A CO-SCR denitration catalyst used under high space velocity oxygen-containing conditions and a preparation method thereof

Abstract

The application relates to a CO-SCR denitration catalyst under high space velocity oxygen-containing conditions and a preparation method thereof, which comprises a carrier and an active component, and the catalyst composition is IrRu / AxByO z , the Ir and Ru are active components, the Ir loading is 1-5 wt%, the Ru loading is 1-5 wt%, and the Ir and Ru exist in the form of a metallic alloy; the AxByO z carrier is a perovskite or a structure similar to a titanite, wherein A is one and more than one of Mg, Ca, Sr, Ba, Fe, Co and Ni, B is Ti, 0.7

Description

Technical Field

[0001] This invention relates to the fields of environmental catalysis and industrial waste gas treatment, specifically to a CO-SCR denitrification catalyst and its preparation method that utilizes CO contained in the waste gas as a reducing agent to reduce NOx to N2 under high-speed aerobic conditions, thereby achieving the purpose of treating waste with waste. Background Technology

[0002] NO x Both CO and nitrogen oxides (NOx) are air pollutants and byproducts of many industrial processes. The "2021 China Ecological Environment Statistical Yearbook" indicated that the total emissions of NOx from waste gas nationwide reached 9.884 million tons, of which 3.689 million tons were from industrial sources. The top three industries were power and heat production and supply, non-metallic mineral products, and ferrous metal smelting and rolling, accounting for 82.1% of the total industrial NOx emissions nationwide. Besides large amounts of CO, industrial waste gas also contains a significant amount of O2, which is a major obstacle to CO-SCR reactions.

[0003] Denitrification technologies mainly include wet and dry methods. Currently, the most commercially viable denitrification technology is NH3-SCR, but it requires the introduction of NH3 as a reducing agent, which can cause secondary pollution such as pipeline corrosion and ammonia leaks. Therefore, utilizing CO contained in industrial waste gas as a reducing agent for denitrification is a more ideal and promising technology. In research, transition metal catalysts have become the preferred choice for CO-SCR reactions due to their low cost; however, the presence of even a small amount of oxygen can significantly reduce denitrification performance.

[0004] Currently, most catalysts used for CO-SCR reactions under aerobic conditions are Ir-based catalysts. For example, patent CN1113275008A prepared a catalyst with synergistic effects using SiO2 spheres as a support, Ir as the active component, and K as a promoter. This catalyst achieved a space velocity of 20,000 h⁻¹. -1 In the presence of oxygen-rich (5% O2) and SO2 (20ppm), the denitrification efficiency remains above 70% within the temperature range of 225-350℃. Besides the noble metal Ir, Ru and Ag have also been studied as active components in CO-SCR reactions under excess oxygen conditions: Patent CN 106984304B prepared a composite denitrification catalyst with γ-Al2O3 as the support and Ru-Ag bimetallic active components, wherein the Ru loading is 0.01%–1.0% and the Ag loading is 1%–10%. This catalyst showed good performance under conditions of 25% excess oxygen and GHSV = 37500 h⁻¹. -1Under the condition that, the NO conversion rate reaches about 65% within the range of 250 - 400 °C. Benyong Yang et al. (Industrial & Engineering Chemistry Research 2020, 59, 20, 9655–9665) prepared a supported denitration catalyst with TiO2 as the carrier and noble metal Ir as the active component. Among them, the loading amount of Ir is 0 - 1.5%. It was found that although the reaction activity gradually shifted to the low-temperature region with the increase of the Ir loading content, the NO x removal rate in the high-temperature region gradually decreased.

[0005] Based on the above, the noble metal catalyst has good catalytic performance for the CO-SCR reaction, but there are still the following problems: the occurrence of the CO oxidation side reaction under aerobic conditions in the high-temperature region significantly reduces the denitration rate; it is difficult to maintain a wide temperature window at a high space velocity when using only a single noble metal as the active component. Therefore, by selecting a suitable carrier, developing a dual-noble metal alloy catalyst with high activity and a wide temperature operation window under high space velocity and aerobic conditions has certain industrial application prospects. Summary of the Invention

[0006] Aiming at the disadvantages of the existing Ir-based catalyst, such as limited temperature window under aerobic conditions and high price of noble metal Ir, the present invention provides a CO-SCR denitration catalyst for high space velocity and oxygen-containing conditions and its preparation method. This catalyst has the characteristics of high reaction activity and a wide operating temperature window, and is suitable for the effective removal of NOx under conditions such as industrial waste gas.

