Carbon monoxide catalyst, and preparation method therefor and use thereof

Abstract

The present invention relates to the field of catalysts, and specifically to a carbon monoxide catalyst, and a preparation method therefor and a use thereof. The carbon monoxide catalyst comprises a carrier and metal catalytic particles supported in the carrier, or the metal catalytic particles and metal oxide catalytic particles; metals in the metal catalytic particles or the metal oxide catalytic particles include a noble metal, titanium, cerium, cobalt, nickel, and molybdenum. Since the selected carrier and metals have high stability to acids, the sulfur tolerance and water tolerance of the carbon monoxide catalyst are high, so that the carbon monoxide catalyst has high catalytic stability in sintering flue gas purification. The carbon monoxide catalyst provided by the embodiment of the present invention has the catalysis principle of promoting oxidation-reduction reaction of a target gas, and thus, the carbon monoxide catalyst provided by the embodiment of the present invention can also be used for catalyzing other combustible gases such as methane, ethanol, hydrogen, and low-volatile organic compounds.

Description

Carbon monoxide catalyst and its preparation method and application Technical Field

[0001] The present invention belongs to the field of catalysts, and in particular relates to a carbon monoxide catalyst and a preparation method and application thereof. Background Art

[0002] CO is one of the most widespread and abundant pollutants in the atmosphere, posing significant risks to the environment and human health. To assess air quality, the Air Quality Index (AQI) was introduced in 2012. Six key pollutants—fine particulate matter, respirable particulate matter, sulfur dioxide, nitrogen dioxide, ozone, and carbon monoxide—are considered key indicators. The Environmental Protection Tax Law of the People's Republic of China came into effect on January 1, 2018, making CO emissions from waste gas subject to taxation. Consequently, reducing CO emissions has become a major concern. The steel industry and mobile sources are two major sources of pollution in industrial activities. Mobile source pollution treatment currently has mature CO removal technologies and extensive engineering experience, with significant results. However, the steel industry, a major source of CO emissions, lacks mature catalytic oxidation technology for CO removal.

[0003] In the steel industry, sintering and coking processes are the two main processes that generate CO, with sintering producing the largest emissions. Actual tests show that CO levels in sintering flue gas can reach as high as 6,000 to 10,000 ppm, far exceeding SO₂ and NO₂ emissions. Therefore, purifying CO from sintering flue gas is the most effective way to reduce CO emissions in the steel industry. Currently, the main end-of-pipe treatment technologies for CO in sintering flue gas used by steel companies include direct combustion, cryogenic separation, solution absorption, adsorption, and oxidation. Except for oxidation, these other technologies all have limitations, such as high ignition temperatures, difficulty in direct combustion, ineffective separation of CO and N₂, and high processing costs and energy consumption. Oxidation, on the other hand, is based on the principle of promoting the reaction of CO with O₂ in flue gas to convert it into CO₂. It has been widely acclaimed for its high purification efficiency, low operating temperature, safety, and ease of use. The catalysts widely used for CO purification in this stage are primarily precious metal and non-precious metal catalysts. CO catalysts containing precious metals offer a certain degree of water resistance, excellent catalytic activity, and stability, but are expensive. Non-precious metal CO catalysts, primarily hopcalite, are composed of transition metals and form a multi-metal oxide system. They offer advantages such as high purification efficiency, long service life, wide application, safety, ease of operation, and low cost. However, after desulfurization treatment of sintering flue gas, trace amounts of SO₂ remain. This residual SO₂ can poison the catalyst, reducing purification efficiency. Regeneration requires a high-temperature environment, significantly increasing costs. Summary of the Invention

[0004] To address the above-mentioned issues, the present invention provides a carbon monoxide catalyst, its preparation method, and its application for purifying carbon monoxide from industrial sintering flue gas. The carbon monoxide catalyst exhibits advantages such as sulfur and water resistance. The method adjusts the active components in the carbon monoxide catalyst to promote the synergistic effect of these components. The resulting carbon monoxide catalyst exhibits stable catalytic properties and a prolonged service life.

[0005] The present invention is achieved through the following technical solutions:

[0006] One of the objects of the present invention is to provide a carbon monoxide catalyst, which comprises a carrier and metal catalytic particles supported in the carrier; or metal catalytic particles and metal oxide catalytic particles;

[0007] The metal in the metal catalytic particles or metal oxide catalytic particles includes noble metals, titanium, cerium, cobalt, nickel and molybdenum.

