A denitration catalytic filter material based on carbon-coated low-temperature SCR catalyst
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHANGZHOU INST OF LIGHT IND TECH
- Filing Date
- 2026-04-13
- Publication Date
- 2026-07-03
Abstract
Description
Technical Field
[0001] This invention relates to the field of denitrification catalytic filter media technology, specifically to a denitrification catalytic filter media based on a carbon-coated low-temperature SCR catalyst. Background Technology
[0002] Nitrogen oxides (NO) x NO is one of the main pollutants causing environmental problems such as acid rain, photochemical smog, and haze. Industrial flue gas (such as exhaust gases from coal-fired power plants, steel sintering, and waste incineration) is a major contributor to NO pollution. x The main emission source of air pollution is the flue gas, and its efficient treatment is of great significance. Selective catalytic reduction (SCR) is currently the most widely used flue gas denitrification technology, and its core lies in the research and development of high-performance catalysts. In recent years, loading denitrification catalysts onto the surface of high-temperature resistant filter media to prepare catalytic filter media with both dust removal and denitrification functions has attracted much attention because it can simplify the process and reduce equipment investment.
[0003] Ideal catalytic filter media not only need to possess excellent low-temperature catalytic activity, but also require that the active components be firmly loaded and uniformly dispersed on the surface of the filter media fibers, and be able to adapt to complex and ever-changing flue gas conditions. To this end, researchers have explored various surface modification strategies. Among them, using natural polyphenol compounds rich in catechol structures to perform surface functionalization modification on inert filter media, thereby anchoring the catalytically active components, has become one of the important technical approaches in this field.
[0004] Chinese invention patent CN 117504439 A discloses a technical solution for "Denitrification catalytic filter media based on tannic acid modification and its preparation method and application". This solution utilizes tannic acid to chemically modify the surface of the filter media, through the reaction of tannic acid with metal ions (such as Mn)... 2+ Ce 3+ Through the complexation reaction produced by potassium permanganate and the redox reaction between the complexed ions, the metal oxide denitration catalyst is firmly loaded onto the surface of the polymer filter media, thus preparing a catalytic composite filter media with low-temperature denitration function. This technology makes full use of the wide availability, low price, and high phenolic hydroxyl content of tannic acid, providing a useful approach for the development of denitration catalytic filter media.
[0005] However, in practical applications, the inventors found that the above-mentioned technical solution still has room for further improvement. Tannic acid is a thermosensitive natural polyphenol compound with a low glass transition temperature (Tg) (approximately 116℃) and a thermal decomposition initiation temperature of approximately 182℃. When the catalytic filter material is used in medium-low temperature denitrification conditions of 150-180℃, especially under long-term operation or flue gas temperature fluctuations, the micro-nano structures formed by the self-assembly of tannic acid are prone to softening, collapse, or even thermal decomposition and rearrangement. This structural evolution leads to two adverse effects: firstly, the catalytically active component (manganese cerium oxide) originally chelated and anchored by tannic acid migrates and agglomerates due to loss of support, reducing the dispersion and utilization rate of active sites; secondly, the tar-like substances produced by the decomposition of tannic acid may clog catalyst pores or cover active sites, thus adversely affecting the long-term stability of denitrification efficiency. Therefore, how to improve the structural stability of the modified layer under denitrification conditions while retaining the excellent anchoring ability of tannic acid has become a technical problem that urgently needs to be solved in this field.
