Preparation method of nitrogen-doped activated carbon composite zirconium-based metal organic framework material

Abstract

The application provides a preparation method and application of a nitrogen-doped activated carbon composite zirconium-metal organic framework material. The zirconium-metal organic framework is compounded with the nitrogen-doped activated carbon, mixed and ground, and the mixed powder is bonded into a form by using a binder to obtain a broad-spectrum adsorption material capable of carrying multiple adsorption sites and synergistically acting on various toxic and harmful gas pollutants; then, the broad-spectrum adsorption material is impregnated and loaded with ammonium bicarbonate, basic copper carbonate, basic zinc carbonate, silver nitrate, ammonium molybdate tetrahydrate and potassium hydroxide by using ammonia water; the nitrogen-doped activated carbon composite zirconium-metal organic framework material has good protection capability for benzene, chloroethane, hydrocyanic acid, cyanogen chloride, sulfur dioxide, hydrogen sulfide and ammonia gas.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of broad-spectrum protective materials, in particular to a nitrogen-doped activated carbon composite zirconium-based metal-organic framework adsorption material and a preparation method thereof. BACKGROUND

[0002] At present, the filter-type protective materials at home and abroad mainly use ASZM-TEDA type impregnated activated carbon as the protective material, and the protective ability of the activated carbon to most toxic industrial chemicals such as SO2, NO2 and NH3 is relatively limited, and the toxic substance molecules physically adsorbed on the surface of the activated carbon are prone to desorption at room temperature. However, the environmental adsorption material and the protection technology are generally only aimed at one kind or several similar pollutants, especially in some limited (closed) environments and emergency accident handling, various gases with different properties, such as acidic SO2, H2S and alkaline NH3, inorganic gases (CNCl, HCN, etc.) and organic VOCs (benzene vapor, etc.) coexist, which requires the development of a multifunctional broad-spectrum adsorbent that can carry multiple adsorption sites on the material and synergistically act on various toxic and harmful gas pollutants.

[0003] The activated carbon is widely used in the adsorption of toxic and harmful gases in the environment due to its high specific surface area, good stability and rich micropore content, but the adsorption of the activated carbon is relatively single, the protection of acid and alkali gases is not balanced, and the general activated carbon has the defects of small pore volume, wide pore size distribution, low adsorption capacity and insufficient deep adsorption capacity. The nitrogen-doped activated carbon can make the nitrogen-containing groups highly dispersed on the pore surface of the activated carbon, significantly increase the contact area between the alkaline active sites on the surface of the activated carbon and the acid gas molecules, and promote the rapid oxidation and conversion of the acid gas molecules.

[0004] Metal-organic frameworks (MOFs) have high specific surface area and diverse structures, and the modular construction method enables people to flexibly design the properties of MOFs as needed, so MOFs are considered to be the most potential new protective materials for realizing the broad-spectrum protection and in-situ disinfection of toxic substances. The Zr-MOFs have the characteristics of high specific surface area, high porosity, small pore size, controllable structure, excellent hydrothermal stability and chemical stability, and can overcome the defects of poor stability of many other MOFs materials, so the Zr-MOFs are widely used in the field of gas adsorption. However, the low density and large void space of the Zr-MOFs make the dispersion force in the pores weak, and small molecules are prone to escape from the material. Therefore, by simultaneously utilizing the advantages of the activated carbon material and the Zr-MOFs, a new broad-spectrum adsorption material with good protective ability to gases with different properties can be prepared. SUMMARY

[0005] The application aims to provide a preparation method of activated carbon composite metal organic framework broad-spectrum adsorption material with good protection ability for toxic and harmful gases with different properties. The prepared adsorption material realizes balanced protection of multiple gases, improves the protection efficiency of the catalyst, and provides significant exploration for the large-scale research and production of a new generation of broad-spectrum protection material.

