Metal organic framework porous material and preparation method thereof
By controlling the reaction conditions and ligand ratio, metal organic skeleton porous materials with high specific surface area and pore volume were prepared, which solved the problem of insufficient adsorption and selectivity of existing materials in efficient adsorption of separated gases, and achieved significant application potential in the field of gas selective adsorption.
Patent Information
- Application Number
- CN202411871784.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-18
- Publication Date
- 2025-06-20
AI Technical Summary
Metal-organic skeleton porous materials are limited by the amount of adsorption and low selectivity in applications where separation gases are efficiently adsorbed.
By dissolving tetraimidazolyltetraphenylmethane, metal salt and terephthalic acid in a mixed solvent of methanol and water, heat treatment after ultrasonic treatment, controlling the reaction conditions and ligand ratio, a metal organic framework porous material with high specific surface area and pore volume was prepared.
The prepared metal-organic skeleton porous materials show great application potential in the field of gas selective adsorption, especially in the separation of CO2, SO2, NO and N2.
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Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of porous materials, and particularly relates to a metal-organic framework porous material and a preparation method thereof. Background Art
[0003] Metal-organic framework porous materials (MOF) have a large specific surface area, permanent pore structure, and adjustable pore shape and size, and can be widely used in the fields of adsorption and separation. They also have a certain selective adsorption ability for some gases, enabling the capture and separation of gases. However, their adsorption capacity and selectivity are still relatively low, which limits the application of metal-organic framework porous materials in the efficient adsorption and separation of gases. Summary of the Invention
[0004] In view of the above technical problems, the present invention provides a metal-organic framework porous material and a preparation method thereof.
[0005] Technical Solution: A preparation method of a metal-organic framework porous material includes the following steps: Dissolve tetramidotetraphenylmethane, metal salt, and terephthalic acid in a mixed solvent of methanol and water under ultrasonic conditions, add an alkali solution to adjust the pH to neutral, and magnetically stir at room temperature for 20 - 30 min; Transfer the reaction mixture to a reaction kettle with a polytetrafluoroethylene liner, heat-treat at 110 - 180 °C for 20 - 24 h, cool to room temperature, and then centrifuge to collect the product. After washing the solid and drying, the metal-organic framework porous material is obtained. The structure of tetramidotetraphenylmethane is as follows: .
[0006] Further, the metal salt is one or more of Fe 3+ , Al 3+ , Co 2+ and Zn 2+ .
[0007] Further, the metal salt is one or more combinations of nitrates, sulfates, and chlorides corresponding to metal ions.
[0008] Further, the molar ratio of the metal salt, tetramidotetraphenylmethane, and terephthalic acid is 2 - 3:1 - 2:2 - 5. Preferably, the molar ratio is 2:1:2.
[0009] Further, the volume ratio of methanol to water is 3:5 - 7.
[0010] Further, the alkali solution is sodium hydroxide solution, potassium hydroxide solution, or ammonia water.
[0011] Furthermore, when preparing the tetramidazolyl tetraphenylmethane, tetrabromotetraphenylmethane and imidazole are used as raw materials, anhydrous copper sulfate is used as a catalyst, and sodium carbonate or potassium carbonate is used as an acid-binding agent.
[0012] Beneficial effects: In the present invention, tetramidazolyl tetraphenylmethane is used as the first ligand and terephthalic acid is used as the second ligand. By controlling the ratio of the two ligands, a metal-organic framework porous material is prepared. The prepared material has a large specific surface area and pore volume, and has great application potential in the field of gas selective adsorption. Specific embodiments
[0013] The present invention will be specifically described below.
[0014] Example 1: Preparation of tetramidazolyl tetraphenylmethane: 7.63 g of tetrabromotetraphenylmethane and 6.53 g of imidazole were dissolved in 150 mL of DMF, 6.36 g of sodium carbonate and 50 mg of copper sulfate were added, and the mixture was stirred at room temperature for 24 h. After the reaction, 5.1 g of tetramidazolyl tetraphenylmethane was obtained by purification, and the yield was 71.28%.
[0015] Example 2: A method for preparing a metal-organic framework porous material, comprising the following steps: Dissolve 58 mg of tetramidazolyl tetraphenylmethane, 54 mg of FeCl3·6H2O and 33 mg of terephthalic acid in a mixed solvent of methanol and water (volume ratio 3:6) under ultrasonic conditions, and add 0.5 mol / L sodium hydroxide solution to adjust the pH to neutral. Stir magnetically at room temperature for 20 - 30 min; Transfer the reaction mixture to a reaction kettle with a polytetrafluoroethylene lining, heat-treat at 120 °C for 20 h, cool to room temperature, centrifuge to collect the product, wash the solid and dry to obtain the metal-organic framework porous material.
