Combustion catalyst with high activity and stability as well as preparation method and application of combustion catalyst
The AOx-BOx support was prepared by sol-gel method and loaded with noble metal N, which solved the problems of noble metal catalysts being easily poisoned in complex environments and having low activity at high temperatures. This resulted in a highly active and stable combustion catalyst suitable for the oxidation reactions of VOCs and methane.
Patent Information
- Application Number
- CN202511916825.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-17
- Publication Date
- 2026-04-17
AI Technical Summary
Existing precious metal catalysts are prone to poisoning and deactivation in complex real-world environments, and the number of active sites decreases at high temperatures, leading to a decline in catalytic performance and making it difficult to remove multiple pollutants efficiently and for a long time under complex operating conditions.
An AOx-BOx support was prepared by sol-gel method, and after pre-reduction treatment, noble metal N was loaded by equal volume impregnation method to form a solid solution, thereby realizing covalent and electronic interactions between noble metal N, transition metal AOx and inert support BOx, and preparing a supported combustion catalyst.
The prepared catalyst exhibits high activity and excellent stability at low temperatures, effectively removing pollutants such as VOCs and methane. It has a wide range of applications, is simple to operate, and uses readily available raw materials.
Smart Images
Figure CN121869349A_ABST
Abstract
Description
Technical Field
[0001] This application relates to a combustion catalyst with both high activity and stability, its preparation method and application, belonging to the field of catalysis technology. Background Technology
[0002] Currently, the world is facing the dual challenges of severe environmental pollution and climate change. Various gaseous pollutants emitted from industrial production activities not only directly harm human health but also have a profound impact on the global climate system. These pollutants mainly include various volatile organic compounds (such as alkanes, alkenes, aromatic hydrocarbons, halogenated hydrocarbons, oxygen-containing and nitrogen / sulfur-containing compounds, etc.), carbon monoxide, and methane. They are widespread and complex in composition, collectively exacerbating environmental problems at the regional and even global levels.
[0003] Among numerous pollution control technologies, catalytic oxidation is considered a mature and efficient strategy for purifying hazardous gases. Noble metal catalysts (such as Pt, Pd, and Rh) have become one of the core materials that were first commercially applied due to their excellent catalytic activity against a variety of pollutants. However, in actual operating conditions, the composition of waste gas is complex, often containing SO2, water vapor, and NO. x Interfering components can easily cause catalyst poisoning and deactivation. In addition, under high-temperature reaction conditions such as methane combustion, the noble metal active components are prone to sintering and agglomeration, leading to a reduction in active sites and a decline in catalytic performance.
[0004] Therefore, how to design and develop a broad-spectrum noble metal catalytic material that combines excellent low-temperature activity, high resistance to poisoning, and good thermal stability, so that it can remove a variety of pollutants efficiently and for a long time in complex real-world environments, has become a key technical challenge that researchers in this field urgently need to overcome. Summary of the Invention
[0005] To address the aforementioned technical problems, this application provides a widely applicable supported noble metal combustion catalyst, its preparation method, and its application. AO is prepared via the sol-gel method. x -BO x A supported noble metal combustion catalyst was prepared by pre-reduction treatment of the support and then by an equal-volume impregnation method. This preparation method is simple to operate and the raw materials are inexpensive and readily available. The prepared supported noble metal catalysts were used in the oxidation reactions of VOCs, methane, and CO, and all showed high activity and excellent stability to varying degrees.
[0006] According to a first aspect of this application, a combustion catalyst with both high activity and stability is provided.
[0007] A combustion catalyst that combines high activity and stability, the catalyst comprising an active component and a support, wherein the active component is supported on the support; The active component includes the noble metal N; The carrier includes a transition metal carrier AO. x and inert carrier BO x The AO x With the BO x ABO solid solution x or AO x -BO x It exists in the form of.
[0008] Optionally, the noble metal N is Pt, Pd, Ru, or Rh.
[0009] Optionally, the transition metal carrier AO x The intermediate transition metal A is Cu, Ce, Fe, Mn, or Co.
[0010] Optionally, the inert carrier BO x B in the figure represents Ti, Al, Sn, Zn, or Si.
[0011] The transition metal carrier AO x It has reducing properties; the noble metal N and the transition metal carrier AO x There is a covalent interaction between the noble metal N and the inert carrier BO. x There are strong electron-electron interactions between them.
