A preparation method of a Cu-MOF adsorbent for CO2 adsorption capture

Abstract

The application discloses a preparation method of a Cu-MOF adsorbent for CO2 adsorption and capture. A 4mL mixed solution of N,N-dimethylformamide and 2-8mL acetonitrile is prepared in a test tube, 60mg of pyrazine-2,5-dicarboxylic acid is added into the mixed solution, and ultrasonic mixing is performed to form a solution 1; then a 2mL mixed solution of N,N-dimethylformamide and 1-3mL acetonitrile is prepared, and is carefully spread on the upper layer of the solution 1 by using a 5mL dropper to form a solution 2 as a slow diffusion layer to avoid rapid crystallization; 30mg of copper nitrate is added into a 4mL mixed solution of N,N-dimethylformamide and 2-8 mL acetonitrile, and then is ultrasonically dissolved, and is carefully spread on the upper layer of the solution 2 by using a 5mL dropper; finally, the test tube is sealed, and is placed at room temperature of 25 DEG C for 12-24h; the solution after ultrasonic treatment is subjected to centrifugal treatment at a speed of 6000-8000, and is washed with anhydrous acetonitrile and ethanol for three times, and then is freeze-dried to obtain the product. The Cu-MOF prepared by the method has a nanoflower structure, uniform size and good dispersity, and can be applied to air capture of CO2.

Description

Technical Field

[0001] This invention belongs to the field of nanomaterials technology, and particularly relates to a method for preparing Cu-MOF adsorbents for CO2 adsorption and capture. Background Technology

[0002] Carbon dioxide capture technology has received widespread attention in order to mitigate global warming and climate change caused by the rapid rise in atmospheric carbon dioxide concentration. Since the partial pressure of carbon dioxide in flue gas mixtures is relatively low (8-15%) within the atmospheric pressure range, developing highly selective and cost-effective carbon dioxide stripping methods under near-environmental conditions is crucial for reducing carbon footprint and emissions.

[0003] As part of the capture process, amine washing, pure oxygen combustion, and calcium cycling have reached a level of maturity suitable for commercial applications, but all involve significant energy consumption. Alongside these proposed technologies, the use of solid adsorbents has been explored, as these adsorbents can capture carbon dioxide at low temperatures and have lower energy requirements. Solid adsorption methods often employ porous materials such as zeolites, mesoporous silica, carbon nanotubes, metal-organic frameworks (MOFs), covalent organic frameworks (COFs), and hydrogen-bonded organic frameworks (HOFs). Furthermore, considerable research has achieved further tuning of the topology, kinetic diameter, and physicochemical properties of porous materials to adapt to CO2 capture requirements under different conditions. Among other materials studied, MOFs have emerged as an exciting potential carbon dioxide adsorbent. MOFs are a class of crystalline and porous materials, consisting of networks of metal ions or metal clusters linked to multidentate organic molecules through strong metallic coordination bonds. Their tunable structure, high specific surface area, and highly selective carbon dioxide adsorption capacity make them particularly promising materials.

[0004] Since the properties of a material are closely related to its morphology, including factors such as its specific size and shape, the controllable preparation of the material's morphology and size has become an important way to regulate its properties. Summary of the Invention

[0005] To address the problems existing in the prior art, the present invention provides a method for preparing Cu-MOF adsorbents for CO2 adsorption and capture.

[0006] This invention is achieved by providing a method for preparing a Cu-MOF adsorbent for CO2 adsorption and capture, comprising the following steps:

[0007] S101, prepare a mixed solution of 4 mL N,N-dimethylformamide and 2-8 mL acetonitrile in a test tube, add 60 mg pyrazine-2,5-dicarboxylic acid to the above mixed solution, and mix evenly by ultrasonication to form solution 1;

[0008] Then prepare a mixed solution of 2 mL N,N-dimethylformamide and 1-3 mL acetonitrile to form solution 2, and carefully spread it on top of solution 1 using a 5 mL dropper;

[0009] S102, dissolve 30 mg of copper nitrate by sonication in a mixed solution consisting of 4 mL of N,N-dimethylformamide and 2-8 mL of acetonitrile, and carefully spread it on the upper layer of solution 2 using a 5 mL dropper;

[0010] S103, at room temperature (25℃), the test tube is sealed and left to stand for 12-24 hours. The solution in the test tube is then sonicated and centrifuged. After washing three times with anhydrous acetonitrile and ethanol respectively, the Cu-MOF product is obtained by freeze drying.

[0011] Furthermore, the ultrasonic mixing process in S101 takes 5-20 minutes.

[0012] Furthermore, the Cu-MOF is in the form of nanoflowers, and the nanoflower-shaped Cu-MOF is prepared using the above-described method for preparing Cu-MOF adsorbents.

