Sulfur-tolerant co, nh3 syngas oxidation honeycomb catalyst, method of making and use thereof

Abstract

The present application belongs to the field of catalysts, and particularly relates to a sulfur-tolerant CO and NH3 co-oxidation honeycomb catalyst, a preparation method and application thereof. The sulfur-tolerant CO and NH3 co-oxidation honeycomb catalyst comprises a honeycomb carrier, a composite coating arranged on the honeycomb carrier, and a metal component arranged on the composite coating; the metal component comprises a noble metal component and a non-noble metal component. The catalyst exhibits good activity and stability under simulated industrial flue gas conditions, and these characteristics make it have broad application prospects in the end-of-pipe treatment of flue gas in the steel and coking industries, and provide an economic and efficient solution for the co-control of multiple pollutants.

Description

Technical Field

[0001] This invention belongs to the field of catalysts, specifically relating to a sulfur-resistant CO and NH3 synergistic oxidation honeycomb catalyst, its preparation method, and its application. Background Technology

[0002] Flue gas emitted from industrial processes such as steelmaking and coking contains large amounts of NO. X Pollutants such as CO. In actual treatment processes, the CO catalyst is usually located at the end of the NH3-SCR denitrification system to meet NO requirements. X To meet emission requirements, the ammonia injection rate in NH3-SCR denitrification systems is typically higher than the theoretically calculated rate (NH3:NO = 1), leading to NH3 escape during actual operation. Escaping NH3 competes for adsorption on the active sites of the CO catalyst, affecting CO oxidation efficiency. Simultaneously, steel and coking flue gas also contains a certain concentration of SO2. SO2 adsorbed on the active sites reacts with active components to form sulfates, causing permanent catalyst deactivation. Therefore, developing a catalyst capable of simultaneously and efficiently purifying CO and NH3 in complex sulfur-containing flue gas environments, while also exhibiting good resistance to SO2 poisoning, is of great significance for end-of-pipe treatment of industrial flue gas. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a sulfur-resistant CO and NH3 synergistic oxidation honeycomb catalyst, its preparation method and application.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0005] A sulfur-resistant CO and NH3 synergistic oxidation honeycomb catalyst includes a honeycomb support, a composite coating disposed thereon, and a metal component disposed on the composite coating; the metal component includes a noble metal component and a non-noble metal component.

[0006] The composite coating includes titanium dioxide and an acidic carrier; the mass ratio of titanium dioxide to acidic carrier is (1-10):1, preferably (2-4):1.

[0007] The acidic support is at least one of Cu-SSZ-13, SiO2, Al2O3, H-SSZ-13, and ZSM-5; preferably Cu-SSZ-13.

[0008] The noble metal component is at least one of Pt and Pd;

[0009] Preferably, it is a mixture of Pt and Pd; more preferably, the mass ratio of Pt to Pd is 3:1.

[0010] Preferably, the total loading of noble metal elements in the noble metal active component is 0.1-2 wt% of the catalyst mass.

[0011] The non-precious metal component is at least one of Mn, Co, W, Cr, and Nb;

[0012] Preferably, the non-precious metal component includes at least Mn, Cr, and W;

[0013] Preferably, the non-precious metal components include W, Cr, and Mn; the molar ratio of W, Cr, and Mn is (1-3):(1-2):(1-2); more preferably, it is 2:1:1;

[0014] Preferably, the non-precious metal components include W, Cr, Nb, and Mn; the molar ratio of W, Cr, Nb, and Mn is (1-3):(1-2):(1-2):(1-2); more preferably, it is 2:1:1:1.

[0015] Preferably, the honeycomb carrier is one or more of cordierite, mullite, and corundum.

