Honeycomb catalyst for CO and NOx synergistic coupling removal and preparation method thereof

Abstract

The invention relates to a honeycomb catalyst for CO and NOx synergistic coupling removal and a preparation method, the catalyst takes nano TiO2-CeO2 as a carrier, and the surface of the carrier is loaded with an active component; the active component comprises a main catalyst and an auxiliary catalyst, the main catalyst is LaCuOx active powder, and the auxiliary catalyst is SmFeOx active powder. According to the present invention, the active material of the conventional catalyst is changed, and the carrier performance of the conventional catalyst is modified, such that the catalyst has good chemical activity and good thermal stability so as to achieve the purpose of stable and synergistic CO removal and NOx removal; meanwhile, the catalyst material is high in mechanical strength and long in chemical life, and the water resistance and the sulfur resistance of the catalyst material are also verified.

Description

Technical Field

[0001] This application relates to the field of CO removal technology for sintering flue gas, and in particular to a honeycomb catalyst and its preparation method for the synergistic coupling removal of CO and NOx. Background Technology

[0002] Carbon monoxide (CO) is a significant component of pollutants in flue gas, requiring synergistic treatment. Achieving rapid conversion of carbon monoxide is a key challenge in purifying flue gas pollutants from furnaces and kilns. Carbon monoxide can be purified by directly converting it into non-toxic and pollution-free carbon dioxide. This process involves the activation of carbon monoxide molecules with oxygen molecules, making a catalyst an essential component in the oxidation and conversion of carbon monoxide.

[0003] Prior art CN114643065A discloses a noble metal catalyst for catalytic oxidation of CO and its preparation method. This method employs a one-step mechanical ball milling process to load one or more noble metals selected from Pt, Ag, Pd, Rh, Ir, Ru, Os, or Au onto the surface of anatase TiO2, and adds one or more promoters selected from Co, Cr, Zr, Sn, Mo, W, Fe, Ce, Ni, and Nb. Prior art CN117839773A discloses a monolithic carbon monoxide catalyst, its preparation method, and its application, comprising a support and metal catalytic particles supported on the surface of the support. The metal catalytic particles include one or more selected from titanium particles, cerium particles, cobalt particles, nickel particles, ruthenium particles, rhodium particles, palladium particles, iridium particles, platinum particles, and molybdenum particles. The support includes one or more selected from cordierite, honeycomb, and hierarchical porous carbon.

[0004] The catalysts in the aforementioned prior art are precious metal catalysts. Precious metal catalysts have problems such as scarce reserves, high price, easy poisoning and deactivation, easy sintering, and easy over-oxidation. The large amount of water vapor and SO2 present in the flue gas can easily cause catalyst deactivation and generate new liquid or solid waste, which need to be replaced in a short period of time, resulting in high operating costs. Even if non-precious metal catalysts are used, there are still problems such as low CO activity, easy poisoning and deactivation, easy sintering, and poor water resistance.

[0005] Therefore, it is necessary to design a honeycomb catalyst and preparation method for the synergistic coupling removal of CO and NOx to solve the above-mentioned technical problems. Summary of the Invention

[0006] Based on this, a honeycomb catalyst for the synergistic coupling removal of CO and NOx and its preparation method are provided. The active material of conventional catalysts is changed, and the support performance of conventional catalysts is modified and altered, so that the catalyst has good chemical activity and thermal stability, achieving the purpose of stable denitrification under high temperature conditions. At the same time, the catalyst also has strong wear resistance and can be applied to some extreme dust conditions.

[0007] To address the above issues, this application provides a honeycomb catalyst for the synergistic coupling removal of CO and NOx. The catalyst uses nano-TiO2-CeO2 as a support, and the surface of the support is loaded with active components. The active components include a main catalyst and a co-catalyst. The main catalyst is LaCuOx active powder, and the co-catalyst is SmFeOx active powder.

[0008] Alternatively, the nano-TiO2-CeO2 accounts for 50-70% of the total mass of the catalyst; the LaCuOx active powder accounts for 5-20% of the total mass of the catalyst; and the SmFeOx active powder accounts for 2-10% of the total mass of the catalyst.

[0009] Alternatively, CeO2 accounts for 7-8% of the total mass of nano-TiO2-CeO2; CuOx accounts for 40-60% of the total mass of LaCuOx active powder; and FeOx accounts for 40-60% of the total mass of SmFeOx active powder.

[0010] Alternatively, the particle size of the nano-TiO2-CeO2 is 10~50nm; and the particle size of the LaCuOx active powder is 1~5μm.

