Covalent organic framework material for purifying aluminum ions in propiophenone production process and preparation method of covalent organic framework material

Abstract

The invention discloses a covalent organic framework material for purifying aluminum ions in a propiophenone production process and a preparation method of the covalent organic framework material, the two-dimensional covalent organic framework material with carboxyl is prepared from 2, 4, 6-trihydroxybenzene-1, 3, 5-tricarboxaldehyde (THBT) and 4, 4, 6-trihydroxybenzene-1, 3, 5-tricarboxaldehyde (THBT), and the two-dimensional covalent organic framework material with carboxyl is a covalent organic framework material with carboxyl. A two-dimensional covalent organic framework with a terphenyl and hydroxyl structure is formed by condensation of a 4, 4 '-diamino-[1, 1': 4 ', 1'-triphenyl]-2 ', 5'-diol (DMTPD) building unit, and then the two-dimensional covalent organic framework is modified by ethylene diamine tetraacetic acid dianhydride (EDTAD) to obtain the high-molecular polymer. The covalent organic framework material is high in crystallinity, rich in carboxyl, capable of being combined with aluminum ions in the propiophenone synthesis process, beneficial to adsorption separation of the aluminum ions and good in application prospect in the field of adsorption separation.

Description

Technical Field

[0001] This invention relates to the field of crystalline covalent organic framework materials and adsorption separation technology, and particularly to a covalent organic framework material for purifying aluminum ions in the production of acetone and its preparation method. Background Technology

[0002] Covalent organic frameworks (COFs) are a class of crystalline porous organic materials, typically characterized by low density, high specific surface area, good thermal stability, and customizable functionalization. They are currently widely used in gas adsorption and separation. Furthermore, their rich building block structures and ease of functionalization result in abundant pore structures and environments, making them potentially valuable for adsorption and separation applications. Adsorption methods have gained widespread attention due to their low cost, high efficiency, and environmental friendliness. The key to effective adsorption lies in the selection of the adsorbent material. Currently, carbon-based materials, biochar, iron oxides, clay minerals, and iron sulfides are widely used for the adsorption and removal of heavy metals. However, crystalline porous COFs with high specific surface area and high stability are ideal adsorbent materials, possessing significant potential for environmental remediation applications in this field.

[0003] Friedel-Crafts acylation is a particularly important reaction in the synthesis of fine chemicals. This reaction can be used to directly introduce carbonyl groups onto simple aromatic rings to synthesize aromatic ketones. For example, the most widely used Friedel-Crafts acylation reaction in the production of acetone uses anhydrous aluminum trichloride as a catalyst, which raises a series of thorny environmental and safety issues. After the reaction, the post-treatment hydrolysis of aluminum chloride not only affects the selectivity of the reaction, reducing the selectivity of the acylated product, but also makes the purification of the acylated product more difficult. Therefore, it is necessary to adsorb and separate aluminum ions during the production process to purify acetone. Summary of the Invention

[0004] The purpose of this invention is to overcome the limitations of COFs applications by introducing carboxyl functional groups into the COF-OH-1 material framework through a post-synthesis modification strategy, thereby synthesizing a carboxyl-functionalized ketone-enamine covalent organic framework material COF-COOH-1. This invention provides a two-dimensional covalent organic framework material with a carboxyl structure for aluminum ion adsorption and separation in the acetone production process, as well as its preparation method.

[0005] On one hand, the present invention provides a covalent organic framework material for purifying aluminum ions in the process of acetone production, comprising two two-dimensional covalent organic framework materials having hydroxyl and carboxyl groups respectively, with the following structural formula:

[0006]

[0007] In some embodiments, the two-dimensional covalent organic framework material having a hydroxyl structure is formed by the condensation of 2,4,6-trihydroxybenzene-1,3,5-tricarboxaldehyde (THBT) and 4,4'-diamino-[1,1':4',1'-triphenyl]-2',5'-diol (DMTPD) building units;

[0008] The structural formulas of the building units are as follows:

[0009]

