Carbon nanotube confinement catalyst synthesized by using anhydrous supercritical method and having CO / CH and NOx synergistic removal function as well as preparation method and application of carbon nanotube confinement catalyst

Abstract

The invention discloses a carbon nanotube confinement catalyst which is synthesized by an anhydrous supercritical method and has a function of synergistically removing CO / CH and NOx as well as a preparation method and application of the carbon nanotube confinement catalyst, and belongs to the field of industrial flue gas purification. The catalyst is a carbon nanotube confinement catalyst Me1Ox-Me2Ox-Me (I) Ox-R1O2-hierarchical pore carbon nanotube synthesized by an anhydrous supercritical method, wherein Me1 is one of V, Mn and Fe; me2 is one of Pt, Pd, Au, Cu, Mn and Co, Me (I) is one of W and Ce, R1 is one of Ce, Ti and Al, x is equal to 1-3, and the hierarchical porous carbon nanotube is a composite carrier. The hierarchical porous carbon nanotube is used as a composite carrier, the catalyst is synthesized in one step through an anhydrous supercritical method, and the obtained catalyst has excellent low-temperature catalytic performance and anti-poisoning performance and is suitable for flue gas treatment in the non-power industry, especially the industries of steel, waste incineration and the like.

Description

Technical Field

[0001] The present invention belongs to the field of industrial flue gas purification, and particularly relates to a carbon nanotube-confined catalyst synthesized by an anhydrous supercritical method and having the function of synergistically removing CO / CH and NO x , and a preparation method and application thereof. Background Art

[0002] With the rapid development of industrialization, flue gas generated by non-electric power industries such as steel and waste incineration contains a large amount of CO, hydrocarbons (CH), and nitrogen oxides (NO x ), and these pollutants pose a serious threat to the environment and human health. Traditional flue gas purification technologies are difficult to efficiently remove CO / CH and NO simultaneously x , especially at low temperatures, the activity and anti-poisoning performance of the catalyst significantly decline.

[0003] Currently, the NH3-SCR (selective catalytic reduction) technology is the main method for removing NO x , but its efficiency is low at low temperatures, and it is difficult to synergistically remove CO / CH. In addition, sulfides and heavy metals in flue gas are likely to cause catalyst poisoning, further limiting its application. Therefore, developing a highly efficient catalyst with the function of synergistically removing CO / CH and NO x , especially a catalyst with excellent activity and anti-poisoning performance at low temperatures, is of great significance.

[0004] Due to its unique confinement effect, high specific surface area, and excellent electrical conductivity, carbon nanotubes are widely used in the field of catalyst carriers. By confining the active components inside the carbon nanotubes, the dispersion and stability of the active components can be effectively improved, while protecting the active components from poisoning by sulfides and heavy metals. However, the existing preparation methods of carbon nanotube-based catalysts are complex and difficult to achieve large-scale application. Summary of the Invention

[0005] In order to overcome the deficiencies of the prior art, the object of the present invention is to provide a carbon nanotube-confined catalyst synthesized by an anhydrous supercritical method and having the function of synergistically removing CO / CH and NO x , and a preparation method and application thereof. Through the anhydrous supercritical fluid technology, the in-situ generation of carbon nanotubes and the confined loading of metal nanoparticles are achieved in one step under high temperature and high pressure conditions, forming a highly efficient catalyst with the function of synergistically removing CO, CH (such as CH4), and NO x . The core lies in using the high diffusivity and low surface tension characteristics of supercritical fluids to promote the rapid pyrolysis of carbon sources to form carbon nanotube structures, while uniformly dispersing and confining the denitrification active precursor, oxidation active precursor, additives, and carriers in the tubes to avoid particle agglomeration.

[0006] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0007] A carbon nanotube-confined catalyst with the function of synergistically removing CO / CH and NO x The catalyst is a carbon nanotube-confined catalyst Me1O x -Me2O x -Me (Ⅰ) O x -R1O2 - hierarchical porous carbon nanotubes, where Me1 is one of V, Mn, and Fe; Me2 is one of Pt, Pd, Au, Cu, Mn, and Co, Me (Ⅰ) is one of W and Ce, R1 is one of Ce, Ti, and Al, x = 1 - 3, and the hierarchical porous carbon nanotubes are a composite support.

