Catalytic combustion catalyst, and preparation method and application thereof

Abstract

The application provides a catalytic combustion catalyst and a preparation method and application thereof, and the preparation method comprises the following steps: mixing a carrier, an active metal precursor and a solvent, solid-liquid separation, drying and calcination to obtain a supported catalyst; mixing a carbon source, a coating agent precursor and the supported catalyst, solid-liquid separation, drying and calcination to obtain the catalytic combustion catalyst. According to the preparation method, a nano coating layer is introduced on the surface of the catalyst by introducing the carbon source, so that the catalyst shows strong activity to CO, and the water resistance and sulfur resistance stability of the catalyst is improved, so that the catalytic combustion catalyst shows strong CO catalytic combustion stability under the condition of industrial flue gas containing water and sulfur.

Description

Technical Field

[0001] This invention belongs to the field of polluted gas treatment technology, and relates to a catalytic combustion catalyst, its preparation method and application. Background Technology

[0002] Carbon monoxide (CO), a common atmospheric pollutant, mainly originates from the incomplete combustion of fossil fuels and some chemical production processes. Because CO is a toxic and harmful gas, its emission into the atmosphere not only causes environmental pollution but also harms human health. Therefore, developing technologies that can significantly reduce CO emissions is of great significance for protecting the environment and human health. Catalytic combustion is a feasible method to convert the toxic and harmful CO in exhaust gases into non-toxic and harmless CO2.

[0003] The technology of converting carbon monoxide into carbon dioxide has advantages such as high CO removal efficiency, low energy consumption, no secondary pollution, and wide applicability to various concentrations. However, for some special flue gases emitted by industries such as steel, coal chemical, pharmaceutical, and metallurgy, even if ultra-low emission standards are met, they may still contain as much as 35 mg / m³. 3 The emissions include SO2, a certain amount of H2O, and impurities such as dust. Noble metal catalysts and metal oxide catalysts are traditional CO removal catalysts. Although these catalysts exhibit extremely high activity for CO catalytic combustion, in the presence of sulfides, their activity rapidly decreases and becomes irreversible due to the combination of sulfides with active components or the formation of sulfates on the support surface. Therefore, designing and developing highly efficient, water-resistant, and sulfur-poison-resistant CO catalytic combustion catalysts is crucial for addressing these emission sources.

[0004] For example, CN 116251586A discloses a sulfur-resistant CO oxidation catalyst, its preparation method, and its application. In the preparation method of the sulfur-resistant CO oxidation catalyst, a coating slurry is prepared, the coating is applied to a honeycomb ceramic carrier, and then dried and calcined to obtain a honeycomb ceramic carrier with a firmly coated composite oxide coating. That is, it mainly uses a wave-assisted method to increase the specific surface area and pore volume of the TiO2-SiO2 coating, optimizes the pore structure of the catalyst, and improves the problem of catalyst deactivation caused by the sulfate generated by impurity SO2 participating in the side reaction blocking the micropores of the catalyst.

[0005] For example, CN 114210335A discloses a low-temperature, water- and sulfur-resistant non-precious metal catalyst for removing carbon monoxide. This catalyst is a perovskite-type transition metal oxide with cobalt as the main active component and doped with a certain amount of lanthanum and strontium. It can overcome the problems of high cost and poor stability of traditional precious metal catalysts and has strong water and sulfur resistance. However, although the catalyst disclosed in the above-mentioned prior art has a certain degree of sulfur resistance, its water and sulfur resistance needs to be further improved.

[0006] Based on the above research, there is a need to provide a method for preparing a catalytic combustion catalyst, which can obtain a catalyst that exhibits strong activity against CO and has excellent water and sulfur resistance. Summary of the Invention

[0007] The purpose of this invention is to provide a catalytic combustion catalyst, its preparation method, and its application, particularly a water-resistant and sulfur-resistant CO catalytic combustion catalyst, its preparation method, and its application. The preparation method introduces a carbon source during calcination, thereby introducing a nano-coating layer on the catalyst surface. This not only makes the catalyst exhibit strong activity for CO but also improves the catalyst's water and sulfur resistance, enabling the catalytic combustion catalyst to exhibit strong CO catalytic combustion stability under water- and sulfur-containing industrial flue gas conditions.