[0010] Secondly, the present invention provides a method for preparing a covalent organic framework material for purifying aluminum ions during the production of acetone, characterized in that the two-dimensional covalent organic framework material COF-OH-1 with a hydroxyl structure is prepared by the following steps:

[0011] 1) Place THBT and DMPTD in a reaction vessel, add solvent, and sonicate to mix them evenly;

[0012] 2) Add an aqueous acetic acid solution to the reaction vessel as a catalyst, then freeze the reaction vessel with liquid nitrogen, evacuate it to remove air, and seal the reaction vessel under vacuum conditions. Subsequently, heat the reaction system to carry out an aldehyde-amine condensation reaction. After the reaction is completed, post-treatment is performed to obtain the imine-bonded two-dimensional covalent organic framework material COF-OH-1.

[0013] In some embodiments, the molar ratio of THBT and DMPTD in step 1) is 1:1.5 to 2; the solvent in step 1) is one or two of o-dichlorobenzene, n-butanol, mesitylene, 1,4-dioxane, and chloroform, and the ratio of the two solvents is 1 to 9:1 by volume or a single solvent.

[0014] In some embodiments, the concentration of the acetic acid aqueous solution in step 2) is 3-12M; the amount of acetic acid aqueous solution added is 0.1-0.4 times the volume of the solvent in step 1); and the amine condensation reaction conditions in step 2) are: reaction at 110-130°C for 72-168 hours.

[0015] Thirdly, the present invention provides a method for preparing a covalent organic framework material for purifying aluminum ions during the production of acetone. The two-dimensional covalent organic framework material COF-COOH-1 with a carboxyl group structure is prepared by the following steps:

[0016] 1) Place THBT and DMPTD in a reaction vessel, add solvent, and sonicate to mix them evenly;

[0017] 2) Add acetic acid aqueous solution to the reaction vessel as a catalyst, then freeze the reaction vessel with liquid nitrogen, evacuate it to remove air, and seal the reaction vessel under vacuum conditions. Then, heat the reaction system to carry out aldehyde-amine condensation reaction. After the reaction is completed, post-treatment is performed to obtain the imine bond-linked two-dimensional covalent organic framework material COF-OH-1.

[0018] 3) Add COF-OH-1 and ethylenediaminetetraacetic acid dianhydride to a reaction vessel, add solvent, sonicate to mix evenly, heat to react for a certain time at a certain temperature, and after the reaction is completed, treat the reaction product with NaHCO3 solution to obtain a two-dimensional covalent organic framework COF-COOH-1 with carboxyl group structure.

[0019] In some embodiments, the two-dimensional covalent organic framework COF-COOH-1 with a carboxyl group structure is obtained by grafting and modifying the two-dimensional covalent organic framework (COF-OH-1) with a hydroxyl group structure with ethylenediaminetetraacetic dianhydride (EDTAD).

[0020] In some embodiments, the molar ratio of THBT and DMPTD in step 1) is 1:1.5-2; the solvent in step 1) is one or two of o-dichlorobenzene, n-butanol, mesitylene, 1,4-dioxane, and chloroform, and the ratio of the two solvents is 1-9:1 by volume or a single solvent; the concentration of the acetic acid aqueous solution in step 2) is 3-12M; the amount of acetic acid aqueous solution added is 0.1-0.4 times the volume of the solvent in step 1); the amine condensation reaction conditions in step 2) are: reaction at 110-130°C for 72-168h.

[0021] In some embodiments, the molar ratio of ethylenediaminetetraacetic dianhydride to COF-OH-1 in step 3) is 1:1.2 to 1.5.

[0022] In some embodiments, the solvent in step 3) is one of N,N-dimethylformamide and N,N-dimethylacetamide.

[0023] In some implementations, the temperature in step 3) is 60–80°C; and the time is 36–54 h.

[0024] In some embodiments, the post-treatment in step 3) includes soaking the reaction product in a 5 wt% NaHCO3 solution for 3 hours and filtering. The product is then washed three times each with tetrahydrofuran (THF), ultrapure water, and ethanol. The product is dried under vacuum at 50°C to obtain COF-COOH-1, which is stored in a desiccator for later use.