[0011] This application also provides a method for preparing a honeycomb catalyst for the synergistic coupling removal of CO and NOx, the preparation method comprising the following steps: Preparation of S1 honeycomb catalyst semi-finished product; Nano-TiO2-CeO2, LaCuOx active powder, SmFeOx active powder and additives are mixed and stirred evenly, and then dried to obtain a honeycomb catalyst semi-finished product. Preparation of S2 honeycomb catalyst product; The honeycomb catalyst semi-finished product prepared by S1 is calcined to obtain the honeycomb catalyst finished product.

[0012] An optional approach is that the process of mixing and stirring nano-TiO2-CeO2, LaCuOx active powder, and SmFeOx active powder until uniform, followed by drying, yields a honeycomb catalyst semi-finished product, comprising: Nano-TiO2-CeO2, LaCuOx active powder, and SmFeOx active powder are mixed and a lubricant is added and stirred. Then, water and a humectant are added and mixed evenly. Short-cut glass fibers are added and mixed evenly. Finally, plasticizers and rheology modifiers are added and mixed evenly to obtain catalyst slurry. The catalyst slurry is aged at room temperature. The obtained catalyst slurry is filtered and then extruded through an extrusion molding device to obtain a honeycomb catalyst wet preform. The wet preform is slowly dried in multiple stages to obtain a honeycomb catalyst semi-finished product.

[0013] Alternatively, the lubricant accounts for 0.5-1.5% of the total mass of the catalyst; the plasticizer accounts for 1-3% of the total mass of the catalyst; the rheology modifier accounts for 0.5-1.5% of the total mass of the catalyst; the humectant accounts for 2-4% of the total mass of the catalyst; and the chopped glass fiber accounts for 10-20% of the total mass of the catalyst.

[0014] An alternative approach is to use the following drying process conditions: moisture content <2%, and a gradient temperature increase for drying.

[0015] An optional approach is to use the following calcination process conditions: calcination temperature of 400-500℃, holding time of 3-5h, and heating rate of 2-4℃ / min.

[0016] This application has at least the following beneficial effects: 1. The catalyst support in this application is modified titanium dioxide (nano TiO2-CeO2 powder). The main active components are LaCuOx and SmFeOx, which can achieve synergistic coupling removal of CO and NOx at 180~270℃. The CO removal efficiency reaches more than 80% and the NOx denitrification efficiency reaches more than 80% at temperatures above 250℃. The performance is reliable, effectively improving the activity of denitrification catalysts at flue gas temperatures (180~270℃) in sintering, pelletizing, coking, glass, and chemical industries, as well as the removal of high concentrations of CO.

[0017] (2) In the preparation of the catalyst, this application uses specially made LaCuOx active powder and SmFeOx active powder and adopts extrusion molding method. On the one hand, it ensures the uniformity of SmFeOx and LaCuOx dual active components on the modified titanium dioxide (nano TiO2-CeO2) carrier. On the other hand, it also ensures the advantages of high mechanical strength, high thermal conductivity and high utilization rate of active components of honeycomb catalyst. It can solve some difficulties in production extrusion molding and improve the yield of products in the molding process.

[0018] (3) The catalyst of this application is particularly suitable for the field of flue gas synergistic coupling removal in medium and low temperature tail gas denitrification and decarbonization devices in sintering pelletizing, coking, glass kiln, chemical industry, etc. It has good chemical activity and stability, and the material has high mechanical strength and long chemical life. It can be used stably under flue gas containing a certain amount of H2O and a certain amount of SO2. It also has the advantages of long service life and wide application range. Attached Figure Description

[0019] Figure 1 This is a schematic flowchart of a method for preparing a honeycomb catalyst for the synergistic coupling removal of CO and NOx in this embodiment; Figure 2 This is a graph showing the carbon monoxide removal efficiency of the catalyst under operating conditions in this embodiment. Figure 3 This is a graph showing the carbon monoxide removal efficiency of the catalyst under operating condition two in this embodiment. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0021] It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of this application. Therefore, the drawings only show the components related to this application and are not drawn according to the number, shape and size of the components in actual implementation. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0022] The structures, proportions, sizes, etc., shown in the accompanying drawings are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the implementation conditions of this application. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size should still fall within the scope of the technical content disclosed in this application, provided that they do not affect the effects and purposes that this application can produce.

[0023] Currently reported catalysts for removing carbon monoxide are mainly noble metal catalysts (rhodium Rh, platinum Pt, iridium Ir, ruthenium Ru, gold Au, silver Ag, palladium Pd, etc.) or non-noble metal catalysts (manganese Mn, cobalt Co, nickel Ni, etc.), whose function is to catalyze the oxidation reaction of carbon monoxide to produce carbon dioxide.