[0007] The object of the present invention can be achieved by the following technical solutions: A CO-SCR denitration catalyst for high space velocity and oxygen-containing conditions, this catalyst comprises a carrier and an active component, and the catalyst composition is IrRu / AxByO z ,

[0008] Furthermore, the Ir and Ru are active components, wherein the Ir loading amount is 1 - 5 wt%, the Ru loading amount is 1 - 5 wt%, and they exist in the form of a metal-state alloy;

[0009] Furthermore, the AxByO z carrier has a perovskite or ilmenite-like structure, where the A-site is one or more of Mg, Ca, Sr, Ba, Fe, Co, and Ni, the B-site is Ti, 0.7 < x / y < 1.3, and z is determined according to the stoichiometric ratio of A and B.

[0010] Furthermore, the active component IrRu metal-state alloy exists in the form of flakes or rods.

[0011] Furthermore, the AxByO zThe carrier, when Ba is present at site A, has a tetragonal structure;

[0012] When the A site contains Mg or Sr, its structure is a hexagonal phase;

[0013] When site A contains Ca, its structure is a monoclinic phase.

[0014] This invention also provides a method for preparing a CO-SCR denitration catalyst under high-space-velocity oxygen-containing conditions, characterized by comprising the following steps:

[0015] (1)AxByO z Preparation of the carrier;

[0016] AxByO was prepared by precipitation of A-site precursor and B-site Ti precursor. z The carrier; specifically, the A-site precursor and the B-site Ti precursor are mixed in stoichiometric ratio, hydrothermally aged at 150–200 °C for 12–20 h under alkaline conditions, cooled, washed with glacial acetic acid and deionized water, dried at 50–80 °C for 12–36 h, and calcined at 800–1000 °C for 10–14 h to obtain AxByO. z Carrier.

[0017] (2) Catalyst preparation:

[0018] An aqueous solution of Ir precursor and Ru precursor was mixed, and the active component was loaded onto AxByO by impregnation. z On the vector, IrRu / AxByO was obtained. z catalyst.

[0019] Furthermore, the Ir precursor is one of iridium chloride, iridium acetylacetonate, iridium acetate, and chloroiridium acid.

[0020] Furthermore, the Ru precursor is one of ruthenium chloride, ruthenium nitrate, and ruthenium acetate;

[0021] Furthermore, the A-site precursor is one or more of nitrate, chloride, hydroxide, and acetate; the B-site Ti precursor is one or more of tetrabutyl titanate, titanium tetrachloride, and titanium sulfate.

[0022] Furthermore, AxByO z Organic complexing agents can also be added to the carrier during the preparation process to prepare highly dispersed nanoparticles. The added organic complexing agent is one or more of ethylene glycol, acetic acid, glycerol, malic acid, and hexadecyl ammonium bromide. The ratio of the amount of organic complexing agent added to the total molar concentration of metal ions in the carrier is 0.01-1.1:1.

[0023] Furthermore, after loading the metal precursor solution of IrRu by impregnation, the supported IrRu alloy catalyst is obtained by drying, calcining and reduction activation.

[0024] Furthermore, the calcination temperature is between 500-800℃, and the calcination time is between 0.5-12h; the catalyst needs to be reduced and activated before use, and the selected reducing agent is one or more of CO, H2, and NH3, and the reduction and activation temperature is between 500-700℃.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. The catalyst preparation process of this invention is simple and easy to implement. A is synthesized via a hydrothermal method. x Ti y The Oz support uses an impregnation method to load the active components onto the support surface. The formation of the IrRu alloy can regulate the adsorption of CO and NO in the reaction gas and promote the interaction between the support and the active components, thereby improving the denitrification performance of the catalyst.

[0027] 2. The perovskite and ilmenite structured support A prepared in this invention x Ti y Oz (x / y = 0.7 to 1.3, z is determined according to the stoichiometric ratio of A and B) has high thermal stability.

