium carbonate in the third mixed solution was filtered to obtain a filtrate. The filtrate was evaporated to dryness and purified by column chromatography to obtain the final product.

[0105] Furthermore, NaOH was placed in a methanol solution and stirred for 2–3 hours to obtain a fourth mixed solution. This fourth mixed solution was then extracted and evaporated to dryness to obtain…

[0106] Furthermore, Acrylonitrile and methanol were placed in a solution of methanol and stirred at room temperature to carry out a Michael addition reaction to obtain a fifth mixed solution. The fifth mixed solution was purified by column chromatography to obtain...

[0107] Furthermore, 2-Chloromethyl-6-methylpyridine was placed in acetonitrile and stirred at 40°C to obtain a sixth mixed solution. NaOH was slowly added dropwise to the sixth mixed solution, and the mixture was refluxed and heated for 48 hours to carry out a substitution reaction, yielding a seventh mixed solution. The seventh mixed solution was purified by column chromatography to obtain...

[0108] Furthermore, The mixture was mixed with an aqueous solution of hydroxylamine to obtain an eighth mixed solution. This eighth mixed solution was then placed in ethanol and refluxed for 48 hours to induce an addition-elimination reaction, yielding a ninth mixed solution. This ninth mixed solution was then purified by column chromatography to obtain...

[0109] Further, take 50mg 40 mg Zn(NO3)2·6H2O and 35 mg template molecule (4-nitrobenzyl) diethyl phosphate were dissolved in 5 ml of a mixed solution of acetonitrile and methanol, and stirred at room temperature for 12 h to obtain a molecularly imprinted pre-assembled complex.

[0110] Further, 2g of UiO-66-NH2 was dispersed in 10ml of dichloromethane, followed by the addition of 1.95ml of triethylamine. The mixture was poured into a 50ml flask and placed in an ice-water bath. Under N2 protection, 700μl of methacryloyl chloride was slowly added dropwise to the mixture using a constant-pressure dropping funnel. The reaction was then carried out in an ice-water bath for 1 hour, followed by a reaction at room temperature for 18 hours to obtain vinyl-functionalized UiO-66-NH2.

[0111] Further, 37.5 mg of Zn-coordinated molecularly imprinted pre-assembled complex and 37.5 mg of sodium acrylate monomer were dissolved in 400 μl of N,N-dimethylformamide / water mixed solution, 5.6 mg of potassium persulfate initiator and 16.6 mg of N,N-methylenebisacrylamide crosslinking agent were added, and finally 25 mg of vinyl-functionalized UiO-66-NH2 was added. The mixed dispersion was ultrasonically dispersed for 5–15 min.

[0112] Further, the above mixed dispersion was placed in a reaction vessel and heated at 60°C for 12 hours under N2 protection. After the reaction was completed, a composite catalyst was obtained, labeled as MIP / UiO-66-NH2.

[0113] Figure 1The SEM image of the internal structure of MIP / UiO-66-NH2 shows irregular granular material, which is a typical morphological feature of UiO-66-NH2. This proves that UiO-66-NH2 and the molecularly imprinted polymer are successfully combined, and that UiO-66-NH2 is uniformly distributed in the pores of the molecularly imprinted polymer matrix.

[0114] Example 2

[0115] N-methylethylenediamine and ethyl trifluoroacetate were placed in dichloromethane and reacted with stirring at room temperature for 24 hours to obtain a second mixed solution. This second mixed solution was washed with saturated brine, dried overnight with anhydrous MgSO4, and then filtered through the MgSO4. The filtrate was collected and evaporated to dryness to obtain the final product.

[0116] Furthermore, 4-Vinylbenzyl chloride and anhydrous potassium carbonate were placed in acetonitrile and refluxed at 60°C for 20 h to obtain a third mixed solution. The anhydrous potassium carbonate in the third mixed solution was filtered to obtain a filtrate. The filtrate was evaporated to dryness and purified by column chromatography to obtain the final product.