[0024] While precious metal catalysts have made significant progress over the past few decades, they still face challenges such as scarce reserves, high prices, susceptibility to poisoning and deactivation, easy sintering, and susceptibility to over-oxidation. Non-precious metal catalysts, on the other hand, suffer from low CO activity, susceptibility to poisoning and deactivation, easy sintering, and poor water resistance. Furthermore, impurities such as moisture in furnace flue gas can lead to non-permanent catalyst deactivation. Therefore, developing a novel, highly stable carbon monoxide oxidation catalyst with high water resistance, stable efficiency, and long lifespan for flue gas purification in steel sintering and furnaces is of great significance.

[0025] This application provides a honeycomb catalyst for the synergistic removal of CO and NOx and its preparation method. The honeycomb catalyst of this application is particularly suitable for sintering and pelletizing, coking, glass, chemical industry and other fields. It can synergistically remove NOx and high concentration CO in flue gas. At the same time, it can be used stably under flue gas conditions containing a certain amount of H2O and SO2. Its water resistance and sulfur resistance have also been verified. It can also be applied under some extreme dust conditions.

[0026] The following provides a detailed description of a honeycomb catalyst for the synergistic coupling removal of CO and NOx provided in this embodiment. The catalyst uses nano-TiO2-CeO2 as a support, and the surface of the support is loaded with active components. The active components include a main catalyst and a co-catalyst. The main catalyst is LaCuOx active powder, and the co-catalyst is SmFeOx active powder.

[0027] Among numerous flue gas denitrification methods, selective catalytic reduction (SCR) technology is currently the most widely used. Meanwhile, high concentrations of CO in flue gas from sintering, pelletizing, coking, glass, and chemical industries pose a significant challenge. Therefore, based on this objective, developing a catalytic oxidation catalyst for CO in high-concentration flue gas containing sulfur and water is the most economical and suitable option to achieve simultaneous removal of NOx and high-concentration CO under medium- and low-temperature conditions. This not only meets environmental protection requirements but also offers significant economic and environmental benefits through successful application. Therefore, the honeycomb catalyst in this application primarily focuses on the synergistic removal of NOx and high-concentration CO from flue gas and must be used stably under flue gas conditions containing a certain amount of H2O and SO2.

[0028] Specifically, the catalyst in this application uses modified titanium dioxide (nano-TiO2-CeO2) as a carrier. By modifying the titanium dioxide, it can be stably used under flue gas conditions containing a certain amount of H2O and SO2, and can also achieve synergistic coupling removal of CO and NOx at 180~270℃. The modified titanium dioxide (nano-TiO2-CeO2) has the following functions: Enhance oxygen storage capacity: through Doping with titanium dioxide to form a composite carrier structure, The introduction of this significantly enhances the oxygen storage capacity (OSC) of the carrier, enabling it to function effectively in redox cycles. Valence state transitions promote the formation of oxygen vacancies, enhancing electron transfer between the active component and the support.

[0029] Enhanced sulfur and water resistance: Priority and Reaction generation ,reduce Poisoning of active components; at the same time Surface hydroxylation can inhibit Competitive adsorption of molecules at active sites. Secondly, nano-TiO2-CeO2 has a relatively high specific surface area. It increases porosity by about 30% and porosity by 15%, which is beneficial for the dispersion of active components.

[0030] Compared to traditional The carrier can enhance the sulfur poisoning resistance of modified titanium dioxide (e.g., by improving its resistance to sulfur poisoning). The tolerance concentration is increased to 50~100ppm, and the hydrothermal stability is improved (e.g., the specific surface area retention rate is improved after aging at 500℃ / 12h).

[0031] Optimization of temperature window using modified titanium dioxide: Functions of composite carriers Improved oxygen storage capacity (OSC): Redox pairs provide a dynamic oxygen pool, buffering the supply of reactive oxygen species during temperature fluctuations.

[0032] Sulfur- and water-resistant design: Preferential adsorption generate Protect active sites; Hydrophobic modification (contact angle enhancement) inhibits Competitive adsorption.

[0033] Optimization of pore structure: Hierarchical pores reduce mass transfer resistance and decrease apparent activation energy.

[0034] The active components of this application include a main catalyst and a co-catalyst. The main catalyst is LaCuOx active powder, and the co-catalyst is SmFeOx active powder. Through the synergistic effect of the main catalyst and the co-catalyst, CO and NOx can be synergistically removed from flue gas. The specific principle is as follows: LaCuOx active powder... Redox pairs are responsible for the low-temperature oxidation of CO (Mars-van Krevelen mechanism). The electronic additive effect lowers the oxidation activation energy of Cu. SmFeOx active powder... Cycling promotes the adsorption and dissociation of NO (increases the amount of NO adsorbed). Increased strong electronegativity active( (Adsorption strength enhancement). The synergistic anti-sulfurization mechanism of LaCuOx and SmFeOx active powders is mainly due to the interaction of Fe in SmFeOx with... Priority Formation The desorption temperature was increased from 250℃ to 400℃ to protect the LaCuOx active sites; at the same time... The carrier achieves self-regeneration through a sulfur storage-desulfation mechanism.