[0008] To achieve this objective, the present invention adopts the following technical solution:

[0009] In a first aspect, the present invention provides a method for preparing a catalytic combustion catalyst, the method comprising the following steps:

[0010] (1) The support, active metal precursor and solvent are mixed, separated into solid and liquid, dried and calcined to obtain a supported catalyst;

[0011] (2) The carbon source, coating agent precursor and the supported catalyst described in step (1) are mixed, separated into solid and liquid, dried and calcined to obtain the catalytic combustion catalyst.

[0012] This invention first mixes, separates, dries, and calcines a support, a catalytically active metal precursor, and a solvent to prepare a supported catalyst. Then, the coating step (2) is performed. Since the carbon source is easily loaded onto the surface of the support described in step (1), and the carbon source in step (2) is used as an auxiliary coating agent, it will first combine with the coating agent precursor. Therefore, the carbon source will bring the coating agent precursor to the surface of the support. Finally, after calcination to remove the carbon source, the coating agent is achieved. The presence of the coating layer greatly improves the catalytic activity and water and sulfur resistance of the catalyst.

[0013] Preferably, the coating agent precursor in step (2) includes a metal salt and / or a silicon source, preferably a metal salt.

[0014] The coating agent of the present invention is preferably a metal salt. Since the metal salt can interact with the active center, such as Pt, to form a Pt-OM metal bond, such as Pt-O-Ti, the -O- in it has strong oxidizing properties and can oxidize carbon monoxide to carbon dioxide. Moreover, SO2 will not be adsorbed on -O-, so SO2 will not cause Pt poisoning and the sulfur resistance stability of the catalyst is improved.

[0015] Preferably, the metal salt includes titanium salts and / or zirconium salts, exemplary of which are zirconium nitrate and / or titanium nitrate.

[0016] Preferably, the silicon source comprises tetraethyl orthosilicate.

[0017] Preferably, the mass ratio of the coating agent precursor in step (2) to the supported catalyst in step (1) is (0.05-0.3):1, for example, it can be 0.05:1, 0.1:1, 0.15:1, 0.2:1, 0.25:1 or 0.3:1, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0018] The amount of coating agent precursor described in this invention will affect the thickness of the coating layer. If the amount of coating agent precursor is too large, a thicker coating layer will be formed, and the reactant (CO) will not be able to contact the active center, and the activity of the catalyst will decrease. If the amount of coating agent precursor is too small, it will result in the incomplete formation of coating on the active center (e.g., Pt), and it will not play a role in protecting the active center.

[0019] Preferably, the mass ratio of the carbon source to the coating agent precursor in step (2) is (8-50):1, for example, it can be 10:1, 20:1, 30:1, 40:1 or 50:1, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0020] Preferably, the carbon source in step (2) includes dopamine hydrochloride.

[0021] The carbon source described in this invention is preferably dopamine hydrochloride. Since dopamine hydrochloride can complex with the coating agent precursor, and after polymerization, dopamine hydrochloride will firmly adhere to the catalyst surface, thereby bringing the coating agent precursor to the catalyst surface and forming an encapsulated form.

[0022] Preferably, the mixing in step (2) includes first dispersing the carbon source in water with a pH of 7.5 to 10.5, for example, 7.5, 8.5 or 10.5, then adding the coating agent precursor, stirring, and then adding the supported catalyst and continuing to stir.

[0023] Preferably, the stirring time is 1-4 hours, for example, it can be 1 hour, 2 hours, 3 hours or 4 hours, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0024] Preferably, after the mixing in step (2) is completed, solid-liquid separation, washing and drying are performed first, followed by calcination.

[0025] Preferably, the roasting atmosphere in step (2) includes a nitrogen atmosphere and an air atmosphere.

[0026] Preferably, the calcination in step (2) includes first calcining in a nitrogen atmosphere at a temperature of 700-900°C, for example, 700°C, 800°C or 900°C for 3-5 hours, for example, 3 hours, 4 hours or 5 hours, and then calcining in an air atmosphere at a temperature of 400-600°C, for example, 400°C, 500°C or 600°C for 3-5 hours, for example, 3 hours, 4 hours or 5 hours, but not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0027] Preferably, the carrier in step (1) includes a hydrophobic carrier.