[0008] One of the purposes of the present invention is to provide a carbon monoxide catalyst, wherein the carrier is used to support metal particles, thereby increasing the surface area and active sites of the catalyst; the metal catalytic particles and the metal oxide catalytic particles are both used to catalyze carbon monoxide to produce environmentally friendly compounds. The precious metal is used to reduce the activation energy of carbon monoxide oxidation, thereby catalyzing oxidation; the titanium is used to improve the stability of the precious metal catalyst; and the cerium, cobalt, nickel, and molybdenum are used to improve the precious metal's resistance to poisoning. Due to the high acid stability of the selected carrier and metal, the carbon monoxide catalyst has high sulfur and water resistance, resulting in high catalytic stability in sintering flue gas purification. The carbon monoxide catalyst has high activity and a suitable temperature range, starting catalytic oxidation at 120°C and achieving a catalytic efficiency of over 90% at 220°C.

[0009] Furthermore, the carbon monoxide catalyst has a particle size range of 50 nm to 200 nm. Within this particle size range, the carbon monoxide catalyst can catalytically purify CO in sintering flue gas without poisoning. Furthermore, the nanoscale carbon monoxide catalyst, due to its support, has a high carbon monoxide adsorption capacity and is less likely to agglomerate during the catalytic process.

[0010] Furthermore, the loading amount of the metal catalytic particles is: 90 kg / m 3 ~150kg / m 3 Within this metal loading range, the carbon monoxide catalyst has a high adsorption capacity for carbon monoxide and is not prone to agglomeration during the catalytic process.

[0011] Furthermore, the loading amount of the metal oxide particles is: 90 kg / m 3 ~150kg / m 3 Within this metal loading range, the carbon monoxide catalyst has a high adsorption capacity for carbon monoxide and is not prone to agglomeration during the catalytic process.

[0012] Furthermore, the particle size of the metal catalytic particles ranges from 1 nm to 100 nm. Within this particle size range, the size of the metal catalytic particles can be controlled at the nanometer level, enabling highly uniform dispersion on the support. This allows the metal catalytic particles to be well supported on the support, and the resulting catalyst can maintain stable high catalytic efficiency even under the complex conditions of sintering flue gas.

[0013] Furthermore, the metal oxide catalytic particles have a particle size range of 1 nm to 100 nm. Within this particle size range, the metal oxide catalytic particles are nanometer-sized, enabling highly uniform dispersion on the support. This allows the metal oxide catalytic particles to be well supported on the support, and the resulting catalyst can maintain stable high catalytic efficiency even under the complex conditions of sintering flue gas.

[0014] Furthermore, the noble metal includes one or more of gold, silver, ruthenium, rhodium, palladium, osmium, iridium, and platinum. These noble metals are active components for catalyzing carbon monoxide and can effectively catalyze carbon monoxide.

[0015] Furthermore, the carrier includes one or more of cordierite, honeycomb ceramics, glass fiber, porous carbon material, and hierarchical porous carbon material.

[0016] Furthermore, the mass fractions of the metal elements in the carbon monoxide catalyst include: 0.5% to 1.0% of precious metals, 0.5% to 1.0% of titanium, 0.5% to 1.0% of cerium, 0.5% to 1.0% of cobalt, 0.5% to 1.0% of nickel, and 0.5% to 1.0% of molybdenum.

[0017] A second object of the present invention is to provide a method for preparing a carbon monoxide catalyst, the method comprising the following steps:

[0018] A first powder is prepared by using a first noble metal salt solution, a cerium nitrate solution and a first titanium dioxide suspension;

[0019] preparing a second powder by using a first cobalt salt solution, a first metal ammonium salt solution, and a first carbonate solution;

[0020] preparing a catalytic particle aqueous solution by using the first powder and the second powder;

[0021] The carbon monoxide catalyst is prepared by using the catalytic particle aqueous solution, the first binder solution, the first thickener solution, the first dispersant solution and the water retaining agent.

[0022] A second objective of the present invention is to provide a method for preparing a carbon monoxide catalyst. The method includes first preparing an aqueous solution of catalytic particles, then mixing it with a first loading slurry. The first loading slurry is then combined with a first carrier to prepare the carbon monoxide catalyst. Preparing the aqueous solution of catalytic particles first can reduce the molecular distance between catalytically active components (metal catalytic particles, metal oxide catalytic particles), allowing for more active sites for catalysis under the same conditions. Furthermore, while maintaining the same catalytic effect, the loading amount of the first carrier can be reduced, and the catalytically active components can be evenly distributed on the carrier, ultimately resulting in a larger specific surface area and loading strength for the carbon monoxide catalyst. The catalyst is then formulated into a first loading slurry, subjected to a first loading treatment with the first carrier, and then calcined to load the catalytic particles onto the first carrier.

