A carbon-based catalyst, PTFE catalytic filter material, and their preparation methods and applications

Abstract

The present invention discloses a carbon-based catalyst, a PTFE catalytic filter material, and their preparation methods and applications. The preparation of the photocatalyst includes the preparation of a carbon-based carrier, the loading of active components, and the optimization of carbon quantum dots (CQDs). The prepared CQDs-MnCe / C catalyst uses carbon quantum dots to optimize the electron transport channels of the catalyst, and utilizes the metal-interaction between Mn and Ce and the carbon quantum dots to regulate the surface acidic sites and active sites, effectively improving the low-temperature catalytic performance. The CQDs-MnCe / C catalyst is combined with a PTFE calendered film using a binder, and then through steps such as stretching, slitting, curling, and needling, a PTFE catalytic filter material in which the catalyst is firmly bonded to the filter material surface is formed. The binder is used to strengthen the bonding strength between the catalyst and the filter cloth, alleviating the loss of the catalyst during use, overcoming the problem of the catalyst being encapsulated, and improving the low-temperature catalytic performance of the catalytic filter material.

Description

Technical Field

[0001] The present invention relates to the technical field of flue gas pollution control, and particularly relates to a carbon-based catalyst, a PTFE catalytic filter material, and a preparation method and application thereof. Background Art

[0002] The existing waste incineration flue gas treatment process steps are as follows: semi-dry reaction tower, bag filter, selective catalytic reduction reactor, spray tower, etc. If the dust removal bag can be upgraded to have a catalytic function, the subsequent flue gas control equipment can be reduced.

[0003] The reaction temperature window of the denitrification catalyst provided by Patent CN114225936B "Waste Incineration Flue Gas Denitrification Catalyst and Its Preparation Method" is 200-300°C, but it is still higher than the incineration flue gas (<200°C), and equipment needs to be added to reheat the flue gas, increasing the flue gas treatment cost. Patent CN113304550B "Preparation Method of a Dust Removal and Denitrification Multifunctional Composite Filter Material" provides a preparation method of a dust removal and denitrification multifunctional composite filter material. After preparing a catalytic filter membrane by loading a composite transition metal oxide catalyst onto the surface of a breathable base membrane by molecular self-assembly and then thermocompounding it with a filter material base fabric, due to the strong chemical stability of polytetrafluoroethylene resin, the combination of the catalyst and the filter material is still mainly physical adsorption, with weak bonding strength and easy peeling of the catalyst. Therefore, it is necessary to develop a catalyst and catalytic filter material preparation technology for multi-pollutant synergistic control to overcome problems such as low activity of the catalyst at low temperature (<200°C) and easy loss of the catalyst during use. Summary of the Invention

[0004] In order to solve at least one of the above problems, the present invention provides a carbon-based catalyst, a PTFE catalytic filter material, and a preparation method and application thereof. The catalytic filter material prepared by the method of the present invention has a closer combination between the catalyst and the filter cloth, and can ensure the low-temperature synergistic removal efficiency of particulate matter, volatile organic compounds (VOCs), and nitrogen oxides (NO x ) in incineration flue gas.

[0005] To achieve the above object, the present invention adopts the following technical means:

[0006] The first aspect of the present invention provides a preparation method of a carbon-based catalyst, comprising the following steps:

[0007] (1) Preparation of a carbon-based carrier

[0008] Mix biomass, a nitrogen-containing activating agent, and a foaming activating agent evenly according to a mass ratio of (0.5-1.5):(1-5):(1-5), place them in a muffle furnace, and calcine at a temperature of 700-1000°C for 1-3 h to obtain a carbon-based carrier;

[0009] (2) Loading of active components

[0010] Add a manganese metal precursor, a cerium metal precursor and a carbon-based support to an aqueous solution in a mass ratio of (0.5 - 1.5):(0.5 - 1.5):(5 - 12), stir at room temperature for 1 - 5 h, then dry at 90 - 110 °C, and calcine at 250 - 350 °C for 2 - 6 h under a calcination atmosphere to obtain a MnCe / C catalyst;

[0011] (3) Optimization of carbon quantum dots (CQDs)

[0012] Dissolve glucose in an aqueous solution, add a sodium hydroxide solution, ultrasonically treat for 1 - 6 h, adjust the pH to neutral with an acid solution, and add an equal volume of an ethanol solution to obtain a mixed solution A;

[0013] Add the MnCe / C catalyst and the mixed solution A to an aqueous solution in a mass-to-volume ratio of 1 g:(0.3 - 1) ml, stir at room temperature for 25 - 35 min, and then dry at 90 - 110 °C to obtain a carbon-based catalyst: CQDs-MnCe / C catalyst.