[0006] The application is implemented by using the following technical scheme:

[0007] Step one, preparation of zirconium-based metal organic framework material: a DMF solution of zirconium tetrachloride is added to a DMF solution containing 2,2-bipyridine-5,5-dicarboxylic acid and 2-amino terephthalic acid, and a zirconium-based metal organic framework material is obtained after a solvothermal reaction;

[0008] Step two, preparation of activated carbon containing nitrogen groups: a urea aqueous solution is added to coconut shell carbon and mixed uniformly, and then pyrolysis carbonization is performed under an inert atmosphere to obtain activated carbon containing nitrogen material;

[0009] Step three, preparation of activated carbon containing nitrogen material composite zirconium-based metal organic framework material: the zirconium-based metal organic framework material obtained in step one is mixed with the activated carbon containing nitrogen material obtained in step two, and then a binder is used for binding to form composite adsorption material particles;

[0010] Step four, preparation of carbon material composite zirconium-based metal organic framework impregnated with metal components: a metal active component is dissolved in an ammonia solution, and then added to the composite adsorption material particles obtained in step three for impregnation and adsorption, dried, and then triethylenediamine is added to obtain nitrogen-doped activated carbon composite zirconium-based metal organic framework material.

[0011] Preferably, in step one, the molar ratio of zirconium tetrachloride to 2,2-bipyridine-5,5-dicarboxylic acid and 2-amino terephthalic acid is 4-12:3-9:1-3.

[0012] In step one, the mass ratio of urea to coconut shell carbon is 1-5:5, and urea can be replaced by melamine or aniline.

[0013] Preferably, the pyrolysis carbonization temperature in step two is 300-800 DEG C, and in some embodiments, as long as the carbonization process of the urea solution in the coconut shell carbon can be realized, the activated carbon containing nitrogen material can be realized.

[0014] Preferably, the coconut activated carbon can be replaced by coal activated carbon, wood activated carbon, etc.

[0015] Preferably, the mass ratio of the zirconium-based metal organic framework material to the nitrogen-containing activated carbon is 1:20-100.

[0016] Preferably, the adhesive is one of asphalt, coal tar, silica sol. The purpose of the adhesive is to realize the process of zirconium-based metal organic framework material and nitrogen-containing activated carbon into balls, for the surface stability adsorption phenomenon in the impregnation process.

[0017] Preferably, the particle size of the composite adsorbent material in step three is 12-26 mesh.

[0018] Preferably, the metal active component in step four is selected from one or more of ammonium bicarbonate, basic copper carbonate, basic zinc carbonate, silver nitrate, ammonium molybdate, potassium hydroxide.

[0019] As a preferred solution, the mass ratio of the metal active component of basic copper carbonate, basic zinc carbonate, ammonium bicarbonate, silver nitrate, potassium hydroxide is 1-5:0.1-2:2-7:0.001-0.1:1-5; potassium hydroxide can be replaced by sodium hydroxide.

[0020] Preferably, the drying of the composite adsorbent material after impregnation adsorption can be replaced by water bath heating, microwave-assisted heating and other heating methods.

[0021] The present application has the following beneficial effects:

[0022] (1) The preparation method of the nitrogen-doped activated carbon composite zirconium-based metal organic framework material provided by the present application is to composite zirconium-based metal organic framework and nitrogen-doped activated carbon, mix and grind, and then use a binder to bond the mixed powder into a shape to obtain a broad-spectrum adsorbent material that can carry multiple adsorption sites and synergistically act on various toxic and harmful gas pollutants. The present application uses activated carbon and zirconium MOF to composite, which can provide additional adsorption sites for activated carbon, optimize the pore size of zirconium MOF, form new pores and provide additional adsorption sites, improve the adsorption capacity, and the prepared nitrogen-doped activated carbon composite zirconium-based metal organic framework material has good protection capability for gases with different properties, and the price is relatively low, which has good engineering application prospect.