[0016] This invention also includes a method for preparing the sulfur-resistant CO and NH3 synergistic oxidation honeycomb catalyst, comprising the following steps:

[0017] S1. Coating of the composite coating: Titanium dioxide and acidic carrier powder are mixed in proportion, binder and deionized water are added, and stirred to form a slurry. The slurry is coated on the surface of the honeycomb carrier, dried, and then calcined at 300-600℃ for 3-5 hours. Preferably, the solid content of the slurry is 10-30%; more preferably 20%; preferably, the amount of binder added is 0.1-1% of the slurry, more preferably 0.5%.

[0018] S2. Loading of non-precious metal component additives: Dissolve the non-precious metal component precursor in deionized water to obtain an impregnation solution, and load it onto the coating obtained in S1 by impregnation method, followed by drying and calcination at 400-600℃ for 2-4 hours; preferably, the non-precious metal component precursor is a nitrate or acetate of the non-precious metal component.

[0019] S3. Loading of noble metal components: Pt and / or Pd precursors are dissolved in deionized water in a certain proportion to obtain an impregnation solution, which is then loaded onto the support treated in S2. After drying and calcination at 300-500℃ for 3-5 hours, the final catalyst is obtained.

[0020] In step S2, the loading order of the non-precious metal component additives is to load W and Cr first, and then load Mn.

[0021] The present invention also includes the application of the sulfur-resistant CO and NH3 synergistic oxidation honeycomb catalyst described above.

[0022] Preferably, it is used for the synergistic oxidation of CO and escaped NH3 in industrial flue gas. Preferably, the flue gas conditions include: CO concentration 500-20000 ppm, NH3 concentration 10-300 mg / m³. 3 SO2 concentration 50-300 mg / m³ 3 Temperature 100-400℃.

[0023] Compared with the prior art, the beneficial effects of the present invention are:

[0024] (1) Highly efficient synergistic oxidation performance of CO and NH3: The composite coating design of titanium dioxide and acidic molecular sieve is adopted, which utilizes the high efficiency of titanium dioxide for CO oxidation and promotes the adsorption and activation of escaped NH3 through the acidic sites of the acidic molecular sieve, so as to achieve simultaneous purification of CO and NH3. This solves the problem of competitive adsorption under the coexistence of NH3 and improves the overall purification efficiency.

[0025] (2) Excellent resistance to sulfur poisoning: This invention improves the acidity of the catalyst surface and regulates the electronic structure of active sites by introducing non-precious metal additives (such as W, Cr, Nb, etc.), selectively inhibiting the competitive adsorption of SO2, and reducing the formation of sulfate, thereby significantly improving the catalyst's resistance to sulfur. This invention maintains high activity and extends the catalyst's lifespan even in industrial flue gas environments containing SO2.

[0026] (3) High economic efficiency: This invention utilizes non-precious metal additives (such as Mn and Co) to promote the regeneration of surface oxygen species, while enhancing oxidation activity through the synergistic effect of Pt and Pd. Compared with traditional precious metal catalysts, this invention reduces costs while ensuring activity, making it more suitable for industrial applications.

[0027] (4) The catalyst has a stable structure and strong adaptability, making it suitable for complex flue gas environments. This invention uses a honeycomb carrier as a base and combines it with a coating process to form a robust composite coating, giving the catalyst high mechanical strength and thermal stability. Simultaneously, the catalyst is designed for typical industrial flue gas conditions, and through component and process optimization, it maintains high activity and stability over a wide temperature window. It is particularly suitable for the synergistic treatment of multiple pollutants in end-of-pipe flue gas from industries such as steel and coking.

[0028] (5) The preparation process is simple and reproducible. The present invention adopts a step-by-step coating and impregnation method, which has strong process controllability and is easy to scale up production. Attached Figure Description

[0029] Figure 1 This is a sample image of the catalyst obtained by the preparation method of this invention;

[0030] Figure 2 This is a graph showing the CO conversion rate of Test Example 1 of this invention;

[0031] Figure 3This is a graph showing the CO and NH3 conversion rates in Test Example 2 of this invention;

[0032] Figure 4 This is a graph showing the CO and NH3 conversion rates in Test Example 3 of this invention;

[0033] Figure 5 This is a graph showing the CO and NH3 conversion rates from the catalyst activity test in Example 1 of this invention.