[0006] Polydopamine, a representative material in mussel-inspired biochemistry, not only contains abundant catechol functional groups, enabling efficient anchoring of metal ions through chelation, but also exhibits higher structural stability in its cross-linked network formed under weakly alkaline conditions. More importantly, polydopamine is rich in nitrogen, and after carbonization in an inert atmosphere, it forms a nitrogen-doped carbon framework. This carbon framework not only possesses excellent thermal stability (withstanding temperatures above 300℃), but also exhibits a potential electronic synergistic effect between the nitrogen-doped carbon and manganese cerium oxide, which is beneficial for further enhancing low-temperature denitrification activity. Based on this, this patent proposes a denitrification catalytic filter material based on a carbon-coated low-temperature SCR catalyst and its preparation method, to overcome the defect of easy structural collapse of the tannic acid-modified layer under denitrification conditions in existing technologies, achieving simultaneous improvement in denitrification efficiency and high-temperature stability of the catalytic filter material. Summary of the Invention
[0007] The existing technology has the problem that the denitrification efficiency and stability of conventional denitrification catalytic filter media need to be further improved. To address the above technical problems, this invention provides a denitrification catalytic filter media based on a carbon-coated low-temperature SCR catalyst, the preparation method of which includes the following steps:
[0008] (1) Primary modification: The filter material is immersed in a hydrochloric acid dopamine solution and undergoes a self-assembly polymerization reaction under weakly alkaline conditions to form a polydopamine coating on the surface of the filter material. After removal, it is processed for later use.
[0009] (2) Loading of active components: The filter material modified in step (1) is immersed in a mixed solution containing manganese salt, cerium salt and nano titanium dioxide. The reaction is fully carried out so that the metal ions and nano titanium dioxide are loaded onto the polydopamine coating. The filter material is then removed, dried, and the above loading is repeated 2-3 times.
[0010] (3) Secondary modification: The filter material after step (2) is immersed again in the hydrochloric acid dopamine solution and carried out a secondary self-assembly polymerization reaction under weakly alkaline conditions. After being taken out and processed for later use;
[0011] (4) Oxidation treatment: Immerse the filter material obtained in step (3) in potassium permanganate solution for at least 1 hour, then remove, clean and dry;
[0012] (5) Carbonization heat treatment: The filter material obtained in step (4) is placed in an inert atmosphere for carbonization heat treatment to obtain denitrification catalytic filter material.
[0013] Preferably, the concentration of the dopamine hydrochloride solution in step (1) and / or step (3) is 0.1-10 mg / mL, more preferably 2-8 mg / mL; the pH value of the weakly alkaline condition is 8.0-9.0, preferably adjusted by trihydroxyaminomethane.
[0014] Preferably, the self-assembly polymerization reaction in step (1) takes 6-24 hours, and the secondary self-assembly polymerization reaction in step (3) takes 4-12 hours.
[0015] Preferably, the manganese salt in step (2) is at least one of manganese acetate, manganese nitrate or manganese chloride; the cerium salt is selected from one or more of cerium chloride, cerium nitrate and cerium acetate; the molar ratio of the manganese salt to the cerium salt is (1-10):(1-10), preferably (1-2):(1-2).
[0016] Preferably, the nano-titanium dioxide in step (2) is anatase nano-titanium dioxide with a particle size of 10-30 nm; the mass concentration of nano-titanium dioxide in the mixed solution is 2.5-7.5 mg / mL.
[0017] Preferably, the concentration of the potassium permanganate solution in step (4) is 0.05-0.5 mol / L, and the time for each oxidation reaction is 0.5-2 hours.
[0018] Preferably, the carbonization heat treatment in step (5) is carried out at a temperature of 200-350°C for 0.5-2 hours; the inert atmosphere is nitrogen or argon.
[0019] Preferably, the carbonization heat treatment in step (5) adopts a segmented carbonization process: first, maintain a constant temperature of 150-200℃ for 0.5-1 hour, and then raise the temperature to 250-320℃ and maintain a constant temperature for 1-2 hours.
[0020] Preferably, the filter media is a needle-punched filter media formed by polytetrafluoroethylene filter media, polyphenylene sulfide filter media, polyimide filter media, or a combination thereof, with an average pore size between 0.3 and 300 μm, a thickness of 0.5 to 5 mm, and a density of 100 to 500 kg / m³.3 .