[0035] The catalyst of this application can achieve synergistic coupling removal of CO and NOx under medium and low temperature conditions of 180-270℃, and the CO removal efficiency reaches over 80% and the NOx denitrification efficiency reaches over 80% at temperatures above 250℃. Among these, CO removal is... The catalyst plays a role in removing NO. The catalyst plays a role, which will be explained in detail below: The synergistic catalytic mechanism of the active components is mainly: LaCuOx main active site (CO oxidation dominant, CO removal catalysis) Low-temperature activity activation: The redox couple can be activated at 180℃, catalyzing CO oxidation via the Mars-van Krevelen mechanism: (Involvement of lattice oxygen); Electronic regulation: The 4f orbital electrons of La are injected into Cu sites, reducing the activation energy of CO adsorption.

[0036] SmFeOx co-active sites (NOx reduction-dominant) Cycling: Above 200℃, quilt Restore to Promotes NO adsorption and dissociation: ; Acid regulation: The strong electronegativity of Sm enhances surface acidity ( (Adsorption capacity increased), optimization Path selectivity.

[0037] Dual active site synergy The tandem reaction of CO and NOx: reactive oxygen species released by CO oxidation. Participating in the oxidation of NO to This, in turn, accelerates the SCR reaction: ; CO adsorption peaks were observed and The coexistence of intermediates confirms the cooperative path.

[0038] The non-precious metal rare earth catalyst of this application exhibits good chemical activity and thermal stability, compared with existing precious metal catalysts (such as...). Regarding this catalyst: its CO conversion rate (88%) at 250℃ is close to that of Pt-based catalysts (92%), but its cost is reduced by 90%; compared to monofunctional catalysts (such as... In this application, the catalyst has the added function of CO oxidation and NOx conversion performance.

[0039] In this embodiment, it should be noted that nanometers Powder, acting as a carrier, accounts for 50-70% of the total catalyst mass, such as 50%, 55%, 60%, 65%, 70%, etc., while nanoparticles... in powder nanometer 7-8% of the total mass of the powder, such as 7%, 7.5% or 8%.

[0040] LaCuOx active powder is the main active component of the catalyst, accounting for 5% to 20% of the total catalyst mass, such as 5%, 10%, 16%, and 20%. CuOx in the LaCuOx active powder accounts for 40% to 60% of the total mass, such as 40%, 45%, 50%, 55%, and 60%. SmFeOx active powder is the co-catalyst, accounting for 2% to 10% of the total catalyst mass, such as 2%, 4%, 6%, 8%, and 10%. In SmFeOx active powder, FeOx accounts for 40-60% of the total mass of SmFeOx active powder, such as 40%, 45%, 50%, 55%, 60%, etc.

[0041] In this embodiment, it should be noted that nanometers The particle size of the powder is 10~50nm, such as 10nm, 15nm, 18nm, 22nm, 28nm, 32nm, 37nm, 40nm, 45nm, 50nm, etc.; the particle size of the LaCuOx active powder is 1~5μm, such as 1μm, 2μm, 3μm, 4μm, 5μm, etc.

[0042] This application also provides a method for preparing a honeycomb catalyst for the synergistic coupling removal of CO and NOx, please refer to... Figure 1 As shown, the preparation method includes the following steps: Preparation of S1 honeycomb catalyst semi-finished product; nano LaCuOx active powder, SmFeOx active powder and additives are mixed and stirred evenly, and then dried to obtain a honeycomb catalyst semi-finished product. Preparation of S2 honeycomb catalyst product; The honeycomb catalyst semi-finished product prepared by S1 is calcined to obtain the honeycomb catalyst finished product.

[0043] The preparation method of this application adopts a two-step molding method, which ensures that the dual active components of SmFeOx and LaCuOx are effectively combined in the modified titanium dioxide (nano-sized) On the one hand, it ensures the uniformity of the carrier, and on the other hand, it also ensures the advantages of high mechanical strength, high thermal conductivity, and high utilization rate of active ingredients in honeycomb catalysts.

[0044] In this embodiment, it should be noted that nano- The LaCuOx active powder, SmFeOx active powder, and additives are mixed and stirred evenly, and then dried to obtain a honeycomb catalyst semi-finished product, specifically including: nano LaCuOx active powder and SmFeOx active powder were mixed, and a lubricant was added and stirred for 10 minutes. Then, water and a humidifier were added and mixed evenly for 15 minutes. The temperature was raised to 90°C and dehumidified for 60 minutes. Then, short-cut glass fibers were added and mixed evenly. Finally, pore-forming agent, silica sol, plasticizer and rheology modifier were added and mixed evenly to obtain catalyst slurry. The moisture content of the catalyst slurry was tested to be 26-28%. The catalyst slurry was aged at room temperature for 48 hours.