[0028] 3. The catalyst of this invention can be carried out under high space velocity and oxygen-containing conditions. The IrRu alloy with plate-like or rod-like shapes increases the catalyst's oxygen resistance, thereby enabling CO to participate in the selective reduction of NOx. Attached Figure Description

[0029] Figure 1 XRD patterns of the support and catalyst;

[0030] Figure 2 High-resolution electron microscopy (HR-STEM) image of the catalyst;

[0031] Figure 3 This refers to the cyclic stability of the catalyst. Detailed Implementation

[0032] The CO-SCR catalyst and its preparation method described in this invention are further illustrated below with specific embodiments. It should be noted that the following embodiments are only used to describe the invention, and the scope of protection of this invention is not limited to these embodiments. Simple modifications or substitutions to the catalyst preparation methods, steps, or conditions in this invention without departing from the spirit and essence of this invention are all within the scope of this invention. Unless otherwise specified, the basic operations used in the embodiments are conventional methods well known to those skilled in the art, and the raw materials used are all commercially available.

[0033] The CO-SCR activity evaluation of the catalysts obtained in the following examples and comparative examples was carried out in a fixed-bed reactor. The reaction test conditions were: 0.1% NO, 0.8% CO, 0.8% O2, with the remainder being Ar, and the mass hourly space velocity was 200,000-400,000 mL / g·h.

[0034] Example 1

[0035] 0.009 mol Ba(NO3)2, 0.011 mol tetrabutyl titanate, and 0.9 mol NaOH were weighed and poured into a 100 ml reaction vessel. 80 ml of H2O was added, and the mixture was hydrothermally aged at 180 °C for 15 h. After cooling, the mixture was washed with glacial acetic acid and deionized water, dried at 60 °C for 24 h, and calcined at 900 °C for 12 h to obtain Ba. 0.9 Ti 1.1 O3 support. The obtained support was impregnated in aqueous solutions of Ir and Ru precursors, and after impregnation at room temperature for 5 h, it was dried at 60 °C for 24 h and calcined in air at 500 °C for 12 h to obtain IrRu / Ba. 0.9 Ti 1.1 The catalyst is an O3 catalyst with an Ir loading of 0.05 mmol and a Ru loading of 0.05 mmol.

[0036] Example 2

[0037] 0.0095 mol Ba(NO3)2, 0.0105 mol tetrabutyl titanate, and 0.9 mol NaOH were weighed and poured into a 100 ml reaction vessel. 80 ml of H2O was added, and the mixture was hydrothermally aged at 180 °C for 15 h. After cooling, the mixture was washed with glacial acetic acid and deionized water, dried at 60 °C for 24 h, and calcined at 900 °C for 12 h to obtain Ba. 0.95 Ti 1.05 O3 support. The obtained support was impregnated in aqueous solutions of Ir and Ru precursors, and after impregnation at room temperature for 5 h, it was dried at 60 °C for 24 h and calcined in air at 500 °C for 12 h to obtain Ir. 0.95 Ru 1.05 The catalyst is a BaTiO3 catalyst with an Ir loading of 0.05 mmol and a Ru loading of 0.05 mmol.

[0038] Example 3

[0039] 0.01 mol Ba(NO3)2, 0.01 mol tetrabutyl titanate, and 0.9 mol NaOH were weighed and poured into a 100 ml reactor. 80 ml H2O was added, and the mixture was hydrothermally aged at 180 °C for 15 h. After cooling, the mixture was washed with glacial acetic acid and deionized water, dried at 60 °C for 24 h, and calcined at 900 °C for 12 h to obtain the BaTiO3 support. The obtained support was impregnated in aqueous solutions of Ir and Ru precursors for 5 h at room temperature, dried at 60 °C for 24 h, and calcined in air at 500 °C for 12 h to obtain the IrRu / BaTiO3 catalyst, wherein the Ir loading was 0.05 mmol and the Ru loading was 0.05 mmol.

[0040] Example 4

[0041] 0.0105 mol Ba(NO3)2, 0.0095 mol tetrabutyl titanate, and 0.9 mol NaOH were weighed and poured into a 100 ml reaction vessel. 80 ml of H2O was added, and the mixture was hydrothermally aged at 180 °C for 15 h. After cooling, the mixture was washed with glacial acetic acid and deionized water, dried at 60 °C for 24 h, and calcined at 900 °C for 12 h to obtain Ba. 1.05 Ti 0.95 O3 support. The obtained support was impregnated in aqueous solutions of Ir and Ru precursors, and after impregnation at room temperature for 5 h, it was dried at 60 °C for 24 h and calcined in air at 500 °C for 12 h to obtain IrRu / Ba. 1.05 Ti 0.95 The catalyst is an O3 catalyst with an Ir loading of 0.05 mmol and a Ru loading of 0.05 mmol.