[0014] In some embodiments of the present invention, in step (1), the biomass is one of wheat straw, corn straw, yellow bamboo, pine wood, corn cob, and α-cellulose; the nitrogen-containing activator can be one or more of ammonium oxalate, urea, and ammonium nitrate; the foaming activator can be one or more of sodium bicarbonate or potassium bicarbonate. Preferably, the biomass is selected as α-cellulose, the nitrogen-containing activator is selected as ammonium oxalate, and the foaming activator is selected as sodium bicarbonate.

[0015] In some embodiments of the present invention, the calcination atmosphere in step (1) is one of nitrogen, air, and vacuum.

[0016] In some embodiments of the present invention, in step (2), the manganese metal precursor is one or more of manganese sulfate, manganese nitrate, manganese carbonate, and manganese acetate; the cerium metal precursor is one or more of cerium nitrate, cerium sulfate, and cerium carbonate. Preferably, the manganese metal precursor is selected as manganese nitrate, and the cerium metal precursor is selected as cerium nitrate.

[0017] In some embodiments of the present invention, in step (3), the concentration of the sodium hydroxide solution is 1 - 3 mol / L. Preferably, the concentration of the sodium hydroxide solution is selected as 1 mol / L.

[0018] In some embodiments of the present invention, in step (3), the acid solution is one of nitric acid, hydrochloric acid, and sulfuric acid. Preferably, the acid solution is selected as hydrochloric acid, and the concentration of the acid solution is 2 mol / L.

[0019] The second aspect of the present invention provides a method for preparing a PTFE catalytic filter cloth. The catalytic filter cloth is prepared by blending and drawing to combine the CQDs-MnCe / C catalyst prepared by the method described in the first aspect with a PTFE filter cloth. The steps are as follows: Mix an auxiliary agent and a polytetrafluoroethylene resin in a mass ratio of (0.1-2):(0.5-2) evenly, let it stand at 70 °C for 24-48 h, then take out the above mixture and extrude it into a cylindrical shape under a pressure of 3 Mpa, and obtain a PTFE calendered film through a calendering step at 40-80 °C. Then, apply a thin layer of binder on the surface of the calendered film and spray 25 wt%-35 wt% of the CQDs-MnCe / C catalyst in a spraying manner. Finally, obtain the PTFE catalytic filter cloth through longitudinal drawing, slitting, coiling and needling steps.

[0020] In some embodiments of the present invention, the auxiliary agent is one of white oil, aviation kerosene, liquid paraffin or petroleum ether; the binder is one of coal tar, organic titanium coupling agent or epoxy resin adhesive. Preferably, the auxiliary agent is white oil and the binder is epoxy resin adhesive.

[0021] The third aspect of the present invention provides a PTFE catalytic filter cloth prepared by the method described in the second aspect.

[0022] The CQDs-MnCe / C catalyst prepared by the method described in the first aspect and the PTFE catalytic filter cloth described in the third aspect are used in the preparation of products for synergistically controlling particulate matter, VOCs and NO x in flue gas from incineration.

[0023] Advantages of the present invention

[0024] Compared with the prior art, the present invention has the following advantages:

[0025] (1) The present invention provides a carbon-based catalyst - CQDs-MnCe / C catalyst. Using this catalyst as the catalytically active component of the catalytic filter material, the regulation of surface acidic sites and active sites is achieved by the metal interaction between Mn and Ce. The large specific surface area and hierarchical pore structure of biochar are utilized to promote the adsorption and conversion of pollutants such as VOCs and NO x etc. The regeneration of acidic sites and active sites is strengthened by CQDs, effectively improving the synergistic disposal of VOCs and NOx at low temperatures. Among them, CQDs serves as an ultrafast electron transport channel to promote the low-temperature conversion of pollutants.