[0117] Furthermore, NaOH was placed in a methanol solution and stirred for 2–3 hours to obtain a fourth mixed solution. This fourth mixed solution was then extracted and evaporated to dryness to obtain…

[0118] Furthermore, Acrylonitrile and methanol were placed in a solution of methanol and stirred at room temperature to carry out a Michael addition reaction to obtain a fifth mixed solution. The fifth mixed solution was purified by column chromatography to obtain...

[0119] Furthermore, The solution was mixed with an aqueous solution of hydroxylamine to obtain a sixth mixed solution. This sixth mixed solution was then placed in ethanol and refluxed for 48 hours to induce an addition-elimination reaction, yielding another sixth mixed solution. The ninth mixed solution was then purified by column chromatography to obtain...

[0120] Further, take 50mg 40 mg Zn(NO3)2·6H2O and 35 mg template molecule stirophos were dissolved in a mixed solution of 5 ml acetonitrile and methanol, and stirred at room temperature for 12 h to obtain a molecularly imprinted pre-assembled complex.

[0121] Further, 2g of Nu-1000-NH2 was dispersed in 10ml of dichloromethane, followed by the addition of 1.95ml of triethylamine. The mixture was poured into a 50ml flask and placed in an ice-water bath. Under N2 protection, 700μl of methacryloyl chloride was slowly added dropwise to the mixture using a constant-pressure dropping funnel. The reaction was then carried out in an ice-water bath for 1 hour, followed by a reaction at room temperature for 18 hours to obtain vinyl-functionalized Nu-1000-NH2.

[0122] Further, 46.5 mg of Zn-coordinated molecularly imprinted pre-assembled complex and 18.5 mg of sodium methacrylate were dissolved in 400 μl of N,N-dimethylformamide / water mixed solution, 5.6 mg of potassium persulfate initiator and 16.6 mg of N,N-methylenebisacrylamide crosslinking agent were added, and finally 12.5 mg of vinyl-functionalized Nu-1000-NH2 was added. The mixed dispersion was ultrasonically dispersed for 5–15 min.

[0123] Further, the above mixed dispersion was placed in a reaction vessel and heated at 70°C for 12 hours under N2 protection. After the reaction was completed, a composite catalyst was obtained, namely the molecularly imprinted polymer / MOF composite artificial enzyme material MIP / Nu-1000-NH2.

[0124] Example 3

[0125] N-methylethylenediamine and ethyl trifluoroacetate were placed in dichloromethane and reacted with stirring at room temperature for 24 hours to obtain a second mixed solution. This second mixed solution was washed with saturated brine, dried overnight with anhydrous MgSO4, and then filtered through the MgSO4. The filtrate was collected and evaporated to dryness to obtain the final product.

[0126] Furthermore, 3-Chloropropene and anhydrous potassium carbonate were placed in acetonitrile and refluxed at 60°C for 10–24 h to obtain a third mixed solution. The anhydrous potassium carbonate in the third mixed solution was filtered to obtain a filtrate. The filtrate was evaporated to dryness and purified by column chromatography to obtain the final product.

[0127] Furthermore, NaOH was placed in a methanol solution and stirred for 2–3 hours to obtain a fourth mixed solution. This fourth mixed solution was then extracted and evaporated to dryness to obtain…

[0128] Furthermore, 2-Chloroethanol was placed in methanol and stirred at room temperature. NaOH was then added to the solution, and the mixture was heated under reflux for 24 hours to obtain a fifth mixture. This fifth mixture was purified by column chromatography to obtain…

[0129] Furthermore, 4-(chloromethyl)-1H-imidazolium hydrochloride and anhydrous potassium carbonate were placed in chloroform and stirred at 40–60 °C to obtain a sixth mixed solution. NaOH was slowly added dropwise to the sixth mixed solution, and the mixture was refluxed and heated for 48 h to carry out the substitution reaction. The anhydrous potassium carbonate was filtered to obtain the filtrate. The filtrate was evaporated to dryness and purified by column chromatography to obtain the desired product.

[0130] Further, take 50mg 23 mg AgNO3 and 35 mg template molecule bis(4-nitrobenzene) phosphate were dissolved in 5 ml of a mixed solution of acetonitrile and methanol, and stirred at room temperature for 12 h to obtain a molecularly imprinted pre-assembled complex.