[0023] The metal elements in the catalytic particles prepared by the method for preparing the carbon monoxide catalyst provided by the second object of the present invention include: noble metal elements, cerium elements and titanium elements.

[0024] Furthermore, the step of preparing the first powder includes: performing a first mixing process on a first precious metal salt solution, a cerium nitrate solution, and a first titanium dioxide suspension to obtain a first mixed solution; and performing a first drying process and a first calcination process on the first mixed solution to obtain the first powder. In this case, the first powder is prepared to reduce the molecular distance between the catalytically active components (metal catalytic particles and metal oxide catalytic particles) in the first powder.

[0025] Furthermore, in the first noble metal salt solution, the noble metal salt includes one or more of nitrates, chlorates, and chlorides of gold, silver, ruthenium, rhodium, palladium, osmium, iridium, and platinum. These noble metal salts are easily soluble in water to form a homogeneous aqueous solution.

[0026] Furthermore, in the first noble metal salt solution, the noble metal salt concentration is 10 g / L to 15 g / L. Within this concentration range, stable catalytic efficiency and production cost can be taken into account.

[0027] Furthermore, the method for preparing the first noble metal salt solution includes the steps of: mixing a noble metal salt and water in a specified mass ratio to obtain the first noble metal salt solution.

[0028] Furthermore, the molar concentration of the cerium nitrate solution is 0.5 mol / L to 1.0 mol / L. In this case, the cerium nitrate is selected because the nitrate ions are easily removed during calcination by generating nitrogen oxide gas. Within this cerium nitrate concentration range, the cerium nitrate is well dispersed in the first mixed solution while ensuring complete dissolution.

[0029] Furthermore, the preparation method of the first titanium dioxide suspension includes the steps of: pre-treating the first titanium dioxide and mixing it with water and stirring to obtain the first titanium dioxide suspension.

[0030] Furthermore, the titanium dioxide content in the first titanium dioxide suspension is 500 g / L to 800 g / L. Within this content range, the titanium dioxide can encapsulate the precious metal ions, reducing the distribution of the precious metal ions in the aqueous phase, improving the coating efficiency, and ensuring the overall catalytic performance of the catalyst.

[0031] Furthermore, the first mixing step includes:

[0032] After stirring the first titanium dioxide suspension for 30 minutes to 45 minutes at a temperature of 25° C. to 60° C., the first precious metal salt solution and the cerium nitrate solution are added to the first titanium dioxide suspension while stirring to obtain the first mixed solution; wherein the adding method includes dropwise addition.

[0033] Furthermore, the first drying treatment step includes: stirring the first mixed liquid for 5 hours to 10 hours, and then drying it at 120° C. to 130° C. for 10 hours to 12 hours.

[0034] Furthermore, in the first drying step, drying is performed in a blast drying oven.

[0035] Furthermore, the first calcination step includes: grinding the first mixture after the first drying treatment into powder, heating it to 500°C~600°C at a heating rate of 3°C / min~5°C / min and calcining it for 1.5h~2h, and then cooling it to room temperature to obtain the first powder.

[0036] Furthermore, in the first calcination step, the first mixture is ground into powder using an agate mortar.

[0037] Furthermore, in the first calcination step, the powdered first mixture is calcined in a muffle furnace.

[0038] Furthermore, the step of preparing the second powder includes: subjecting the first cobalt salt solution, the first metal ammonium salt solution, and the first carbonate solution to a second mixing process to obtain a second mixed liquid; and subjecting the second mixed liquid to a second drying process and a second calcination process to obtain the second powder. In this case, the second powder is prepared to reduce the molecular distance between the catalytically active components (metal catalytic particles and metal oxide catalytic particles) in the second powder.

[0039] Furthermore, the concentration of cobalt ions in the first cobalt salt solution is 0.02 g / L to 0.10 g / L. Within this concentration range, cobalt ions have good dispersibility.

[0040] Furthermore, the first cobalt salt solution includes an organic acid cobalt salt solution, which includes at least one of a cobalt acetate solution, a cobalt formate solution, and a cobalt oxalate solution. These cobalt salt solutions can improve the catalyst's resistance to poisoning while not introducing other impurities.

