A catalyst for catalytic oxidation of co and its preparation method and application

Abstract

The application provides a catalyst for catalytic oxidation of CO and a preparation method and application thereof. The preparation method comprises the following steps: mixing an iron precursor, a precursor of a first synergistic additive, water and a molecular sieve to obtain a mixture; mixing the mixture and a precipitant, and performing heating treatment to obtain an intermediate product; drying and calcining the intermediate product to obtain the catalyst for catalytic oxidation of CO; the precursor of the first synergistic additive comprises one of a Ce salt, a Cu salt and a Mn salt; wherein the Fe2O3 formed by calcining the iron precursor and the metal oxide formed by calcining the precursor of the first synergistic additive each account for 5-15wt% of the mass percentage of the catalyst for catalytic oxidation of CO. The catalyst has high catalytic efficiency and can adapt to the application environment of sintering flue gas.

Description

Technical Field

[0001] This invention relates to the field of carbon monoxide catalysis technology, and more specifically, to a catalyst for the catalytic oxidation of CO, its preparation method, and its application. Background Technology

[0002] Sintering flue gas contains a large amount of carbon monoxide (8000ppm~12000ppm), which is usually not treated in traditional end-of-pipe treatment processes and is directly discharged into the atmosphere.

[0003] Carbon monoxide in sintering flue gas has a much lower combustibility compared to traditional steel industry gas, making it difficult to use as a fuel. Carbon monoxide capture technologies are mostly pressure swing adsorption (PSA) and molecular sieve adsorption, which suffer from large space requirements and low capture efficiency. However, if a catalyst is used to catalytically oxidize carbon monoxide in the flue gas to produce carbon dioxide, carbon dioxide is not only easier to capture, but the toxicity of carbon monoxide to humans is also reduced. Furthermore, the heat released during oxidation can be recovered and utilized, offering multiple advantages.

[0004] Researchers have conducted some studies on the catalytic oxidation of carbon monoxide in recent years. Most of the catalysts used are precious metal catalysts, which are expensive. In the steel industry, the main users of CO catalytic oxidation technology are sintering flue gas. Non-precious metal catalysts are not very resistant to sulfur dioxide in sintering flue gas. Therefore, catalysts with lower cost and better resistance to sulfur and alkali metals are the top priority for the application of CO catalytic oxidation in the steel industry. Summary of the Invention

[0005] To address the problems in the prior art, the present invention aims to provide a catalyst for the catalytic oxidation of CO, its preparation method, and its applications. The catalyst of the present invention exhibits high catalytic efficiency and is adaptable to the application environment of sintering flue gas.

[0006] To address the aforementioned technical problems, according to a first aspect of the present invention, a method for preparing a catalyst for the catalytic oxidation of CO is provided, comprising the following steps: The iron precursor, the precursor of the first synergist, water, and molecular sieve were mixed to obtain a mixture. The mixture and precipitant are mixed and then heated to obtain an intermediate product; The intermediate product is dried and calcined to obtain the catalyst for CO catalytic oxidation. The precursor of the first synergist includes one of Ce salt, Cu salt, and Mn salt; The Fe2O3 formed by calcining the iron precursor and the metal oxides (CeO2, CuO, MnO2) formed by calcining the precursor of the first synergist each account for 5-15 wt% of the mass percentage of the catalyst used for CO catalytic oxidation.

[0007] Among them, oxides refer to metal oxides (Fe2O3) formed by calcining the iron precursor and metal oxides (CeO2, CuO, MnO2) formed by calcining the first synergistic agent precursor.

[0008] The first synergistic agent precursor of the present invention does not use multiple salts at the same time, which can avoid the introduction of too many elements into the catalyst, which would cause the crystal lattice to mix and deform, resulting in unpredictable and unanalyzable changes.

[0009] In some preferred embodiments of the present invention, the metal oxide (Fe2O3) formed by calcining the iron precursor and the metal oxide (CeO2, CuO, MnO2) formed by calcining the precursor of the first synergist each account for 7-13 wt% of the mass percentage of the catalyst used for CO catalytic oxidation. At the above-mentioned preferred contents, the catalyst of the present invention has a more comprehensive CO catalytic oxidation capability and a better catalytic oxidation rate.

