High-dispersion Pt-based CO oxidation honeycomb forming catalyst and preparation method thereof

Abstract

The invention discloses a high-dispersion Pt-based CO oxidation honeycomb forming catalyst and a preparation method thereof, and belongs to the technical field of industrial flue gas tail end CO treatment. The preparation method comprises the following steps: coating a mixture of titanium dioxide, an auxiliary agent and a platinum source as a coating material on a main body framework, and drying and calcining to obtain the high-dispersion Pt-based CO oxidation honeycomb forming catalyst. The auxiliary agent comprises an organic ligand and a binder. The catalyst has high specific surface area and high catalytic activity, can be used for efficiently removing CO in industrial flue gas, shows excellent poisoning resistance, and can be widely applied to flue gas treatment at the tail end of industries such as steel and iron.

Description

Technical Field

[0001] The present invention belongs to the technical field of CO treatment at the end of industrial flue gas, and in particular relates to a highly dispersed Pt-based CO oxidation honeycomb-molded catalyst and a preparation method thereof. Background Art

[0002] Industries such as steel and coal-fired power plants are the main sources of CO emissions. Among them, the steel industry accounts for 67% of the total anthropogenic emissions and is the main source of CO emissions. As one of the best solutions for flue gas CO purification, the research and development of its core material catalysts has attracted widespread attention. In reported studies, precious metal catalysts have shown excellent CO oxidation activity and have attracted widespread attention due to their good catalytic performance and high anti-poisoning ability at low temperatures. In existing studies, Pt-based catalysts have been extensively studied for catalytic oxidation and are considered to be the most commonly used precious metal CO oxidation catalysts. The atomic dispersion and oxygen supply capacity of Pt-based catalysts are important factors affecting the stability and activity of the catalyst. Therefore, the selection of catalyst carriers and the regulation of the dispersion of Pt particles on the catalyst carriers can effectively improve the CO oxidation activity of the catalyst.

[0003] CN114950469A discloses a carbon monoxide catalyst, its preparation method, and use. The carbon monoxide catalyst is prepared from raw materials including a carrier, an active component precursor, a pore-enlarging agent, and a binder. The catalyst preparation process involves first mixing the carrier to obtain a first premix; then mixing the first premix with the pore-enlarging agent to obtain a second premix; then wet-mixing an aqueous solution containing the active component precursor with the second premix to obtain a third premix; and finally, mixing the third premix with the binder to obtain a slurry. The resulting CO catalyst exhibits a high carbon monoxide conversion rate over a wide temperature window. However, the catalyst cannot effectively address the poisoning and deactivation that can occur in complex flue gas environments.

[0004] Therefore, in view of the above defects, there is an urgent need to develop a catalyst that can be used for efficient oxidation of CO and has a certain anti-poisoning ability to achieve efficient removal of CO in complex flue gas environments. Summary of the Invention

[0005] To address these technical challenges, the present invention proposes a highly dispersed Pt-based CO oxidation honeycomb catalyst and its preparation method. By coating the catalyst's skeleton with Pt active sites, the resulting catalyst exhibits highly dispersed active components and excellent catalytic performance, resulting in a highly efficient, sulfur-resistant CO oxidation catalyst. This catalyst achieves efficient CO removal in complex flue gas environments, facilitating its industrial application and widespread adoption.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] One of the objectives of the present invention is to provide a method for preparing a highly dispersed Pt-based CO oxidation honeycomb catalyst, wherein a mixture of titanium dioxide, an additive, and a platinum source is coated on a main skeleton as a coating material, and then dried and calcined to obtain a highly dispersed Pt-based CO oxidation honeycomb catalyst.

[0008] The auxiliary agent includes an organic ligand and a binder.

[0009] The highly dispersed Pt-based CO oxidation honeycomb catalyst provided by the present invention consists of a catalyst skeleton, commercial titanium dioxide powder coated on the catalyst skeleton, a binder for regulating the catalyst's mechanical properties, pore structure, and chemical stability, an organic ligand, and precious metal active centers doped in the commercial titanium dioxide powder. Using trace Pt species as active centers, they are anchored to the surface of the commercial titanium dioxide support via organic ligands, achieving single-atom-level dispersion, significantly reducing the amount of precious metal used while exposing more active sites and improving CO oxidation efficiency. The multi-level pore structure of titanium dioxide regulated by the binder reduces the coverage of Pt active sites by sulfate deposition, thereby improving the catalyst's anti-poisoning ability and enabling the catalyst to maintain excellent CO conversion rates even under complex flue gas conditions. The highly dispersed Pt-based CO oxidation honeycomb catalyst uses a metal skeleton as a rigid substrate, combined with the chemical bonding of the binder, to enhance the catalyst's sintering resistance under high-temperature conditions and optimize its mechanical strength. The use of commercial titanium dioxide powder as a support, combined with a coating process, effectively reduces the catalyst's preparation cost, facilitating its industrial application and promotion.