[0034] Figure 6 This is a graph showing the CO and NH3 conversion rates from the catalyst stability test in Example 1 of this invention. Detailed Implementation

[0035] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and preferred embodiments.

[0036] Example 1: A sulfur-resistant CO and NH3 synergistic oxidation honeycomb catalyst and its preparation method, specifically including the following steps:

[0037] 1) Rinse the cordierite (length × width = 15cm × 15cm, thickness = 10cm) with deionized water and dry it at 100℃ for 3 hours before use;

[0038] 2) Mix titanium dioxide and Cu-SSZ-13 molecular sieve at a mass ratio of 4:1, add aluminum sol (so that the mass fraction of aluminum sol is 0.5wt% of the slurry) and deionized water, and ball mill for 6 hours to obtain a uniform slurry with a solid content of 20%.

[0039] 3) The slurry is vacuum-coated onto the cordierite carrier, dried at 110℃ for 3 hours, and then calcined at 550℃ for 4 hours to form a composite coating.

[0040] 4) Using the impregnation method, ammonium metatungstate and chromium nitrate are impregnated on the carrier obtained in step 3), dried at 110°C for 3 hours, and calcined at 550°C for 3 hours. Then, manganese acetate is impregnated on the carrier with a W:Cr:Mn mass ratio of 2:1:1 and a total non-precious metal element loading of 5wt%. The carrier is dried at 110°C for 3 hours and calcined at 550°C for 3 hours.

[0041] 5) Using an impregnation method, chloroplatinic acid and palladium nitrate solution (Pt:Pd mass ratio 3:1, total loading of noble metal elements 0.2wt%) were loaded onto the catalyst, dried at 110℃ for 3 h, and then calcined at 550℃ for 3 h to obtain the final catalyst, such as... Figure 1 As shown.

[0042] Example 2: A sulfur-resistant CO and NH3 synergistic oxidation honeycomb catalyst and its preparation method, specifically including the following steps:

[0043] 1) Rinse the cordierite (length × width = 15cm × 15cm, thickness = 10cm) with deionized water and dry it at 100℃ for 3 hours before use;

[0044] 2) Mix titanium dioxide and Cu-SSZ-13 molecular sieve at a mass ratio of 2:1, add aluminum sol and deionized water, and ball mill for 6 hours to obtain a uniform slurry with a solid content of 20%.

[0045] 3) The slurry is vacuum-coated onto the cordierite carrier, dried at 110℃ for 3 hours, and then calcined at 550℃ for 4 hours to form a composite coating.

[0046] 4) Using the impregnation method, ammonium metatungstate and chromium nitrate are impregnated on the carrier obtained in step 3), dried at 110°C for 3 hours, and calcined at 550°C for 3 hours. Then, manganese acetate is impregnated on the carrier with a W:Cr:Mn mass ratio of 2:1:1 and a total non-precious metal element loading of 5wt%. The carrier is dried at 110°C for 3 hours and calcined at 550°C for 3 hours.

[0047] 5) Using the impregnation method, chloroplatinic acid and palladium nitrate solution (Pt:Pd mass ratio 3:1, total loading of noble metal elements 0.2wt%) were loaded onto the catalyst, dried at 110℃ for 3h, and then calcined at 550℃ for 3h to obtain the final catalyst.

[0048] Example 3: A sulfur-resistant CO and NH3 synergistic oxidation honeycomb catalyst and its preparation method, specifically including the following steps:

[0049] 1) Rinse the cordierite (length × width = 15cm × 15cm, thickness = 10cm) with deionized water and dry it at 100℃ for 3 hours before use;

[0050] 2) Mix titanium dioxide and H-SSZ-13 molecular sieve at a mass ratio of 4:1, add aluminum sol and deionized water, and ball mill for 6 hours to obtain a uniform slurry with a solid content of 20%.