[0028] Preferably, the hydrophobic support comprises hydrophobic alumina and / or hydrophobic silicon oxide.

[0029] Preferably, the solvent used in step (1) includes an organic solvent.

[0030] In order to match the hydrophobic carrier, the present invention preferably uses organic solvent dispersion, thereby improving the dispersion of active metals.

[0031] Preferably, the organic solvent includes any one or a combination of at least two of methanol, ethanol, acetic acid, ethyl acetate or methyl ethyl ketone.

[0032] Preferably, the metal element in the active metal precursor in step (1) includes any one or a combination of at least two of Pd, Pt, Cu, Mn or Co.

[0033] Preferably, in the supported catalyst of step (1), the loading of Pd and / or Pt is 0-1wt%, for example, it can be 0wt%, 0.2wt%, 0.4wt%, 0.6wt%, 0.8wt% or 1wt%, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0034] Preferably, in the supported catalyst of step (1), the loading of any one or at least two of Cu, Mn or Co is 5-10 wt%, for example, it can be 5 wt%, 7 wt%, 9 wt% or 10 wt%, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0035] Preferably, during the mixing in step (1), an additive is also added, and the metal element in the additive includes any one or a combination of at least two of Co, Ce, La, Zr, Cu or Mn.

[0036] Preferably, in the supported catalyst of step (1), the loading of metal elements in the promoter is 0-10wt%, but not including 0wt%. For example, it can be 1wt%, 3wt%, 5wt%, 7wt%, 9wt% or 10wt%, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0037] Preferably, the mixing in step (1) includes mixing the carrier with the solvent, then adding the active metal precursor and the additive and continuing to stir.

[0038] Preferably, the roasting temperature in step (1) is 450-550℃, for example, 450℃, 500℃ or 550℃, and the time is 3-5h, for example, 3h, 4h or 5h, but not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0039] Preferably, the drying temperature in step (1) is 80-100℃, for example, 80℃, 90℃ or 100℃, and the time is 4-8h, for example, 4h, 5h, 6h, 7h or 8h, but not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0040] As a preferred embodiment of the preparation method of the present invention, the preparation method includes the following steps:

[0041] (1) After mixing the hydrophobic support, active metal precursor, additives and organic solvent, separating the solid and liquid, drying at 80-100℃ for 4-8h and calcining at 450-550℃ for 3-5h, a supported catalyst is obtained.

[0042] The metal element in the active metal precursor includes any one or a combination of at least two of Pd, Pt, Cu, Mn or Co; in the supported catalyst of step (1), the loading of Pd and / or Pt is 0-1 wt%, and the loading of any one or a combination of at least two of Cu, Mn or Co is 5-10 wt%.

[0043] The metal element in the additive includes any one or a combination of at least two of Co, Ce, La, Zr, Cu or Mn. In the supported catalyst of step (1), the loading of the metal element in the additive is 0-10 wt%, but does not include 0 wt%.

[0044] (2) Disperse dopamine hydrochloride in water with a pH of 7.5 to 10.5, then add a coating agent precursor, stir, add a supported catalyst and continue stirring, then perform solid-liquid separation, washing and drying, then calcine in an air-nitrogen atmosphere at a temperature of 700-900℃ for 3-5 hours, and then calcine in an air atmosphere at a temperature of 400-600℃ for 3-5 hours to obtain the catalytic combustion catalyst;

[0045] The mass ratio of the coating agent precursor to the supported catalyst in step (1) is (0.05-0.3):1, and the mass ratio of the carbon source to the coating agent precursor is (8-50):1; the coating agent precursor includes any one or a combination of at least two of titanium salt, zirconium salt or silicon source.

[0046] In a second aspect, the present invention provides a catalytic combustion catalyst, which is prepared by the preparation method described in the first aspect.

[0047] Thirdly, the present invention provides an application of the catalytic combustion catalyst as described in the second aspect, the application including conversion of carbon monoxide under industrial flue gas conditions.

[0048] Compared with the prior art, the present invention has the following beneficial effects:

[0049] This invention introduces a carbon source during the calcination process and introduces a nano-coating layer on the catalyst surface, which not only makes the catalyst exhibit strong activity for CO, but also improves the catalyst's water and sulfur resistance stability. This enables the catalytic combustion catalyst to exhibit strong CO catalytic combustion performance and stability under industrial flue gas conditions containing water and sulfur. Attached Figure Description

[0050] Figure 1 This is a graph showing the change in the reactivity of the catalytic combustion catalyst described in Example 1 of the present invention under aqueous and sulfur-containing conditions as a function of reaction time. Detailed Implementation

[0051] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention.