[0042] Example 5

[0043] 0.011 mol Ba(NO3)2, 0.009 mol tetrabutyl titanate, and 0.9 mol NaOH were weighed and poured into a 100 ml reaction vessel. 80 ml of H2O was added, and the mixture was hydrothermally aged at 180 °C for 15 h. After cooling, the mixture was washed with glacial acetic acid and deionized water, dried at 60 °C for 24 h, and calcined at 900 °C for 12 h to obtain Ba. 1.1 Ti 0.9 O3 support. The obtained support was impregnated in aqueous solutions of Ir and Ru precursors, and after impregnation at room temperature for 5 h, it was dried at 60 °C for 24 h and calcined in air at 500 °C for 12 h to obtain IrRu / Ba. 1.1 Ti 0.9 The catalyst is an O3 catalyst with an Ir loading of 0.05 mmol and a Ru loading of 0.05 mmol.

[0044] Example 6

[0045] 0.011 mol Ba(NO3)2, 0.009 mol tetrabutyl titanate, and 0.9 mol NaOH were weighed and poured into a 100 ml reaction vessel. 2 ml ethylene glycol and 78 ml H2O were added, and the mixture was hydrothermally aged at 180 °C for 15 h. After cooling, the mixture was washed with glacial acetic acid and deionized water, dried at 60 °C for 24 h, and calcined at 900 °C for 12 h to obtain Ba. 1.1 Ti 0.9 O3 support. The obtained support was impregnated in aqueous solutions of Ir and Ru precursors, and after impregnation at room temperature for 5 h, it was dried at 60 °C for 24 h and calcined in air at 500 °C for 12 h to obtain IrRu / Ba. 1.1 Ti 0.9 The catalyst is an O3 catalyst with an Ir loading of 0.05 mmol and a Ru loading of 0.05 mmol.

[0046] Example 7

[0047] 0.01 mol Mg(NO3)2, 0.01 mol tetrabutyl titanate, and 0.9 mol NaOH were weighed and poured into a 100 ml reactor. 80 ml H2O was added, and the mixture was hydrothermally aged at 180 °C for 15 h. After cooling, the mixture was washed with glacial acetic acid and deionized water, dried at 60 °C for 24 h, and calcined at 900 °C for 12 h to obtain the BaTiO3 support. The obtained support was impregnated in aqueous solutions of Ir and Ru precursors for 5 h at room temperature, dried at 60 °C for 24 h, and calcined in air at 500 °C for 12 h to obtain the IrRu / MgTiO3 catalyst, wherein the Ir loading was 0.05 mmol and the Ru loading was 0.05 mmol.

[0048] Example 8

[0049] 0.01 mol Sr(NO3)2, 0.01 mol tetrabutyl titanate, and 0.9 mol NaOH were weighed and poured into a 100 ml reactor. 80 ml H2O was added, and the mixture was hydrothermally aged at 180 °C for 15 h. After cooling, the mixture was washed with glacial acetic acid and deionized water, dried at 60 °C for 24 h, and calcined at 900 °C for 12 h to obtain the BaTiO3 support. The obtained support was impregnated in aqueous solutions of Ir and Ru precursors for 5 h at room temperature, dried at 60 °C for 24 h, and calcined in air at 500 °C for 12 h to obtain the IrRu / SrTiO3 catalyst, wherein the Ir loading was 0.05 mmol and the Ru loading was 0.05 mmol.

[0050] Example 9

[0051] 0.01 mol Ca(NO3)2, 0.01 mol tetrabutyl titanate, and 0.9 mol NaOH were weighed and poured into a 100 ml reactor. 80 ml H2O was added, and the mixture was hydrothermally aged at 180 °C for 15 h. After cooling, the mixture was washed with glacial acetic acid and deionized water, dried at 60 °C for 24 h, and calcined at 900 °C for 12 h to obtain the BaTiO3 support. The obtained support was impregnated in aqueous solutions of Ir and Ru precursors. After impregnation at room temperature for 5 h, it was dried at 60 °C for 24 h and calcined in air at 500 °C for 12 h to obtain the IrRu / caTiO3 catalyst, wherein the Ir loading was 0.05 mmol and the Ru loading was 0.05 mmol.

[0052] Comparative Example 1

[0053] Weigh 1g of Al2O3 support and immerse it in an aqueous solution of Ir precursor. After immersion at room temperature for 5h, dry at 60℃ for 24h and calcine in air at 500℃ for 12h to obtain Ir / Al2O3 catalyst, wherein the Ir loading is 0.1mmol.