[0051] 3) The slurry is vacuum-coated onto the cordierite carrier, dried at 110℃ for 3 hours, and then calcined at 550℃ for 4 hours to form a composite coating.

[0052] 4) Using the impregnation method, ammonium metatungstate and chromium nitrate are impregnated on the carrier obtained in step 3), dried at 110°C for 3 hours, and calcined at 550°C for 3 hours. Then, manganese acetate is impregnated on the carrier with a W:Cr:Mn mass ratio of 2:1:1 and a total non-precious metal element loading of 5wt%. The carrier is dried at 110°C for 3 hours and calcined at 550°C for 3 hours.

[0053] 5) Using the equal-volume impregnation method, chloroplatinic acid and palladium nitrate solution (Pt:Pd mass ratio 3:1, total loading of noble metal elements 0.2wt%) were loaded onto the catalyst, dried at 110℃ for 3h, and then calcined at 550℃ for 3h to obtain the final catalyst.

[0054] Example 4: A sulfur-resistant CO and NH3 synergistic oxidation honeycomb catalyst and its preparation method, specifically including the following steps:

[0055] 1) Rinse the cordierite (length × width = 15cm × 15cm, thickness = 10cm) with deionized water and dry it at 100℃ for 3 hours before use;

[0056] 2) Mix titanium dioxide and Cu-SSZ-13 molecular sieve at a mass ratio of 4:1, add aluminum sol and deionized water, and ball mill for 6 hours to obtain a uniform slurry with a solid content of 20%.

[0057] 3) The slurry is vacuum-coated onto the cordierite carrier, dried at 110℃ for 3 hours, and then calcined at 550℃ for 4 hours to form a composite coating.

[0058] 4) Using the impregnation method, ammonium metatungstate and chromium nitrate are impregnated on the carrier obtained in step 3), dried at 110°C for 3 hours, and calcined at 550°C for 3 hours. Then, cobalt nitrate is impregnated on the carrier with a W:Cr:Co mass ratio of 2:1:1 and a total non-precious metal element loading of 5wt%. The carrier is dried at 110°C for 3 hours and calcined at 550°C for 3 hours.

[0059] 5) Using the impregnation method, chloroplatinic acid and palladium nitrate solution (Pt:Pd mass ratio 3:1, total loading of noble metal elements 0.2wt%) were loaded onto the catalyst, dried at 110℃ for 3h, and then calcined at 550℃ for 3h to obtain the final catalyst.

[0060] Example 5: A sulfur-resistant CO and NH3 synergistic oxidation honeycomb catalyst and its preparation method, specifically including the following steps:

[0061] 1) Rinse the cordierite (length × width = 15cm × 15cm, thickness = 10cm) with deionized water and dry it at 100℃ for 3 hours before use;

[0062] 2) Mix titanium dioxide and Cu-SSZ-13 molecular sieve at a mass ratio of 4:1, add aluminum sol and deionized water, and ball mill for 6 hours to obtain a uniform slurry with a solid content of 20%.

[0063] 3) The slurry is vacuum-coated onto the cordierite carrier, dried at 110℃ for 3 hours, and then calcined at 550℃ for 4 hours to form a composite coating.

[0064] 4) Using the impregnation method, ammonium metatungstate and chromium nitrate are impregnated on the carrier obtained in step 3), dried at 110°C for 3 hours, and calcined at 550°C for 3 hours. Then, manganese acetate is impregnated on the carrier with a W:Cr:Mn mass ratio of 1:1:2 and a total non-precious metal element loading of 5wt%. The carrier is dried at 110°C for 3 hours and calcined at 550°C for 3 hours.

[0065] 5) Using the impregnation method, chloroplatinic acid and palladium nitrate solution (Pt:Pd mass ratio 3:1, total loading of noble metal elements 0.2wt%) were loaded onto the catalyst, dried at 110℃ for 3h, and then calcined at 550℃ for 3h to obtain the final catalyst.