[0008] The present invention is further configured such that the denitrification active component in the catalyst is Me1O x , the oxidation active component is Me2O x , the promoter is Me (Ⅰ) O x , and the support is R1O2.

[0009] The present invention is further configured such that the specific surface area of the catalyst is 1050 - 1725 m 2 / g, the number of surface acid sites is greater than 70 μmol / g, and the average pore diameter is less than 25 nm.

[0010] A preparation method of a carbon nanotube-confined catalyst with the function of synergistically removing CO / CH and NO x includes the following steps:

[0011] S1. Mix the denitrification active precursor, oxidation active precursor, promoter, support, and hierarchical porous carbon nanotube precursor in an anhydrous supercritical solvent to obtain a mixed slurry A;

[0012] S2. Place the mixed slurry A obtained in step S1 in a closed reaction kettle and perform one-step synthesis under anhydrous supercritical conditions to obtain catalyst powder;

[0013] S3. Make the catalyst powder into a slurry, then adjust the rheological properties and perform dispersion treatment, and then process it into a catalyst module through a 3D printing process. Subsequently, dry the catalyst module and calcine it in a N2 / Air atmosphere to form a final module.

[0014] The present invention is further configured such that the catalyst module is honeycomb-shaped, spherical, or clover-shaped.

[0015] The present invention is further configured such that the catalyst is made from raw materials in the following mass ratios: the mass ratio of the denitrification active precursor, oxidation active precursor, promoter, carrier, and hierarchical porous carbon nanotube precursor is (1 - 10):(0.1 - 5):(1 - 10):(5 - 20):(170 - 270).

[0016] The present invention is further configured such that the denitrification active precursor is one of ammonium metavanadate, vanadyl oxalate, vanadium oxychloride, manganese nitrate, and iron nitrate; the oxidation active precursor is one of platinum nitrate, palladium nitrate, gold chloride, copper nitrate, manganese nitrate, and cobalt nitrate; the promoter is one of ammonium metatungstate and cerium nitrate; the carrier is one of cerium dioxide, titanium dioxide, and alumina; and the hierarchical porous carbon nanotube precursor is one of glucose and chitosan.

[0017] The present invention is further configured such that in step S1, the anhydrous supercritical solvent is anhydrous ethanol or CO2, the mixing time is 0.5 - 2.5 h, and the final state after mixing is a suspension;

[0018] The present invention is further configured such that in step S2, the anhydrous supercritical conditions are a temperature of 400 - 600 °C and a pressure of 10 - 30 MPa;

[0019] The present invention is further configured such that in step S3, the slurry is made from catalyst powder, organic carrier, and SiO2, and the mass ratio of catalyst powder, organic carrier, and SiO2 is (98 - 102):(93 - 105):(0.5 - 1.5);

[0020] The present invention is further configured such that in step S3, the temperature during rheological property adjustment is 25 °C and the shear rate is 10 s -1 and the viscosity of the slurry after rheological property adjustment is controlled at 8000 - 12000 mPa·s;

[0021] The present invention is further configured such that in step S3, the dispersion treatment is performed by combining high - speed ball milling and ultrasonic vibration; the high - speed ball milling rate is 300 - 500 rpm and the time is 2 - 4 h; the ultrasonic vibration frequency is 40 kHz and the time is 30 min;

[0022] The present invention is further configured such that in step S3, the parameters of the 3D printing process are: the nozzle diameter is 0.4 mm, the extrusion pressure is 0.4 MPa, the layer thickness is 0.2 mm, and the speed is 10 mm / s;

[0023] The present invention is further configured such that in step S3, the final module size is Φ100×150 mm and the pressure drop < 200 Pa.

[0024] The present invention is further configured such that the organic carrier is composed of HPMC, PEG-400, and deionized water, and the mass ratio of HPMC, PEG-400, and deionized water is (2 - 5):(1 - 2):(93 - 97).

[0025] Application of a carbon nanotube-confined catalyst with the function of synergistically removing CO / CH and NO synthesized by an anhydrous supercritical method in flue gas treatment in non-electric power industries x

[0026] The beneficial effects of the present invention are as follows:

[0027] 1. One-step synthesis: The anhydrous supercritical method integrates carbon tube synthesis and metal loading, avoiding multi-step processes such as traditional impregnation and calcination, simplifying the process and reducing costs.