[0054] Comparative Example 2

[0055] Weigh 1g of Al2O3 support and immerse it in an aqueous solution of Ru precursor. After immersion at room temperature for 5h, dry at 60℃ for 24h and calcine in air at 500℃ for 12h to obtain Ru / Al2O3 catalyst with Ru loading of 0.1mmol.

[0056] Comparative Example 3

[0057] 1 g of Al2O3 support was weighed and impregnated in aqueous solutions of Ir and Ru precursors. After impregnation at room temperature for 5 h, it was dried at 60 °C for 24 h and calcined in air at 500 °C for 12 h to obtain the IrRu / Al2O3 catalyst, wherein the Ir loading was 0.05 mmol and the Ru loading was 0.05 mmol.

[0058] Comparative Example 4

[0059] 1 g of TiO2 support was weighed and impregnated in aqueous solutions of Ir and Ru precursors. After impregnation at room temperature for 5 h, it was dried at 60 °C for 24 h and calcined in air at 500 °C for 12 h to obtain the IrRu / LaMnO3 catalyst, wherein the Ir loading was 0.05 mmol and the Ru loading was 0.05 mmol.

[0060] Comparative Example 5

[0061] 1 g of LaMnO3 support was weighed and impregnated in aqueous solutions of Ir and Ru precursors. After impregnation at room temperature for 5 h, it was dried at 60 °C for 24 h and calcined in air at 500 °C for 12 h to obtain the IrRu / LaMnO3 catalyst, wherein the Ir loading was 0.05 mmol and the Ru loading was 0.05 mmol.

[0062] The CO-SCR activity of the catalysts obtained in Comparative Examples 1-5 and Examples 1-6 was tested. The denitrification performance of each catalyst was evaluated under atmospheric pressure in a fixed-bed reactor (quartz tube, inner diameter 6 mm). The catalyst mass was 75 mg (40-60 mesh), the NO concentration was 0.1%, the CO concentration was 0.8%, the O2 concentration was 0.8%, the total flow rate was 250 mL / min, and the mass hourly space velocity (WHSV) was 200,000 mL·g. -1 ·h -1 Before the reaction test, the catalyst was pretreated in situ under a reducing atmosphere. During the reaction test, the catalyst bed temperature was increased from 25℃ to 200℃, then incremented by 20℃ increments up to 500℃, with each temperature point stabilized for 15 minutes before sampling. CO concentration was analyzed using a GC9790 gas chromatograph equipped with a flame ionization detector (FID), and NO, NO2, and NO3 were detected at the outlet using a Thermo Scientific 42i-HL nitrogen oxide analyzer. x The concentrations of CO and NO. x The conversion rate formula is:

[0063]

[0064] Among them, [X] in [X] out NO x / CO concentration at import and export levels.

[0065] The temperature range with a NOx conversion rate of 90% was used as the evaluation index.

[0066] The temperature at which the highest NOx conversion rate is achieved in the low-temperature region is used as the criterion for evaluating the low-temperature activity of the catalyst; while the temperature range in which the catalyst maintains a 90% conversion rate is used as the operating temperature range. The wider the operating temperature window, the better the operability of the catalyst.

[0067] Table 1: Evaluation Results of Catalyst CO-SCR Activity

[0068]

[0069]

[0070] As can be seen from Table 1 above, the catalysts obtained in Examples 1-9 have higher conversion rates. Although Comparative Example 4 achieves a NOx conversion rate of 92% and the lowest temperature for reaching the highest NOx conversion rate is 250°C, its operating temperature window is very narrow, only 250-300°C. It is evident that the interaction between the sheet-like or rod-shaped IrRu alloy described in this application and the AxByOz support with a specific metal perovskite or ilmenite structure broadens the temperature window of the Ir-based catalyst under aerobic conditions. Compared to Example 5, Example 6, with the addition of the complexing agent ethylene glycol, exhibits higher reactivity and a wider operating temperature window.

[0071] Figure 1 The XRD patterns of the catalysts obtained in Examples 3 / 7 / 8 / 9 are shown in the figures. It can be seen from the figures that when A contains Ba, the catalyst structure is tetragonal; when A contains Mg or Sr, the catalyst structure is hexagonal; and when A contains Ca, the catalyst structure is monoclinic. Referring to Table 1, it can be seen that the catalysts IrRu / AxByO with these structures... z All of them have the characteristics of high reactivity and wide operating temperature window. Figure 2 The image shows a high-resolution electron microscope (HR-STEM) image of the catalyst obtained in Example 3. As can be seen from the image, the IrRu metallic alloy exists in the form of rods. Combined with Table 1, it can be seen that the IrRu alloy with plate-like or rod-like shapes increases the oxygen resistance of the catalyst.