[0012] Optionally, the content of the precious metal N is 0.05-2.0% based on the total mass of the catalyst. In terms of molar amounts of elements, the molar ratio of the transition metal A to the noble metal N is (5-10):1, and the molar ratio of the transition metal A to the noble metal B is 1:(25-100).
[0013] According to a second aspect of this application, a method for preparing a combustion catalyst that combines high activity and stability is provided.
[0014] A method for preparing a combustion catalyst that combines high activity and stability, the method comprising the following steps: S1, AO x precursors, BO x The precursor, dispersant, chelating agent, and hydrolysis accelerator were mixed and reacted to obtain a gel, which was then subjected to centrifugation, drying, and calcination to obtain AO. x -BO x carrier; S2, the AO x -BO x The carrier is reduced to obtain the reduced AO. x -BO x carrier; S3, in the restored AO x -BO x The precursor solution of the noble metal N is impregnated on the support and allowed to stand, and then dried and calcined in sequence to obtain the catalyst that has both high activity and stable combustion.
[0015] Optionally, in S1, AO x precursors, BO x The precursor, dispersant, chelating agent and hydrolysis accelerator are mixed together, including: The AO x The precursor is dissolved in water to obtain solution A; The BO x The precursor, dispersant, and chelating agent are mixed to obtain solution B; Add solution A to solution B, and then add a hydrolysis accelerator.
[0016] Optionally, in S1, the AO x The precursor is selected from nitrates containing A, wherein the nitrate containing A is Cu(NO3)2, Ce(NO3)3, Fe(NO3)3, Mn(NO3)2 or Co(NO3)2.
[0017] Optionally, the concentration of solution A is 1-20 mg / mL.
[0018] Optionally, the addition rate of solution A is 1-2 mL / min.
[0019] Optionally, adding solution A to solution B includes adding solution A dropwise to solution B using a pipette.
[0020] Optionally, in S1, the BO x The precursor is selected from B-containing alkoxides, wherein the B-containing alkoxide is tetrabutyl titanate, aluminum isopropoxide, tin ethoxide, zinc ethoxide, or tetraethyl silicate.
[0021] Optionally, in S1, the dispersant is ethanol.
[0022] Optionally, in S1, the BO x The volume ratio of the precursor to the dispersant is 1:10.
[0023] Optionally, in S1, the chelating agent is acetylacetone, with a volume of 1-3 mL.
[0024] Optionally, in S1, the hydrolysis promoter is hydrochloric acid, with a volume of 3-9 mL.
[0025] Optionally, in S1, the volume ratio of the chelating agent to the hydrolysis promoter is 1:3.
[0026] The chelating agent and the hydrolysis promoter coexist and form a dynamic equilibrium, thereby achieving a controllable sol-gel process.
[0027] Optionally, in S1, the reaction temperature is 60-90°C, and the reaction time is 2-6 hours.
[0028] Optionally, in step S1, the centrifugation speed is 5000-8000 rpm, the centrifugation time is 5-20 min, and the number of centrifugations is 2-5.
[0029] Optionally, in step S1, the drying temperature is 80-120°C, and the drying time is 12-48 hours.
[0030] Optionally, in step S1, the calcination temperature is 400-800℃, and the calcination time is 2-6 hours.
[0031] Optionally, in S2, the reduction process is H2 reduction or liquid phase reduction.
[0032] Optionally, the atmosphere for H2 reduction is H2 / Ar, wherein, based on the total volume of H2 / Ar, the H2 content is 10% and the total gas flow rate is 10-100 mL / min; The H2 reduction is carried out at a temperature of 200-500℃ for a time of 0.5-2 hours.
[0033] Optionally, the liquid-phase reduction uses an aqueous solution of NaBH4 as a reducing agent to soak the AO. x -BO x The carrier is exposed to the medium for 10-60 minutes, and the concentration of the NaBH4 aqueous solution is 0.01-0.1 mol / L.
[0034] Optionally, in step S2, the carrier is sequentially subjected to tableting and crushing / screening processes, with the sieve mesh size being 40-60 mesh. Optionally, in step S3, the precursor solution of the noble metal N is an aqueous solution of N-containing nitric acid.
[0035] Optionally, in step S3, the drying temperature is 80-120°C, and the drying time is 12-48 hours.
[0036] Optionally, in step S3, the calcination temperature is 400-600℃, and the calcination time is 2-6 hours.
[0037] Optionally, in S1 and S3, the heating rate for both drying and calcination is 1-10℃ / min.