[0066] Example 6: A sulfur-resistant CO and NH3 synergistic oxidation honeycomb catalyst and its preparation method, specifically including the following steps:

[0067] 1) Rinse the cordierite (length × width = 15cm × 15cm, thickness = 10cm) with deionized water and dry it at 100℃ for 3 hours before use;

[0068] 2) Mix titanium dioxide and Cu-SSZ-13 molecular sieve at a mass ratio of 4:1, add aluminum sol and deionized water, and ball mill for 6 hours to obtain a uniform slurry with a solid content of 20%.

[0069] 3) The slurry is vacuum-coated onto the cordierite carrier, dried at 110℃ for 3 hours, and then calcined at 550℃ for 4 hours to form a composite coating.

[0070] 4) Using the impregnation method, ammonium metatungstate, chromium nitrate, and niobium oxalate are impregnated on the carrier obtained in step 3), dried at 110°C for 3 hours, and calcined at 550°C for 3 hours. Then, manganese acetate is impregnated on the obtained carrier with a W:Cr:Nb:Mn mass ratio of 2:1:1:1 and a total non-precious metal element loading of 5wt%. The carrier is dried at 110°C for 3 hours and calcined at 550°C for 3 hours.

[0071] 5) Using the impregnation method, chloroplatinic acid and palladium nitrate solution (Pt:Pd mass ratio 3:1, total loading of noble metal elements 0.2wt%) were loaded onto the catalyst, dried at 110℃ for 3h, and then calcined at 550℃ for 3h to obtain the final catalyst.

[0072] Comparative Example 1: Its basic synthesis steps are the same as those of Example 1. The difference is that the acidic carrier Cu-SSZ-13 is not added in step 2). Specifically, in step 2), only titanium dioxide is added to aluminum sol and deionized water, and ball milled for 6 hours to obtain a uniform slurry with a solid content of 20%.

[0073] Comparative Example 2: Its basic synthesis steps are the same as those of Example 1. The difference is that titanium dioxide is not added in step 2). Specifically, in step 2), only Cu-SSZ-13 is added to aluminum sol and deionized water, and ball milled for 6 hours to obtain a uniform slurry with a solid content of 20%.

[0074] Comparative Example 3: Its basic synthesis steps are the same as those of Example 1. The difference is that it does not include the impregnation of non-metallic components, specifically step 4), and the precious metal is directly loaded after the composite coating is applied.

[0075] Comparative Example 4: Its basic synthesis steps are the same as those of Example 1. The difference is that in step 4), an impregnation method is used to impregnate ammonium metatungstate, chromium nitrate, and niobium oxalate onto the support obtained in step 3), which is then dried at 110°C for 3 hours and calcined at 550°C for 3 hours. The mass ratio of W:Cr:Nb is 1:1:1, and the total loading is 5wt%.

[0076] Comparative Example 5: Its basic synthesis steps are the same as those of Example 1. The differences include: in step 4), the impregnation method is used to impregnate manganese acetate and cobalt nitrate onto the carrier obtained in step 3), which is then dried at 110°C for 3 hours and calcined at 550°C for 3 hours. The Co:Mn mass ratio is 1:1 and the total loading is 5 wt%.

[0077] Comparative Example 6: Its basic synthesis steps are the same as those of Example 1. The differences include: in step 4), ammonium metatungstate, chromium nitrate, and manganese acetate are simultaneously impregnated on the carrier obtained in step 3) by the impregnation method, dried at 110°C for 3 hours, and calcined at 550°C for 3 hours. The mass ratio of W:Cr:Mn is 2:1:1, and the total loading is 5wt%.

[0078] It should be noted that the comparative examples in this application are only for ease of comparison and are still part of the embodiments, and are within the protection scope of this application.

[0079] Test Example 1: The prepared example catalyst and the comparative catalyst were subjected to a fixed-bed reaction. CO gas concentration: 15000 ppm, O2 concentration: 12 vol.%, N2: balance gas, gas hourly space velocity: 20000 h⁻¹ -1 Reaction temperature: 200℃.