[0045] The aged catalyst sludge is filtered and then extruded through an extrusion molding device to obtain a honeycomb catalyst wet preform. The wet preform is wrapped in paper and then dried under gradient temperature to reduce the moisture content to less than 2%, thus obtaining a honeycomb catalyst semi-finished product.

[0046] In some embodiments, the lubricant functions to improve the flowability of extrusion molding and reduce the friction coefficient of the slurry. The lubricant can be stearic acid, which accounts for 0.5 to 1.5% of the total mass of the catalyst, such as 0.5%, 0.8%, 1.0%, 1.3%, 1.5%, etc.

[0047] In some embodiments, the humectant functions to delay the drying and cracking of the mud and reduce the rate of moisture gradient descent. The humectant can be glycerol, which accounts for 2-4% of the total mass of the catalyst, such as 2%, 2.4%, 2.7%, 3%, 3.3%, 3.6%, 4%, etc.

[0048] In some embodiments, chopped glass fiber is used as a skeleton reinforcement material to improve the mechanical strength and thermal shock resistance of the catalyst (reduce the coefficient of thermal expansion). The chopped glass fiber accounts for 10-20% of the total mass of the catalyst, such as 10%, 12%, 14%, 16%, 18%, 20%, etc.

[0049] In some embodiments, the pore-forming agent functions by generating pores through thermal decomposition. The gas forms through-pores, increasing the porosity and altering the acidity / alkalinity of the clay, increasing its zeta potential and improving its extrusion flowability. The pore-forming agent can be oxalic acid, which accounts for 1-3% of the total mass of the catalyst, such as 1%, 1.3%, 1.6%, 1.8%, 2.0%, 2.4%, 2.8%, 3%, etc.

[0050] In some embodiments, the role of silica sol is to form a Si-O-Si network structure during calcination at 400~500℃, thereby improving the thermal stability of the carrier. Silica sol can be a high-temperature binder, and the high-temperature binder accounts for 0~5% of the total mass of the catalyst, such as 0%, 1%, 2%, 3%, 4%, 5%, etc.

[0051] In some embodiments, the plasticizer functions to improve the plasticity and wet strength of the clay. The plasticizer can be hydroxypropyl methylcellulose, which accounts for 1-3% of the total mass of the catalyst, such as 1%, 1.3%, 1.6%, 1.8%, 2.0%, 2.4%, 2.8%, 3%, etc. Using other plasticizers such as carboxymethyl cellulose (CMC): the dosage needs to be increased to 2-4%, but this will lead to a decrease in the thixotropy of the clay; polyvinyl alcohol (PVA): it needs to be pre-dissolved into a 5% gel, but the drying shrinkage rate increases by 15%. Therefore, using the hydroxypropyl methylcellulose (HPMC) in this application is more compatible with the clay plasticity, thixotropy, and drying shrinkage rate of the active component and carrier material.

[0052] In some embodiments, the rheology modifier functions to control the thixotropy of the slurry and prevent extrusion deformation. The rheology modifier can be polyethylene oxide, which accounts for 0.5 to 1.5% of the total mass of the catalyst, such as 0.5%, 0.8%, 1.0%, 1.3%, 1.5%, etc.

[0053] In this embodiment, it should also be noted that in step S1, the drying requirements are: the moisture content after drying must be <2% (measured by gravimetric method), and the drying temperature is increased in a gradient: 80℃ (2h) → 110℃ (4h) → 150℃ (2h). This parameter can avoid cracking caused by rapid water loss (the crack rate is reduced from 15% to <3%), while ensuring the integrity of the carrier pore structure.

[0054] In step S2, the calcination process conditions are as follows: calcination temperature is 400-500℃, such as 400℃, 450℃, 470℃, 500℃, etc.; holding time is 3-5h, such as 3h, 3.5h, 4h, 4.5h, 5h, etc.; heating rate is 2-4℃ / min, such as 2℃ / min, 2.2℃ / min, 2.4℃ / min, 2.6℃ / min, 2.8℃ / min, 3℃ / min, 3.5℃ / min, 3.7℃ / min, 3.8℃ / min, 4℃ / min, etc. In the second step, through the calcination process, SmFeOx diffuses into the support lattice through solid-phase diffusion (Sm diffuses to a depth of 200nm in TiO2-CeO2), forming a core-shell structure with LaCuOx (forming LaCuOx@SmFeOx composite active sites).