[0038] If the calcination temperature is too low, it is difficult to form the target configuration; if the calcination temperature is too high, sintering is likely to occur, reducing catalytic efficiency.
[0039] The catalyst support mentioned above is a solid solution of ABO. x or AO x -BO x The support was prepared by the sol-gel method; the active component of the catalyst was the noble metal N, which was loaded by the equal volume impregnation method. This preparation method is simple to operate and the raw materials are inexpensive and readily available.
[0040] According to a third aspect of this application, a combustion catalyst with both high activity and stability is provided for use in the oxidation reaction of methane, volatile organic compounds, and carbon monoxide.
[0041] The beneficial effects that this application can produce include: (1) This application provides a combustion catalyst with both high activity and stability, its preparation method and application, wherein a solid solution of ABO is prepared by the sol-gel method. x or AO x -BO x The active component N is loaded onto the pre-reduced support by a simple impregnation method to obtain a supported noble metal combustion catalyst. The preparation method of this catalyst is simple to operate, the raw materials are inexpensive and readily available, and it has strong universality.
[0042] (2) In the catalyst with both high activity and stable combustion prepared in this application, the activity and stability are improved synergistically through the interaction between the dual metal-support, and the active component N and AO x There is a covalent interaction between N and BO. x Due to the existence of strong electronic interactions, the catalysts prepared have advantages such as wide application range and strong universality. Attached Figure Description
[0043] The catalyst support is CeO x The following diagram illustrates the example of the complete oxidation of methane using TiO2, with Pt as the active component: Appendix Figure 1 The conversion rate of CH4 by the combustion catalysts prepared in Examples 1-4 and Comparative Examples 1-2 of this application is given.
[0044] Appendix Figure 2 The combustion catalysts prepared in Example 1 and Comparative Examples 1-2 were tested for long-term stability at 400°C.
[0045] Appendix Figure 3The combustion catalysts prepared in Example 1 and Comparative Examples 1-2 were tested for long-term stability at 600°C. Detailed Implementation
[0046] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.
[0047] Unless otherwise specified, all raw materials used in the embodiments of this application were purchased through commercial channels.
[0048] Unless otherwise specified, all test methods are standard and all instrument settings are those recommended by the manufacturer.
[0049] In the embodiments of this application, the conversion rate is calculated as follows:
[0050] In the embodiments of this application, the conversion rate of CH4 is calculated based on the number of carbon moles.
[0051] As a preferred embodiment, a method for preparing a combustion catalyst that combines high activity and stability includes the following steps: S1, B corresponding alkoxides (20 mL), dispersant (200 mL), and chelating agent (1 mL) were stirred at room temperature for 1 h. Then, an aqueous solution containing A nitrate (1-20 mg / mL) and a hydrolysis accelerator (3 mL) were slowly added sequentially. The mixture was heated to 80 °C and reacted for 4 h to form an AB mixed gel. After the gel cooled naturally to room temperature, the solid was collected by centrifugation 3-5 times. The solid was then vacuum dried at 80 °C for 24 h. The solid sample was thoroughly ground into powder and calcined in a muffle furnace at 700 °C for 5 h to obtain AO. x -BO x carrier; S2, against AO x -BO x The carrier was subjected to reduction treatment. H2 reduction conditions were controlled at 10% H2 / Ar (50 mL / min) at 450℃ for 2 h; liquid-phase reduction conditions were soaking in 0.1 mol / L NaBH4 solution at room temperature for 10 min to obtain reduced AO. x -BO x carrier; S3, for the restored AO x -BO x The carrier is tableted and crushed and sieved to collect 40-60 mesh particles. The same volume of the particles are impregnated with an aqueous solution of nitric acid containing nitrogen, left to stand at room temperature for 12 hours, dried at 110℃ for 12 hours, and calcined at 500℃ for 4 hours to obtain a catalyst with both high activity and stable combustion.
[0052] Example 1 Measure 20 mL of tetrabutyl titanate (C 16 H36 O4Ti) was added to 200 mL of anhydrous ethanol, and 1 mL of acetylacetone chelating agent was added. The mixture was stirred at room temperature (25 °C) for 1 h at a speed of 500-800 rpm. This solution was designated as solution B.
[0053] Weigh 0.25g of Ce(NO3)3·6H2O into 20mL of deionized water, stir for 1h at a speed of 500-800rpm, and denote this as solution A.