[0041] Furthermore, in the first metal ammonium salt solution, the mass fraction of the first metal ammonium salt is 0.1% to 0.5%. Within this mass fraction range, the first metal ammonium salt can have good dispersibility.

[0042] Furthermore, the preparation method of the first metal ammonium salt solution includes: mixing the first metal ammonium salt with water, and stirring for at least 30 minutes to obtain the first metal ammonium salt solution.

[0043] Furthermore, the metal ammonium salt in the first metal ammonium salt solution includes at least one of ammonium molybdate, ammonium tungstate, and ammonium metavanadate. In this case, the metal element in the catalytic particles produced by the method for producing a carbon monoxide catalyst provided in the second objective of the present invention also includes at least one of molybdenum, tungsten, and vanadium.

[0044] Furthermore, the first carbonate solution has a concentration of 1 mol / L to 1.5 mol / L. Within this concentration range, carbonate has good dispersibility and stability.

[0045] Furthermore, in the first carbonate solution, the carbonate includes one or more of sodium carbonate, potassium carbonate, and lithium carbonate.

[0046] Furthermore, the second mixing treatment step includes: mixing the first cobalt salt solution and the first metal ammonium salt solution, and then dropwise adding the first carbonate solution until the pH reaches 10 to obtain a suspension;

[0047] The suspension was stirred for 3 to 4 hours, and then allowed to stand for aging for more than 2 hours. The suspension was then filtered and the filtrate was washed until neutral to obtain a paste.

[0048] Furthermore, the second drying step includes drying the paste at a temperature of 120° C. to 130° C. for 9 h to 10 h.

[0049] Furthermore, in the second drying step, the paste is dried in a drying oven.

[0050] Furthermore, the second calcination step includes: heating the paste after the second drying treatment to 400°C~500°C in an air atmosphere at a heating rate of 3°C / min~5°C / min, calcining for 2h~3h, and cooling to room temperature to obtain the second powder.

[0051] Furthermore, the mass ratio of the first powder to the second powder is 6:(1-2). Within this mass ratio range, the catalytic performance of the precious metal can be maximized.

[0052] Furthermore, the steps of preparing the catalytic particle aqueous solution include: mixing the first and second powders, performing a first ball milling process, performing a third drying process, and then performing a third calcination process, and then grinding and screening to obtain catalytic particles; and mixing the catalytic particles with water to obtain the catalytic particle aqueous solution. In this case, ball milling the first and second powders can further reduce the molecular distance between the catalytic particles and increase the loading capacity of the catalytic particles.

[0053] Furthermore, the step of mixing the first powder and the second powder includes: mixing the first powder, the second powder and deionized water to obtain a powder mixture.

[0054] Furthermore, the first ball milling treatment includes the steps of: ball milling the powder mixture clockwise for 60 min to 80 min and counterclockwise for 60 min to 80 min at a rotation speed of 400 r / min to obtain a ball-milled product.

[0055] Furthermore, in the first ball milling process, the particle size of the grinding balls is not higher than 1 mm. Furthermore, in the first ball milling process, the particle size of the grinding balls is not higher than 1 mm. Furthermore, in the first ball milling process, the grinding balls include at least one of zirconia balls, alumina balls, and agate balls. Furthermore, in the first ball milling process, the ball milling temperature is 25°C to 30°C. In this case, the particle size of the product obtained after ball milling the first powder and the second powder is nanometer-scale, and after subsequent drying, calcination, and further grinding, dry nanometer-scale catalytic particles (1nm to 100nm) can be obtained.

[0056] Furthermore, the third drying treatment step includes: drying the ball-milled material at 120° C. to 130° C. for 10 h to 12 h.

[0057] Furthermore, the third calcination treatment step includes: calcining at 400° C. to 500° C. for 1 hour to 2 hours.

[0058] Furthermore, the step of preparing the carbon monoxide catalyst includes: performing a third mixing treatment using the catalytic particle aqueous solution, the first binder solution, the first thickener solution, the first dispersant solution and the water retaining agent to obtain a first loaded slurry; performing a first loading treatment on the first loaded slurry and the first carrier, and then performing a fourth calcination treatment to obtain the carbon monoxide catalyst.