[0080] Test Example 2: The prepared example catalyst and the comparative catalyst were subjected to a fixed-bed reaction. CO gas concentration: 15000 ppm, NH3 gas concentration: 100 mg / m³. 3 O2 concentration: 12 vol.%, N2: balance gas, gas hourly space velocity: 20000 h⁻¹ -1 Reaction temperature: 200℃.

[0081] Test Example 3: The prepared example catalyst and the comparative catalyst were subjected to a fixed-bed reaction. CO gas concentration: 15000 ppm, NH3 gas concentration: 100 mg / m³. 3 SO2 gas concentration: 100 mg / m³ 3 O2 concentration: 12 vol.%, N2: balance gas, gas hourly space velocity: 20000 h⁻¹ -1 Reaction temperature: 200℃.

[0082] Catalyst activity was tested under the conditions of Test Example 1, Test Example 2, and Test Example 3. The test results for CO and NH3 are shown in Table 1. Figure 2 , Figure 3 , Figure 4 As shown;

[0083] Table 1

[0084]

[0085] Key role of composite coatings:

[0086] Example 1 used a composite coating of titanium dioxide:Cu-SSZ-13 = 4:1, which exhibited a CO conversion rate of 95.8% and an NH3 conversion rate of 92.6% in Test Example 2. The acidic sites of Cu-SSZ-13 and the Cu in the framework... 2+ Ions effectively promote NH3 adsorption activation, while titanium dioxide provides excellent CO oxidation activity. In Comparative Example 1, the NH3 conversion rate without Cu-SSZ-13 dropped sharply to 64.8%, and the CO oxidation conversion rate also decreased to 75.3%. This may be because NH3 molecules form strong coordination bonds with the active sites on the catalyst surface through lone pairs of electrons, resulting in the long-term occupation of CO oxidation active sites. Cu-SSZ-13 molecular sieves effectively reduce the competitive adsorption of NH3 by titanium dioxide, thus ensuring efficient purification of CO and NH3. In Example 3, after replacing Cu-SSZ-13 with H-SSZ-13, the CO and NH3 conversion rates decreased to 90.3% and 87.5%, respectively. Although H-SSZ-13 is acidic, it lacks the key Cu sites, and its activity in Test Examples 1 and 2 was worse than the combination of titanium dioxide and Cu-SSZ-13. The above comparisons also demonstrate the key role of Cu-SSZ-13 in CO and NH3 purification.

[0087] Comparative Example 2, without the addition of titanium dioxide, showed weaker CO oxidation activity than Comparative Example 1 in Test Example 1, demonstrating the crucial role of titanium dioxide in regulating active sites during CO oxidation. Test Example 2 in Example 2 showed slightly lower CO oxidation activity than Example 1. An excessively high Cu-SSZ-13 ratio may affect coating uniformity and the regulatory effect of titanium dioxide on active sites. Therefore, the 4:1 ratio in Example 1 is superior.

[0088] Key role of non-precious metal additive layer:

[0089] Examples 1 and 4 maintained high CO and NH3 activity in Test Example 2. Comparative Example 4, without the addition of Mn and Co, but only with the addition of strongly acidic W, Cr, and Nb, showed a significant decrease in CO and NH3 activity in Test Example 2, as Mn and Co effectively promote the cycling of oxygen species on the surface. In Example 4, using Co instead of Mn reduced the CO and NH3 conversion rates to 88.4% and 85.1%, respectively. Although Co has excellent redox capabilities, Mn effectively promotes the regeneration of surface oxygen species, leading to a decrease in the overall activity of Example 4. This also demonstrates that Mn is more active than Co in the synergistic oxidation of CO and NH3.