[0054] Solution A was slowly added dropwise to solution B, followed by 3 mL of hydrochloric acid (37.5%) to control the gel formation rate. The temperature was then raised to 80°C and stirred at this temperature for 4 hours, followed by natural cooling. The mixed gel was then transferred to centrifuge tubes and centrifuged at 8000 rpm for 5 minutes, using ethanol as a washing agent, for 2-5 centrifugations until the filtrate was clear and transparent. The collected solid was placed in a vacuum oven and vacuum dried at 80°C for 24 hours. The dried powder was then thoroughly ground and calcined in a muffle furnace at 700°C for 5 hours to obtain CeO with a Ce / Ti molar ratio of 1:25. x -TiO2 support.
[0055] For the prepared CeO x -TiO2 support was reduced by heating to 450℃ for 2 h at a rate of 10℃ / min under a 10% H2 / Ar (50 mL / min) atmosphere to obtain reduced CeO2. x -TiO2 support.
[0056] The pre-reduced carrier was tableted at 20 MPa for 2 minutes, then crushed and sieved to obtain 40-60 mesh particles. 2.0 g of CeO was weighed. x -TiO2 support is used as a backup.
[0057] Using a pipette, measure specific volumes of Pt(NO3)2 solution and deionized water to ensure a Pt loading of 1 wt% and a volume of impregnation solution equal to the saturated water absorption rate of the TiO2 support. Slowly add the prepared impregnation solution dropwise to a 40-60 mesh CeO2 container. x After standing for 12 hours on a TiO2 support, the sample was transferred to an oven and heated at 110°C for 12 hours, and then calcined at 500°C for 4 hours in a muffle furnace to obtain Pt / CeO loaded with the noble metal Pt. x -TiO2 catalyst.
[0058] Example 2 The only difference between this embodiment and Example 1 is that the mass of Ce(NO3)3·6H2O weighed is 0.5g. The remaining steps are the same as in Example 1.
[0059] Example 3 The only difference between this embodiment and Embodiment 1 is that the mass of Ce(NO3)3·6H2O weighed is 0.75g, and the other steps are the same as in Embodiment 1.
[0060] Example 4 The only difference between this embodiment and Embodiment 1 is that the mass of Ce(NO3)3·6H2O weighed is 1.0g, and the other steps are the same as in Embodiment 1.
[0061] Comparative Example 1 Measure 15 mL of tetrabutyl titanate (TBOT) and add it to 120 mL of anhydrous ethanol. Add 1 mL of acetylacetone chelating agent and stir at room temperature (25℃) for 1 h with the stirring speed controlled at 500-800 rpm. This solution is denoted as A.
[0062] Next, 20 mL of deionized water and 3 mL of hydrochloric acid (37.5%) were slowly added dropwise to solution A to control the gel formation rate. The temperature was then raised to 80 °C, stirred at this temperature for 4 hours, and then allowed to cool naturally. The mixed gel was then transferred to centrifuge tubes and centrifuged at 8000 rpm for 5 minutes, using ethanol as a washing agent, for 2-5 centrifugations until the filtrate was clear and transparent. The solid obtained by centrifugation was placed in a vacuum oven and vacuum dried at 80 °C for 24 hours. The dried powder was then thoroughly ground and calcined in a muffle furnace at 700 °C for 5 hours to obtain the TiO2 support.
[0063] The prepared TiO2 support was reduced by heating to 450℃ for 2 h at a rate of 10℃ / min under a 10% H2 / Ar (50 mL / min) atmosphere to obtain the reduced TiO2 support.
[0064] The pre-reduced support was compressed into tablets at 20 MPa for 2 minutes, then crushed and sieved to obtain 40-60 mesh particles. 2.0 g of TiO2 support was weighed out for later use.
[0065] A certain volume of Pt(NO3)2 solution and deionized water were measured separately using a pipette to load Pt. The amount is 1 wt%, and the volume of the impregnation solution is the saturated water absorption rate of the TiO2 support. The prepared impregnation solution... Slowly add the solution dropwise onto a 40-60 mesh TiO2 support, let it stand for 12 hours, then transfer it to an oven and heat at 110°C. The catalyst was calcined at 500℃ for 4 hours after being heated for 12 hours in a muffle furnace to obtain the Pt / TiO2 catalyst loaded with the noble metal Pt.
[0066] Comparative Example 2 A certain amount of Ce(NO3)3·6H2O was weighed and placed directly in a muffle furnace and heated at 700℃ for 5 hours to obtain CeO2 support.