[0026] (2) For the catalytic filter material of the present invention, the catalyst is combined with the filter cloth by a binder, so that the catalyst exists on the surface of the fiber, strengthening the adhesion strength between the catalyst and the filter cloth and reducing the loss rate of the catalyst during use. At the same time, it avoids the problem that the catalyst is wrapped in the conventional blending and drawing method, which affects the physical properties of the filter cloth and the weak catalytic performance.

[0027] (3) When the catalytic filter cloth of the present invention is applied, there is no need to add or transform equipment. Only by replacing the filter material on the existing bag-type dust removal equipment can multi-pollutant collaborative control be achieved and the input cost of flue gas pollution control equipment be effectively reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 Shows the flow chart for preparing the PTFE catalytic filter media;

[0029] Figure 2 Shows a schematic diagram of the catalytic performance evaluation device; where 1, nitrogen gas cylinder; 2, oxygen gas cylinder; 3, nitric oxide gas cylinder; 4, ammonia gas cylinder; 5-9, mass flow meters; 10, bubbling tank; 11, mixing tank; 12, tubular furnace; 13, gas chromatograph; 14, flue gas analyzer; 15, PTFE catalytic filter media.

[0030] Figure 3 Is the catalytic performance graph of the catalytic filter media prepared in Examples 1-3 of the present invention for the co-removal of chlorobenzene and NO.

[0031] Figure 4 Is the catalytic performance graph of the catalytic filter media prepared in Examples 3-5 of the present invention for the co-removal of chlorobenzene and NO.

[0032] Figure 5 Is the catalytic performance graph of the catalytic filter media prepared in Example 3 and Comparative Example 1 of the present invention for the co-removal of chlorobenzene and NO.

[0033] Figure 6 Is the SEM graph of the catalytic filter media prepared in Example 3 and Comparative Example 1 of the present invention; where a, Example 1; b, Comparative Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0034] The following examples are used here to demonstrate the preferred implementation schemes of the present invention. Those skilled in the art will understand that the technologies disclosed in the following examples represent the technologies discovered by the inventor that can be used to implement the present invention, and thus can be regarded as the preferred schemes for implementing the present invention. However, those skilled in the art should understand according to this specification that many modifications can be made to the specific embodiments disclosed here, and still obtain the same or similar results without departing from the spirit or scope of the present invention.

[0035] The present invention discloses a carbon-based catalyst, a PTFE catalytic filter media and its preparation method and application. The catalytic filter media can be used for the collaborative control of particulate matter, VOCs and NO in incineration flue gas x , and the specific preparation steps of the catalytic filter media are as Figure 1As shown below: The catalyst is prepared through steps such as carbon-based carrier preparation, active component loading, and CQDs optimization. Then, with the binder as the connecting bridge, the catalyst is sprayed on the PTFE calendered film, and through steps such as longitudinal stretching, slitting, curling, and needling, a catalytic filter material with the catalyst firmly bonded to the filter cloth is formed.

[0036] A preparation method of a carbon-based catalyst includes the following steps:

[0037] (1) Preparation of the carbon-based carrier

[0038] Mix biomass, a nitrogen-containing activator, and a foaming activator evenly according to the mass ratio of (0.5 - 1.5):(1 - 5):(1 - 5), and calcine at 700 - 1000 °C for 1 - 3 h to obtain the carbon-based carrier; wherein, the biomass is one of wheat straw, corn straw, yellow bamboo, pinewood, corn cob, and α-cellulose; the nitrogen-containing activator is one or more of ammonium oxalate, urea, and ammonium nitrate; the foaming activator is one or more of sodium bicarbonate or potassium bicarbonate;