[0028] 2. Confining effect: The physical confining effect of carbon nanotubes can inhibit high-temperature sintering of metal particles (particle size < 6 nm) and reduce carbon deposition, improving stability.

[0029] 3. Synergistic catalysis: Multiple metal components form composite active sites through electronic interactions, respectively targeting CO oxidation, CH4 activation, and NO x selective reduction to achieve synergistic removal of pollutants.

[0030] 4. Environmental adaptability: It is applicable to a wide temperature window of 300 - 600 °C and high space velocity conditions of 2000 - 3000 h -1 to meet the requirements of industrial flue gas treatment.

[0031] The present invention adopts an anhydrous supercritical one-step synthesis method. Through carbon nanotube confinement and multi-metal synergistic catalysis design, it provides a new idea for the efficient removal of complex flue gas pollutants. In the future, supercritical parameters (such as temperature gradient control) and metal ratios can be further optimized and extended to other multi-pollutant synergistic treatment scenarios. Description of the Drawings

[0032] Figure 1 SEM image of the catalyst synthesized in Example 1;

[0033] Figure 2 Comparison chart of denitrification experiment results of the freshly synthesized catalysts in Example 1 and Comparative Example 1;

[0034] Figure 3 Comparison chart of CO catalytic oxidation experiment results of the freshly synthesized catalysts in Example 1 and Comparative Example 1. Detailed Embodiments

[0035] ​Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0036] The carbon nanotube-confined catalyst with the function of synergistically removing CO / CH and NO synthesized by the anhydrous supercritical method of the present invention is a carbon nanotube-confined catalyst Me1O x -Me2O x -Me x -Me (Ⅰ) O x -R1O2-mesoporous carbon nanotubes, where Me1 is one of V, Mn, Fe; Me2 is one of Pt, Pd, Au, Cu, Mn, Co, Me (Ⅰ) is one of W, Ce, R1 is one of Ce, Ti, Al, x = 1-3, and the mesoporous carbon nanotubes are a composite support. The denitrification active component in the catalyst is Me1O x , and the oxidation active component is Me2O x , the promoter is Me (Ⅰ) O x , and the support is R1O2.

[0037] The preparation method of the carbon nanotube-confined catalyst with the function of synergistically removing CO / CH and NO synthesized by the anhydrous supercritical method includes the following steps: x The preparation method of the carbon nanotube-confined catalyst with the function of synergistically removing CO / CH and NO synthesized by the anhydrous supercritical method includes the following steps:

[0038] S1. Mix the denitrification active precursor, oxidation active precursor, promoter, support, and mesoporous carbon nanotube precursor in an anhydrous supercritical solvent (anhydrous ethanol or CO2) for 0.5-2.5 h to obtain a mixed slurry A (the final state after mixing is a suspension);

[0039] The mass ratio of the denitrification active precursor, oxidation active precursor, promoter, support, and mesoporous carbon nanotube precursor is (1-10):(0.1-5):(1-10):(5-20):(170-270);

[0040] The denitrification active precursor is one of ammonium metavanadate, vanadyl oxalate, vanadyl trichloride, manganese nitrate, and iron nitrate; the oxidation active precursor is one of platinum nitrate, palladium nitrate, gold chloride, copper nitrate, manganese nitrate, and cobalt nitrate; the promoter is one of ammonium metatungstate and cerium nitrate; the support is one of cerium dioxide, titanium dioxide, and alumina; the mesoporous carbon nanotube precursor is one of glucose and chitosan.

[0041] S2. Place the mixed slurry A obtained in step S1 in a closed reaction kettle and carry out one-step synthesis under anhydrous supercritical conditions (temperature 400 - 600 °C, pressure 10 - 30 MPa) to obtain catalyst powder;