[0010] In some preferred embodiments of the present invention, the first synergist precursor comprises a Ce salt. Under this preferred component selection, the resulting catalyst exhibits superior catalytic performance at high temperatures (≥150°C).

[0011] In some preferred embodiments of the present invention, the first synergist precursor comprises a Cu salt. With this preferred component selection, the resulting catalyst exhibits superior catalytic performance at both room temperature and low temperatures (below 150°C).

[0012] In some preferred embodiments of the present invention, the mixture further includes a precursor of a second synergist, comprising 0.04 to 16 wt% of the catalyst for CO catalytic oxidation, wherein the precursor of the second synergist comprises one or more salts of V, Nb, Mo, and W or their complexes. Adding the precursor of the second synergist can further enhance the catalytic activity of the catalyst.

[0013] In some preferred embodiments of the present invention, the raw materials for preparing the catalyst for CO catalytic oxidation do not contain precious metal elements. The catalyst of the present invention does not contain precious metal elements, is low in cost, and is suitable for industrialization.

[0014] In some preferred embodiments of the present invention, the ratio of the iron precursor to water in the mixture is (10.156~45.375) g : (200~500) ml.

[0015] In some preferred embodiments of the present invention, the iron precursor includes one or more of Fe(NO3)3, FeCl3, and Fe2(SO4)3.

[0016] In some preferred embodiments of the present invention, the precursor of the first synergist includes one of Ce nitrate, Cu nitrate, and Mn nitrate.

[0017] In some preferred embodiments of the present invention, the precursor of the second synergist includes V(C2O4)2, C 10 H5NbO 20 Mo(NO3)4, (NH4)6W7O 24 One or more of the ingredients in 6H2O.

[0018] In some preferred embodiments of the present invention, the V(C2O4)2 accounts for 0.734 to 2.934 wt% of the catalyst used for CO catalytic oxidation.

[0019] In some preferred embodiments of the present invention, the C 10 H5NbO 20 The mass percentage of the catalyst used for CO catalytic oxidation is 2.015~8.060 wt%.

[0020] In some preferred embodiments of the present invention, the Mo(NO3)4 accounts for 0.431 to 1.722 wt% of the mass percentage of the catalyst used for CO catalytic oxidation.

[0021] In some preferred embodiments of the present invention, the (NH4)6W7O 24 The mass percentage of 6H2O in the catalyst used for CO catalytic oxidation is 0.581~2.325 wt%.

[0022] In some preferred embodiments of the present invention, the second synergistic agent precursor comprises V(C2O4)2 and (NH4)6W7O. 24 6H2O. It has good resistance to sulfur and NO. xThe performance allows the catalyst itself to also remove some other pollutants from the flue gas. V-based oxides have amphoteric oxide properties, which improves the catalyst's resistance to both acidic and alkaline environments. The introduction of W element can greatly increase the catalyst's sulfur resistance.

[0023] In some preferred embodiments of the present invention, the second synergistic adjuvant precursor includes C 10 H5NbO 20 And Mo(NO3)4. The introduction of Mo element greatly improves the sulfur resistance of the catalyst, while the introduction of Nb element has similar properties to V2O5, and improves both catalysis and sulfur resistance to a certain extent.

[0024] In some preferred embodiments of the present invention, the second synergistic adjuvant precursor includes C 10 H5NbO 20 , Mo(NO3)4 and (NH4)6W7O 24 6H2O.

[0025] In some preferred embodiments of the present invention, the specific surface area of ​​the molecular sieve is ≥350 m². 2 / g. Molecular sieves with this specific surface area are more conducive to the uniform loading of active components, thereby improving catalytic activity.

[0026] In some preferred embodiments of the present invention, the molecular sieve includes one or more of ZSM-5, 5A, and SAPO-34.

[0027] In some preferred embodiments of the present invention, the heating temperature is 50~80°C, and the time is 15~30 minutes. Preferably, water bath heating is performed. Controlling the water bath heating temperature within the above range can effectively improve the solubility of the precursor and the movement of ions in the solution, promoting uniform mixing. The temperature should not be too high because stirring requires a certain amount of time, and the evaporation rate of the liquid will also be accelerated at high temperatures, which may cause some components with low solubility to precipitate prematurely, which is not conducive to uniform mixing.