[0052] Example 1

[0053] This embodiment provides a method for preparing a catalytic combustion catalyst, the method comprising the following steps:

[0054] (1) Take 5g of hydrophobic alumina (purity: 99.5%, specific surface area BET: 280m²) 2 / g (particle size 15-30nm) was added to a mixed solution of 300mL ethyl acetate and 100mL ethanol and stirred for 1h. Then, 0.15g of active metal precursor and 0.079g of promoter were added and stirred for another 4h. After filtration, washing with deionized water, drying at 80℃ for 4h and calcining at 500℃ for 4h, the supported catalyst was obtained.

[0055] The active metal precursor is a 10% platinum nitrate solution. In the supported catalyst of step (1), the loading of Pt is 0.3 wt%. The auxiliary agent is cerium nitrate hexahydrate. In the supported catalyst of step (1), the loading of metal elements in the auxiliary agent is 0.5 wt%.

[0056] (2) Disperse 2.5g of dopamine hydrochloride in 500mL of water with pH 8.5, then add 0.09g of coating agent precursor, stir for 1h, then add 1g of the supported catalyst described in step (1) and continue stirring for 4h, then filter, wash with deionized water and dry at 80℃ for 8h, then calcine at 800℃ for 4h in a nitrogen atmosphere, and then calcine at 500℃ in an air atmosphere for 4h to obtain the catalytic combustion catalyst;

[0057] The coating agent precursor is titanium nitrate, and the mass ratio of titanium nitrate to the supported catalyst in step (1) is 0.09:1. The mass ratio of dopamine hydrochloride to the coating agent precursor is 28:1.

[0058] In this embodiment, 0.5 g of the catalytic combustion catalyst was weighed and placed in a fixed-bed reactor. A mixed gas with a flow rate of 250 ml / min was introduced into the reactor. The mixed gas composition was 8000 ppm CO, 50 ppm SO2, 10% water vapor, 10% O2, and nitrogen. The reactor was continuously reacted at 200 °C for 200 h. The change in catalyst activity over time was recorded. The resulting graph shows the change in reaction activity over time. Figure 1 As shown.

[0059] Example 2

[0060] This embodiment provides a method for preparing a catalytic combustion catalyst, the method comprising the following steps:

[0061] (1) Take 5g of hydrophobic silica (CAS No.: 60676-86-0, Macklin, purity: 99.8%, specific surface area BET: 230m²). 2 / g, with a particle size of 7-40nm) was placed in 400mL of ethyl acetate and stirred for 1h. Then, 0.95g of copper nitrate trihydrate and 1.61g of manganese nitrate hexahydrate were added and stirred for another 4h. The mixture was then filtered, washed with deionized water, dried at 100℃ for 4h, and calcined at 550℃ for 3h to obtain the supported catalyst.

[0062] In the supported catalyst described in step (1), the loading of Cu is 5 wt% and the loading of Mn is 6 wt%.

[0063] (2) Disperse 2.5g of dopamine hydrochloride in 500mL of water with pH 8.5, then add 0.05g of coating agent precursor, stir for 1h, then add 1g of the supported catalyst described in step (1) and continue stirring for 4h, then filter, wash with deionized water and dry at 100℃ for 4h, then calcine at 700℃ for 5h in a nitrogen atmosphere, and then calcine at 600℃ for 5h in an air atmosphere to obtain the catalytic combustion catalyst;

[0064] The coating agent precursor is titanium nitrate, and the mass ratio of titanium nitrate to the supported catalyst in step (1) is 0.05:1. The mass ratio of dopamine hydrochloride to the coating agent precursor is 50:1.

[0065] Example 3

[0066] This embodiment provides a method for preparing a catalytic combustion catalyst, the method comprising the following steps:

[0067] (1) Take 5g of hydrophobic silica (CAS No.: 60676-86-0, Macklin, purity: 99.8%, specific surface area BET: 230m²). 2 / g, with a particle size of 7-40nm) was placed in 400mL of ethyl acetate and stirred for 1h. Then, copper nitrate trihydrate and manganese nitrate hexahydrate were stirred for another 4h. The mixture was filtered, washed with deionized water, dried at 80℃ for 4h, and calcined at 450℃ for 5h to obtain the supported catalyst.