[0010] Furthermore, the main skeleton is selected from one or more of cordierite, mullite and corundum.

[0011] The main skeleton materials such as cordierite, mullite and corundum have good thermal stability and mechanical strength, and can remain stable in high-temperature and high-pressure industrial flue gas environments, preventing the catalyst bed from collapsing, thereby ensuring the long-term stable operation of the catalyst.

[0012] Furthermore, the organic ligand is selected from one or more of citric acid monohydrate, polyvinyl pyrrolidone and ethylene glycol.

[0013] Organic ligands such as monohydrated citric acid, polyvinyl pyrrolidone, and ethylene glycol possess different functional groups and coordination capabilities, forming stable coordination compounds with the platinum source, further improving the dispersion and stability of the platinum. For example, the carboxyl groups in monohydrated citric acid can form coordination bonds with the platinum source, uniformly distributing the platinum particles on the titanium dioxide support surface, reducing platinum particle aggregation and increasing the exposure of active sites, thereby enhancing CO oxidation activity.

[0014] Furthermore, the binder is selected from one or more of sesbania powder, starch and hydroxypropyl cellulose.

[0015] Binders such as sesbania powder, starch, and hydroxypropyl cellulose possess excellent adhesion and film-forming properties, firmly attaching the coating material to the catalyst's skeleton and enhancing its mechanical strength and stability. Furthermore, the binder forms a porous structure during calcination, increasing the catalyst's specific surface area and porosity. This facilitates the diffusion of reactants and products, improving the catalyst's mass transfer efficiency and further enhancing its CO oxidation performance.

[0016] Furthermore, the preparation method specifically comprises the following steps:

[0017] S1. Mixing titanium dioxide with an additive to obtain a solid powder;

[0018] S2. Adding a platinum source to deionized water and stirring to obtain a mixed solution;

[0019] S3. The mixed solution is added to the solid powder and stirred to obtain a coating material;

[0020] Titanium dioxide and additives are mixed to form a solid powder. A platinum source is then added to deionized water and stirred to form a mixed solution. The mixed solution is then added to the solid powder and stirred to thoroughly mix the platinum source, titanium dioxide, and additives. This step ensures that the platinum source is evenly dispersed on the titanium dioxide support and that the organic ligands and binders in the additives are in full contact with the platinum source and titanium dioxide, exerting their coordination and bonding properties, laying the foundation for subsequent coating and calcination processes.

[0021] S4. coating the coating material on the main skeleton, drying, and calcining to obtain a highly dispersed Pt-based CO oxidation honeycomb catalyst.

[0022] The coating material is evenly applied to the main skeleton, allowing the platinum source, titanium dioxide, and additives to be evenly distributed on the main skeleton surface, forming a uniform coating. This step helps increase the specific surface area and the number of active sites of the catalyst, while also enhancing the mechanical strength and stability of the catalyst.

[0023] The drying process removes moisture from the coating material, making the coating more compact and uniform. The calcination process decomposes the organic ligands in the platinum source, evenly distributing the platinum particles on the titanium dioxide support and forming highly dispersed active centers. Furthermore, the calcination process creates a porous structure in the binder, increasing the specific surface area and porosity of the catalyst and improving its mass transfer efficiency. Furthermore, the calcination process strengthens the bond between the main skeleton and the coating, further enhancing the mechanical strength and stability of the catalyst.

[0024] Furthermore, the mass ratio of titanium dioxide to the auxiliary agent is (100-150): (5-50);

[0025] The auxiliary agent comprises an organic ligand and a binder, and the mass ratio of the organic ligand and the binder is (1-5):10.

[0026] When the additive content is appropriate, the organic ligand can form a stable coordination complex with the platinum source, improving the dispersion and stability of the platinum. The binder can enhance the mechanical strength and stability of the catalyst while also forming a porous structure, increasing the catalyst's specific surface area and porosity. Excessive or insufficient additive content can affect catalyst performance. For example, excessive additive content may reduce the mechanical strength of the catalyst or the dispersion of the platinum source; while excessively low additive content may not fully utilize the organic ligand and binder, affecting catalyst performance. Therefore, by limiting the mass ratio of titanium dioxide to additive, the catalyst's composition and structure can be optimized, resulting in better dispersibility and resistance to poisoning.

[0027] Furthermore, the usage ratio of the platinum source to deionized water is (0.01-0.2) g: (100-200) mL. The platinum source is chloroplatinic acid.