[0028] In some preferred embodiments of the present invention, the preparation method includes: first, mixing the iron precursor, the precursor of the first synergist, and water, then heating the mixture in a water bath to 50-80°C and stirring; next, adding the molecular sieve and stirring for 15-30 minutes; then adding the precipitant at a rate of 30-60 ml / min, maintaining the water bath temperature and continuing to stir for 15-30 minutes to obtain the intermediate product.

[0029] In some preferred embodiments of the present invention, the drying method includes drying at 105~120°C for 6~12 hours. Controlling the drying temperature within the above range can effectively prevent condensation in the drying environment, while ensuring that the drying rate is not too fast, thus preventing the formation of a large number of pores inside the material. The dense structure is conducive to the formation of a good crystal phase during calcination, which is beneficial to improving the reaction activity of the catalyst.

[0030] In some preferred embodiments of the present invention, the roasting treatment method includes: After drying, the sample is kept at 250-300℃ for 1-3 hours, and then at 500-550℃ for 2-4 hours.

[0031] Preferably, the calcination treatment method includes: heating the dried sample to 250-300°C at a heating program of 3-5°C / min, holding at this temperature for 1-3 hours, and then heating it again to 500-550°C at a heating program of 3-5°C / min and holding at this temperature for 2-4 hours. The reason for this two-step calcination process is that a preheating at a medium-low temperature, as demonstrated by lattice phase analysis, effectively promotes the formation of crystal nuclei, and a sufficient number of crystal nuclei can effectively improve the uniformity of the crystal grains. Holding at a high temperature is to promote crystal growth; the reason for limiting the temperature within this range is that high temperatures can accelerate lattice growth, and excessively rapid growth will result in excessively large crystal grains in the finished catalyst, which is detrimental to the activity of the catalytic reaction.

[0032] In some preferred embodiments of the present invention, after the calcination is completed, the temperature is lowered to room temperature at a rate of 5~10℃ / min to obtain the catalyst for CO catalytic oxidation.

[0033] In some preferred embodiments of the present invention, the precipitant comprises one or a combination of two or more of ammonium bicarbonate, sodium bicarbonate, and ammonia. Preferably, the precipitant comprises ammonium bicarbonate, which has suitable alkalinity, and its use is more conducive to the formation of crystal nuclei and further improves the quality of the finished catalyst. Sodium bicarbonate and ammonia also have suitable weak alkalinity; however, special attention needs to be paid to the addition rate of ammonia to avoid excessive alkalinity. Sodium bicarbonate introduces Na ions during precipitation, which may have a certain adverse effect on catalytic performance. Although sulfides such as sodium sulfide can also induce iron ion precipitation, the introduction of sulfur may cause secondary pollution during catalyst calcination. Therefore, the present invention preferably uses ammonium bicarbonate as the precipitant, and ammonia is the next most preferred.

[0034] According to another aspect of the present invention, a catalyst for the catalytic oxidation of CO obtained according to the above-described preparation method is provided.

[0035] According to another aspect of the present invention, the application of the above-described catalyst for CO catalytic oxidation as a catalyst in CO catalytic oxidation is provided.

[0036] In some preferred embodiments of the present invention, when the temperature for CO catalytic oxidation is below 150°C, a catalyst for CO catalytic oxidation is used, wherein Cu salt and / or Mn salt are used as precursors for the first synergistic agent.

[0037] In some preferred embodiments of the present invention, when the temperature for CO catalytic oxidation is not lower than 150°C, a catalyst for CO catalytic oxidation using Ce salt as the first synergistic promoter precursor is used. At this temperature, such a preferred catalyst has better performance, possibly because at high temperatures, the Fe-Ce combination contains more oxygen vacancies, which can promptly adsorb oxygen in the atmosphere and transform it into a crystal lattice, thus allowing the catalyst to continuously cycle and react, while the other two components may have been largely reduced and thus lost their activity.

[0038] In some preferred embodiments of the present invention, the catalyst for CO catalytic oxidation is used for the catalytic oxidation of CO in sintering flue gas.

[0039] The post-treatment process of sintering flue gas typically includes three steps: dust removal, desulfurization, and denitrification. In these steps, most catalyst components have a certain degree of sulfur poisoning effect, which can affect the catalyst's performance. The catalyst of this invention has significant sulfur resistance, and since it is arranged together with the subsequent denitrification catalyst after desulfurization, it can effectively reduce the SO2 concentration in the flue gas. Furthermore, the denitrification process requires heating, and the CO catalyst process can generate some heat, reducing heating energy consumption, making it very suitable for use in this process.