[0059] Furthermore, the mass ratio of the aqueous solution of catalytic particles, the first binder solution, the first thickener solution, the first dispersant solution, and the water-retaining agent is: (1-5): (0.5-4): (0.5-3): (0.5-2): 1. Within this mass ratio range, the slurry is more stable, thereby improving the loading amount, loading uniformity, and mechanical stability of the catalyst active components.

[0060] Furthermore, in the aqueous solution of the catalytic particles, the mass ratio of the catalytic particles to water is 1:(0.3-3). Within this mass ratio range, the catalytic particles can be uniformly dispersed in the first loading slurry.

[0061] Furthermore, the mesh size of the catalytic particles is 20 to 40. Within this mesh size range, the catalyst has a large specific surface area and good mechanical stability.

[0062] Furthermore, in the first binder solution, the mass fraction of the first binder is 1% to 15%. Within this mass fraction range, the binder can be well dispersed in the first loading slurry.

[0063] Furthermore, the first binder includes one or more of calcium silicate, sodium silicate, calcium aluminate, phenolic resin, diatomaceous earth, aluminum sol, silica sol, kaolin, attapulgite, sodium silicate, bentonite, montmorillonite, and pseudo-boehmite.

[0064] Furthermore, the method for preparing the first binder solution includes the following steps: mixing a specified amount of the first binder with water and stirring for at least 30 minutes to obtain the first binder solution; preparing a binder solution having a mass fraction of 1% to 15% using deionized water as the solvent, and stirring at 100 to 150 rpm for 30 minutes before adding the binder solution. This speed and stirring time ensures that the binder and deionized water are thoroughly mixed and dispersed in the first load slurry.

[0065] Furthermore, in the first thickener solution, the mass fraction of the first thickener is 1% to 20%. Within this mass fraction range, the first thickener can be well dispersed in the first loading slurry.

[0066] Furthermore, the first thickener includes one or more of hydroxymethyl cellulose, hydroxymethylpropyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, hydroxyethyl methyl cellulose, cellulose ether, and starch.

[0067] Furthermore, the method for preparing the first thickener solution comprises the steps of: mixing a specified amount of the first thickener with water, and stirring for at least 30 minutes to obtain the first thickener solution.

[0068] Furthermore, in the first dispersant solution, the mass fraction of the first dispersant is 1% to 20%, and the mass fraction of water is 80% to 99%. Within this mass fraction range, the dispersant can be well dispersed in the first loading slurry.

[0069] Furthermore, the first dispersant includes one or more of polyacrylic acid, polypropylene, polystyrene, polyethylene wax, polyethylene ether, polyethylene ester, polyvinyl acetate, polyethylene, polyacrylamide, sodium polyacrylate, polyethylene glycol, and polyvinyl alcohol.

[0070] Furthermore, the water-retaining agent includes one or more of glycerol, lignin, sodium alginate, polyacrylamide, sodium polyacrylate, potassium polyacrylate and ammonium polyacrylate.

[0071] Furthermore, the third mixing treatment step includes: first mixing and stirring the first binder solution and the first dispersant solution according to a specified ratio, adding the catalytic particle aqueous solution and stirring, adding the first thickener solution and the water-retaining agent and stirring, and finally adjusting the pH value to 4-10 to obtain the first loaded slurry. The first binder and the first dispersant are mixed first to ensure that the two are fully mixed and evenly mixed. The addition of the catalytic particle aqueous solution allows the catalyst particles to be evenly dispersed therein under the action of the first dispersant. The final addition of the water-retaining agent is to retain water after the slurry is stabilized. The addition of the thickener after the catalytic particles and before the water-retaining agent allows the catalytic particles to be evenly dispersed in the loaded slurry, while also allowing the thickener itself to be evenly dispersed in the loaded slurry. Therefore, preparing in this order can improve the loading amount, loading uniformity, and mechanical stability of the catalyst active component in the first carrier.

[0072] Furthermore, the first binder solution and the first dispersant solution are mixed and stirred at a stirring rate of 50 r / min to 400 r / min for 1 to 2 hours. At this stirring rate and time, the first binder solution and the first dispersant solution are evenly mixed to form a homogeneous solution.

[0073] Furthermore, the stirring rate of the aqueous solution containing the catalytic particles is 50 r / min to 400 r / min, and the stirring time is 0.5 h to 1 h. Under this stirring rate and stirring time, the catalytic particles can be evenly dispersed, thereby improving the catalytic stability.