[0131] Further, 2g of MOF-808-NH2 was dispersed in 10ml of dichloromethane, followed by the addition of 1.95ml of triethylamine. The mixture was poured into a 50ml flask and placed in an ice-water bath. Under N2 protection, 700μl of methacryloyl chloride was slowly added dropwise to the mixture using a constant-pressure dropping funnel. The reaction was then carried out in an ice-water bath for 1 hour, followed by a reaction at room temperature for 18 hours to obtain vinyl-functionalized MOF-808-NH2.

[0132] Further, 54.5 mg of Ag-coordinated molecularly imprinted pre-assembled complex and 10.5 mg of sodium acrylate monomer were dissolved in 400 μl of N,N-dimethylformamide / water mixed solution, 5.6 mg of potassium persulfate initiator and 16.6 mg of N,N-methylenebisacrylamide crosslinking agent were added, and finally 12.5 mg of vinyl-functionalized MOF-808-NH2 was added. The mixed dispersion was ultrasonically dispersed for 5–15 min.

[0133] Further, the above mixed dispersion was placed in a reaction vessel and heated at 70°C for 8 hours under N2 protection. After the reaction was completed, a composite catalyst was obtained, namely the molecularly imprinted polymer / MOF composite artificial enzyme material MIP / MOF-808-NH2.

[0134] Example 4: Experimental Test on the Catalytic Hydrolysis Performance of Organophosphate Nerve Agents

[0135] Molecularly imprinted polymer / MOF composite catalysts were prepared according to the preparation method in Example 1 above. The mass ratios of the molecularly imprinted pre-assembled complex to UiO-66-NH2 were 1:0.25, 1:0.5, and 1:0.75, respectively. The prepared composite catalysts were labeled as MIP / UiO-66-NH2-0.25, MIP / UiO-66-NH2-0.5, and MIP / UiO-66-NH2-0.75, respectively.

[0136] Pure UiO-66-NH2 and pure molecularly imprinted polymer were used as control blanks, with the pure molecularly imprinted polymer being MIP-(PAAO-AAs). 5 / 5 )express.

[0137] like Figure 2 As shown, from top to bottom are MIP-(PAAO-AAs) 5 / 5 The infrared spectra of MIP / UiO-66-NH2-0.25, MIP / UiO-66-NH2-0.5, and MIP / UiO-66-NH2-0.75 are shown. The spectra can be observed in the range of 3100–3600 cm⁻¹. -1 A strong and broad absorption band appears at 1715 cm⁻¹, corresponding to the stretching vibration peaks of -OH and -NH₂ on MIP / UiO-66-NH₂. -1 and 1651cm -1 The stretching vibration peaks at 766 cm⁻¹ correspond to the C=O and C=N bonds, respectively, and are attributed to the carboxyl group on the UiO-66-NH₂ ligand and the amylopyridine oxime group on the organic functional ligand in the molecularly imprinted polymer. -1 The presence of characteristic peaks corresponding to the Zr-O bonds on UiO-66-NH2 demonstrates the successful preparation of molecularly imprinted polymer / MOF composite catalysts MIP / UiO-66-NH2-0.25, MIP / UiO-66-NH2-0.5, and MIP / UiO-66-NH2-0.75.

[0138] The experimental steps for testing the catalytic hydrolysis performance of organophosphate nerve agents are as follows:

[0139] Add 15 mg of sample to 1.5 ml of deionized water. Pre-dissolve the organophosphate substrate methyl parathion in acetonitrile to prepare a 0.25 M stock solution. Extract 100 μl of the stock solution and add it to the solution containing the composite catalyst. Monitor the concentration of hydrolysis products every 5 min to track catalytic reaction kinetics. For each test, dilute 20 μl of the test solution to 980 μl of 0.45 M NEM buffer. Measure the absorbance of the hydrolysis product p-nitrophenol at 407 nm using UV-Vis absorption spectroscopy. Calculate the corresponding concentration based on the established characterization curve.