[0023] (2) The nitrogen-doped activated carbon composite zirconium-based metal organic framework material provided by the present application is broken into large particles after being formed by bonding, and then impregnated, which is beneficial to the impregnation of active components and is not easy to be covered, and the catalyst has better gas adsorption performance.

[0024] (3) The zirconium MOF material in the nitrogen-doped activated carbon composite zirconium-based metal organic framework material provided by the present application has a special pore structure and surface activity compared with zirconium oxide, and can efficiently adsorb and catalytically degrade gases with different properties. DETAILED DESCRIPTION

[0025] The present application will be further described below in conjunction with specific examples.

[0026] Example 1

[0027] (1) 0.466 g of ZrCl4 was dissolved in 30 mL of DMF, 0.366 g of 2,2-bipyridine-5,5-dicarboxylic acid, 87 mg of 2-amino terephthalic acid were added to 79 mL of DMF, ultrasonic dispersion, then the two were added to the reaction kettle tetrafluoroethylene inner container and mixed evenly, then 10 mL of glacial acetic acid was added, ultrasonic dispersion for 10 min and mixed evenly, then reacted at 90°C for 18 h. After the reaction was completed, the metal organic framework material was washed with DMF three times by centrifugation, and then dried at 80°C under vacuum for 24 h to obtain a zirconium-based metal organic framework material;

[0028] (2) 25 g of urea was dissolved in 50 mL of ultrapure water, then 50 g of coconut shell charcoal was added and kneaded for 3 h, then placed in an oven at 80°C for 24 h; after taking out, the dried material was placed in a rotary tube furnace, pyrolyzed and carbonized under N2 atmosphere at a heating rate of 5°C / min to 500°C for 2 h, and finally cooled to room temperature under nitrogen to take out the solid sample, which was a nitrogen-containing activated carbon;

[0029] (3) The zirconium-based metal organic framework material obtained in step (1) and the nitrogen-containing activated carbon obtained in step (2) were ground to a particle size of 200 mesh at a ratio of 1:20;

[0030] (4) The mixed powder obtained in step (3) was bonded and formed with coal tar pitch, and a composite adsorbent material particle with a particle size of 16-26 mesh was prepared for standby;

[0031] (5) 9 g of basic copper carbonate, 1.5 g of basic zinc carbonate, 5 g of ammonium bicarbonate, and 0.015 g of silver nitrate were weighed and dissolved in 60 mL of ammonia water solution, and stirred at 60°C until completely dissolved;

[0032] (6) The solution obtained in step (5) was added to the composite adsorbent material obtained in step (4), stirred uniformly at room temperature, dried at 90°C for 1.5 h, and then dried at 150°C for 3 h;

[0033] (7) The mixed adsorbent material of step (6) was added to 3% TEDA, then sealed and placed at 65°C for 1 h to obtain a nitrogen-doped activated carbon composite zirconium-based metal organic framework material.

[0034] Example 2

[0035] The method and steps are the same as in Example 1, except that the zirconium-based metal organic framework material and the nitrogen-containing activated carbon are ground to a particle size of 200 mesh at a ratio of 1:50.

[0036] Example 3

[0037] The method and steps are the same as in Example 1, except that the zirconium-based metal organic framework material and the nitrogen-containing activated carbon are ground to a particle size of 200 mesh at a ratio of 1:100.

[0038] Example 4

[0039] (1) 0.666 g of ZrCl4 was dissolved in 30 mL of DMF. 0.366 g of 2,2-bipyridine-5,5-dicarboxylic acid, 87 mg of 2-amino terephthalic acid, 79 mL of DMF were added, ultrasonically dispersed, and then mixed evenly in the tetrafluoroethylene inner container of the reaction kettle. 10 mL of glacial acetic acid was added, mixed evenly for 10 min under ultrasonication, and then reacted at 90°C for 18 h. After the reaction was completed, the zirconium-based metal organic framework material was washed with DMF three times by centrifugation, and then dried at 80°C under vacuum for 24 h.