[0055] In this embodiment, it should be noted that the preparation method of this application further includes nanotechnology before S1. The preparation of powders, LaCuOx active powders, and SmFeOx active powders will be described in detail below.

[0056] nanometer The powder is prepared as follows: Raw materials include: titanium dioxide ( Industrial grade, particle size 50~100nm), cerium nitrate ( (Analytical grade), deionized water (for solution preparation and washing).

[0057] The preparation includes the following steps: Step 1: Preparation of cerium precursor solution Cerium nitrate ( Dissolve it in deionized water to prepare a transparent solution of 0.1~0.3 mol / L.

[0058] Step 2: Carrier Mixing and Loading Weigh out industrial grade Ti according to a Ti:Ce molar ratio of 10:1 to 5:1. The powder was added to the cerium solution.

[0059] Turn on the magnetic stirrer (500~800 rpm), heat the water bath to 60~80℃, and stir continuously for 2 hours. Uniformly adsorbed on surface.

[0060] Step 3: Aging and Fixation Stop heating and let stand for 12-24 hours while stirring to promote the interaction of Ce species with... Interface integration.

[0061] Step 4: Firing and Shaping The precipitate was placed in a muffle furnace and heated to 400-500℃ at a rate of 3℃ / min, and calcined for 3-5 hours (at air atmosphere). After natural cooling, it was ball-milled (300 rpm, 1 hour) to obtain nanoparticles. Modified titanium dioxide (particle size 20~50nm, specific surface area >90m² / g).

[0062] The preparation of LaCuOx active powder is as follows: Raw materials include: Lanthanum nitrate ( (analytical purity) Copper nitrate ( (analytical purity) ammonia( (25%~28%, used for pH adjustment) Deionized water (for preparing solutions and washing).

[0063] The preparation includes the following steps: Step 1: Preparation of Lanthanum-Copper Precursor Solution Weigh out lanthanum nitrate and copper nitrate according to a La:Cu molar ratio of 2:1 to 1:2, dissolve them in deionized water, and prepare a mixed solution with a total metal ion concentration of 0.2 to 0.5 mol / L. Add ammonia to adjust the pH to 8.0 to 9.0, and stir magnetically until the solution is clear.

[0064] Step 2: Co-precipitation and loading Transfer the mixed solution to a reaction vessel, heat it in a water bath to 70-90°C, and stir continuously for 4-6 hours.

[0065] The pH was maintained stable (±0.2) by adding ammonia dropwise, promoting... and Co-precipitation.

[0066] Step 3: Aging and Crystallization Stop heating and allow to stand for 18-24 hours to allow the precipitate crystals to grow completely. Centrifuge to separate the precipitate and wash with deionized water to remove residual nitrate.

[0067] Step 4: Calcination and Activation The precipitate was placed in a muffle furnace and calcined at 500-600℃ at a rate of 2℃ / min for 4-6 hours (air atmosphere). After natural cooling, it was ball-milled (300 rpm, 1 hour) to obtain LaCuOx active powder (particle size 30-60 nm, specific surface area). The CuO crystal phase accounts for 40% to 60%.

[0068] The preparation of SmFeOx active powder is as follows: Raw materials include: samarium nitrate ( (analytical purity) Ferric nitrate ( (analytical purity) Sodium hydroxide (NaOH, analytical grade, used for pH adjustment) Deionized water (for solution preparation and washing) The preparation method includes the following steps: Step 1: Preparation of samarium iron precursor solution Weigh samarium nitrate and ferric nitrate according to the Sm:Fe molar ratio of 1:3 to 3:1, dissolve them in deionized water, and prepare a mixed solution with a total metal ion concentration of 0.3 to 0.6 mol / L.

[0069] Adjust the pH to 9.0-10.0 by adding 1 mol / L NaOH solution dropwise, and stir magnetically until a uniform suspension is formed.

[0070] Step 2: Hydrothermal Synthesis and Loading Transfer the suspension to a reaction vessel and maintain the temperature at 70-90°C for 4-6 hours to promote [the reaction]. and Co-precipitation and crystallization.

[0071] After the reaction is complete, allow the mixture to cool naturally to room temperature, then centrifuge to separate the precipitate.

[0072] Step 3: Washing and Drying The precipitate was repeatedly washed with deionized water until the pH of the filtrate was approximately 7.0 (neutral). The precipitate was then placed in an oven and dried at 80°C for 12 hours to obtain the precursor powder.

[0073] Step 4: Calcination and Crystal Phase Control The dried powder is placed in a tube furnace and heated to 500-600°C at a rate of 5°C / min, and calcined for 4-6 hours (in air).

[0074] After cooling, the powder was ball-milled (300 rpm, 1 hour) to obtain SmFeOx active powder (particle size 30~60 nm, specific surface area). , The crystalline phase accounts for 50% to 70%.