[0042] S3. Make the catalyst powder into a slurry [the slurry is made of catalyst powder, organic carrier, and SiO2, and the mass ratio of catalyst powder, organic carrier, and SiO2 is (98 - 102):(93 - 105):(0.5 - 1.5). The organic carrier consists of HPMC, PEG - 400, and deionized water, and the mass ratio of HPMC, PEG - 400, and deionized water is (2 - 5):(1 - 2):(93 - 97)]. Then, adjust the rheological properties and perform dispersion treatment (the temperature during rheological property adjustment is 25 °C, and the shear rate is 10 s -1 , and the viscosity of the slurry after rheological property adjustment is controlled at 8000 - 12000 mPa·s. The dispersion treatment is carried out by combining high - speed ball milling and ultrasonic vibration; the high - speed ball milling rate is 300 - 500 rpm, and the time is 2 - 4 h; the ultrasonic vibration frequency is 40 kHz, and the time is 30 min). Then, process it into a catalyst module in the shape of honeycomb, sphere, or clover through 3D printing technology (the process parameters are: nozzle diameter is 0.4 mm, extrusion pressure is 0.4 MPa, layer thickness is 0.2 mm, and speed is 10 mm / s). Subsequently, dry the catalyst module and calcine it in an N2 / Air atmosphere to form the final module (size is Φ100×150 mm, pressure drop < 200 Pa).

[0043] The specific surface area of the catalyst of the present invention is 1050 - 1725 m 2 / g, the number of surface acid sites is greater than 70 μmol / g, and the average pore diameter is less than 25 nm, which can be applied to the flue gas treatment in the non - power industry.

[0044] The preferred embodiments are as follows:

[0045] Example 1

[0046] S1. Mix 2.8 g of ammonium metavanadate, 3.2 g of copper nitrate, 2.4 g of ammonium metatungstate, 6.5 g of titanium dioxide, and 177.4 g of glucose in 500 mL of anhydrous ethanol to obtain mixed slurry A, and the mixing time is 2 h;

[0047] S2. Place the mixed slurry A in step S1 into a closed reaction kettle and carry out one - step synthesis at 550 °C (heating at a rate of 10 °C / min) and 15 MPa (utilize the confinement effect of carbon nanotubes to improve the dispersion degree and synergy of active components) to obtain catalyst powder;

[0048] S3, 100g of catalyst powder was mixed with 3g of HPMC, 1.5g of PEG-400, 1g of nano-SiO2 and 95g of deionized water to prepare a slurry, and the rheological properties were adjusted at 25°C (shear rate was 10s -1 ), high-speed ball milling was carried out at a rate of 400 rpm for 3 h, ultrasonic oscillation was carried out at a frequency of 40 kHz for 30 min, and honeycomb catalyst modules were processed by 3D printing (3D printing parameters were: nozzle diameter of 0.4 mm, extrusion pressure of 0.4 MPa, layer thickness of 0.2 mm, speed of 10 mm / s, honeycomb hole density of 300 cpsi, and hole wall thickness of 0.2 mm), followed by drying. The dried module was calcined at 550 ° C in a N2 / Air atmosphere for 4 h to form a final module (size of Φ100×150 mm, pressure drop <200 Pa), and sample 1 was obtained.

[0049] Comparative Example 1

[0050] 177.4 g of glucose and 0.23 g of nickel nitrate were mixed in 100 mL of deionized water to obtain a mixed solution A, and the mixing time was 2 h;

[0051] The mixed solution A is placed in a hydrothermal reactor and subjected to a hydrothermal reaction at 150° C. for 24 hours. After the reaction is completed, the reactor is allowed to cool naturally to room temperature, and then centrifuged and washed to obtain carbon nanotubes.

[0052] 2.8 g of ammonium metavanadate, 3.2 g of copper nitrate, 2.4 g of ammonium metatungstate, 6.5 g of titanium dioxide and 96 g of carbon nanotubes were mixed in 500 mL of deionized water to obtain a mixed solution B, and the mixing time was 2 h;

[0053] The mixed solution B was transferred to a round-bottom flask and dried by rotary evaporation to obtain a block solid, which was then calcined in an air atmosphere at a calcination temperature of 550°C (heating rate of 10°C / min) and a calcination time of 4h;

[0054] 100 g of catalyst powder was mixed with 3 g of HPMC, 1.5 g of PEG-400, 1 g of nano-SiO2 and 95 g of deionized water to prepare a slurry. The rheological properties were adjusted at 25 °C (shear rate was 10 s -1), high-speed ball milling was carried out at a rate of 400 rpm for 3 h, ultrasonic oscillation was carried out at a frequency of 40 kHz for 30 min, and it was processed into a honeycomb catalyst module by 3D printing (3D printing parameters: nozzle diameter is 0.4 mm, extrusion pressure is 0.4 MPa, layer thickness is 0.2 mm, speed is 10 mm / s, honeycomb pore density is 300 cpsi, pore wall thickness is 0.2 mm). Subsequently, drying was carried out, and the dried module was calcined at 550 °C in an N2 / Air atmosphere for 4 h to form the final module (size: Φ100×150 mm, pressure drop <200 Pa), and sample 2 was obtained.