[0028] An appropriate amount of platinum source ensures sufficient active sites in the catalyst, enhancing CO oxidation activity. A suitable amount of deionized water ensures that the platinum source is fully dissolved and dispersed in the solution, allowing it to be evenly distributed on the titanium dioxide support. Chloroplatinic acid, as a platinum source, has excellent solubility and stability, dissolving fully in deionized water to form a uniform solution. During the subsequent coating and calcination processes, chloroplatinic acid decomposes into platinum particles, which are evenly distributed on the titanium dioxide support, forming highly dispersed active centers and thus improving catalyst performance.

[0029] Furthermore, the mass ratio of the mixed solution to the solid powder is (0.6-1.4):1.

[0030] The appropriate amount of mixed solution ensures that the platinum source fully contacts the titanium dioxide and additives, forming a uniform coating material. The appropriate amount of solid powder ensures that the catalyst has sufficient specific surface area and active sites. Excessive or insufficient mixed solution can affect the uniformity and performance of the coating material. For example, excessive mixed solution may reduce the dispersion of the platinum source on the titanium dioxide support or increase the viscosity of the coating material, affecting the coating effect. Excessive mixed solution may result in insufficient platinum source, affecting catalyst activity. Therefore, by limiting the mass ratio of mixed solution to solid powder, the composition and performance of the coating material can be optimized, resulting in better dispersion and activity of the catalyst.

[0031] Furthermore, the specific operation steps of the drying are: drying at 80-160°C for 8-16 hours.

[0032] An appropriate drying temperature removes moisture from the coating material, resulting in a denser and more uniform coating. An appropriate drying time ensures sufficient moisture removal, preventing excess moisture from remaining in the coating and impacting catalyst performance. Excessively high drying temperatures or prolonged drying times can decompose or denature the organic ligands and binders in the coating, impacting catalyst performance. Excessively low drying temperatures or short drying times can lead to incomplete moisture removal, affecting coating uniformity and stability. Therefore, by defining specific drying steps, the catalyst preparation process can be optimized, ensuring catalyst quality and performance.

[0033] Furthermore, the specific operation steps of the calcination treatment are: calcining at 300-700°C for 3-5h.

[0034] An appropriate calcination temperature can decompose the organic ligands in the platinum source, allowing the platinum particles to be evenly distributed on the titanium dioxide support, forming highly dispersed active centers. At the same time, the calcination process can also form a porous structure in the binder, increasing the specific surface area and porosity of the catalyst and improving the mass transfer efficiency of the catalyst. In addition, the calcination process can also strengthen the bonding force between the main skeleton and the coating, further improving the mechanical strength and stability of the catalyst. If the calcination temperature is too high or the time is too long, the titanium dioxide may transform from the anatase phase to the rutile phase, reducing the catalytic activity. If the calcination temperature is too low or the time is too short, the platinum source may not be completely converted into platinum active sites, affecting the activity of the catalyst. Therefore, by limiting the specific operating steps of the calcination treatment, the catalyst preparation process can be optimized to ensure that the catalyst has high dispersion, high activity and good anti-poisoning ability.

[0035] A second object of the present invention is to provide a highly dispersed Pt-based CO oxidation honeycomb catalyst, which is prepared using the above-mentioned preparation method.

[0036] The catalyst is prepared by the above-mentioned optimized preparation method and has highly dispersed platinum active centers, good carrier-active component interaction, porous structure and stable skeleton. These characteristics enable the catalyst to exhibit excellent performance in CO oxidation reactions. The highly dispersed platinum active centers provide a large number of active sites, which can efficiently adsorb and activate CO and O2, promoting the oxidation reaction of CO; the good carrier-active component interaction enhances the stability and anti-sintering ability of platinum, so that it can still maintain efficient catalytic activity under high temperature and complex flue gas environments; the porous structure and stable skeleton are conducive to the diffusion of reactants and products, improving the mass transfer efficiency of the catalyst, while enhancing the mechanical strength and anti-poisoning ability of the catalyst, so that it can adapt to complex industrial flue gas environments and achieve efficient CO removal.

[0037] A third object of the present invention is to provide a highly dispersed Pt-based CO oxidation honeycomb catalyst for use in catalyzing CO reactions.

[0038] The catalyst exhibits excellent performance in catalyzing CO reactions, mainly due to its highly dispersed platinum active centers, good carrier-active component interaction, porous structure and stable skeleton. In the CO oxidation reaction, the platinum active centers can efficiently adsorb and activate CO and O2 to form active intermediates, thereby promoting the oxidation reaction of CO to produce CO2. At the same time, the porous structure and stable skeleton of the catalyst are conducive to the diffusion of reactants and products, improving the mass transfer efficiency of the catalyst and further increasing the oxidation rate of CO. In addition, the catalyst's anti-poisoning ability enables it to maintain high catalytic activity in complex flue gas environments containing impurities such as sulfides and nitrogen oxides, achieving efficient removal of CO, thereby providing an efficient, stable and green solution for the treatment of CO at the end of industrial flue gas.