[0039] (2) Loading of the active component

[0040] Add a manganese metal precursor, a cerium metal precursor, and the carbon-based carrier to an aqueous solution according to the mass ratio of (0.5 - 1.5):(0.5 - 1.5):(5 - 12), stir at room temperature for 1 - 5 h, then dry at 90 - 110 °C, and calcine at 250 - 350 °C for 2 - 6 h in a calcination atmosphere to obtain the MnCe / C catalyst; wherein, the manganese metal precursor is one or more of manganese sulfate, manganese nitrate, manganese carbonate, and manganese acetate; the cerium metal precursor is one or more of cerium nitrate, cerium sulfate, and cerium carbonate; the calcination atmosphere is one of nitrogen, air, and vacuum;

[0041] (3) Optimization of carbon quantum dots

[0042] Dissolve glucose in an aqueous solution, add a sodium hydroxide solution with a concentration of 1 - 3 mol / L, perform ultrasonic treatment for 1 - 6 h, adjust the pH to neutral with an acid solution, and add an equal volume of an ethanol solution to obtain a mixed solution A; the acid solution is one of nitric acid, hydrochloric acid, and sulfuric acid, and the concentration of the acid solution is 2 mol / L;

[0043] Add the MnCe / C catalyst and the mixed solution A to an aqueous solution according to the mass-volume ratio of 1 g:(0.3 - 1) ml, stir at room temperature for 25 - 35 min, and then dry at 90 - 110 °C to obtain the carbon-based catalyst: CQDs-MnCe / C catalyst.

[0044] (4) Composite of the catalyst and the PTFE calendered film

[0045] The auxiliary agent and polytetrafluoroethylene resin are mixed evenly at a mass ratio of (0.1 - 2):(0.5 - 2), left standing at 70 °C for 24 - 48 h, and then the above mixture is taken out and extruded into a cylindrical shape under a pressure of 3 Mpa, and a PTFE calendered film is obtained through a calendering step at 40 - 80 °C. Then, a thin layer of binder is coated on the surface of the calendered film and a certain mass of CQDs-MnCe / C catalyst is sprayed in a spraying manner. Finally, through the steps of longitudinal drawing, slitting, curling and needling. Among them, the auxiliary agent is one of white oil, aviation kerosene, liquid paraffin or petroleum ether; the binder is one of coal tar, organic titanium coupling agent or epoxy resin adhesive, and a PTFE catalytic filter cloth is prepared.

[0046] The catalytic performance evaluation device includes a nitrogen gas cylinder 1, an oxygen gas cylinder 2, a nitric oxide cylinder 1, an ammonia gas cylinder 4, mass flow meters 5 - 9, a bubbling tank 10, a mixing tank 11, a tubular furnace 12, a gas chromatograph 13, a flue gas analyzer 14, and a PTFE catalytic filter medium 15. It is connected through pipelines according to the Figure 2 connection structure shown, and the PTFE catalytic filter medium 15 is located inside the tubular furnace 12.

[0047] The test process is as follows: Install the catalytic filter medium to be tested in the catalytic reaction furnace, open all the gas cylinders 1 - 4 and the tubular furnace 12, adjust the concentrations of various pollutants in the reaction atmosphere, and after the concentrations of various pollutants in the reaction atmosphere are stable, introduce them into the tubular furnace 12, and use the gas chromatograph 13 and the flue gas analyzer 14 to detect the concentrations of various pollutants in the tail gas pipe.

[0048] The catalyst content and loss situation of the catalytic filter medium are calculated by the weight of the filter cloth before and after use.

[0049] The technical solutions of this patent will be further described in detail below in combination with specific embodiments, and the specific embodiments are not used as a limitation to the protection scope.

[0050] Example 1

[0051] The specific preparation steps of the catalytic filter medium in this example are as follows:

[0052] (1) Preparation of carbon-based carrier

[0053] Mix α-cellulose, ammonium oxalate, and sodium bicarbonate evenly at a mass ratio of 1:3:3 and place them in a muffle furnace, and calcine at a calcination temperature of 900 °C for 1 h to obtain a carbon-based carrier.

[0054] (2) Loading of active components

[0055] Add manganese nitrate, cerium nitrate and the carbon-based carrier to 50 ml of aqueous solution at a mass ratio of 1:1:10, stir at room temperature for 1 h, then dry at 105 °C, and finally calcine at 300 °C for 4 h in a calcination atmosphere to obtain the MnCe / C catalyst.