[0055] Comparative Example 2

[0056] The difference between this comparative example and Example 1 is that in step S1, only 2.4 g of ammonium metatungstate, 6.5 g of titanium dioxide and 177.4 g of glucose were added and then mixed. Other conditions and operations were the same as those in Example 1, and the obtained product was named sample 3.

[0057] Comparative Example 3

[0058] The difference between this comparative example and Example 1 is that in step S1, only 3.2 g of copper nitrate, 2.4 g of ammonium metatungstate, 6.5 g of titanium dioxide and 177.4 g of glucose were added. Other conditions and operations were the same as those in Example 1, and the obtained product was named sample 4.

[0059] Comparative Example 4

[0060] The difference between this comparative example and Example 1 is that in step S1, the hierarchical porous carbon nanotube precursor was not added, and only 2.8 g of ammonium metavanadate, 3.2 g of copper nitrate, 2.4 g of ammonium metatungstate, and 6.5 g of titanium dioxide were added. Other conditions and operations were the same as those in Example 1, and the obtained product was named sample 5.

[0061] Application Example

[0062] The catalysts obtained in the above examples and comparative examples were subjected to denitrification and CO co-catalysis experiments. The experimental conditions were as follows: The concentrations of each gas (vol%) were controlled by a mass flow meter, NO: 500 ppm, NH3: 500 ppm, CO: 4000 ppm, O2: 5%, H2O: 10%, N2 was the balance gas, the total gas flow rate was 1000 mL / min, the catalyst dosage was 800 mg, and the test temperature range was 150 - 550 °C, including fresh catalysts, 100 ppm sulfur-poisoned catalysts, and catalysts forcibly poisoned with 3 wt% PbO for heavy metals.

[0063] The comparison of the denitrification experimental results of the fresh catalyst synthesized in Example 1 and its corresponding hydrothermal sample (Comparative Example 1) is as follows Figure 2As shown; The experimental results of CO catalytic oxidation of the freshly synthesized catalyst and its corresponding hydrothermal sample (Comparative Example 1) in Example 1 are compared as follows Figure 3 as shown.

[0064] The experimental results of denitrification and CO catalytic oxidation of different catalysts at 225°C are shown in Table 1, and the results of various characterization parameters of different catalysts are shown in Table 2.

[0065] Table 1

[0066]

[0067] Table 2

[0068]

[0069] The denitrification efficiency calculation formula is η(NO x ) = (C1 - C2) / C1 × 100%, and the CO degradation efficiency calculation formula is η(CO) = (C3 - C4) / C3 × 100%, where C1 and C3 are the inlet concentrations of NO x and CO respectively, and C2 and C4 are the outlet concentrations of NO x and CO respectively, which are obtained by testing with a flue gas analyzer.

[0070] The above is only the preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions falling within the idea of the present invention belong to the protection scope of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A carbon nanotube-confined catalyst synthesized by an anhydrous supercritical method and having the function of synergistically removing CO / CH and NO x is characterized in that The catalyst is a carbon nanotube-confined catalyst Me1O x -Me2O x -Me (Ⅰ) O x -R1O2-mesoporous carbon nanotubes, where Me1 is one of V, Mn, and Fe; Me2 is one of Pt, Pd, Au, Cu, Mn, and Co, Me (Ⅰ) is one of W and Ce, R1 is one of Ce, Ti, and Al, x = 1 - 3, and the mesoporous carbon nanotubes are a composite support.