[0039] Compared with the prior art, the present invention has the following advantages and technical effects:

[0040] (1) The highly dispersed Pt-based CO oxidation honeycomb catalyst provided by the present invention has the advantages of low precious metal loading and high dispersion. The catalyst uses trace Pt species as the active center and is anchored on the surface of a commercial titanium dioxide carrier through organic ligands to achieve atomic-level dispersion, significantly reducing the amount of precious metals used while exposing more active sites and improving the CO oxidation efficiency.

[0041] (2) The highly dispersed Pt-based CO oxidation honeycomb catalyst provided by the present invention enhances the catalyst's ability to resist sulfur poisoning. Through the multi-level pore structure of titanium dioxide regulated by the binder, it selectively inhibits SO2 adsorption and reduces the coverage of sulfate deposition on Pt active sites, thereby maintaining an excellent CO conversion rate in sulfur-containing flue gas.

[0042] (3) The highly dispersed Pt-based CO oxidation honeycomb-molded catalyst provided by the present invention enhances the catalyst's excellent structural stability and flue gas adaptability. The catalyst uses a metal skeleton as a rigid base and is combined with a high-temperature resistant binder. The anti-sintering performance under high-temperature conditions is significantly improved, and it has excellent mechanical strength.

[0043] (4) The highly dispersed Pt-based CO oxidation honeycomb catalyst provided by the present invention strengthens the catalyst and reduces catalyst preparation costs, resulting in significant economic benefits. The catalyst utilizes commercial titanium dioxide powder as a carrier, combined with a scalable coating process, significantly reducing catalyst costs. This is beneficial for the industrial application and promotion of the catalyst. DETAILED DESCRIPTION

[0044] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0045] It should be understood that the terms described herein are intended only to describe particular embodiments and are not intended to limit the present invention. In addition, for numerical ranges herein, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Each smaller range between any intermediate value within a stated value or stated range and any other stated value or intermediate value within the stated range is also encompassed by the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded within the scope.

[0046] Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of any conflict with any incorporated document, the contents of this specification shall prevail.

[0047] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments described herein without departing from the scope or spirit of the invention. Other embodiments will be apparent to those skilled in the art from the description of the invention. The description and examples are intended to be illustrative only.

[0048] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0049] The present invention provides a method for preparing a highly dispersed Pt-based CO oxidation honeycomb catalyst, which specifically includes the following steps:

[0050] 1) Mixing commercial titanium dioxide powder with an additive and stirring to obtain a solid powder;

[0051] 2) adding an industrial platinum source to deionized water and stirring to obtain a mixed solution;

[0052] 3) adding the mixed solution to the solid powder and stirring to obtain a coating material;

[0053] 4) coating the coating material on the main frame, drying, and calcining to obtain a highly dispersed Pt-based CO oxidation honeycomb catalyst.

[0054] In some optional embodiments of the present invention, in step 1), the mass ratio of the commercial titanium dioxide powder to the additive is (100-150):(5-50); as an example, in the following preferred embodiments of the present invention, the mass ratio of the commercial titanium dioxide powder to the additive is (100-145):(5-50), such as 100:50:110:40, 130:20 or 145:5.

[0055] In some optional embodiments of the present invention, in step 1), the auxiliary agent includes an organic ligand and a binder, and the mass ratio of the organic ligand and the binder is (1-5):10. By way of example, in the following preferred embodiments of the present invention, the mass ratio of the binder and the organic ligand is 1:10, 2:10, 3:10, 4:10, or 5:10. The organic ligand includes one or more of citric acid monohydrate, polyvinyl pyrrolidone, and ethylene glycol. By way of example, in the following preferred embodiments of the present invention, the organic ligand is citric acid monohydrate, polyvinyl pyrrolidone, or ethylene glycol. The binder includes one or more of sesbania powder, starch, and hydroxypropyl cellulose. By way of example, in the following preferred embodiments of the present invention, the binder is sesbania powder, starch, or hydroxypropyl cellulose.

[0056] In some optional embodiments of the present invention, in step 1), the stirring time is 10-60 min. As an example, in the following preferred embodiments of the present invention, the stirring time is 10 min, 20 min, 30 min, 50 min or 60 min.

[0057] In some optional embodiments of the present invention, in step 2), the usage ratio of the platinum source (chloroplatinic acid) and deionized water is (0.01-0.2) g: (100-200) mL; as an example, in the following preferred embodiments of the present invention, the usage ratio of the platinum source (chloroplatinic acid) and deionized water is 0.01 g: 100 mL, 0.05 g: 120 mL, 0.1 g: 190 mL, 0.15 g: 180 mL or 0.2 g: 200 mL.