[0140] Figure 3 The figures shown are MIP / UiO-66-NH2-0.25, MIP / UiO-66-NH2-0.5, MIP / UiO-66-NH2-0.75, UiO-66-NH2 and MIP-(PAAO-AAs). 5 / 5The catalytic hydrolysis kinetics of methyl paraoxon in pure water liquid medium are shown, including the catalytic hydrolysis performance test of UiO-66-NH2 in alkaline N-ethylmorpholine buffer (NEM, pH=9). Figure 3 The results showed that MIP-(PAAO-AAs) 5 / 5 MIP / UiO-66-NH2 exhibits a synergistic effect with UiO-66-NH2 in the catalytic process. Under pure water reaction conditions, the hydrolysis rates of organophosphorus substrates by MIP / UiO-66-NH2-0.25, MIP / UiO-66-NH2-0.5, and MIP / UiO-66-NH2-0.75 are significantly faster than those of the single-component material MIP-(PAAO-AAs). 5 / 5 The catalytic hydrolysis rate of MIP-(PAAO-AAs) or UiO-66-NH2 was observed. Furthermore, UiO-66-NH2 exhibited the fastest catalytic rate in alkaline buffer solution, while its performance significantly declined in water, showing the lowest catalytic activity. The significant improvement in catalytic performance after combining the molecularly imprinted polymer with MOF also demonstrates the effectiveness of MIP-(PAAO-AAs). 5 / 5 The pH self-buffering properties of the matrix promote the hydrolysis of the composite catalytic system.

[0141] Example 5: Solid-state hydrolysis performance test of composite catalyst in high humidity air environment

[0142] Using MIP / UiO-66-NH2-0.25, MIP / UiO-66-NH2-0.5, MIP / UiO-66-NH2-0.75, UiO-66-NH2 and MIP-(PAAO-AAs) from Example 4 5 / 5 The experiment was conducted, and the experimental steps are as follows:

[0143] 90 mg of the composite catalyst sample was taken and incubated in a 99% RH humidity chamber for 24 h for pretreatment. Then, 100 μl of 0.25 M methyl paraphosphine acetonitrile solution was added dropwise to the sample. At 10 min detection intervals, the sample was digested with 0.6 ml of D2SO4 / DMSO-d6 (15 / 100, v / v). The hydrolysis reaction conversion process was monitored by 31 P NMR spectroscopy.

[0144] Figure 4 The figures shown are MIP / UiO-66-NH2-0.25, MIP / UiO-66-NH2-0.5, MIP / UiO-66-NH2-0.75, UiO-66-NH2 and MIP-(PAAO-AAs). 5 / 5 The kinetic curves of the solid-state catalytic hydrolysis reaction of methyl paraphosphine in a high-humidity air environment are shown. Figure 4The results showed that MIP / UiO-66-NH2-0.25, MIP / UiO-66-NH2-0.5, and MIP / UiO-66-NH2-0.75 exhibited superior and faster solid-state catalytic hydrolysis capabilities, with MIP / UiO-66-NH2-0.5 showing the best performance. Its half-life (t) for the solid-phase hydrolysis degradation of methyl para-oxophosphorus was [not specified in the original text]. 1 / 2 It reached 28.6 min (k = 0.0242 min). -1 ), compared to UiO-66-NH2(t 1 / 2 =122.5min, k=0.0057min -1 It's an order of magnitude faster, which is MIP-(PAAO-Aas) 5 / 5 )(t 1 / 2 =60.6min, k=0.0114min -1 More than twice that of other materials. This demonstrates that the molecularly imprinted polymer / MOF composite catalyst, which integrates self-buffering, high hygroscopic capacity, and two active catalytic systems, exhibits excellent potential as a high-efficiency and practical detoxification material for organophosphates.