[0021] Beneficial effects:
[0022] (1) This invention uses polydopamine as a functionalized modified layer on the surface of the filter material, overcoming the problem of insufficient thermal stability of tannic acid modified layers under denitrification conditions. Although tannic acid is rich in phenolic hydroxyl groups, its glass transition temperature is low (about 116°C). It is prone to softening and collapse during long-term operation at 150-180°C, leading to the migration and aggregation of active components. In contrast, the cross-linked network structure formed by polydopamine under weakly alkaline conditions is more stable. After carbonization heat treatment, it is transformed into a nitrogen-doped carbon skeleton, which can withstand high temperatures above 300°C and maintain structural integrity under denitrification conditions, ensuring that the active components are firmly anchored.
[0023] (2) This invention achieves dual anchoring protection of catalytic active components by constructing a nitrogen-doped carbon framework. On the one hand, the catechol groups in polydopamine capture manganese and cerium ions through chelation, thereby achieving uniform dispersion of active components; on the other hand, the nitrogen-doped carbon framework formed after carbonization encapsulates and embeds manganese and cerium oxide nanoparticles, effectively inhibiting the migration and aggregation of active components at high temperatures, and significantly improving the long-term stability of the catalytic filter material.
[0024] (3) In this invention, there is an electronic synergistic effect between the polydopamine-derived nitrogen-doped carbon skeleton and manganese cerium oxide, which is beneficial to improving the low-temperature denitrification activity. Nitrogen atom doping changes the electronic structure of the carbon skeleton, which can act as an electron donor to interact with transition metal oxides, promote the activation of NH3 and the oxidation of NO at the active sites, and broaden the active temperature window of the catalytic filter material, so that it can maintain a denitrification efficiency of more than 85% in the range of 150-200℃.
[0025] (4) The present invention adopts a process design of "first modification-active loading-second modification" to form a unique coating structure. The second modification of polydopamine encapsulates the loaded active component inside, which not only further enhances the loading strength, but also reacts in situ with potassium permanganate during the subsequent oxidation treatment, so that the newly generated MnO2 particles are embedded in the carbon skeleton together with the original active component, forming a multi-layered catalytic active layer.
[0026] (5) In the active component loading step of this invention, nano-titanium dioxide is introduced. Anatase TiO2 not only has good dispersibility but also produces a synergistic catalytic effect with manganese and cerium oxides. The introduction of an appropriate amount of TiO2 increases the dispersion of the active component and adjusts the distribution of acidic sites on the catalyst surface, which is beneficial to improving the resistance to sulfur poisoning. At the same time, TiO2 acts as a physical spacer in the carbon skeleton, preventing the agglomeration and sintering of active nanoparticles.
[0027] (6) The preparation method provided by this invention has strong process controllability. By adjusting parameters such as dopamine concentration, polymerization time, oxidation times and carbonization temperature, the thickness of the catalyst layer, the loading of active components and the carbon skeleton structure can be controlled to meet the application requirements under different working conditions. The filter material selection is flexible and can be adapted to various high-temperature resistant filter materials such as polytetrafluoroethylene, polyphenylene sulfide and polyimide, which has good industrial application prospects. Detailed Implementation
[0028] The present invention will be described in detail below with reference to embodiments. However, it should be understood that the following embodiments are merely illustrative examples of implementation of the present invention and are not intended to limit the scope of the present invention.
[0029] The experimental apparatus and reaction conditions used to test the denitrification effect of the denitrification catalytic filter media in the following embodiments of the present invention are completely consistent with Example 4 in Chinese Invention Patent CN 117504439 A.
[0030] Example 1
[0031] A denitrification catalytic filter material based on a carbon-coated low-temperature SCR catalyst is prepared as follows:
[0032] (1) Primary modification: Weigh 0.2g of dopamine hydrochloride and dissolve it in a mixed solvent of 45mL water and 5mL acetone. Adjust the pH to 8.5 with trihydroxyaminomethane to prepare a dopamine hydrochloride solution with a concentration of 4mg / mL. Use circular polyphenylene sulfide filter media with a diameter of 4.5cm (average pore size 50μm, thickness 1.8mm, density 380kg / m³) 3 Immerse the material in the above solution and react at room temperature in the dark for 12 hours to allow dopamine to fully self-polymerize and deposit, forming a polydopamine coating on the surface of the filter material. Remove the material and drain it slightly for later use.