[0040] In some preferred embodiments of the present invention, the operating conditions of the sintering flue gas include a gas space velocity of 2000 h⁻¹. -1 ~5000h -1 , 180~300℃, 0~12000ppm CO, 3~21vol% O2.

[0041] Compared to existing technologies, this invention provides a low-cost and highly efficient catalyst for the catalytic oxidation of CO. This catalyst exhibits high catalytic efficiency and is adaptable to the application environment of sintering flue gas. Most non-metallic catalysts in the prior art only demonstrate significant catalytic activity above 220°C, while commercial catalysts typically require temperatures above 250°C to achieve a catalytic efficiency of over 90%. In contrast, the catalyst of this invention achieves good catalytic performance at a lower reaction temperature. Attached Figure Description

[0042] Figure 1The catalytic oxidation rate diagram of the catalyst used for the catalytic oxidation of CO is shown.

[0043] Figure 2 A schematic diagram illustrating the effect of the catalyst on flue gas temperature rise is shown.

[0044] Figure 3 The relationship between the catalytic oxidation rate of the catalyst and the precipitant is shown.

[0045] Figure 4 The catalytic oxidation rate of the catalyst in Example 4 is shown.

[0046] Figure 5 The catalytic oxidation rate of the catalyst in Example 5 is shown.

[0047] Figure 6 The catalytic oxidation rate of the catalyst in Example 5 is shown. Detailed Implementation

[0048] In order to provide a clearer understanding of the technical features, objectives and beneficial effects of the present invention, the technical solution of the present invention will now be described in detail below, but it should not be construed as limiting the scope of implementation of the present invention.

[0049] Example 1

[0050] This embodiment provides a catalyst for the catalytic oxidation of CO, and the preparation method of the catalyst includes: Dissolve 30.25g of Fe(NO3)3 and 18.9535g of Ce(NO3)3 in 359ml of deionized water; heat the water bath to 68℃, stir thoroughly to dissolve, then add 80g of ZSM-5 molecular sieve and stir thoroughly for 20min to obtain a mixture.

[0051] Dissolve 40g of ammonium bicarbonate in 200ml of 20℃ deionized water, add it to the mixture at a rate of 20ml / min, keep the water bath temperature constant, and continue stirring for 30min.

[0052] The sample was then dried at 110℃ for 12 hours. After drying, the sample was calcined in a muffle furnace with a heating program of 3℃ / min to 260℃, held for 2 hours, then heated again at 3℃ / min to 540℃ and held for 3 hours. Finally, it was cooled to room temperature at 6℃ / min to complete the preparation, yielding a catalyst for CO catalytic oxidation, denoted as 10wt%Fe2O3-10wt%CeO2. The prepared sample weighed approximately 100g and was ground to pass through a 150-mesh sieve for later use.

[0053] Example 2

[0054] This embodiment is based on Example 1, with other conditions remaining unchanged, but the amounts of Fe(NO3)3 and Ce(NO3)3 in the raw materials are modified. The mass of Fe(NO3)3 and Ce(NO3)3 and the corresponding catalyst names are as follows: 0g / 0g (0%Fe2O3-0%CeO2), used as a comparison; 15.125g / 0g (5%Fe2O3-0%CeO2), used as a comparison; 15.125g / 18.9535g(5%Fe2O3-10%CeO2); 30.25g / 18.9535g (10%Fe2O3-10%CeO2, consistent with Example 1); 30.25g / 28.4303g(10%Fe2O3-15%CeO2); 45.375g / 18.9535g(15%Fe2O3-10%CeO2).

[0055] The above catalysts were then used for the catalytic oxidation of CO. Unless otherwise specified, the catalytic performance tests for each catalyst were conducted under the following conditions: The test flue gas operating conditions were: gas flow rate 0.0855 Nm³. 3 / h, 10000ppm CO, 8 vol% O2, carrier gas is N2. The gas inlet temperatures in each group of experiments were 80℃, 90℃, 100℃, 110℃, 120℃, 130℃, 140℃, 150℃, 160℃, 170℃, 180℃, 190℃, 200℃, 210℃, 220℃, 230℃, 240℃, 250℃, 260℃, 270℃, 280℃, 290℃, 300℃, 310℃, and 320℃.