[0090] The CO conversion rate of Test Example 3 in Example 6 (with Nb added) was 90.6%, lower than that of Example 1. The composite oxide formed by W and Cr optimized the surface acidity and selectively inhibited SO2 adsorption. Although Nb had excessively strong surface acidity, it easily formed stable sulfates with SO2, which reduced the sulfur resistance. The performance of Test Example 3 in Comparative Example 4 (W:Cr:Nb mass ratio 1:1:1) further verified this. The CO and NH3 conversion rates of Test Example 3 in Example 5 (W:Cr:Mn mass ratio 1:1:2) and Comparative Example 5 (without W, Cr, Nb added) were significantly lower than those in Example 1. This was because the reduced content of acidic oxides in the non-precious metal additive layer led to SO2 adsorption on the active sites, resulting in a decrease in activity.

[0091] Example 1 employs a stepwise loading method, first adding W and Cr, then Mn, while the performance of simultaneous impregnation of W, Cr, and Mn in Example 6 is poor. Stepwise loading is beneficial for W and Cr to first form a surface acidic framework, followed by Mn filling to enhance redox properties, and avoids mutual shielding between metal species.

[0092] Comparative Example 3 (without additives) showed a sharp drop in CO and NH3 conversion rates during testing, demonstrating the crucial role of non-precious metal coatings in redox reactions and preventing sulfur poisoning.

[0093] Example 1: Catalyst Activity and Stability Test: The catalyst of Example 1 was subjected to a fixed-bed reaction with CO gas concentration of 15000 ppm and NH3 gas concentration of 100 mg / m³. 3 SO2 gas concentration: 100 mg / m³ 3 O2 concentration: 12 vol.%, N2: balance gas, gas hourly space velocity: 20000 h⁻¹ -1 Activity test: 140-240℃; Stability test: reaction temperature: 240℃.

[0094] Based on the test results of catalyst activity and stability tests in Example 1 ( Figure 5 , Figure 6Example 1 shows that the catalyst achieves complete conversion of CO and NH3 at 240℃ under sulfur-containing conditions, and can operate effectively at 240℃ for 100 hours, exhibiting good catalytic activity and stability.

[0095] In summary, the sulfur-resistant CO and NH3 synergistic oxidation honeycomb catalyst and its preparation method described in this invention achieve highly efficient synergistic purification of CO and NH3 and excellent sulfur resistance by optimizing the design of the composite coating and non-precious metal auxiliary layer. Specifically, the advantages of this invention are reflected in the following aspects:

[0096] First, the key role of the composite coating is particularly prominent. Taking the combination of titanium dioxide and Cu-SSZ-13 as an example, titanium dioxide provides high CO oxidation efficiency, while the acidic sites and Cu sites of Cu-SSZ-13 effectively adsorb and activate escaped NH3, reducing the competitive adsorption of NH3 on the CO oxidation reaction.

[0097] The design of the non-precious metal promoter layer further enhances the overall performance of the catalyst. In the W, Cr, and Mn ternary system, W and Cr form acidic sites, selectively inhibiting SO2 adsorption; while the Mn promoter promotes the regeneration of surface oxygen species. Utilizing the non-precious metal coating not only saves costs and improves catalytic efficiency, but also effectively suppresses the strong adsorption behavior of SO2 on precious metal surfaces, improving stability in applications.

[0098] In terms of preparation method, a stepwise impregnation and calcination process is adopted to ensure that the active components are uniformly dispersed on the surface of the honeycomb carrier. For example, in Example 1, the stepwise loading of W and Cr additives followed by Mn additives avoids mutual shielding of metal species and enhances the synergistic effect between acidic sites and redox sites. This method is simple and easy to implement, and requires no additional binder, ensuring the stability and reproducibility of the catalyst.

[0099] Ultimately, the catalyst exhibited good activity and stability under simulated industrial flue gas conditions. These characteristics make it a promising candidate for end-of-pipe treatment of flue gas in industries such as steel and coking, providing an economical and efficient solution for the synergistic control of multiple pollutants.

[0100] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A sulfur-resistant CO and NH3 synergistic oxidation honeycomb catalyst, characterized in that, It includes a cellular carrier, a composite coating, and a metal component disposed on the composite coating; the metal component includes a noble metal component and a non-noble metal component.