[0033] (2) Loading of active components: Weigh 0.10 g of anatase nano-titanium dioxide (particle size 10 nm), ultrasonically disperse it in 20 mL of deionized water, and prepare a uniform TiO2 dispersion of 5 mg / mL. Add all of the above TiO2 dispersion to a 100 mL beaker, and then add 0.49 g of manganese acetate tetrahydrate and 0.43 g of cerium nitrate (controlling the molar ratio of Mn to Ce to be 2:1), and stir magnetically for 10 min until completely dissolved and mixed. Immerse the filter material modified in step (1) into the above mixed solution and react fully for 2 h to load the metal ions and nano-titanium dioxide onto the polydopamine coating, and then remove and air dry. Repeat the above loading process twice.
[0034] (3) Secondary modification: Prepare 0.2g of dopamine hydrochloride solution (pH 8.5) fresh according to the method in step (1), immerse the filter material treated in step (2) into the solution again, react at room temperature in the dark for 6 hours, and then take it out and drain it for later use.
[0035] (4) Oxidation treatment: Immerse the filter material obtained in step (3) in 20 mL of potassium permanganate solution with a concentration of 0.1 mol / L, react for 1 h, take it out and wash it with deionized water and anhydrous ethanol until the leaching liquid is colorless and then dry it.
[0036] (5) Carbonization heat treatment: The filter material obtained in step (4) is placed in a tube furnace and heated to 220°C under a nitrogen atmosphere. The temperature is kept constant for 1 hour and then cooled naturally to obtain the denitrification catalytic filter material.
[0037] Tests showed that the denitrification catalytic filter material prepared in this embodiment achieved a denitrification efficiency of 93.2% for nitrogen oxides at 180℃, and the efficiency retention rate was 97.1% after 100 hours of continuous operation.
[0038] The preparation method of Example 2 is basically the same as that of Example 1, except that the types and molar ratios of manganese salt and cerium salt are adjusted in step (2) of Example 2, as follows:
[0039] In step (2), manganese salt is manganese nitrate, added at a rate of 0.51 g; cerium salt is cerium chloride, added at a rate of 0.37 g (the molar ratio of Mn to Ce is controlled at 1:1). The amount and particle size of nano-titanium dioxide are the same as in Example 1. The active component loading process is repeated 3 times. The remaining steps are the same as in Example 1.
[0040] Tests showed that the denitrification catalytic filter material prepared in this embodiment achieved a denitrification efficiency of 92.8% for nitrogen oxides at 180°C, and the efficiency retention rate was 96.9% after 100 hours of continuous operation.
[0041] Example 3
[0042] A denitrification catalytic filter material based on a carbon-coated low-temperature SCR catalyst is prepared as follows:
[0043] (1) Primary modification: Weigh 0.3g of dopamine hydrochloride and dissolve it in a mixed solvent of 45mL water and 5mL acetone. Adjust the pH to 8.5 with trihydroxyaminomethane to prepare a dopamine hydrochloride solution with a concentration of 6mg / mL. Use circular polyphenylene sulfide filter media with a diameter of 4.5cm (average pore size 50μm, thickness 1.8mm, density 380kg / m³) 3 Immerse it in the above solution and react at room temperature in the dark for 12 hours. Remove and drain for later use.
[0044] (2) Loading of active components: Weigh 0.15 g of anatase nano-titanium dioxide (particle size 30 nm), ultrasonically disperse it in 20 mL of deionized water, and prepare a uniform TiO2 dispersion of 7.5 mg / mL. Add all of the above TiO2 dispersion to a 100 mL beaker, and then add 0.49 g of manganese acetate tetrahydrate and 0.86 g of cerium nitrate (controlling the molar ratio of Mn to Ce to be 1:2), and stir magnetically for 10 min. Immerse the filter material modified in step (1) into the mixed solution, react for 2 h, and then remove and air dry. Repeat the above loading process twice.