[0016] Example 3: A method for preparing a metal-organic framework porous material, comprising the following steps: Dissolve 58 mg of tetramidazolyl tetraphenylmethane, 133 mg of Al2(SO4)3·18H2O and 33 mg of terephthalic acid in a mixed solvent of methanol and water (volume ratio 3:6) under ultrasonic conditions, and add 0.5 mol / L sodium hydroxide solution to adjust the pH to neutral. Stir magnetically at room temperature for 20 - 30 min; Transfer the reaction mixture to a reaction kettle with a polytetrafluoroethylene lining, heat-treat at 120 °C for 20 h, cool to room temperature, centrifuge to collect the product, wash the solid and dry to obtain the metal-organic framework porous material.
[0017] Example 4: A preparation method of a metal-organic framework porous material, comprising the following steps: dissolving 58 mg of tetraimidazolyl tetraphenylmethane, 58 mg of Co(NO3)2·6H2O, and 33 mg of terephthalic acid in a mixed solvent of methanol and water (volume ratio 3:6) under ultrasonic treatment, adding 0.5 mol / L sodium hydroxide solution to adjust the pH to neutral, and magnetically stirring at room temperature for 20 - 30 min; transferring the reaction mixture to a reaction kettle with a polytetrafluoroethylene liner, heat-treating at 120 °C for 20 h, centrifuging to collect the product after cooling to room temperature, washing the solid, and drying to obtain the metal-organic framework porous material.
[0018] Example 5: A preparation method of a metal-organic framework porous material, comprising the following steps: dissolving 58 mg of tetraimidazolyl tetraphenylmethane, 47 mg of ZnNO3·6H2O, and 33 mg of terephthalic acid in a mixed solvent of methanol and water (volume ratio 3:6) under ultrasonic treatment, adding 0.5 mol / L sodium hydroxide solution to adjust the pH to neutral, and magnetically stirring at room temperature for 20 - 30 min; transferring the reaction mixture to a reaction kettle with a polytetrafluoroethylene liner, heat-treating at 120 °C for 20 h, centrifuging to collect the product after cooling to room temperature, washing the solid, and drying to obtain the metal-organic framework porous material.
[0019] Test example: The metal-organic framework porous materials prepared in Examples 2 - 5 were vacuum-treated with an ordinary oil pump at 100 °C for 10 hours, and the vacuum degree was less than 10 -3 mmHg; at 25 °C and 0 - 1 atmosphere, the CO2, SO 2、 NO, and N2 adsorption capacities of the metal-organic framework porous materials were tested on a Micrometrics ASAP2420 type gas adsorption instrument. The adsorption amounts of each gas are shown in Table 1.
[0020] Table 1: As can be seen from the above table, the adsorption amount of N2 by the metal-organic framework porous material is relatively low, much smaller than the adsorption amounts of CO2, SO2, and NO under the same conditions, indicating that this compound has potential application value in the separation of CO2, SO 2、 NO and N2.
[0021] Although the present invention has been disclosed above with preferred embodiments, they are not used to limit the present invention. Any person skilled in this art can make various changes or modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention should be defined by the protection scope of the claims of this application.
Claims
1. A method for preparing a metal organic framework porous material, characterized in that: The following steps are involved: Tetraimidazolyl tetraphenylmethane, metal salt and terephthalic acid are dissolved in a mixed solvent of methanol and water under ultrasound, and an alkali solution is added dropwise to adjust the pH to neutral, and magnetic stirring is performed at room temperature for 20-30 minutes; the reaction mixture is transferred to a polytetrafluoroethylene-lined reactor, and heat-treated at 110-180° C. for 20-24 hours, and the product is collected by centrifugation after cooling to room temperature, and the solid is washed and dried to obtain the metal organic framework porous material. The structure of tetraimidazolyl tetraphenylmethane is as follows: 。 2. The method for preparing a metal organic framework porous material according to claim 1, characterized in that: The metal salt is Fe 3+ 、Al 3+ 、Co 2+ and Zn 2+ One or more of .
3. The method for preparing a metal organic framework porous material according to claim 2, characterized in that: The metal salt is one or more combinations of nitrates, sulfates and chlorides corresponding to metal ions.
4. The method for preparing a metal organic framework porous material according to any one of claims 1 to 3, characterized in that: The molar ratio of the metal salt, tetraimidazolyltetraphenylmethane and terephthalic acid is 2-3:1-2:2-5.
5. The method for preparing a metal organic framework porous material according to claim 4, characterized in that: The molar ratio of the metal salt, tetraimidazolyltetraphenylmethane and terephthalic acid is 2:1:
2.
6. The method for preparing a metal organic framework porous material according to claim 1 or 4, characterized in that: The volume ratio of the methanol to water is 3:5-7.
7. The method for preparing a metal organic framework porous material according to claim 6, characterized in that: The alkali solution is sodium hydroxide solution, potassium hydroxide solution or ammonia water.
8. The method for preparing a metal organic framework porous material according to claim 7, characterized in that: The tetraimidazolyltetraphenylmethane is prepared by using tetrabromotetraphenylmethane and imidazole as raw materials, anhydrous copper sulfate as a catalyst, and sodium carbonate or potassium carbonate as an acid-binding agent.