[0067] The prepared CeO2 support was reduced by heating to 450℃ for 2 h at a rate of 10℃ / min under a 10% H2 / Ar (50 mL / min) atmosphere to obtain reduced CeO2. x -TiO2 support.
[0068] The pre-reduced support was compressed into tablets at 20 MPa for 2 minutes, then crushed and sieved to obtain 40-60 mesh particles. 2.0 g of CeO2 support was weighed out for later use.
[0069] A certain volume of Pt(NO3)2 solution and deionized water was measured separately using a pipette to ensure that the Pt loading was 1 wt% and the volume of the impregnation solution was equal to the saturated water absorption rate of the CeO2 support. The prepared impregnation solution was slowly added dropwise to a 40-60 mesh CeO2 support. After standing for 12 hours, the support was transferred to an oven and heated at 110°C for 12 hours. Then, it was calcined in a muffle furnace at 500°C for 4 hours to obtain the Pt / CeO2 catalyst loaded with the noble metal Pt.
[0070] The platinum-based methane combustion catalysts prepared in Examples 1-4 and Comparative Examples 1-2 were used in the methane combustion reaction. The specific steps included: Weigh 0.2 g of 40-60 mesh catalyst and dilute it to 1 mL with quartz sand, mixing thoroughly (to prevent heat transfer limitation). Control the reaction mass hourly space velocity (WHSV) at 60000 mL·g. cat -1 ·h -1 The gas composition was CH4:O2 = 0.4 vol%: 4 vol%, with N2 as the equilibrium gas. The activity test temperature range was 200-600℃, and the stability test temperatures were 400℃ and 600℃, respectively. An Agilent GC7890A chromatograph was used for online analysis, and the concentration of methane at the outlet was detected by an FID detector. The performance and stability test results of the above catalysts are recorded in Tables 1 and 2.
[0071] Table 1. Test results of methane combustion performance with different catalysts
[0072] Note: T 10 T 50 T 90 These represent the temperatures corresponding to CH4 conversion rates of 10%, 50%, and 90%, respectively.
[0073] Table 2. Stability test results of methane combustion reaction with different catalysts
[0074] According to Table 1 (e.g.) Figure 1 As shown), Table 2 (as shown) Figure 2 , Figure 3 As shown in the figure and in conjunction with Examples 1-4, the composite oxide cerium titanium support prepared by the sol-gel method, and the combustion catalyst prepared by impregnation with the noble metal platinum after pre-reduction, exhibits a low ignition temperature, excellent activity, and excellent stability in the methane combustion reaction.
[0075] Comparative Examples 1 and 2 show that the combustion catalyst prepared by impregnating a single-component TiO2 support with platinum after reduction using the sol-gel method exhibits excellent initial activity, but it quickly deactivates, with an even faster deactivation rate at high temperatures. In contrast, the Pt combustion catalyst supported on a single-component CeO2 support, while exhibiting lower activity, demonstrates excellent stability.
[0076] As can be seen from Examples 1-4 and Comparative Examples 1-2, the Pt / CeO prepared in this application... x -TiO2 catalysts combine the advantages of both TiO2 and CeO2 while overcoming their disadvantages, constructing a platinum-based catalyst with both high activity and high stability through dual metal-support interactions. The conversion efficiency of the methane combustion catalyst can be further controlled by adjusting the molar ratio of the titanium and cerium sources.
[0077] In summary, this application prepared a cerium-titanium support via the sol-gel method and then performed a pre-reduction treatment. After treatment, Pt / CeO was prepared by equal-volume impregnation. x -TiO2 combustion catalyst, the preparation The method is simple to operate, uses inexpensive and readily available raw materials, and exhibits excellent activity and stability when applied to the catalytic combustion reaction of low-concentration methane.
Claims
1. A combustion catalyst possessing both high activity and stability, characterized in that, The catalyst includes an active component and a support, wherein the active component is loaded on the support; The active component includes the noble metal N; The carrier includes a transition metal carrier AO. x and inert carrier BO x The AO x With the BO x ABO solid solution x or AO x -BO x It exists in the form of.
2. The catalyst with both high activity and stable combustion according to claim 1, characterized in that, The precious metal N is Pt, Pd, Ru, or Rh; The transition metal carrier AO x The intermediate transition metal A is Cu, Ce, Fe, Mn, or Co; The inert carrier BO x B is Ti, Al, Sn, Zn or Si.