[0068] In the supported catalyst described in step (1), the loading of Cu is 7 wt% and the loading of Mn is 10 wt%.

[0069] (2) Disperse 2.5g of dopamine hydrochloride in 500mL of water with pH 8, then add 0.3g of coating agent precursor, stir for 1h, then add 1g of the supported catalyst described in step (1) and continue stirring for 4h, then filter, wash with deionized water and dry at 80℃ for 4h, then calcine at 900℃ for 3h in a nitrogen atmosphere, and then calcine at 400℃ for 3h in an air atmosphere to obtain the catalytic combustion catalyst;

[0070] The coating agent precursor is zirconium nitrate, and its mass ratio with the supported catalyst in step (1) is 0.3:1. The mass ratio of dopamine hydrochloride to the coating agent precursor is 8.3:1.

[0071] Example 4

[0072] This embodiment provides a method for preparing a catalytic combustion catalyst. The preparation method is the same as in Example 1, except that the hydrophobic alumina in step (1) is replaced by γ-Al2O3 by mass.

[0073] Example 5

[0074] This embodiment provides a method for preparing a catalytic combustion catalyst. The preparation method is the same as that in Example 1, except that no additives are added in step (1).

[0075] Example 6

[0076] This embodiment provides a method for preparing a catalytic combustion catalyst. Except for step (2), where the coating agent precursor is tetraethyl orthosilicate, the preparation method is the same as in Example 1.

[0077] Example 7

[0078] This embodiment provides a method for preparing a catalytic combustion catalyst. Except for the mass ratio of the coating agent precursor in step (2) to the supported catalyst in step (1) being 0.02:1, the preparation method is the same as in Example 1.

[0079] Example 8

[0080] This embodiment provides a method for preparing a catalytic combustion catalyst. Except for the mass ratio of the coating agent precursor in step (2) to the supported catalyst in step (1) being 0.4:1, the preparation method is the same as in Example 1.

[0081] Comparative Example 1

[0082] This comparative example provides a method for preparing a catalytic combustion catalyst, the method comprising the following steps:

[0083] Weigh 0.95g of copper nitrate trihydrate and 1.61g of manganese nitrate hexahydrate, and dissolve them in 2.5g of deionized water to form an impregnation solution. Slowly add the above solution dropwise to 5g of γ-Al2O3 while stirring. After the solution is added, let it stand for 4 hours, dry it at 80℃ for 8 hours, and then calcine it at 500℃ for 4 hours to obtain the catalytic combustion catalyst.

[0084] Comparative Example 2

[0085] This comparative example provides a method for preparing a catalytic combustion catalyst. The preparation method is the same as that in Example 1, except that dopamine hydrochloride is not added in step (2).

[0086] Comparative Example 3

[0087] This comparative example provides a method for preparing a catalytic combustion catalyst, which is the same as that in Example 1 except that step (2) is not calcined.

[0088] Comparative Example 4

[0089] This comparative example provides a method for preparing a catalytic combustion catalyst. Except for step (2), which involves directly mixing the coating agent precursor with the supported catalyst and then calcining the mixture, the preparation method is the same as in Example 1.

[0090] Step (2) of this comparative example includes: mixing 0.09g of coating agent precursor with 1g of the supported catalyst described in step (1) for 4h, then calcining at 700-900℃ for 3-5h in a nitrogen atmosphere, and then calcining at 400-600℃ for 3-5h in an air atmosphere.

[0091] The catalysts obtained in the above examples and comparative examples were tested for activity, sulfur resistance, and water and sulfur resistance. The activity test method included: weighing 0.5g of powdered catalyst into a fixed-bed reactor, introducing a mixed gas at a rate of 250ml / min into the reactor, the mixed gas composition being 8000ppmCO, 10%O2 and nitrogen, starting from 50℃, and measuring the concentration of carbon monoxide in the reactor tail gas under different reaction temperature conditions by programmed temperature rise, calculating the carbon monoxide conversion rate based on the change in carbon monoxide concentration, recording the temperature at which the carbon monoxide conversion rate reached 99%, and testing to obtain the T99 of the fresh catalyst.