[0056] The bulk density of the above-mentioned ground catalyst sample is 3.5 t / m³. 3 The sample volume was 28.5 ml, and the gas hourly space velocity (VHSV) was set to 3000 h⁻¹ during the catalyst test. -1 All the catalysts prepared above were packed into an 8mm diameter quartz tube reactor, and quartz cotton plugs were used as a fixing layer inside the tube. The catalyst was fixed by two layers of fixing. The catalyst layer used in the CO catalytic oxidation device was heated by a Shenzhen Kejing Zhida OTF-1200X-S 1200℃ miniature open-type tube furnace. Temperature measurement was performed using a Chongqing Chuanyi K-type thermocouple. Then, the CO concentration and temperature in the purified flue gas were detected at the flue gas outlet using a Testo 400 intelligent reference-grade multifunctional measuring instrument. All experimental gases were cylinder gases provided by Beijing Tianhai Industry.

[0057] Test results are as follows Figure 1 , Figure 2 As shown, the catalytic effect exhibits a trend where the higher the reaction temperature, the higher the catalytic efficiency. The catalytic efficiencies of the following samples at 100℃, 160℃, and 220℃ are as follows: 2.9%, 15.4%, 22.1%; 5.7%, 85.6%, 99.8%; 6.5%, 90.1%, 99.6%; 9.4%, 95.1%, 99.6%; 11.5%, 89.4%, 99.8%; and 27.2%, 91.2%, 99.1%. Some of the samples showed reduced efficiency at high temperatures, and the sample with the best overall performance was the 10%-Fe2O3-10%-CeO2 group.

[0058] Figure 1 The diagram shows the catalytic oxidation rate of catalysts used for the catalytic oxidation of CO. The catalytic oxidation rate is calculated as follows: .

[0059] Depend on Figure 1 It is evident that the catalyst of this invention possesses excellent catalytic ability, achieving a CO catalytic oxidation rate of over 90% at 160°C.

[0060] Figure 2 A schematic diagram illustrating the effect of the catalyst on flue gas temperature rise is shown.

[0061] Depend on Figure 2 It can be seen that the temperature rises of the 0%-Fe2O3-0%CeO2 sample, the 10%-Fe2O3-10%CeO2 sample, and the 15%-Fe2O3-10%CeO2 sample at reaction temperatures of 120℃, 160℃, and 220℃ are 2.5℃, 10℃, and 13℃; 15℃, 60℃, and 63℃; and 31℃, 57℃, and 62℃, respectively. The catalyst of this invention, at a suitable activation temperature, can raise the flue gas temperature by 60℃ during the catalytic process, effectively improving the heat utilization value of low-grade heat sources.

[0062] Example 3

[0063] This embodiment is based on the catalyst 10%Fe2O3-10%CeO2 in Example 1 to explore the effect of the type of precipitant on the catalyst.

[0064] The difference between this embodiment and Embodiment 1 is that the precipitant is different.

[0065] The following precipitants were used in each group of experiments: 53.7g of Na2CO3 was dissolved in 200ml of deionized water (precipitant A), 45.2g of NaHCO3 was dissolved in 200ml of deionized water (precipitant B), 172ml of 5% ammonia water (precipitant C), and 40g of NH4HCO3 was dissolved in 200ml of deionized water (precipitant D), the same as in Example 1, as controls.

[0066] The relationship between the catalytic oxidation rate of the catalyst and the precipitant is as follows: Figure 3 As shown, the catalytic performance of the catalyst in this embodiment was tested. At 160°C, using the precipitant AD, the corresponding carbon monoxide oxidation rates of the catalyst were 91.2%, 93.9%, 89.1%, and 95.1%, respectively. Figure 3 The results show that the choice of precipitant has little impact on catalyst performance. The group using ammonia as the precipitant exhibits the lowest catalytic activity, possibly due to rapid precipitation leading to poor catalyst dispersion during calcination. The catalysts from the sodium carbonate and sodium bicarbonate groups also show lower catalytic energies compared to ammonium bicarbonate, possibly due to their slightly stronger alkalinity and the presence of Na+. + Adverse effects caused by the introduction of ions.