3. The catalyst with both high activity and stable combustion according to claim 1, characterized in that, Based on the total mass of the catalyst, the content of the precious metal N is 0.05-2.0%; In terms of molar amounts of elements, the molar ratio of the transition metal A to the noble metal N is (5-10):1, and the molar ratio of the transition metal A to the noble metal B is 1:(25-100).
4. A method for preparing a catalyst with both high activity and stable combustion as described in any one of claims 1 to 3, characterized in that, The preparation method includes the following steps: S1, a precursor of AO x S2, a precursor of BO x S3, a dispersant, a chelating agent and a hydrolysis promoter are mixed, reacted to obtain a gel, and then sequentially subjected to centrifugation, drying and calcination to obtain AO x -BO x a support; S2, the AO x -BO x reduction treatment to the carrier to obtain the reduced AO x -BO x carrier; S3, in the restored AO x -BO x The precursor solution of the noble metal N is impregnated on the support and allowed to stand, and then dried and calcined in sequence to obtain the catalyst that has both high activity and stable combustion.
5. The method for preparing a catalyst with both high activity and stable combustion according to claim 4, characterized in that, In S1, AO x precursors, BO x The mixture of precursors, dispersants, chelating agents, and hydrolysis accelerators includes: dissolving the AO x precursor in water to obtain an A solution; The BO x precursor, dispersant and chelating agent are mixed to obtain B solution; Add solution A to solution B, and then add a hydrolysis accelerator; Preferably, in S1, the AO x The precursor is selected from nitrates containing A, wherein the nitrate containing A is Cu(NO3)2, Ce(NO3)3, Fe(NO3)3, Mn(NO3)2 or Co(NO3)2; Preferably, the concentration of solution A is 1-20 mg / mL; Preferably, the addition rate of solution A is 1-2 mL / min.
6. The method for preparing a catalyst with both high activity and stable combustion according to claim 4, characterized in that, In said S1, said BO x a precursor of said B0 is selected from B-containing alkoxides, which are tetrabutyl titanate, aluminum isopropoxide, tin ethoxide, zinc ethoxide or tetraethyl silicate; Preferably, in S1, the dispersant is ethanol; Preferably, in S1, the BO x The volume ratio of the precursor to the dispersant is 1:10; Preferably, in S1, the chelating agent is acetylacetone, and the volume is 1-3 mL; Preferably, in step S1, the hydrolysis promoter is hydrochloric acid, and the volume is 3-9 mL; Preferably, in S1, the volume ratio of the chelating agent to the hydrolysis accelerator is 1:
3.
7. The method for preparing a catalyst with both high activity and stable combustion according to claim 4, characterized in that, In S1, the reaction temperature is 60-90℃, and the reaction time is 2-6 hours. Preferably, in step S1, the centrifugation speed is 5000-8000 rpm, the centrifugation time is 5-20 min, and the number of centrifugations is 2-5. Preferably, in step S1, the drying temperature is 80-120°C, and the drying time is 12-48 hours. Preferably, in step S1, the calcination temperature is 400-800℃, and the calcination time is 2-6 hours.
8. The method for preparing a catalyst with both high activity and stable combustion according to claim 4, characterized in that, In S2, the reduction process is H2 reduction or liquid phase reduction; Preferably, the atmosphere for H2 reduction is H2 / Ar, wherein, based on the total volume of H2 / Ar, the H2 content is 10% and the total gas flow rate is 10-100 mL / min; The H2 reduction is carried out at a temperature of 200-500℃ for a time of 0.5-2 hours. Preferably, the liquid-phase reduction uses an aqueous solution of NaBH4 as a reducing agent to soak the AO. x -BO x The carrier is exposed to the medium for 10-60 minutes, and the concentration of the NaBH4 aqueous solution is 0.01-0.1 mol / L.
9. The method for preparing a catalyst with both high activity and stable combustion according to claim 4, characterized in that, In step S3, the precursor solution of the noble metal N is an aqueous solution of N-containing nitric acid; Preferably, in step S3, the drying temperature is 80-120°C, and the drying time is 12-48 hours. Preferably, in step S3, the calcination temperature is 400-600℃, and the calcination time is 2-6 hours. Preferably, in S1 and S3, the heating rate for both drying and calcination is 1-10℃ / min.
10. The application of a catalyst with both high activity and stable combustion as described in any one of claims 1 to 3 in the oxidation reaction of methane, volatile organic compounds, and carbon monoxide.