[0056] (3) Optimization of Carbon Quantum Dots (CQDs)

[0057] Dissolve 6 g of glucose in 50 ml of aqueous solution, then add 50 ml of sodium hydroxide solution (1 mol / L), sonicate for 1 h, then adjust the pH to neutral with 2 mol / L hydrochloric acid solution, and finally add an equal volume of ethanol solution to obtain a mixed solution A; Add 1 g of MnCe / C catalyst and 0.5 ml of mixed solution A to 30 ml of aqueous solution, stir at room temperature for 30 min, and then dry at 105 °C to obtain the CQDs-MnCe / C catalyst.

[0058] (4) Composite of Catalyst and PTFE Calendered Film

[0059] Mix white oil and PTFE resin evenly according to a weight ratio of 0.5:4, let it stand at 70 °C for 24 h, then take out the above mixture and extrude it into a cylindrical shape under a pressure of 3 Mpa, obtain the PTFE calendered film through a calendering step at 40 °C, then coat a thin layer of epoxy resin adhesive on the surface of the calendered film and spray 10 wt% of the CQDs-MnCe / C catalyst on the PTFE calendered film in a spraying manner, and finally obtain the PTFE catalytic filter cloth through the steps of longitudinal stretching, slitting, curling and needling.

[0060] The catalyst content of the PTFE catalytic filter prepared by the above method is 65.2 g / m 2 .

[0061] Example 2

[0062] The preparation steps of the catalytic filter in this example are similar to those in Example 1, only increasing the spraying amount of the catalyst in step (5) to 20 wt%. The catalyst content of the PTFE catalytic filter prepared by the above method is 121.9 g / m 2 .

[0063] Example 3

[0064] The preparation steps of the catalytic filter in this example are similar to those in Example 1, only increasing the spraying amount of the catalyst in step (5) to 30 wt%. The catalyst content of the PTFE catalytic filter prepared by the above method is 210.6 g / m 2 .

[0065] Example 4

[0066] The preparation steps of the catalytic filter in this example are similar to those in Example 3, only adjusting the ratio of adding 1 g of MnCe / C catalyst and 0.5 ml of mixed solution A to 30 ml of aqueous solution in step (4) to adding 1 g of MnCe / C catalyst and 1 ml of mixed solution A to 30 ml of aqueous solution. The catalyst content of the PTFE catalytic filter prepared by the above method is 213.4 g / m 2。

[0067] Example 5

[0068] The preparation steps of the catalytic filter material in this example are similar to those in Example 1, except that the ratio of adding 1 g of MnCe / C catalyst and 0.5 ml of mixed solution A to 30 ml of aqueous solution in step (4) is adjusted to adding 1 g of MnCe / C catalyst and 0.3 ml of mixed solution A to 30 ml of aqueous solution. The catalyst content of the PTFE catalytic filter material prepared by the above method is 209.1 g / m 2 。

[0069] Comparative Example 1

[0070] The difference from Example 3 is that this example uses the co-blending and drawing method to prepare the catalytic filter material: in step (4), the MnCe / C catalyst, white oil, and PTFE resin are mixed evenly in a weight ratio of 1.2:0.5:4, and then the catalytic filter material is prepared through steps such as extrusion, calendering, stretching, and needling. The catalyst content of the PTFE catalytic filter material prepared by the above method is 181.2 g / m 2 。

[0071] Catalytic performance analysis

[0072] Place the catalytic filter materials prepared in Examples 1-5 and Comparative Example 1 in the catalytic performance evaluation device, turn on the equipment, and perform the performance analysis of the catalytic filter material under the reaction atmosphere of a total flow rate of 100 ml / min, 100 ppm of chlorobenzene, 500 ppm of NO, 500 ppm of NH3, 11 vol% of oxygen, and the balance of nitrogen.

[0073] (1) The catalytic performance of the catalytic filter materials prepared in Examples 1-5 for the co-removal of chlorobenzene and NO is as Figure 3 and Figure 4 shown. The results show that the catalytic filter material prepared in Example 3 has the highest co-removal ability for NO and chlorobenzene, and the lowest T90 temperature.