[0072] like Figure 3 The figure shows the cycle stability evaluation diagrams of the catalysts obtained in Example 3 and Comparative Example 4. Cycle stability is evaluated by raising the reaction temperature to 500°C, then lowering it to room temperature, and then performing a second temperature increase from room temperature to 500°C. This cycle stability is labeled "cycle-1". Within the evaluated temperature range, the NOx conversion rate changes with temperature. In the low-temperature region, the NOx conversion rate increases with increasing temperature, eventually reaching a stable state and remaining constant within a certain temperature range. However, with further increases in temperature, the NOx conversion rate decreases. The figure shows that the operating temperature window for NOx removal of the fresh Ir / TiO2 catalyst is 240-300°C. After one cycle, the highest NOx removal conversion rate achieved by this catalyst is only 83%, indicating poor catalyst stability. In contrast, the operating temperature window of the IrRu / BaTiO3 catalyst prepared in Example 3 shrinks from the initial 250-500°C to 275-500°C after one cycle stability evaluation.

Claims

1. A catalyst for CO-SCR denitration under high-space velocity oxygen-containing conditions, characterized in that, The catalyst comprises a support and an active component, and its composition is IrRu / AxByO. z , The Ir and Ru are active components, wherein the Ir loading is 1-5 wt% and the Ru loading is 1-5 wt%, and they exist in the form of a metallic alloy. The AxByO z The support has a perovskite structure, wherein the A site is one or more of Mg, Ca, Sr and Ba, the B site is Ti, 0.7 < x / y < 1.3, and z is determined according to the stoichiometric ratio of A and B. The active component IrRu metallic alloy exists in the form of sheets or rods; The AxByO z The carrier, when Ba is present at site A, has a tetragonal structure; When the A site contains Mg or Sr, its structure is a hexagonal phase; When site A contains Ca, its structure is a monoclinic phase.

2. A method for preparing a CO-SCR denitration catalyst under high-space velocity oxygen conditions as described in claim 1, characterized in that: Includes the following steps: (1) AxByO z Preparation of the carrier; AxByO was prepared by precipitation or sol-gel method using A-site precursor and B-site Ti precursor. z carrier; (2) Catalyst preparation: An aqueous solution of Ir precursor and Ru precursor was mixed, and the active component was loaded onto AxByO by impregnation. z On the vector, IrRu / AxByO was obtained. z catalyst.

3. The method for preparing a CO-SCR denitration catalyst under high-space velocity oxygen conditions according to claim 2, characterized in that: The Ir precursor is one of iridium chloride, iridium acetylacetonate, iridium acetate, and chloroiridium acid.

4. The method for preparing a CO-SCR denitration catalyst under high-space velocity oxygen conditions according to claim 2, characterized in that: The Ru precursor is one of ruthenium chloride, ruthenium nitrate, and ruthenium acetate.

5. The method for preparing a CO-SCR denitration catalyst under high-space velocity oxygen conditions according to claim 2, characterized in that: The A-site precursor is one or more of nitrate, chloride, hydroxide, and acetate; the B-site Ti precursor is one or more of tetrabutyl titanate, titanium tetrachloride, and titanium sulfate.

6. The method for preparing a CO-SCR denitration catalyst under high-space velocity oxygen conditions according to claim 2, characterized in that: AxByO z An organic complexing agent is added to the carrier during the preparation process to prepare highly dispersed nanoparticles. The added organic complexing agent is one or more of ethylene glycol, acetic acid, glycerol, malic acid, and hexadecyl ammonium bromide. The ratio of the amount of organic complexing agent added to the total molar concentration of metal ions in the carrier is (0.01~1.1):

1.

7. The method for preparing a CO-SCR denitration catalyst under high-space velocity oxygen conditions according to claim 2, characterized in that: After loading an IrRu metal precursor solution by impregnation, the supported IrRu alloy catalyst is obtained by drying, calcining, and reduction activation.

8. The method for preparing a CO-SCR denitration catalyst under high-space velocity oxygen conditions according to claim 7, characterized in that: The calcination temperature is 500-800 ℃, and the calcination time is 0.5-12 h. The catalyst needs to be reduced and activated before use. The reducing agent selected is one or more of CO, H2, and NH3, and the reduction and activation temperature is between 500-700 ℃.

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