[0075] The beneficial effects of the present invention will be illustrated below through Examples 1-3.

[0076] Example 1 In Example 1, the honeycomb catalyst for the synergistic coupling removal of CO and NOx has a cross-sectional dimension of 150 mm wide and 150 mm high, with 40 × 40 holes. The steel module box has a cross-sectional dimension of 150 mm wide and 300 mm high.

[0077] The preparation of a honeycomb catalyst for the synergistic coupling removal of CO and NOx is carried out according to the following production formula: Step 1: Preparation of honeycomb catalyst semi-finished product: Modified titanium dioxide (nano) 50% LaCuOx active powder (1~5μm) 5% SmFeOx active powder (1~5μm) 2% 10% chopped fiberglass 0.1% silica sol 1% oxalic acid Stearic acid 0.5% Hydroxypropyl methylcellulose 1% PEO 0.5% 2% glycerol Modified titanium dioxide, LaCuOx active powder, and SmFeOx active powder were mixed, and stearic acid was added and stirred for 10 minutes. Then, water and glycerol were added and mixed for 15 minutes respectively. The temperature was raised to 90℃ and dehumidified for 60 minutes. Then, short-cut glass fibers were added and mixed evenly. Finally, oxalic acid, silica sol, hydroxypropyl methylcellulose, and PEO were added and mixed evenly to obtain catalyst slurry. The moisture content of the slurry was tested, aged for 48 hours, and then extruded and dried until the moisture content was reduced to less than 2% to obtain honeycomb catalyst semi-finished product.

[0078] The second step is the preparation of the honeycomb catalyst product: The honeycomb catalyst semi-finished product prepared in the first step was calcined at 400℃ with a heating rate of 2℃ / min and held at that temperature for 3 hours to obtain the honeycomb catalyst finished product.

[0079] Example 2 In Example 2, the honeycomb catalyst for the synergistic coupling removal of CO and NOx has a cross-sectional dimension of 150 mm wide and 150 mm high, with 40 × 40 holes. The steel module box has a cross-sectional dimension of 150 mm wide and 300 mm high.

[0080] The preparation of a honeycomb catalyst for the synergistic coupling removal of CO and NOx is carried out according to the following production formula: Step 1: Preparation of honeycomb catalyst semi-finished product: Modified titanium dioxide (nano) 60% LaCuOx active powder (1~5μm) 15% SmFeOx active powder (1~5μm) 5% 15% chopped fiberglass Silica sol 2.5% 2% oxalic acid 1% stearic acid Hydroxypropyl methylcellulose 2% PEO 1% 3% glycerol Modified titanium dioxide, LaCuOx active powder, and SmFeOx active powder were mixed, and stearic acid was added and stirred for 10 minutes. Then, water and glycerol were added and mixed for 15 minutes respectively. The temperature was raised to 90℃ and dehumidified for 60 minutes. Then, short-cut glass fibers were added and mixed evenly. Finally, oxalic acid, silica sol, hydroxypropyl methylcellulose, and PEO were added and mixed evenly to obtain catalyst slurry. The moisture content of the slurry was tested, aged for 48 hours, and then extruded and dried until the moisture content was reduced to less than 2% to obtain honeycomb catalyst semi-finished product.

[0081] The second step is the preparation of the honeycomb catalyst product: The honeycomb catalyst semi-finished product prepared in the first step was calcined at 450°C with a heating rate of 3°C / min and held at that temperature for 4 hours to obtain the honeycomb catalyst finished product.

[0082] Example 3 In Example 3, the honeycomb catalyst for the synergistic removal of CO and NOx has a cross-sectional dimension of 150 mm wide and 150 mm high, with 40 × 40 holes. The steel module box has a cross-sectional dimension of 150 mm wide and 300 mm high.

[0083] The preparation of a honeycomb catalyst for the synergistic coupling removal of CO and NOx is carried out according to the following production formula: Step 1: Preparation of honeycomb catalyst semi-finished product: Modified titanium dioxide (nano) 70% LaCuOx active powder (1~5μm) 20% SmFeOx active powder (1~5μm) 10% 20% chopped fiberglass 5% silica sol 3% oxalic acid Stearic acid 1.5% Hydroxypropyl methylcellulose 3% PEO 1.5% 4% glycerol Modified titanium dioxide, LaCuOx active powder, and SmFeOx active powder were mixed, and stearic acid was added and stirred for 10 minutes. Then, water and glycerol were added and mixed for 15 minutes respectively. The temperature was raised to 90℃ and dehumidified for 60 minutes. Then, short-cut glass fibers were added and mixed evenly. Finally, oxalic acid, silica sol, hydroxypropyl methylcellulose, and PEO were added and mixed evenly to obtain catalyst slurry. The moisture content of the slurry was tested, aged for 48 hours, and then extruded and dried until the moisture content was reduced to less than 2% to obtain honeycomb catalyst semi-finished product.