2. A carbon nanotube-confined catalyst synthesized by an anhydrous supercritical method for synergistically removing CO / CH and NO according to claim 1, characterized in that, x The denitrification active component in the catalyst is Me1O x , and the oxidation active component is Me2O x , the promoter is Me (Ⅰ) O x , and the carrier is R1O2. ​ 3. A carbon nanotube-confined catalyst synthesized by an anhydrous supercritical method and having the function of synergistically removing CO / CH and NO, according to claim 1, characterized in that x The specific surface area of the catalyst is 1050-1725 m 2 / g, the number of surface acid sites is greater than 70 μmol / g, and the average pore diameter is less than 25 nm. ​ 4. A method for preparing a carbon nanotube-confined catalyst with the function of synergistically removing CO / CH and NO according to any one of claims 1-3, characterized in that, x It includes the following steps: ​ S1. Mix a denitration active precursor, an oxidation active precursor, an auxiliary agent, a carrier, and a hierarchically porous carbon nanotube precursor in an anhydrous supercritical solvent to obtain a mixed slurry A; S2. Place the mixed slurry A obtained in step S1 in a closed reaction kettle and perform one-step synthesis under anhydrous supercritical conditions to obtain catalyst powder; S3. Make the catalyst powder into a slurry, then adjust its rheological properties and perform dispersion treatment, and then process it into a catalyst module through a 3D printing process. Subsequently, dry the catalyst module and calcine it in an N2 / Air atmosphere to form the final module.

5. A preparation method of a carbon nanotube-confined catalyst with the function of synergistically removing CO / CH and NO according to claim 4, characterized in that, x The catalyst module is honeycomb-shaped, spherical, or clover-shaped. ​ 6. A method for preparing a carbon nanotube-confined catalyst with the function of synergistically removing CO / CH and NO by using an anhydrous supercritical method according to claim 4, characterized in that, x The catalyst is made from raw materials with the following mass ratios: the mass ratios of the denitration active precursor, the oxidation active precursor, the auxiliary agent, the carrier, and the hierarchically porous carbon nanotube precursor are (1-10):(0.1-5):(1-10):(5-20):(170-270). ​ 7. A method for preparing a carbon nanotube-confined catalyst with the function of synergistically removing CO / CH and NO by using an anhydrous supercritical method according to claim 4, characterized in that, x The denitration active precursor is one of ammonium metavanadate, vanadyl oxalate, vanadium oxychloride, manganese nitrate, and iron nitrate; the oxidation active precursor is one of platinum nitrate, palladium nitrate, gold chloride, copper nitrate, manganese nitrate, and cobalt nitrate; the auxiliary agent is one of ammonium metatungstate and cerium nitrate; the carrier is one of cerium dioxide, titanium dioxide, and alumina; the hierarchically porous carbon nanotube precursor is one of glucose and chitosan. ​ 8. A preparation method of a carbon nanotube-confined catalyst with the function of synergistically removing CO / CH and NO according to claim 4, characterized in that x In step S1, the anhydrous supercritical solvent is anhydrous ethanol or CO2, the mixing time is 0.5-2.5 h, and the final state after mixing is a suspension; ​ In step S2, the anhydrous supercritical conditions are a temperature of 400-600 °C and a pressure of 10-30 MPa; In step S3, the slurry is made from catalyst powder, an organic carrier, and SiO2, and the mass ratios of the catalyst powder, the organic carrier, and SiO2 are (98-102):(93-105):(0.5-1.5); In step S3, the temperature during the rheological property adjustment is 25 °C, and the shear rate is 10 s -1 , and the viscosity of the slurry after the rheological property adjustment is controlled within 8000 - 12000 mPa·s; In step S3, the dispersion treatment is carried out by combining high-speed ball milling and ultrasonic vibration; the high-speed ball milling rate is 300-500 rpm and the time is 2-4 h; the ultrasonic vibration frequency is 40 kHz and the time is 30 min; In step S3, the parameters of the 3D printing process are: the nozzle diameter is 0.4 mm, the extrusion pressure is 0.4 MPa, the layer thickness is 0.2 mm, and the speed is 10 mm / s; In step S3, the size of the final module is Φ100×150 mm, and the pressure drop is <200 Pa.

9. A method for preparing a carbon nanotube-confined catalyst with the function of synergistically removing CO / CH and NO according to claim 8, characterized in that, x The organic carrier consists of HPMC, PEG-400, and deionized water, and the mass ratios of HPMC, PEG-400, and deionized water are (2-5):(1-2):(93-97). ​ 10. Application of a carbon nanotube-confined catalyst with the function of synergistically removing CO / CH and NO synthesized by an anhydrous supercritical method according to any one of claims 1-3 in flue gas treatment in non-electric power industries. x ​

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