[0013] Furthermore, the nano-flower-like Cu-MOF can be used to prepare CO2 adsorbents.

[0014] Furthermore, solution 2 in S101 is carefully spread on top of solution 1 using a 5mL dropper as a slow diffusion layer to avoid rapid crystallization.

[0015] Furthermore, S102 is carefully spread on top of solution 2 to form a third layer. The reaction rate is controlled by interfacial diffusion, which is beneficial to the formation of nanoflowers.

[0016] Furthermore, S103 is centrifuged at speeds of 4000-8000.

[0017] Based on the above technical solutions and the technical problems solved, the advantages and positive effects of the technical solution to be protected by this invention are as follows:

[0018] The expected benefits and commercial value of the technical solution after transformation are as follows: This invention can realize the preparation of uniformly sized nano-Cu-MOFs, the process is simple, and it has certain commercial value. The Cu-MOFs prepared by this invention have a nano-flower-like structure, high purity, uniform size, and good dispersibility; the technical solution to be protected by this invention has a simple process and does not require high temperature and high pressure. Attached Figure Description

[0019] Figure 1 This is a flowchart of the preparation method of nanoflower-shaped Cu-MOF provided in the embodiments of the present invention.

[0020] Figure 2 This is a scanning electron microscope (SEM) image of the product obtained in Example 1 of the present invention.

[0021] Figure 3 This is the X-ray diffraction (XRD) pattern of the product obtained in Example 1 of the present invention. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] Example 1

[0024] S101, take a test tube and dissolve 60 mg of pyrazine-2,5-dicarboxylic acid in a mixed solution of 4 mL of N,N-dimethylformamide and 2 mL of acetonitrile. Sonicate for 10 minutes to mix evenly to form solution 1; then prepare a mixed solution of 2 mL of N,N-dimethylformamide and 2 mL of acetonitrile to form solution 2, and carefully spread it on top of solution 1 using a 5 mL dropper;

[0025] S102: Dissolve 30 mg of copper nitrate in a mixed solution of 4 mL of N,N-dimethylformamide and 4 mL of acetonitrile, then sonicate for 5 minutes to dissolve, and carefully spread it on the upper layer of solution 2;

[0026] S103, finally seal the test tube with plastic wrap, let it stand at room temperature (25℃) for 12-24 hours. After ultrasonic treatment, the solution is centrifuged at 6000 rpm, washed three times with anhydrous acetonitrile and ethanol, and then freeze-dried to obtain the light green Cu-MOF product.

[0027] The morphology of the Cu-MOF prepared in the embodiments of the present invention is as follows: Figure 2 As shown, it exhibits a nano-flower-like structure; and is uniform in size and well-dispersed; the crystal structure of the obtained product is as follows. Figure 3 As shown, it has high crystallinity and good crystal form; the obtained nano-flower-like Cu-MOF can be used to capture CO2 from the air.

[0028] To demonstrate the inventiveness and technical value of the technical solution of this invention, this section provides specific product or related technology application examples of the technical solution claimed.

[0029] The nano-flower-like Cu-MOF prepared by the method provided in this invention can be applied to capture CO2 from the air.

[0030] The above are merely preferred embodiments of the present invention. It should be noted that the above preferred embodiments should not be considered as limitations on the present invention, and the scope of protection of the present invention should be determined by the scope defined in the claims. For those skilled in the art, several improvements and modifications can be made without departing from the spirit and scope of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing Cu-MOF adsorbent for CO2 adsorption and capture, characterized in that: Includes the following steps, S101, prepare a mixed solution of 4 mL N,N-dimethylformamide and 2-8 mL acetonitrile in a test tube, add 60 mg pyrazine-2,5-dicarboxylic acid to the above mixed solution, and sonicate to mix evenly. The sonication time is 5-20 min to form solution 1. Then prepare a mixed solution of 2 mL N,N-dimethylformamide and 1-3 mL acetonitrile to form solution 2, and carefully spread it on top of solution 1 using a 5 mL dropper; S102, dissolve 30 mg of copper nitrate in a mixed solution consisting of 4 mL of N,N-dimethylformamide and 2-8 mL of acetonitrile using ultrasonication, and carefully spread it on the upper layer of solution 2 using a 5 mL dropper; S103, at room temperature (25℃), the test tube is sealed and left to stand for 12-24 hours. The solution in the test tube is then sonicated and centrifuged. After washing three times with anhydrous acetonitrile and ethanol respectively, the Cu-MOF product is obtained by freeze drying.

2. The method for preparing Cu-MOF adsorbent for CO2 adsorption and capture according to claim 1, characterized in that: The Cu-MOF is in the form of nanoflowers.

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