2. The sulfur-resistant CO and NH3 synergistic oxidation honeycomb catalyst according to claim 1, characterized in that, The composite coating includes titanium dioxide and an acidic carrier; the mass ratio of titanium dioxide to acidic carrier is (1-10):1, preferably (2-4):

1.

3. The sulfur-resistant CO and NH3 synergistic oxidation honeycomb catalyst according to claim 1, characterized in that, The acidic support is at least one of Cu-SSZ-13, SiO2, Al2O3, H-SSZ-13, and ZSM-5; preferably Cu-SSZ-13.

4. The sulfur-resistant CO and NH3 synergistic oxidation honeycomb catalyst according to claim 1, characterized in that, The noble metal component is at least one of Pt and Pd; Preferably, it is a mixture of Pt and Pd; more preferably, the mass ratio of Pt to Pd is 3:

1. Preferably, the total loading of noble metal elements in the noble metal active component is 0.1-2 wt% of the catalyst mass, more preferably 0.2 wt%.

5. The sulfur-resistant CO and NH3 synergistic oxidation honeycomb catalyst according to claim 1, wherein the non-precious metal component is at least one of Mn, Co, W, Cr, and Nb; Preferably, the non-precious metal component includes at least Mn, Cr, and W; Preferably, the non-precious metal components include W, Cr, and Mn, and the molar ratio of W, Cr, and Mn is (1-3):(1-2):(1-2); more preferably, it is 2:1:

1. Preferably, the non-precious metal components include W, Cr, Nb, and Mn; the molar ratio of W, Cr, Nb, and Mn is (1-3):(1-2):(1-2):(1-2); more preferably, it is 2:1:1:

1. Preferably, the total loading of non-precious metal elements in the non-precious metal additive is 1-10 wt% of the catalyst mass, more preferably 5 wt%.

6. The sulfur-resistant CO and NH3 synergistic oxidation honeycomb catalyst according to claim 1, characterized in that, The honeycomb carrier is one or more of cordierite, mullite, and corundum.

7. A method for preparing a sulfur-resistant CO / NH3 synergistic oxidation honeycomb catalyst according to any one of claims 1-5, characterized in that, Includes the following steps: S1. Coating of the composite coating: Titanium dioxide powder and acidic carrier powder are mixed in proportion, binder and deionized water are added, and stirred to form a slurry. The slurry is coated on the surface of the honeycomb carrier, dried, and then calcined at 300-600℃ for 3-5 hours. Preferably, the solid content of the slurry is 10-30%; more preferably 20%; preferably, the amount of binder added is 0.1-1% of the slurry, more preferably 0.5%. S2. Loading of non-precious metal component additives: Dissolve the non-precious metal component precursor in deionized water to obtain an impregnation solution, and load it onto the coating obtained in S1 by impregnation method, followed by drying and calcination at 400-600℃ for 2-4 hours; preferably, the non-precious metal component precursor is a nitrate or acetate of the non-precious metal component. S3. Loading of noble metal components: Pt and / or Pd precursors are dissolved in deionized water in a certain proportion to obtain an impregnation solution, which is then loaded onto the support treated in S2. After drying and calcination at 300-500℃ for 3-5 hours, the final catalyst is obtained.

8. The preparation method according to claim 7, characterized in that, In step S2, the loading order of the non-precious metal component additives is to load W and Cr first, and then load Mn.

9. The application of the sulfur-resistant CO and NH3 synergistic oxidation honeycomb catalyst according to any one of claims 1-6.

10. The application according to claim 9, characterized in that, This method is applied to the synergistic oxidation of CO and escaped NH3 in industrial flue gas. Preferably, the flue gas conditions include: CO concentration of 500-20000 ppm and NH3 concentration of 10-300 mg / m³. 3 SO2 concentration 50-300 mg / m³ 3 Temperature 100-400℃.

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