[0025] The entire reaction equation is:

[0026]

[0027] The present invention has the following beneficial effects:

[0028] 1. This invention provides a method for constructing a two-dimensional covalent organic framework material with hydroxyl and carboxyl structures, resulting in a material with high crystallinity.

[0029] 2. The preparation method provided by this invention is easy to operate. The entire reaction system is a pure organic system with no rare earth ions involved. It is green and environmentally friendly, has low cost, and is easy to industrialize.

[0030] 3. The COF-COOH-1 synthesized in this invention exhibits excellent adsorption and separation performance, and can be applied to the adsorption and separation of aluminum ions in the production of acetone. The adsorption effect is significant, demonstrating great application potential. Attached Figure Description

[0031] Figure 1 The XRD patterns of COF-OH and COF-COOH prepared in Examples 1-1 and 2 of this invention are shown below.

[0032] Figure 2 The bar chart shows the removal rates of different metal ions by COF-OH and COF-COOH prepared in Examples 1-1 and 2. Detailed Implementation

[0033] The present invention will be further described in detail below through embodiments.

[0034] Example 1-1

[0035] A covalent organic framework material with a hydroxyl structure, the preparation method of which includes the following steps:

[0036] (1) Place 67.24 mg (0.32 mmol) THBT and 140.32 mg DMPTD (0.48 mmol) in an ampoule, add 1.2 mL of trimethylbenzene and 2.8 mL of dioxane, and sonicate to disperse the mixture until it is homogeneous.

[0037] (2) Add 0.4 mL of acetic acid solution (3 mol / L) to the ampoule, then freeze the ampoule with liquid nitrogen, evacuate it, and seal the ampoule under vacuum conditions;

[0038] (4) Heat the reaction system to 110℃ and react completely for 72 hours;

[0039] (5) After the reaction is complete, the temperature is lowered to room temperature and the powder is obtained by filtration. The powder is washed with ethanol and dichloromethane in sequence, and then extracted with tetrahydrofuran, methanol, dichloromethane and acetone by Soxhlet extraction in sequence. After vacuum drying, the final product is obtained, which is a covalent organic framework material with a two-dimensional structure, named COF-OH-1.

[0040] Examples 1-2

[0041] A covalent organic framework material with a hydroxyl structure, the preparation method of which includes the following steps:

[0042] (1) Place 67.24 mg (0.32 mmol) THBT and 140.32 mg DMPTD (0.48 mmol) in an ampoule, add 2.8 mL of trimethylbenzene and 1.2 mL of n-butanol, and sonicate to disperse the mixture until it is homogeneous.

[0043] (2) Add 0.4 mL of acetic acid solution (3 mol / L) to the ampoule, then freeze the ampoule with liquid nitrogen, evacuate it, and seal the ampoule under vacuum conditions;

[0044] (4) Heat the reaction system to 110℃ and react completely for 72 hours;

[0045] (5) After the reaction is complete, the temperature is lowered to room temperature and the powder is obtained by filtration. The powder is washed with ethanol and dichloromethane in sequence, and then extracted with tetrahydrofuran, methanol, dichloromethane and acetone by Soxhlet extraction in sequence. After vacuum drying, the final product is obtained, which is a covalent organic framework material with a two-dimensional structure, named COF-OH-1.

[0046] Examples 1-3

[0047] (1) Place 67.24 mg (0.32 mmol) THBT and 140.32 mg DMPTD (0.48 mmol) in an ampoule, add 2 mL of a mixture of trimethylbenzene and 2 mL of o-dichlorobenzene, and sonicate to disperse the mixture until it is homogeneous.

[0048] (2) Add 0.4 mL of acetic acid solution (3 mol / L) to the ampoule, then freeze the ampoule with liquid nitrogen, evacuate it, and seal the ampoule under vacuum conditions;

[0049] (4) Heat the reaction system to 110℃ and react completely for 72 hours;

[0050] (5) After the reaction is complete, the temperature is lowered to room temperature and the powder is obtained by filtration. The powder is washed with ethanol and dichloromethane in sequence, and then extracted with tetrahydrofuran, methanol, dichloromethane and acetone by Soxhlet extraction in sequence. After vacuum drying, the final product is obtained, which is a covalent organic framework material with a two-dimensional structure, named COF-OH-1.