[0040] (2) 50 g of urea was dissolved in 50 mL of ultrapure water, and then mixed and kneaded with 50 g of coconut shell charcoal for 3 h. The mixture was then placed in an oven at 80°C for 24 h. After being taken out, the dried material was placed in a rotary tube furnace, pyrolyzed and carbonized at 500°C for 2 h under N2 atmosphere at a heating rate of 5°C / min, and finally cooled to room temperature under nitrogen to take out the solid sample, which was the nitrogen-containing activated carbon.

[0041] (3) The zirconium-based metal organic framework material obtained in step (1) and the nitrogen-containing activated carbon obtained in step 2) were ground to a particle size of 200 mesh at a ratio of 1:30.

[0042] (4) The mixed powder obtained in step (3) was bonded and shaped with coal tar pitch, and a composite adsorbent material particle with a particle size of 16-26 mesh was prepared for standby use.

[0043] (5) 9 g of basic copper carbonate, 1.5 g of basic zinc carbonate, 5 g of ammonium bicarbonate, and 0.015 g of silver nitrate were weighed and dissolved in 60 mL of ammonia water solution. The solution was stirred at 60°C until completely dissolved.

[0044] (6) The solution obtained in step (5) was added to the composite adsorbent material obtained in step 4), and stirred evenly at room temperature. After drying at 90°C for 1.5 h, it was further dried at 150°C for 3 h.

[0045] (7) The mixed adsorbent material of step (6) was added to 3% TEDA, and then sealed and placed at 65°C for 1 h to obtain a nitrogen-doped activated carbon composite zirconium-based metal organic framework material.

[0046] Comparative Example 1

[0047] The method and steps were the same as in Example 1, except that step (1) was not included, and the zirconium oxide and the obtained nitrogen-containing activated carbon were ground to a particle size of 200 mesh at a ratio of 1:20 to obtain a nitrogen-doped activated carbon zirconium-based metal organic framework material.

[0048] Comparative Example 2

[0049] The method and steps are the same as Example 1, only 2,2-bipyridine-5,5-dicarboxylic acid is added in step (1) instead of 2-amino terephthalic acid to obtain a nitrogen-doped activated carbon zirconium metal organic framework material.

[0050] Comparative Example 3

[0051] The method and steps are the same as Example 1, only 2-amino terephthalic acid is added in step (1) instead of 2,2-bipyridine-5,5-dicarboxylic acid to obtain a nitrogen-doped activated carbon zirconium metal organic framework material.

[0052] Comparative Example 4

[0053] The method and steps are the same as Example 1, only the nitrogen-containing activated carbon obtained in step (2) is added to step (1) for solvothermal reaction, and the technical solutions of steps (3) and (4) are omitted to obtain a nitrogen-doped activated carbon zirconium metal organic framework material.

[0054] The materials prepared in the examples and comparative examples are tested and evaluated for protection time against cyanogen chloride, hydrocyanic acid, sulfur dioxide, ammonia, and hydrogen sulfide.

[0055] Cyanogen chloride: specific speed 0.25 L / min·cm 2 , height 2.5 cm, initial concentration of cyanogen chloride 9.0 mg / L.

[0056] GJB 6239.19-2008

[0057] Hydrocyanic acid: specific speed 0.25 L / min·cm 2 , height 2.5 cm, initial concentration of hydrocyanic acid 9.0 mg / L.GJB6239.18-2008

[0058] Sulfur dioxide: specific speed 0.25 L / min·cm 2 , height 2.5 cm, initial concentration of sulfur dioxide 4.0 mg / L.