[0058] In some optional embodiments of the present invention, in step 2), the stirring time is 10-60 min. As an example, in the following preferred embodiments of the present invention, the stirring time is 10 min, 20 min, 30 min, 50 min or 60 min.

[0059] In some optional embodiments of the present invention, in step 3), the mass ratio of the mixed solution to the solid powder is (0.6-1.4):1; as an example, in the following preferred embodiments of the present invention, the mass ratio of the mixed solution to the solid powder is (0.67-1.3):1, such as 0.67:1, 0.79:1, 0.8:1, 1.2:1 or 1.3:1.

[0060] In some optional embodiments of the present invention, in step 3), the stirring time is 30-90 min. As an example, in the following preferred embodiments of the present invention, the stirring time is 30 min, 40 min, 60 min, 80 min or 90 min.

[0061] In some optional embodiments of the present invention, in step 4), the specific operation step of drying is: drying at 80-160° C. for 8-16 hours. As an example, in the following preferred embodiments of the present invention, the drying temperature is 80° C., 90° C., 120° C., 140° C., or 160° C.; and the drying time is 8 hours, 10 hours, 12 hours, 14 hours, or 16 hours.

[0062] In some optional embodiments of the present invention, in step 4), the specific operation steps of the calcination treatment are: calcination at 300-700°C for 3-5 hours. As an example, in the following preferred embodiments of the present invention, the calcination temperature is 300°C, 400°C, 500°C, 600°C, or 700°C; and the calcination time is 3 hours, 3.5 hours, 4 hours, 4.5 hours, or 5 hours.

[0063] The highly dispersed Pt-based CO oxidation honeycomb catalyst prepared by the above method has a loading of 0.06-0.13 wt% of the active component Pt in commercial titanium dioxide powder. Examples include 0.06 wt%, 0.07 wt%, 0.08 wt%, 0.09 wt%, 0.10 wt%, 0.11 wt%, 0.12 wt%, and 0.13 wt%. The loadings are not limited to the listed values, and other values ​​within the numerical range are also applicable.

[0064] The highly dispersed Pt-based CO oxidation honeycomb catalyst can be used to catalyze CO reactions.

[0065] Exemplarily, the specific steps of the method for preparing a highly dispersed Pt-based CO oxidation honeycomb catalyst provided in the following embodiments of the present invention include:

[0066] 1) mixing 100-150 g (for example, 100 g, 110 g, 120 g, 130 g, 140 g, 150 g, but not limited to the listed values, and other values ​​not listed within the numerical range are also applicable) of commercial titanium dioxide powder with 0-50 g (for example, 10 g, 20 g, 30 g, 40 g, 50 g, 150 g, but not limited to the listed values, and other values ​​not listed within the numerical range are also applicable) of an auxiliary agent, and stirring for 10-60 min (for example, 10 min, 20 min, 30 min, 40 min, 50 min, 60 min, but not limited to the listed values, and other values ​​not listed within the numerical range are also applicable) to obtain a solid powder;

[0067] 2) adding 0.01-0.2 g (for example, 0.01 g, 0.05 g, 0.10 g, 0.15 g, 0.2 g, but not limited to the listed values, and other values ​​not listed in the numerical range are also applicable) of an industrial platinum source to 100-200 mL (for example, 100 mL, 120 mL, 140 mL, 160 mL, 180 mL, 200 mL, but not limited to the listed values, and other values ​​not listed in the numerical range are also applicable) of deionized water, and stirring for 10-60 min (for example, 10 min, 20 min, 30 min, 40 min, 50 min, 60 min, but not limited to the listed values, and other values ​​not listed in the numerical range are also applicable) to obtain a mixed solution;

[0068] 3) adding the mixed solution to the solid powder in a mass ratio of (0.6-1.4):1 (for example, 0.6:1, 0.8:1, 1:1, 1.2:1, 1.4:1, but not limited to the listed values, and other values ​​not listed within the numerical range are also applicable), and stirring for 30-90 minutes (for example, 30 minutes, 40 minutes, 50 minutes, 60 minutes, 70 minutes, 80 minutes, 90 minutes, but not limited to the listed values, and other values ​​not listed within the numerical range are also applicable) to obtain a coating material;

[0069] 4) applying the coating material on the main frame and drying at 80-160°C (for example, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, but not limited to the listed values, other values ​​not listed in the numerical range are also applicable) for 8-16h (for example, 8h, 9h, 10h, 11h, 12h, 13h, 14h, 14h, 16h, but not limited to the listed values, other values ​​not listed in the numerical range are also applicable) The same applies), and then calcined at 300-700 ° C (for example, it can be 300 ° C, 350 ° C, 400 ° C, 450 ° C, 500 ° C, 550 ° C, 600 ° C, 650 ° C, 700 ° C, but not limited to the listed values, other values ​​not listed within the numerical range are also applicable) for 3-5 h (for example, it can be 3 h, 3.5 h, 4 h, 4.5 h, 5 h, but not limited to the listed values, other values ​​not listed within the numerical range are also applicable) to obtain a highly dispersed Pt-based CO oxidation honeycomb molded catalyst.