[0092] 0.5 g of powdered catalyst was weighed into a fixed-bed reactor. A mixed gas with a flow rate of 250 ml / min was introduced into the reactor. The mixed gas consisted of 8000 ppm CO, 50 ppm SO2, 10% O2, and nitrogen. Starting from 50 °C, the concentration of carbon monoxide in the reactor tail gas was measured under different reaction temperature conditions by programmed temperature increase. The conversion rate of carbon monoxide was calculated based on the change in carbon monoxide concentration. The temperature at which the carbon monoxide conversion rate reached 99% was recorded, and the T99 of the catalyst under sulfur-containing conditions was obtained.

[0093] 0.5g of powdered catalyst was weighed into a fixed-bed reactor. A mixed gas with a flow rate of 250ml / min was introduced into the reactor. The mixed gas consisted of 8000ppmCO, 50ppmSO2, 10% water vapor, 10% O2, and nitrogen. Starting from 50℃, the concentration of carbon monoxide in the reactor tail gas was measured under different reaction temperature conditions by programmed temperature increase. The conversion rate of carbon monoxide was calculated based on the change in carbon monoxide concentration. The temperature at which the carbon monoxide conversion rate reached 99% was recorded, and the catalyst T99 under water and sulfur-containing conditions was obtained.

[0094] The test results are shown in Table 1:

[0095] Table 1

[0096]

[0097] As can be seen from Table 1:

[0098] The catalyst obtained by this invention exhibits high activity towards carbon monoxide and possesses high sulfur resistance and high water and sulfur resistance. Under anhydrous and sulfur-free conditions, its T99 temperature can reach below 115°C; under sulfur-containing conditions, it can reach below 120°C; and under anhydrous and sulfur-containing conditions, it can reach below 125°C. As shown in Example 1 and the comparative examples, the catalyst prepared by the traditional impregnation method has poor sulfur and water resistance. As shown in Example 1 and Comparative Examples 2-3, the carbon source of this invention, as an auxiliary coating agent, can carry the coating agent to the surface of the support, and after calcination, it can be... Therefore, the catalyst obtained in Example 1 has superior catalytic activity and water and sulfur resistance stability compared to Comparative Examples 2-3. As can be seen from Example 1 and Comparative Example 4, simply mixing and calcining the coating agent precursor with the supported catalyst results in uneven coating, and the coating metal covers the active center. Therefore, the catalytic activity and water and sulfur resistance stability of the obtained catalyst decrease. As can be seen from Example 1 and Examples 4-8, the selection of the support, the addition of the auxiliary agent, the selection of the coating agent precursor, and the addition of the coating agent precursor all affect the catalyst activity and water and sulfur resistance stability.

[0099] In summary, this invention provides a catalytic combustion catalyst, its preparation method, and its application. The preparation method introduces a carbon source during calcination and introduces a nano-coating layer on the catalyst surface, which not only makes the catalyst exhibit strong activity for CO but also improves the catalyst's water and sulfur resistance stability. This enables the catalytic combustion catalyst to exhibit strong CO catalytic combustion stability under industrial flue gas conditions containing water and sulfur.

[0100] The above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A method for preparing a catalytic combustion catalyst, characterized in that, The preparation method includes the following steps: (1) The support, active metal precursor and solvent are mixed, separated into solid and liquid components, dried and calcined to obtain a supported catalyst; (2) The carbon source, coating agent precursor and the supported catalyst described in step (1) are mixed, separated into solid and liquid, dried and calcined to obtain the catalytic combustion catalyst; The carbon source in step (2) includes dopamine hydrochloride; The metal element in the active metal precursor in step (1) includes any one or a combination of at least two of Pd, Pt, Cu, Mn or Co; The coating agent precursor in step (2) includes a metal salt and / or a silicon source; The metal salts include titanium salts and / or zirconium salts; The silicon source includes tetraethyl orthosilicate; The roasting described in step (2) is first carried out in a nitrogen atmosphere and then in an air atmosphere; The catalytic combustion catalyst has a nano-coating layer introduced on its surface.

2. The preparation method according to claim 1, characterized in that, The mass ratio of the coating agent precursor in step (2) to the supported catalyst in step (1) is (0.05-0.3):

1.