[0145] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a composite catalyst, characterized by, Includes the following steps: S1: Preparation of functional monomer molecules; S2: The functional monomer molecule, metal ion and template molecule are placed in a mixed solution of acetonitrile and methanol and stirred to obtain a molecularly imprinted pre-assembled complex. The template molecule includes one of parathion, paraoxon, trichlorfon, chlorpyrifos, diazinon, stiotronidazole, diethyl (4-nitrobenzyl) phosphate, or bis(4-nitrophenyl) phosphate. S3: Vinyl functionalization of zirconium-based MOFs to obtain vinyl functionalized MOFs includes the following steps: S31: Disperse the zirconium-based MOF in dichloromethane to obtain a second mixed dispersion; S32: Triethylamine is added to the second mixed dispersion to obtain a third mixed dispersion; S33: Under an inert gas atmosphere, methacryloyl chloride is dropped into the third mixed dispersion and stirred to obtain a vinyl-functionalized MOF; The zirconium-based MOF includes one of UiO-66-NH2, MOF-808-NH2 or Nu-1000-NH2; S4: The molecularly imprinted pre-assembled complex, acrylic monomer, crosslinking agent and potassium persulfate are placed in a mixed solution of N,N-dimethylformamide-water and stirred to obtain a first mixed solution. The vinyl functionalized MOF is added to the first mixed solution and ultrasonically dispersed to obtain a first mixed dispersion. S5: In an inert gas atmosphere, the first mixed dispersion is heated to obtain a composite catalyst; The structural formula of the functional monomer molecule is as follows: or ; Wherein, R1 is an alkyl or alkyl alcohol; R2 is vinylbenzyl or allyl; R3 represents one of imidazole, pyridine, ortho-methyl substituted pyridine derivatives, meta-methyl substituted pyridine derivatives, para-methyl substituted pyridine derivatives, amino substituted pyridine derivatives, oxime or amylopyridine; R4 is one of hydroxyl, oxime or amylopyridine; R5 is one of hydroxyl, oxime or amylopyridine.

2. The method for preparing a composite catalyst according to claim 1, characterized in that, Step S1 includes the following steps: S11: Will Ethyl trifluoroacetate was placed in dichloromethane and stirred to obtain a second mixed solution. This second mixed solution was extracted, dried, and then evaporated to dryness to obtain... ; S12: Will , Anhydrous potassium carbonate was placed in acetonitrile and refluxed at 60°C for 10–24 h to obtain a third mixed solution. This third mixed solution was filtered to obtain a filtrate, which was then evaporated to dryness and purified to obtain the final product. ; S13: Will NaOH is placed in a methanol solution and stirred to obtain a fourth mixed solution. The fourth mixed solution is then extracted and evaporated to dryness to obtain... ; S14: Will and The mixture was placed in methanol and stirred to obtain a fifth mixed solution. This fifth mixed solution was then purified to obtain... ; Wherein, X is an aldehyde or cyano group, and R4' is one of a hydroxyl, aldehyde, or cyano group; S15: Will and The mixture was placed in acetonitrile and stirred at 40-60°C to obtain a sixth mixed solution. NaOH was added dropwise to the sixth mixed solution, and the mixture was refluxed and heated to obtain a seventh mixed solution. The seventh mixed solution was purified to obtain... ; Wherein, Y is one of imidazole, pyridine, ortho-methyl substituted pyridine derivative, meta-methyl substituted pyridine derivative, para-methyl substituted pyridine derivative, or amino substituted pyridine derivative; R3' is one of an aldehyde group, a cyanoimidazole group, a pyridine group, a pyridine derivative with ortho-methyl substituted group, a pyridine derivative with meta-methyl substituted group, a pyridine derivative with para-methyl substituted group, or a pyridine derivative with amino substituted group. S16: Will The solution is mixed with an aqueous solution of hydroxylamine to obtain an eighth mixed solution. The eighth mixed solution is then placed in ethanol and refluxed to obtain a ninth mixed solution. The ninth mixed solution is then purified to obtain the functional monomer molecule.

3. The method for preparing a composite catalyst according to claim 1, characterized in that, The metal ion includes one of Zn(II), Ag(I), Cu(II), Co(II), Ni(II), La(II), or Cd(II).

4. The method for preparing a composite catalyst according to claim 1, characterized in that, The acrylic monomer is sodium acrylate or sodium methacrylate.

5. The method for preparing a composite catalyst according to claim 1, characterized in that, The crosslinking agent is one of N,N-methylenebisacrylamide, divinylbenzene, ethylene glycol dimethacrylate, trimethoxypropane trimethacrylate, or pentaerythritol acrylate.

6. A composite catalyst prepared by the method for preparing a composite catalyst according to any one of claims 1-5, characterized in that, The composite catalyst is used to degrade organophosphate poisons.

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