[0067] Example 4

[0068] The difference between this embodiment and Example 1 is that Ce(NO3)3 was replaced with an equimolar amount of Cu precursor Cu(NO3)2 or Mn precursor Mn(NO3)2. The resulting samples were labeled Fe-Ce, Fe-Cu, and Fe-Mn, respectively. Their CO catalytic oxidation capacity was then tested, and the results are as follows: Figure 4 As shown, at 160℃, the catalytic oxidation rates of Fe-Ce, Fe-Cu, and Fe-Mn samples were 95.1%, 88.3%, and 90.4%, respectively.

[0069] Depend on Figure 4 It is evident that at low temperatures, the synergistic effect of Cu, Mn, and Fe catalysts is worse than that of Fe-Ce catalysts, especially the Fe-Cu catalyst. However, once the temperature rises to 150℃, the effect becomes less pronounced than that of the Fe-Ce catalyst. This may be because the Fe-Ce catalyst contains more oxygen vacancies, which can promptly adsorb oxygen in the atmosphere and transform it into a crystal lattice, allowing the catalyst to continuously cycle and react. Meanwhile, the other two components may have been largely reduced, thus losing their activity.

[0070] Example 5

[0071] The difference between this embodiment and Embodiment 1 is that an auxiliary agent was added, and the amounts added to each group are as follows: Group 1: The additives are V(C2O4)2 and Mo(NO3)4, with the following added masses: 0.734g and 0.431g; 0.734g and 0.862g; 0.734g and 1.722g; 1.468g and 0.431g; 1.468g and 0.862g; 1.468g and 1.722g; 2.934g and 0.431g; 2.934g and 0.862g; 2.934g and 1.722g (hereinafter referred to as VMo1~VMo9).

[0072] Group 2: Additives are V(C2O4)2 and (NH4)6W7O 24 The amounts of 6H₂O added were: 0.734g and 0.581g; 0.734g and 1.162g; 0.734g and 1.722g; 1.468g and 0.581g; 1.468g and 1.162g; 1.468g and 1.722g; 2.934g and 0.581g; 2.934g and 1.162g; 2.934g and 1.722g (hereinafter referred to as VW1~VW9).

[0073] Group 3: Additive C 10 H5NbO 20 The amounts of Mo(NO3)4 added were: 2.015 g and 0.431 g; 2.015 g and 0.862 g; 2.015 g and 1.722 g; 4.030 g and 0.431 g; 4.030 g and 0.862 g; 4.030 g and 8.060 g; 2.934 g and 0.431 g; 2.934 g and 0.862 g; 2.934 g and 8.060 g (hereinafter referred to as NbMo1~NbMo9).

[0074] Group 4: Additive C 10 H5NbO 20 and (NH4)6W7O 24 The following amounts of 6H₂O were added in the following quantities: 2.015g and 0.581g; 2.015g and 1.162g; 2.015g and 8.060g; 4.030g and 0.581g; 4.030g and 1.162g; 4.030g and 8.060g; 2.934g and 0.581g; 2.934g and 1.162g; 2.934g and 8.060g (hereinafter referred to as NbW1~NbW9).

[0075] Group 5: Commercially purchased CO catalyst (analyzed to have an active component of 40 wt% CuO, an active additive of 42 wt% ZnO, and an Al2O3 support) and the 10% Fe2O3-10% CeO2 catalyst from Example 1.

[0076] The oxidation efficiency of the above catalysts for CO was compared at temperatures ranging from 80℃ to 300℃, and the results are shown in [reference needed]. Figure 5 , Figure 6 . Figure 6 for Figure 5 A magnified view of a portion of the image. (From...) Figure 5 , Figure 6 It is evident that the VMo6, VW6, NbMo6, and NbW6 samples exhibited the best performance within their respective groups, with oxidation efficiencies of 99.2%, 99.1%, 99.3%, and 98.9% at 160℃, respectively. The addition of the additives significantly enhanced the catalytic oxidation effect of CO, with the VMo6 catalyst showing the best performance.

[0077] As can be seen from the above embodiments, the catalyst for CO catalytic oxidation provided by the present invention has good adaptability when applied to flue gas environments. It can achieve high conversion rates over a wide temperature window and has a good effect on increasing flue gas temperature.