[0070] The raw materials used in the present invention are all purchased from the market.

[0071] The technical solution of the present invention is further illustrated by the following examples.

[0072] Example 1

[0073] A method for preparing a highly dispersed Pt-based CO oxidation honeycomb catalyst, comprising the following steps:

[0074] 1) 130 g of commercial titanium dioxide powder was mixed with 20 g of an additive (wherein the additive was a mixture of sesbania powder and citric acid monohydrate in a mass ratio of 3:10) and stirred for 30 min to obtain a solid powder;

[0075] 2) Add 0.15 g of chloroplatinic acid to 180 mL of deionized water and stir for 30 min to obtain a mixed solution;

[0076] 3) adding the mixed solution from step 2) to the solid powder from step 1) at a mass ratio of 1.2:1, and stirring for 60 minutes to obtain a coating material;

[0077] 4) The coating material is coated on the main skeleton cordierite, and dried at 120° C. for 12 hours, and then calcined at 500° C. for 4 hours in a muffle furnace to obtain a highly dispersed Pt-based CO oxidation honeycomb catalyst.

[0078] Example 2

[0079] A method for preparing a highly dispersed Pt-based CO oxidation honeycomb catalyst, comprising the following steps:

[0080] 1) 100 g of commercial titanium dioxide powder was mixed with 50 g of an additive (wherein the additive was a mixture of starch and polyvinyl pyrrolidone in a mass ratio of 4:10) and stirred for 10 minutes to obtain a solid powder;

[0081] 2) Add 0.01 g of chloroplatinic acid to 100 mL of deionized water and stir for 10 min to obtain a mixed solution;

[0082] 3) adding the mixed solution from step 2) to the solid powder from step 1) at a mass ratio of 0.67:1, and stirring for 30 minutes to obtain a coating material;

[0083] 4) The coating material is coated on the main skeleton mullite, and dried at 80° C. for 8 hours, and then calcined at 300° C. for 3 hours in a muffle furnace to obtain a highly dispersed Pt-based CO oxidation honeycomb catalyst.

[0084] Example 3

[0085] A method for preparing a highly dispersed Pt-based CO oxidation honeycomb catalyst, comprising the following steps:

[0086] 1) 110 g of commercial titanium dioxide powder was mixed with 40 g of an auxiliary agent (wherein the auxiliary agent was prepared by mixing hydroxypropyl cellulose and ethylene glycol in a mass ratio of 5:10) and stirred for 20 minutes to obtain a solid powder;

[0087] 2) Add 0.05 g of chloroplatinic acid to 120 mL of deionized water and stir for 20 min to obtain a mixed solution;

[0088] 3) adding the mixed solution from step 2) to the solid powder from step 1) at a mass ratio of 0.8:1, and stirring for 40 minutes to obtain a coating material;

[0089] 4) The coating material is coated on the main skeleton corundum, dried at 90° C. for 10 hours, and then calcined at 400° C. for 3.5 hours in a muffle furnace to obtain a highly dispersed Pt-based CO oxidation honeycomb catalyst.

[0090] Example 4

[0091] A method for preparing a highly dispersed Pt-based CO oxidation honeycomb catalyst, comprising the following steps:

[0092] 1) 135 g of commercial titanium dioxide powder was mixed with 15 g of an additive (wherein the additive was a mixture of starch and polyvinyl pyrrolidone in a mass ratio of 2:10) and stirred for 50 min to obtain a solid powder;

[0093] 2) Add 0.1 g of chloroplatinic acid to 190 mL of deionized water and stir for 50 min to obtain a mixed solution;

[0094] 3) adding the mixed solution from step 2) to the solid powder from step 1) at a mass ratio of 0.79:1, and stirring for 80 minutes to obtain a coating material;

[0095] 4) The coating material is coated on the main skeleton mullite, and dried at 140° C. for 14 hours, and then calcined at 600° C. for 4.5 hours in a muffle furnace to obtain a highly dispersed Pt-based CO oxidation honeycomb catalyst.