[0084] The second step is the preparation of the honeycomb catalyst product: The honeycomb catalyst semi-finished product prepared in the first step was calcined at 500℃ with a heating rate of 4℃ / min and held at that temperature for 5h to obtain the honeycomb catalyst finished product.

[0085] The performance of the honeycomb catalyst product prepared in Example 2 above was evaluated. The catalyst evaluation system involves taking a 40×40mm catalyst sample, loading it into the catalyst performance evaluation reaction device, and introducing simulated gas to evaluate its activity.

[0086] Operating Condition 1: The exhaust gas composition of simulated gas 1 is as follows: CO (6000ppm), NO (600ppm). (400ppm) (13-15%) (20-35ppm) Water vapor comprises 10-20%, with the remainder being nitrogen. The gas hourly space velocity is: The catalyst prepared achieves a denitrification efficiency of over 85% and a carbon monoxide removal efficiency of over 85% at 250℃ (e.g., Figure 2 (As shown).

[0087] Operating Condition 2: The exhaust gas composition of simulated gas 2 is as follows: CO (6000ppm), NO (600ppm). (400ppm) (13-15%) (35-100ppm) Water vapor comprises 10-20%, with the remainder being nitrogen. The gas hourly space velocity is: The catalyst prepared achieves a denitrification efficiency of over 80% and a carbon monoxide removal efficiency of over 80% at 250℃ (e.g., Figure 3 (As shown).

[0088] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0089] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A honeycomb catalyst for the synergistic coupling removal of CO and NOx, characterized in that, Catalyst in nano The carrier is a carrier on which active components are loaded. The active components include a main catalyst and a co-catalyst, wherein the main catalyst is LaCuOx active powder and the co-catalyst is SmFeOx active powder.

2. The catalyst according to claim 1, characterized in that, The nano It accounts for 50-70% of the total mass of the catalyst; The LaCuOx active powder accounts for 5-20% of the total mass of the catalyst; The SmFeOx active powder accounts for 2-10% of the total mass of the catalyst.

3. The catalyst according to claim 2, characterized in that, The nano middle nanometer 7-8% of the total mass; In the LaCuOx active powder, CuOx accounts for 40-60% of the total mass of the LaCuOx active powder; In the SmFeOx active powder, FeOx accounts for 40-60% of the total mass of the SmFeOx active powder.

4. The catalyst according to claim 1, characterized in that, The nano The particle size is 10~50nm; The particle size of the LaCuOx active powder is 1~5μm.

5. The method for preparing the honeycomb catalyst for synergistic removal of CO and NOx as described in claim 1, characterized in that, The preparation method includes the following steps: Preparation of S1 honeycomb catalyst semi-finished product; nano LaCuOx active powder, SmFeOx active powder and additives are mixed and stirred evenly, and then dried to obtain a honeycomb catalyst semi-finished product. Preparation of S2 honeycomb catalyst product; The honeycomb catalyst semi-finished product prepared by S1 is calcined to obtain the honeycomb catalyst finished product.

6. The preparation method according to claim 5, characterized in that, The nano LaCuOx active powder and SmFeOx active powder are mixed and stirred evenly, and then dried to obtain a honeycomb catalyst semi-finished product, including: nano LaCuOx active powder and SmFeOx active powder are mixed, and lubricant is added and stirred. Then water and humectant are added and mixed evenly. Then short-cut glass fiber is added and mixed evenly. Finally, plasticizer and rheology modifier are added and mixed evenly to obtain catalyst slurry. The catalyst slurry is aged at room temperature. The filtered catalyst sludge is then extruded through an extrusion molding device to obtain a honeycomb catalyst wet preform. The wet preform is then slowly dried in multiple stages to obtain a honeycomb catalyst semi-finished product.

7. The preparation method according to claim 6, characterized in that, The lubricant accounts for 0.5-1.5% of the total mass of the catalyst; The plasticizer accounts for 1-3% of the total mass of the catalyst; The rheology modifier accounts for 0.5-1.5% of the total mass of the catalyst; The humectant accounts for 2-4% of the total mass of the catalyst; The chopped glass fibers account for 10-20% of the total mass of the catalyst.

8. The preparation method according to claim 5, characterized in that, The drying process conditions are: moisture content <2%, and the drying temperature is increased gradually.

9. The preparation method according to claim 5, characterized in that, The roasting process conditions are as follows: roasting temperature is 400-500℃, holding time is 3-5h, and heating rate is 2-4℃ / min.

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