[0074] From Figure 3 By comparing Examples 1-3, it can be seen that the spraying amount of the catalyst has a great influence on the co-removal ability of chlorobenzene and NO, which can be mainly attributed to the influence of the spraying amount of the catalyst on the catalyst loading in the catalytic filter material.

[0075] From Figure 4By comparing Examples 3 - 5, it can be seen that an appropriate amount of CQDs can effectively improve the electron transfer rate of the filter material and enhance the low-temperature catalytic activity of the catalytic filter material. However, excessive loading of CQDs may cover the catalytic active sites, thereby inhibiting the low-temperature catalytic activity of the catalytic filter material. The removal rates of chlorobenzene at 180°C for the catalytic filter materials in Examples 3, 5, and 4 are as follows: Example 3 (94.0%) > Example 5 (86.5%) > Example 4 (59.2%). The NO conversion rates are as follows: Example 3 (100%) > Example 5 (98.2%) > Example 4 (93.2%).

[0076] (2) The catalytic performance of the catalytic filter materials prepared in Example 3 and Comparative Example 1 for the co-removal of chlorobenzene and NO is as Figure 5 shown; the SEM images of the catalytic filter materials prepared in Example 3 and Comparative Example 1 are as Figure 6 shown.

[0077] The results show that the catalytic effect of the catalytic filter material prepared in Comparative Example 1 is far lower than that of the catalytic filter material prepared in Example 3. The catalytic filter material of the present application has a better effect of co-catalytically removing chlorobenzene and NO at low temperatures.

[0078] It can be seen from the SEM images that part of the catalyst in Comparative Example 1 is coated with PTFE, while the catalyst in Example 3 mainly exists on the surface of PTFE, resulting in significantly more surface catalytic active sites in Example 3 than in Comparative Example 1. Therefore, the low-temperature catalytic performance of Comparative Example 1 is relatively lower than that of Example 3.

[0079] (3) The catalyst content and loss of the catalytic filter material are shown in Table 1 below.

[0080] Table 1 Changes in the catalyst content of the catalytic filter material

[0081] Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example 1 <![CDATA[Before performance analysis (g / m 2 )]]> 65.2 121.9 210.6 213.4 209.1 181.2 <![CDATA[After performance analysis (g / m 2 )]]> 60.6 115.7 204.9 205.5 205.2 164.6 <![CDATA[Catalyst loss (g / m 2 )]]> 4.6 6.2 5.7 7.9 3.9 16.6

[0082] By comparing Examples 1 - 3, it can be seen that the spraying amount of the catalyst has a great influence on the catalyst content. The spraying amount of the catalyst in Example 3 has the highest catalyst loading. Compared with Example 2, Example 3 has a higher loading and a smaller catalyst loss. In Examples 3 - 5, different amounts of CQDs are introduced. Although the differences in loading and catalyst loss are not very significant, there are differences in the low-temperature catalytic activities of the catalytic filter materials for chlorobenzene and NO. It can be seen from Figure 4 that Example 3 has better low-temperature catalytic activity.

[0083] By comparing Example 3 and Comparative Example 1, it is found that the binder can effectively improve the adhesion strength between the catalyst and the filter material and reduce the catalyst loss of the catalytic filter material during use. Although part of the catalyst in Comparative Example 1 is coated with PTFE, the catalyst on the surface that is not coated is easily lost.

[0084] However, when the spraying amount of the catalyst is higher, the initial catalyst can appropriately improve the COD removal rate. During the use process, the catalyst is liable to be lost, and the removal rate decreases rapidly.

[0085] (4) The particulate matter removal of the catalytic filter media is shown in Table 2 below.

[0086] Table 2 Particulate matter removal rates of Examples 1-5 and Comparative Example 1

[0087] Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example 1 Particle removal rate (%) 99.9 99.9 99.9 99.9 99.9 99.9

[0088] By comparing Examples 1-5 with Comparative Example 1, it can be seen that the spraying amount of the catalyst and the CQDs loading amount have no significant influence on the particulate matter removal performance of the filter media, and the removal rates of the catalytic filter media can all reach 99.9%.