[0045] (3) Secondary modification: Prepare 0.3g of dopamine hydrochloride solution (pH 8.5) fresh according to the method in step (1), immerse the filter material treated in step (2) into the solution again, react at room temperature in the dark for 6 hours, and then take it out and drain it.
[0046] (4) Oxidation treatment: Same as step (4) in Example 1.
[0047] (5) Carbonization heat treatment: The filter material obtained in step (4) is placed in a tube furnace and heated to 200°C under a nitrogen atmosphere. The temperature is kept constant for 1 hour and then cooled naturally to obtain the denitrification catalytic filter material.
[0048] Tests showed that the denitrification catalytic filter media obtained in this embodiment had a denitrification efficiency of 91.8% for nitrogen oxides at 180°C, and the efficiency retention rate was 96.4% after 100 hours of continuous operation.
[0049] Example 4
[0050] A denitrification catalytic filter material based on a carbon-coated low-temperature SCR catalyst is prepared as follows:
[0051] (1) Primary modification: Weigh 0.2g of dopamine hydrochloride and dissolve it in a mixed solvent of 45mL water and 5mL acetone. Adjust the pH to 8.5 with trihydroxyaminomethane to prepare a dopamine hydrochloride solution with a concentration of 4mg / mL. Use circular polyimide filter media with a diameter of 4.5cm (average pore size 25μm, thickness 1.5mm, density 420kg / m³) 3 Immerse it in the above solution and react at room temperature in the dark for 12 hours. Remove and drain for later use.
[0052] (2) Loading of active components: Weigh 0.10 g of anatase nano-titanium dioxide (particle size 20 nm), ultrasonically disperse it in 20 mL of deionized water, and prepare a uniform TiO2 dispersion of 5 mg / mL. Add all of the above TiO2 dispersion to a 100 mL beaker, and then add 0.49 g of manganese acetate tetrahydrate and 0.43 g of cerium nitrate in sequence, and stir magnetically for 10 min. Immerse the filter material modified in step (1) into the mixed solution, react for 2 h, and then take it out and air dry. Repeat the above loading process 3 times.
[0053] (3) Secondary modification: Prepare 0.2g of dopamine hydrochloride solution (pH 8.5) fresh according to the method in step (1), immerse the filter material treated in step (2) into the solution again, react at room temperature in the dark for 6 hours, and then take it out and drain it.
[0054] (4) Oxidation treatment: Immerse the filter material obtained in step (3) in 20 mL of 0.1 mol / L potassium permanganate solution and react for 1 h. Remove, wash and dry. Repeat the above oxidation process 5 times.
[0055] (5) Carbonization heat treatment: The filter material obtained in step (4) is placed in a tube furnace, heated to 300°C under a nitrogen atmosphere, kept at a constant temperature for 1.5 hours, and then cooled naturally to obtain the denitrification catalytic filter material.
[0056] This embodiment uses polyimide filter media with better temperature resistance and a higher carbonization temperature (300℃) to investigate the effect of high-temperature carbonization on the structure and catalytic activity of nitrogen-doped carbon. The test results showed a denitrification efficiency of 94.8%, with an efficiency retention rate of 97.3% after 100 hours of continuous operation.
[0057] Example 5
[0058] A denitrification catalytic filter material based on a carbon-coated low-temperature SCR catalyst is prepared as follows:
[0059] (1) Primary modification: Weigh 0.1g of dopamine hydrochloride and dissolve it in a mixed solvent of 45mL water and 5mL acetone. Adjust the pH to 8.5 with trihydroxyaminomethane to prepare a dopamine hydrochloride solution with a concentration of 2mg / mL. Use circular polyimide filter media with a diameter of 4.5cm (average pore size 25μm, thickness 1.5mm, density 420kg / m³) 3 Immerse it in the above solution and react at room temperature in the dark for 12 hours. Remove and drain for later use.