[0051] Example 2

[0052] A covalent organic framework material with a carboxyl group structure, the preparation method of which includes the following steps:

[0053] (1) Place 45mg COF-OH-1 and 120mg ethylenediaminetetraacetic acid dianhydride in a thick-walled glass pressure-resistant bottle, add 10mL DMAc, and ultrasonically disperse the mixture until it is homogeneous. Then seal the bottle.

[0054] (2) React at 70℃ for 40 hours;

[0055] (3) After the reaction was completed, the reaction product was soaked in 5 wt% NaHCO3 solution for 3 h and then filtered. It was washed three times each with tetrahydrofuran (THF), ultrapure water and ethanol. The product was dried under vacuum at 50 °C. The obtained product is COF-COOH-1, which was stored in a desiccator for later use.

[0056] like Figure 1 The figure shows the XRD pattern of the covalent organic framework material prepared in this embodiment. As shown in the figure, both COF-OH and COF-COOH have strong diffraction peaks, indicating that COF-OH and COF-COOH are spatially ordered in a long range, and their XRD diffraction peaks are similar in position. The main peak of COF-OH is located at 2.28°, and there are also diffraction peaks representing π-π packing of two-dimensional materials at 20-30°. The main peak of COF-COOH is located at 2.3°, and there are also diffraction peaks at 4.85°, 6.36°, and 8.26°.

[0057] Figure 2 The removal rates of different metal ions by COF-OH and COF-COOH prepared in this embodiment are shown. To investigate the affinity of the carboxyl-functionalized covalent organic framework material COF-COOH-1 for different heavy metal ions and to compare it with COF-OH-1 without carboxyl modification, experiments were conducted using materials containing five different heavy metal ions (Al, Al, and COF-OH-1). 3+ Cd 2+ Cu 2+ Ni 2+ Cr 3+ A mixed solution containing heavy metal ions at a concentration of 0.01 mmol / L and an adsorbent mass of 10 mg. From Figure 2 It can be seen that, compared with the unmodified COF-OH-1 material, the carboxyl-functionalized covalent organic framework material COF-COOH-1 significantly improved the removal rates of the five heavy metal ions studied. COF-COOH-1 also showed improved removal rates of Al... 3+ Cd 2+ Cu 2+ Ni 2+ Cr 3+The removal rates also increased from 8.9%, 85.1%, 3.53%, 4.7%, and 8.5% to 99.99%, 98.5%, 96.4%, 97.8%, and 98.9%, respectively, indicating that COF-COOF-1 has a high affinity for all five heavy metal ions. This suggests that after carboxyl functionalization, the electron cloud density on the surface of COF-COOH-1 increases, resulting in a large number of negative charges, which can adsorb positively charged heavy metal ions through electrostatic interactions. These results demonstrate that carboxylation modification significantly improves the adsorption efficiency of the material for metal ions, and COF-COOH can be used to adsorb and separate aluminum ions during the production of acetone.

[0058] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the inventive concept of the present invention, and these should also be considered within the scope of protection of the invention.

Claims

1. A covalent organic framework material for purifying aluminum ions during the production of acetone, characterized in that, This includes two two-dimensional covalent organic framework materials, one with a hydroxyl group and the other with a carboxyl group, with the following structural formulas:

2. The covalent organic framework material for purifying aluminum ions in the acetone production process according to claim 1, characterized in that, The two-dimensional covalent organic framework material with a hydroxyl structure is formed by the condensation of 2,4,6-trihydroxybenzene-1,3,5-tricarboxaldehyde (THBT) and 4,4'-diamino-[1,1':4',1'-triphenyl]-2',5'-diol (DMTPD) building units; The structural formulas of the building units are as follows:

3. A method for preparing a covalent organic framework material for purifying aluminum ions during the production of acetone, as described in claim 1 or 2, characterized in that, The two-dimensional covalent organic framework material COF-OH-1 with a hydroxyl structure is prepared by the following steps: 1) Place THBT and DMPTD in a reaction vessel, add solvent, and sonicate to mix them evenly; 2) Add an aqueous acetic acid solution to the reaction vessel as a catalyst, then freeze the reaction vessel with liquid nitrogen, evacuate it to remove air, and seal the reaction vessel under vacuum conditions. Subsequently, heat the reaction system to carry out an aldehyde-amine condensation reaction. After the reaction is completed, post-treatment is performed to obtain the imine-bonded two-dimensional covalent organic framework material COF-OH-1.

4. The method for preparing a covalent organic framework material for purifying aluminum ions in the production of acetone according to claim 3, characterized in that, Step 1) The molar ratio of THBT and DMPTD is 1:1.5 to 2; Step 1) The solvent is one or two of o-dichlorobenzene, n-butanol, mesitylene, 1,4-dioxane, and chloroform, and the ratio of the two solvents is 1 to 9:1 by volume or a single solvent.

5. The method for preparing a covalent organic framework material for purifying aluminum ions in the production of phenylacetone according to claim 3, characterized in that, The concentration of the acetic acid aqueous solution in step 2) is 3-12M; the amount of acetic acid aqueous solution added is 0.1-0.4 times the volume of the solvent in step 1); the amine condensation reaction conditions in step 2) are: reaction at 110-130℃ for 72-168h.

6. A method for preparing a covalent organic framework material for purifying aluminum ions during the production of acetone, as described in claim 1 or 2, characterized in that, The two-dimensional covalent organic framework material COF-COOH-1 with a carboxyl group structure is prepared by the following steps: 1) Place THBT and DMPTD in a reaction vessel, add solvent, and sonicate to mix them evenly; 2) Add acetic acid aqueous solution to the reaction vessel as a catalyst, then freeze the reaction vessel with liquid nitrogen, evacuate it to remove air, and seal the reaction vessel under vacuum conditions. Then, heat the reaction system to carry out aldehyde-amine condensation reaction. After the reaction is completed, post-treatment is performed to obtain the imine bond-linked two-dimensional covalent organic framework material COF-OH-1. 3) Add COF-OH-1 and ethylenediaminetetraacetic acid dianhydride to a reaction vessel, add solvent, sonicate to mix evenly, heat to react for a certain time at a certain temperature, and after the reaction is completed, treat the reaction product with NaHCO3 solution to obtain a two-dimensional covalent organic framework COF-COOH-1 with carboxyl group structure.

7. The method for preparing a covalent organic framework material for purifying aluminum ions in the acetone production process according to claim 6, characterized in that, Step 1) The molar ratio of THBT and DMPTD is 1:1.5-2; the solvent in Step 1) is one or two of o-dichlorobenzene, n-butanol, mesitylene, 1,4-dioxane, and chloroform, and the ratio of the two solvents is 1-9:1 by volume or a single solvent; Step 2) The concentration of the acetic acid aqueous solution is 3-12M; the amount of acetic acid aqueous solution added is 0.1-0.4 times the volume of the solvent in Step 1); Step 2) The amine condensation reaction conditions are: reaction at 110-130℃ for 72-168h.

8. The method for preparing a covalent organic framework material for purifying aluminum ions in the production of phenylacetone according to claim 6, characterized in that, In step 3), the molar ratio of ethylenediaminetetraacetic dianhydride to COF-OH-1 is 1:1.2 to 1.

5.

9. The method for preparing a covalent organic framework material for purifying aluminum ions in the production of phenylacetone according to claim 6, characterized in that, The solvent in step 3) is one of N,N-dimethylformamide and N,N-dimethylacetamide.

10. The method for preparing a covalent organic framework material for purifying aluminum ions in the production of phenylacetone according to claim 6, characterized in that, Step 3) The temperature is 60-80℃; the time is 36-54h.

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