[0089] The present invention is not limited to the above embodiments. Based on the technical solutions disclosed in the present invention, those skilled in the art can, according to the disclosed technical content, make some substitutions and improvements to some of the technical features without departing from the principle of the present invention, and these substitutions and improvements should also be regarded as within the protection scope of the present invention.

Claims

1. A method for preparing a catalytic filter cloth, characterized in that: The catalytic filter cloth is prepared by combining a carbon-based catalyst: CQDs-MnCe / C catalyst with a polytetrafluoroethylene filter material by a blending and drawing method, and the steps are as follows: an auxiliary agent and a polytetrafluoroethylene resin are mixed evenly at a mass ratio of (0.1-2): (0.5-2), and the mixture is allowed to stand at 70° C. for 24-48 hours, and then the mixture is taken out and extruded into a cylindrical shape at a pressure of 3 Mpa, and a PTFE calendering film is obtained by a calendering step at 40-80° C., and then a thin layer of adhesive is applied on the surface of the calendering film and 25wt%-35wt% of the CQDs-MnCe / C catalyst is sprayed on it, and finally the PTFE catalytic filter cloth is obtained by longitudinal drawing, slitting, curling and needle punching steps; The preparation method of the carbon-based catalyst comprises the following steps: (1) Preparation of carbon-based carriers The biomass, the nitrogen-containing activator and the foaming activator are uniformly mixed in a mass ratio of (0.5-1.5):(1-5):(1-5), and calcined at 700-1000°C for 1-3 h to obtain a carbon-based carrier; (2) Active ingredient loading A manganese metal precursor, a cerium metal precursor and a carbon-based carrier are added to an aqueous solution in a mass ratio of (0.5-1.5): (0.5-1.5): (5-12), stirred at room temperature for 1-5 h, then dried at 90-110°C, and calcined at 250-350°C for 2-6 h under a calcination atmosphere to obtain a MnCe / C catalyst; (3) Carbon quantum dot optimization Dissolve glucose in aqueous solution, add sodium hydroxide solution, perform ultrasonic treatment for 1-6 h, adjust pH to neutral with acid solution, add an equal volume of ethanol solution to obtain mixed solution A; The MnCe / C catalyst and the mixed solution A were added to the aqueous solution at a mass volume ratio of 1 g: (0.3-1) ml, stirred at room temperature for 25-35 min, and then dried at 90-110° C. to obtain a carbon-based catalyst: CQDs-MnCe / C catalyst.

2. The method for preparing a catalytic filter cloth according to claim 1, characterized in that: In step (1), the biomass is one of wheat straw, corn straw, yellow bamboo, pine wood, corn cob, and α-cellulose; the nitrogen-containing activator is one or more of ammonium oxalate, urea, and ammonium nitrate; and the foaming activator is one or more of sodium bicarbonate or potassium bicarbonate.

3. The method for preparing a catalytic filter cloth according to claim 1, characterized in that: In step (2), the manganese metal precursor is one or more of manganese sulfate, manganese nitrate, manganese carbonate, and manganese acetate; the cerium metal precursor is one or more of cerium nitrate, cerium sulfate, and cerium carbonate; and the calcination atmosphere in step (2) is one of nitrogen, air, and vacuum.

4. The method for preparing a catalytic filter cloth according to claim 1, characterized in that: The concentration of the sodium hydroxide solution in step (3) is 1-3 mol / L.

5. The method for preparing a catalytic filter cloth according to claim 1, characterized in that: The acid solution in step (3) is one of nitric acid, hydrochloric acid and sulfuric acid.

6. The method for preparing a catalytic filter cloth according to claim 1, characterized in that: The auxiliary agent is one of white oil, aviation kerosene, liquid paraffin or petroleum ether.

7. The method for preparing a catalytic filter cloth according to claim 1, characterized in that: The binder is one of coal tar, organic titanium coupling agent or epoxy resin adhesive.

8. A catalytic filter cloth prepared according to the method according to any one of claims 1 to 7.

9. Use of the catalytic filter cloth according to claim 8 in removing volatile organic compounds, nitrogen oxides and particulate matter products.

Images