[0096] Example 5

[0097] A method for preparing a highly dispersed Pt-based CO oxidation honeycomb catalyst, comprising the following steps:

[0098] 1) 145 g of commercial titanium dioxide powder was mixed with 5 g of an auxiliary agent (wherein the auxiliary agent was prepared by mixing hydroxypropyl cellulose and ethylene glycol in a mass ratio of 1:10) and stirred for 60 min to obtain a solid powder;

[0099] 2) Add 0.2 g of chloroplatinic acid to 200 mL of deionized water and stir for 60 min to obtain a mixed solution;

[0100] 3) adding the mixed solution from step 2) to the solid powder from step 1) at a mass ratio of 1.3:1, and stirring for 90 minutes to obtain a coating material;

[0101] 4) The coating material is coated on the main skeleton corundum, dried at 160° C. for 16 hours, and then calcined at 700° C. for 5 hours in a muffle furnace to obtain a highly dispersed Pt-based CO oxidation honeycomb catalyst.

[0102] Example 6

[0103] A method for preparing a highly dispersed Pt-based CO oxidation honeycomb catalyst, comprising the following steps:

[0104] 1) 130 g of commercial titanium dioxide powder was mixed with 20 g of an additive (wherein the additive was a mixture of starch and ethylene glycol in a mass ratio of 5:10) and stirred for 30 min to obtain a solid powder;

[0105] 2) Add 0.15 g of chloroplatinic acid to 180 mL of deionized water and stir for 30 min to obtain a mixed solution;

[0106] 3) adding the mixed solution from step 2) to the solid powder from step 1) at a mass ratio of 1.2:1, and stirring for 60 minutes to obtain a coating material;

[0107] 4) The coating material is coated on the main skeleton cordierite, and dried at 120° C. for 12 hours, and then calcined at 500° C. for 4 hours in a muffle furnace to obtain a highly dispersed Pt-based CO oxidation honeycomb catalyst.

[0108] Comparative Example 1

[0109] The same as Example 1, except that the binder sesbania powder was not added, that is, the 20 g auxiliary agent was all citric acid monohydrate, which is an organic ligand.

[0110] Comparative Example 2

[0111] The same as Example 1, except that the organic ligand monohydrated citric acid is not added, that is, the 20g auxiliary agent is all the binder sesbania powder.

[0112] Comparative Example 3

[0113] Same as Example 1, except that no commercial titanium dioxide powder was added.

[0114] Performance testing:

[0115] The catalytic performance of the highly dispersed Pt-based CO oxidation honeycomb catalysts prepared in Examples 1-6 and Comparative Examples 1-3 was tested. The test conditions included: flue gas composition: [CO] = 10000 ppm, [O2] = 16 vol%, [SO2] = 50 ppm, N2 as carrier gas, and a catalyst dosage of 100 mg; the reactor temperature was 100-400°C, the flue gas flow rate was 200 mL / min, and the maximum CO conversion rate of the catalytic CO reaction and the reaction temperature at which the maximum conversion rate was achieved were shown in Tables 1 and 2.

[0116] Table 1 Catalyst activity under SO2-free atmosphere

[0117] Maximum CO conversion rate / % Reaction temperature to achieve maximum conversion rate / ℃ Example 1 100 180 Example 2 100 230 Example 3 100 210 Example 4 100 250 Example 5 100 270 Example 6 100 250 Comparative Example 1 100 280 Comparative Example 2 100 300 Comparative Example 3 100 320

[0118] Table 2 Catalyst activity under SO2 atmosphere

[0119]

[0120]

[0121] As can be seen from Tables 1 and 2, the highly dispersed Pt-based, high-efficiency, sulfur-resistant CO oxidation honeycomb catalyst provided in Example 1 of the present invention maintains excellent CO oxidation performance in a sulfur-containing atmosphere. In an SO2-free atmosphere, the CO conversion rate reaches 100% at 180°C; in an SO2-containing atmosphere, the CO conversion rate reaches 100% at 200°C.

[0122] From the comparison of Examples 1-3, it can be seen that if the calcination temperature is too low, the Pt precursor will not be completely converted into a Pt active site; from the comparison of Example 1 and Examples 4-5, it can be seen that if the calcination temperature is too high, the titanium dioxide will be transformed from the anatase phase to the rutile phase, reducing the catalytic activity; from the comparison of Example 1 and Example 6, it can be seen that the use of sesbania powder as a binder for regulating the mechanical properties, pore structure and chemical stability of the catalyst can effectively bond the catalyst particles and leave uniform pores after the catalyst is calcined, thereby increasing the specific surface area of ​​the catalyst to expose more active sites; monohydrated citric acid can make the active components more evenly distributed on the surface of the titanium dioxide carrier, reducing the risk of sintering. After calcination, the decomposition of citric acid to produce gas easily causes the catalyst to form a mesoporous structure, thereby increasing the specific surface area and mass transfer efficiency of the catalyst.