Claims

1. A method for preparing a catalyst for the catalytic oxidation of CO, wherein, Includes the following steps: The iron precursor, the precursor of the first synergist, water, and molecular sieve are mixed to obtain a mixture; the precursor of the first synergist includes one of Ce salt, Cu salt, and Mn salt. The mixture and precipitant are mixed and then heated to obtain an intermediate product; The intermediate product is dried and calcined to obtain the catalyst for CO catalytic oxidation. The Fe2O3 formed by calcining the iron precursor and the metal oxide formed by calcining the precursor of the first synergist each account for 5-15 wt% of the mass percentage of the catalyst used for CO catalytic oxidation.

2. The method for preparing the catalyst for CO catalytic oxidation according to claim 1, wherein, The mixture also includes a precursor of a second synergist comprising 0.04 to 16 wt% of the catalyst for the catalytic oxidation of CO, wherein the precursor of the second synergist comprises one or more of salts of V, Nb, Mo, and W or their complexes.

3. The method for preparing the catalyst for CO catalytic oxidation according to claim 1, wherein, The raw materials for preparing the catalyst used for CO catalytic oxidation do not contain any precious metal elements.

4. The method for preparing the catalyst for CO catalytic oxidation according to claim 1, wherein, The iron precursor includes one or more of Fe(NO3)3, FeCl3, and Fe2(SO4)3.

5. The method for preparing the catalyst for CO catalytic oxidation according to claim 1, wherein, The precursor of the first synergist includes one of Ce nitrate, Cu nitrate, and Mn nitrate.

6. The method for preparing the catalyst for CO catalytic oxidation according to claim 2, wherein, The precursors of the second synergist include V(C2O4)2 and C 10 H5NbO 20 Mo(NO3)4, (NH4)6W7O 24 One or more of the ingredients in 6H2O.

7. The method for preparing the catalyst for CO catalytic oxidation according to claim 6, wherein, The V(C2O4)2 constitutes 0.734~2.934 wt% of the catalyst used for CO catalytic oxidation; and / or, The C 10 H5NbO 20 The mass percentage of the catalyst used for CO catalytic oxidation is 2.015~8.060 wt%; and / or, The Mo(NO3)4 constitutes 0.431~1.722 wt% of the catalyst used for CO catalytic oxidation; and / or, The (NH4)6W7O 24 The mass percentage of 6H2O in the catalyst used for CO catalytic oxidation is 0.581~2.325 wt%.

8. The method for preparing the catalyst for CO catalytic oxidation according to claim 6, wherein, The second synergistic precursor includes V(C2O4)2 and (NH4)6W7O 24 6H2O; and / or, The second synergistic adjuvant precursor includes C 10 H5NbO 20 and Mo(NO3)4; and / or, The second synergistic adjuvant precursor includes C 10 H5NbO 20 , Mo(NO3)4 and (NH4)6W7O 24 6H2O.

9. The method for preparing the catalyst for CO catalytic oxidation according to claim 1, wherein, The specific surface area of ​​the molecular sieve is ≥350m². 2 / g.

10. The method for preparing the catalyst for CO catalytic oxidation according to claim 1, wherein, The heating temperature is 50~80℃, and the time is 15~30min.

11. The method for preparing the catalyst for the catalytic oxidation of CO according to claim 1, wherein, The roasting process includes: After drying, the sample is kept at 250-300℃ for 1-3 hours, and then at 500-550℃ for 2-4 hours.

12. The method for preparing the catalyst for CO catalytic oxidation according to claim 1, wherein, The precipitant includes one or a combination of two or more of ammonium bicarbonate, sodium bicarbonate, and ammonia water.

13. A catalyst for the catalytic oxidation of CO, wherein, The catalyst for CO catalytic oxidation is prepared by the method for preparing the catalyst for CO catalytic oxidation according to any one of claims 1 to 12.

14. The use of the catalyst of claim 13 for the catalytic oxidation of CO as a catalyst in the catalytic oxidation of CO.

15. The application according to claim 14, wherein, When the temperature for CO catalytic oxidation is below 150°C, a catalyst for CO catalytic oxidation using Cu salt or Mn salt as the first co-promoter precursor is used; and / or, When the temperature for CO catalytic oxidation is not lower than 150°C, a catalyst for CO catalytic oxidation with Ce salt as the first co-promoter precursor is used for catalytic oxidation.

16. The application according to claim 14, wherein, The catalyst used for the catalytic oxidation of CO is used to catalytically oxidize CO in sintering flue gas.

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