[0060] (2) Loading of active components: Weigh 0.05 g of anatase nano-titanium dioxide (particle size 10 nm), ultrasonically disperse it in 20 mL of deionized water, and prepare a uniform TiO2 dispersion of 2.5 mg / mL. Add all of the above TiO2 dispersion to a 100 mL beaker, and then add 0.49 g of manganese acetate tetrahydrate and 0.43 g of cerium nitrate in sequence, and stir magnetically for 10 min. Immerse the filter material modified in step (1) into the mixed solution, react for 2 h, and then take it out and air dry. Repeat the above loading process twice.
[0061] (3) Secondary modification: Weigh 0.4g of dopamine hydrochloride and dissolve it in a mixed solvent of 45mL water and 5mL acetone. Adjust the pH to 8.5 with trihydroxyaminomethane to prepare a dopamine solution with a concentration of 8mg / mL. Immerse the filter material treated in step (2) in the above solution and react at room temperature in the dark for 12h. Remove and drain for later use.
[0062] (4) Oxidation treatment: Same as step (4) in Example 1, repeat the oxidation process 4 times.
[0063] (5) Carbonization heat treatment: The filter material obtained in step (4) is placed in a tube furnace and carbonized in a segmented manner under a nitrogen atmosphere: first, the temperature is raised to 180℃ and held for 0.5h, then the temperature is raised to 280℃ and held for 1h, and then cooled naturally to obtain the denitrification catalytic filter material.
[0064] This embodiment employs a gradient dopamine structure design with a thin inner layer and a thick outer layer, combined with a segmented carbonization process, to construct a catalytic layer with a gradient structure. Testing showed a denitrification efficiency of 95.5%, exhibiting excellent catalytic activity, and maintaining an efficiency of 96.8% after 100 hours of continuous operation.
[0065] Example 6
[0066] A denitrification catalytic filter material based on a carbon-coated low-temperature SCR catalyst is prepared using a method basically the same as in Example 1, except that the filter material is made of polytetrafluoroethylene, as detailed below:
[0067] The polyphenylene sulfide filter media in Example 1 was replaced with circular polytetrafluoroethylene filter media with a diameter of 4.5 cm (average pore size of 35 μm, thickness of 1.6 mm, and density of 360 kg / m³). 3 In step (1), the impregnation time is extended to 18 hours to ensure sufficient deposition of polydopamine on the low surface energy filter material. The remaining steps are the same as in Example 1.
[0068] Tests showed that the denitrification catalytic filter material prepared in this embodiment achieved a denitrification efficiency of 91.3% for nitrogen oxides at 180°C, and the efficiency retention rate was 96.2% after 100 hours of continuous operation, indicating that the preparation method is also applicable to inert filter materials such as polytetrafluoroethylene.
[0069] Comparative Example 1 is the same as Example 1, except that nano-titanium dioxide was not added in step (2) of Comparative Example 1. Step (2) of Comparative Example 1 is as follows:
[0070] Add 0.49g of manganese acetate tetrahydrate and 0.43g of cerium nitrate to a 100mL beaker, then add 20mL of deionized water and stir magnetically for 10min until completely dissolved and mixed. Immerse the modified filter material from step (1) into the above mixed solution and react fully for 2h to load the metal ions onto the polydopamine coating. Remove and air dry. Repeat the above loading process twice.
[0071] Tests showed that the denitrification catalytic filter material prepared in Comparative Example 1 achieved a denitrification efficiency of 87.5% for nitrogen oxides at 180℃, and the efficiency retention rate was 92.8% after 100 hours of continuous operation.
[0072] Comparative Example 2 is the same as Example 1, except that it skips the secondary modification step (3). Tests showed that the denitrification catalytic filter material prepared in Comparative Example 2 achieved a denitrification efficiency of 90.1% for nitrogen oxides at 180°C, and maintained an efficiency of 91.5% after 100 hours of continuous operation.
[0073] Comparative Example 3 is the same as Example 1, except that the anatase nano-titanium dioxide particles in Comparative Example 3 have a particle size of 100 nm. Testing showed that the denitrification catalytic filter material prepared in Comparative Example 3 achieved a denitrification efficiency of 88.2% for nitrogen oxides at 180°C, and maintained an efficiency of 94.5% after 100 hours of continuous operation.