[0123] From the comparison between Example 1 and Comparative Example 1, it can be seen that adding a binder during the catalyst preparation process can optimize the mechanical strength and molding properties of the catalyst and plays a key role in the structural stability of the catalyst;

[0124] From the comparison between Example 1 and Comparative Example 2, it can be seen that the addition of organic ligands during the catalyst preparation process can effectively regulate the dispersibility of the active component, optimize the catalyst structure, thereby enhancing the interaction between the support and the active component and improving the performance of the catalyst;

[0125] By comparing Example 1 with Comparative Example 3, it can be seen that adding titanium dioxide powder during the catalyst preparation process can significantly improve the structural stability and mechanical strength of the catalyst, so that the catalyst has excellent thermal stability, and the Ti-OH groups on the titanium dioxide surface can anchor the Pt metal particles, thereby improving the dispersion of the active components.

[0126] In summary, the present invention provides a highly dispersed Pt-based high-efficiency sulfur-poisoning-resistant CO oxidation honeycomb-shaped catalyst, which comprises a catalyst main skeleton, commercial titanium dioxide powder coated on the catalyst main skeleton, and a binder, organic ligand, and precious metal active centers doped in the commercial titanium dioxide powder for regulating the mechanical properties, pore structure, and chemical stability of the catalyst. The metal active centers include Pt. Compared with traditional CO oxidation catalysts, the highly dispersed Pt-based high-efficiency sulfur-poisoning-resistant CO oxidation honeycomb-shaped catalyst can exhibit better CO oxidation performance under complex industrial atmospheres. The use of cordierite as the catalyst main skeleton makes the catalyst suitable for high-pressure reaction environments and prevents the catalyst bed from collapsing. The addition of the binder sesbania powder and the organic ligand monohydrate citric acid significantly increases the specific surface area and pore size of the catalyst, effectively optimizing the catalyst structure. The addition of Pt active sites improves the performance of the catalyst, enabling the catalyst to meet the needs of efficient, stable, and green industrial catalysis.

[0127] The above are merely preferred embodiments of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A method for preparing a highly dispersed Pt-based CO oxidation honeycomb catalyst, characterized in that: A mixture of titanium dioxide, an additive, and a platinum source is coated on the main skeleton as a coating material, and then dried and calcined to obtain a highly dispersed Pt-based CO oxidation honeycomb catalyst. The auxiliary agent includes an organic ligand and a binder.

2. The method for preparing a highly dispersed Pt-based CO oxidation honeycomb catalyst according to claim 1, characterized in that: The main skeleton is selected from one or more of cordierite, mullite and corundum; and / or, The organic ligand is selected from one or more of citric acid monohydrate, polyvinyl pyrrolidone and ethylene glycol; and / or, The binder is selected from one or more of sesbania powder, starch and hydroxypropyl cellulose.

3. The method for preparing a highly dispersed Pt-based CO oxidation honeycomb catalyst according to claim 1 or 2, characterized in that: The specific steps include: mixing titanium dioxide with an additive to obtain a solid powder; Adding a platinum source to deionized water and stirring to obtain a mixed solution; adding the mixed solution to the solid powder and stirring to obtain a coating material; The coating material is coated on the main frame, dried, and calcined to obtain a highly dispersed Pt-based CO oxidation honeycomb catalyst.

4. The method for preparing a highly dispersed Pt-based CO oxidation honeycomb catalyst according to claim 3, characterized in that: The mass ratio of titanium dioxide to the auxiliary agent is (100-150): (5-50); The auxiliary agent comprises an organic ligand and a binder, and the mass ratio of the organic ligand and the binder is (1-5):

10.

5. The method for preparing a highly dispersed Pt-based CO oxidation honeycomb catalyst according to claim 3, characterized in that: The ratio of the platinum source to deionized water is (0.01-0.2) g: (100-200) mL; and / or, The platinum source is chloroplatinic acid.

6. The method for preparing a highly dispersed Pt-based CO oxidation honeycomb catalyst according to claim 3, characterized in that: The mass ratio of the mixed solution to the solid powder is (0.6-1.4):

1.

7. The method for preparing a highly dispersed Pt-based CO oxidation honeycomb catalyst according to claim 3, characterized in that: The specific operation steps of the drying are as follows: drying at 80-160° C. for 8-16 hours.

8. The method for preparing a highly dispersed Pt-based CO oxidation honeycomb catalyst according to claim 3, characterized in that: The specific operation steps of the calcination treatment are: calcining at 300-700°C for 3-5 hours.

9. A highly dispersed Pt-based CO oxidation honeycomb catalyst, characterized in that: The compound is prepared by the preparation method according to any one of claims 1 to 8.

10. Use of the highly dispersed Pt-based CO oxidation honeycomb catalyst according to claim 9 in catalyzing CO reaction.

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