3. The preparation method according to claim 1, characterized in that, The mass ratio of the carbon source to the coating agent precursor in step (2) is (8-50):

1.

4. The preparation method according to claim 1, characterized in that, The mixing in step (2) involves first dispersing the carbon source in water with a pH of 7.5-10.5, then adding the coating agent precursor, stirring, and then adding the supported catalyst and continuing to stir.

5. The preparation method according to claim 4, characterized in that, The stirring time is 1-4 hours.

6. The preparation method according to claim 1, characterized in that, After the mixing in step (2) is completed, solid-liquid separation, washing and drying are carried out first, followed by calcination.

7. The preparation method according to claim 1, characterized in that, The calcination in step (2) includes first calcining in a nitrogen atmosphere at a temperature of 700-900℃ for 3-5 hours, and then calcining in an air atmosphere at a temperature of 400-600℃ for 3-5 hours.

8. The preparation method according to claim 1, characterized in that, The carrier mentioned in step (1) includes a hydrophobic carrier.

9. The preparation method according to claim 8, characterized in that, The hydrophobic carrier includes hydrophobic alumina and / or hydrophobic silicon oxide.

10. The preparation method according to claim 1, characterized in that, The solvent used in step (1) includes organic solvents.

11. The preparation method according to claim 10, characterized in that, The organic solvent includes any one or a combination of at least two of methanol, ethanol, acetic acid, ethyl acetate, or methyl ethyl ketone.

12. The preparation method according to claim 1, characterized in that, In the supported catalyst described in step (1), the loading of Pd and / or Pt is 0-1 wt%.

13. The preparation method according to claim 1, characterized in that, In the supported catalyst described in step (1), the loading amount of any one or at least two of Cu, Mn or Co is 5-10 wt%.

14. The preparation method according to claim 1, characterized in that, In step (1), an additive is also added during the mixing process. The metal element in the additive includes any one or a combination of at least two of Co, Ce, La, Zr, Cu or Mn.

15. The preparation method according to claim 14, characterized in that, In the supported catalyst described in step (1), the loading of metal elements in the promoter is 0-10 wt%, but does not include 0 wt%.

16. The preparation method according to claim 1, characterized in that, The roasting temperature in step (1) is 450-550℃ and the time is 3-5h.

17. The preparation method according to claim 1, characterized in that, The drying temperature in step (1) is 80-100℃ and the time is 4-8h.

18. The preparation method according to any one of claims 1-17, characterized in that, The preparation method includes the following steps: (1) After mixing the hydrophobic support, active metal precursor, additives and organic solvent, separating the solid and liquid, drying at 80-100℃ for 4-8h and calcining at 450-550℃ for 3-5h, a supported catalyst is obtained. The metal element in the active metal precursor includes any one or a combination of at least two of Pd, Pt, Cu, Mn or Co; in the supported catalyst of step (1), the loading of Pd and / or Pt is 0-1 wt%, and the loading of any one or a combination of at least two of Cu, Mn or Co is 5-10 wt%. The metal element in the additive includes any one or a combination of at least two of Co, Ce, La, Zr, Cu or Mn. In the supported catalyst of step (1), the loading of the metal element in the additive is 0-10 wt%, but does not include 0 wt%. (2) Disperse dopamine hydrochloride in water with a pH of 7.5-10.5, then add the coating agent precursor, stir, add the supported catalyst and continue stirring, then perform solid-liquid separation, washing and drying, then calcine in a nitrogen atmosphere at a temperature of 700-900℃ for 3-5 hours, and then calcine in an air atmosphere at a temperature of 400-600℃ for 3-5 hours to obtain the catalytic combustion catalyst; The mass ratio of the coating agent precursor to the supported catalyst in step (1) is (0.05-0.3):1, and the mass ratio of the carbon source to the coating agent precursor is (8-50):1; the coating agent precursor includes any one or a combination of at least two of titanium salt, zirconium salt or silicon source.

19. A catalytic combustion catalyst, characterized in that, The catalytic combustion catalyst is prepared using the preparation method described in any one of claims 1-18.

20. The application of a catalytic combustion catalyst as described in claim 19, characterized in that, The applications include the conversion of carbon monoxide under industrial flue gas conditions.

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