[0074] Comparative Example 4 is a denitrification catalytic filter media prepared according to Example 4 of Chinese Invention Patent CN 117504439 A. Testing showed that the denitrification catalytic filter media prepared in Comparative Example 4 achieved a denitrification efficiency of 92% for nitrogen oxides at 180℃, and maintained an efficiency of 85% after 100 hours of continuous operation.
[0075] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.
Claims
1. A denitration catalyst filter material based on a carbon-coated low-temperature SCR catalyst, characterized by, The preparation method includes the following steps: (1) Primary modification: The filter material is immersed in a hydrochloric acid dopamine solution and undergoes a self-assembly polymerization reaction under weakly alkaline conditions to form a polydopamine coating on the surface of the filter material. After removal, it is processed for later use. (2) Loading of active components: The filter material modified in step (1) is immersed in a mixed solution containing manganese salt, cerium salt and nano titanium dioxide. The reaction is fully carried out so that the metal ions and nano titanium dioxide are loaded onto the polydopamine coating. The filter material is then removed, dried, and the above loading is repeated 2-3 times. (3) Secondary modification: The filter material after step (2) is immersed again in the hydrochloric acid dopamine solution and carried out a secondary self-assembly polymerization reaction under weakly alkaline conditions. After being taken out and processed for later use; (4) Oxidation treatment: Immerse the filter material obtained in step (3) in potassium permanganate solution for at least 1 hour, then take it out, clean and dry it; (5) Carbonization heat treatment: The filter material obtained in step (4) is placed in an inert atmosphere for carbonization heat treatment to obtain denitrification catalytic filter material. 2.The carbon-coated low-temperature SCR catalyst-based denitration filter material according to claim 1, characterized in that, The concentration of the dopamine hydrochloride solution in step (1) and / or step (3) is 0.1-10 mg / mL; the pH value of the weakly alkaline condition is 8.0-9.
0. 3.The carbon-coated low-temperature SCR catalyst-based denitration filter material according to claim 1, characterized in that, The self-assembly polymerization reaction in step (1) takes 6-24 hours, and the secondary self-assembly polymerization reaction in step (3) takes 4-12 hours. 4.The carbon-coated low-temperature SCR catalyst-based denitration filter material according to claim 1, characterized in that, The manganese salt mentioned in step (2) is at least one of manganese acetate, manganese nitrate or manganese chloride; the cerium salt is selected from one or more of cerium chloride, cerium nitrate and cerium acetate; the molar ratio of the manganese salt to the cerium salt is (1-2):(1-2).
5. The carbon-coated low-temperature SCR catalyst-based denitration filter material according to claim 1, characterized in that, The nano-titanium dioxide mentioned in step (2) is anatase nano-titanium dioxide with a particle size of 10-30 nm; the mass concentration of nano-titanium dioxide in the mixed solution is 2.5-7.5 mg / mL.
6. The denitrification catalytic filter material based on a carbon-coated low-temperature SCR catalyst according to claim 1, characterized in that, The concentration of the potassium permanganate solution in step (4) is 0.05-0.5 mol / L, and the time for each oxidation reaction is 0.5-2 hours.
7. The denitrification catalytic filter material based on a carbon-coated low-temperature SCR catalyst according to claim 1, characterized in that, The carbonization heat treatment in step (5) is carried out at a temperature of 200-350°C for 0.5-2 hours; the inert atmosphere is nitrogen or argon.
8. The denitrification catalytic filter material based on a carbon-coated low-temperature SCR catalyst according to claim 1, characterized in that, The carbonization heat treatment in step (5) adopts a segmented carbonization process: first, it is kept at a constant temperature of 150-200℃ for 0.5-1 hour, and then the temperature is raised to 250-320℃ and kept at a constant temperature for 1-2 hours.
9. A denitrification catalytic filter material based on a carbon-coated low-temperature SCR catalyst according to claim 1, characterized in that, The filter media is polytetrafluoroethylene filter media, polyphenylene sulfide filter media, polyimide filter media, and needle-punched filter media formed by their combination.