[0059] WJ20642.2-2018

[0060] Ammonia: specific speed 0.25 L / min·cm 2 , height 2.5 cm, initial concentration of ammonia 2.1 mg / L.WJ20642.1-2018

[0061] Hydrogen sulfide: specific speed 0.31 L / min·cm2, height 2.5 cm, initial concentration of hydrogen sulfide 4.0 mg / L.WJ20453.2-2016

[0062] Table 1 Protection time table (min) of cyanogen chloride, hydrocyanic acid, sulfur dioxide, ammonia, and hydrogen sulfide

[0063] Sample Chlorinated cyanogen Hydrocyanic acid Sulfur dioxide Ammonia Hydrogen sulfide Example 1 20 25 64 28 57 Example 2 18 27 56 35 50 Example 3 25 26 81 39 69 Example 4 21 22 75 36 62 Comparative Example 1 12 13 32 18 28 Comparative Example 2 18 14 30 15 30 Comparative Example 3 15 19 28 20 29 Comparative Example 4 16 14 26 20 25

Claims

1. The application of nitrogen-doped activated carbon composite zirconium-based metal-organic framework materials in the protection against one or more of cyanide chloride, hydrogen cyanide, sulfur dioxide, ammonia, and hydrogen sulfide, characterized in that: A method for preparing nitrogen-doped activated carbon composite zirconium-based metal-organic framework materials includes the following steps: Step 1: Preparation of zirconium-based metal-organic framework materials: A DMF solution of zirconium tetrachloride is added to a DMF solution containing 2,2-bipyridine-5,5-dicarboxylic acid and 2-aminoterephthalic acid, and the zirconium-based metal-organic framework material is obtained after a solvothermal reaction. Step 2: Preparation of nitrogen-containing groups in activated carbon: After adding urea aqueous solution to coconut shell carbon and mixing evenly, the mixture is pyrolyzed and carbonized under an inert atmosphere to obtain nitrogen-containing activated carbon material. Step 3: Preparation of zirconium-based metal-organic framework composite material of activated carbon nitrogen-containing material: The zirconium-based metal-organic framework material obtained in Step 1 and the activated carbon nitrogen-containing material obtained in Step 2 are ground and mixed, and then bonded and shaped with a binder to obtain composite adsorbent material particles. Step 4: Preparation of carbon-based composite zirconium-based metal-organic framework impregnated with metal components: The active metal components are dissolved in ammonia water and then added to the composite adsorbent particles obtained in Step 3 for impregnation and adsorption. After drying, triethylenediamine is added and the mixture is sealed to obtain nitrogen-doped activated carbon composite zirconium-based metal-organic framework material.

2. The application according to claim 1, characterized in that: In step one, the molar ratio of zirconium tetrachloride to 2,2-bipyridine-5,5-dicarboxylic acid and 2-aminoterephthalic acid is 4-12:3-9:1-3; In step one, the mass ratio of urea to coconut shell charcoal is 1 to 5:

5. Urea can be replaced by melamine or aniline.

3. The application according to claim 1, characterized in that: The temperature for pyrolysis and carbonization in step two is 300–800℃.

4. The application according to claim 1, characterized in that: In step two, coconut shell activated carbon can be replaced by coal-based activated carbon or wood-based activated carbon.

5. The application according to claim 1, characterized in that: In step three, the mass ratio of zirconium-based metal-organic framework material to nitrogen-containing activated carbon during grinding is 1:20 to 100.

6. The application according to claim 1, characterized in that: In step three, the binder is one of asphalt, coal tar, or silica sol, and the particle size of the composite adsorbent material is 12-26 mesh.

7. The application according to claim 1, characterized in that: In step four, the active metal component is selected from one or more of the following: ammonium bicarbonate, basic copper carbonate, basic zinc carbonate, silver nitrate, ammonium molybdate tetrahydrate, and potassium hydroxide.

8. The application according to claim 7, characterized in that: In step four, the active metal components are basic copper carbonate, basic zinc carbonate, ammonium bicarbonate, silver nitrate, and potassium hydroxide in a mass ratio of 1–5: 0.1–2: 2–7: 0.001–0.1: 1–5; potassium hydroxide can be replaced by sodium hydroxide.

9. The application according to claim 1, characterized in that: The drying of composite adsorbent particles after impregnation and adsorption can be achieved by water bath heating or microwave-assisted heating.