[0074] Furthermore, the first thickener solution and the water-retaining agent are stirred at a stirring rate of 50 to 400 r / min for 2 to 3 hours. This stirring rate and time ensure uniform mixing of all components in the first loading slurry (the first binder, the first dispersant, the first catalytic particles, the first thickener, and the water-retaining agent).

[0075] Furthermore, the first loading treatment step includes applying the first loading slurry to the pretreated first carrier using a vacuum coating machine, and applying the second loading slurry to the second carrier using a coating method. Vacuum coating can increase coating strength, control loading amount, and avoid excessive slurry waste.

[0076] Furthermore, the first carrier is one or more of cordierite, honeycomb ceramics, glass fiber, porous carbon material, and hierarchical porous carbon material.

[0077] Furthermore, the fourth calcination step includes drying the slurry obtained from the first loading treatment at 90°C to 110°C for 12 to 14 hours until the dehydration rate of the slurry is no less than 90%, then heating the slurry to 350°C to 400°C at a heating rate of 2°C / min to 32°C / min and calcining the slurry for 1.5 to 2 hours to obtain the carbon monoxide catalyst. In this case, the slurry is first dried at low temperature and then calcined at high temperature, resulting in a carbon monoxide catalyst with a smooth surface and no cracks.

[0078] The third object of the present invention is to provide a carbon monoxide catalyst provided by the first object of the present invention or a carbon monoxide catalyst prepared by the preparation method provided by the second object of the present invention, and its application in the field of removing carbon monoxide pollutants. BRIEF DESCRIPTION OF THE DRAWINGS

[0079] FIG1 is a schematic flow chart of a method for preparing a carbon monoxide catalyst according to an embodiment of the present invention;

[0080] FIG2 is a schematic flow chart of another method for preparing a carbon monoxide catalyst according to an embodiment of the present invention;

[0081] FIG3 is a schematic diagram of a carbon monoxide adsorption experimental apparatus for the catalysts involved in the Examples and Comparative Examples of the present invention;

[0082] FIG4 is a schematic diagram of the catalytic efficiency of carbon monoxide catalysts prepared in Examples 1 to 6 according to the present invention;

[0083] FIG5 is a schematic diagram of the catalytic efficiency of carbon monoxide catalysts prepared by another preparation method in Examples 7 to 11 of the present invention. DETAILED DESCRIPTION

[0084] In order to make the purpose, technical solutions and advantages of the present invention clearer, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0085] On the contrary, the present invention covers any alternatives, modifications, equivalents, and solutions that fall within the spirit and scope of the present invention as defined by the claims. Furthermore, to facilitate a better understanding of the present invention, certain specific details are described in detail below in the detailed description of the present invention. Those skilled in the art will be able to fully understand the present invention without these details.

[0086] The following examples serve to illustrate the present invention. In the examples, unless otherwise indicated, parts are by weight, percentages are by weight, and temperatures are in degrees Celsius. The relationship between parts by weight and parts by volume is the same as the relationship between grams and cubic centimeters.

[0087] Catalytic oxidation is one of the most effective methods for removing CO. Supported platinum group noble metal catalysts have good catalytic activity for CO oxidation. Currently, research on supported platinum and other noble metal catalysts has focused on improving low-temperature catalytic activity by adjusting the particle size of the noble metal particles, improving the dispersion of the catalyst support on the noble metal, using additives to change the electronic state of the noble metal metal and adjusting the local structural effect of the active site.

[0088] Preparation method is a significant factor influencing catalyst performance. The key to improving the catalytic performance of supported catalysts lies in adjusting the size of the supported catalyst. The method of pre-proportioning significantly influences the catalyst morphology. The preparation method also influences the dispersion of the precious metal particles within the support, which is crucial for achieving high catalytic activity.

[0089] Based on the above, embodiments of the present invention provide a carbon monoxide catalyst, preparation method, and application thereof. The carbon monoxide catalyst exhibits high activity and a wide temperature range, starting catalytic oxidation at 120°C and achieving catalytic efficiency exceeding 90% at 220°C. The carbon monoxide catalyst prepared using an impregnation-reduction method has a higher concentration of negatively charged precious metals and exhibits optimal catalytic activity.

[0090] The specific plan is as follows:

[0091]

Carbon monoxide catalyst

[0092] One of the purposes of the embodiments of the present invention is to provide a carbon monoxide catalyst, the catalyst comprising a carrier and metal catalytic particles supported in the carrier; or metal catalytic particles and metal oxide catalytic particles;

[0093] The metals in the metal catalytic particles or metal oxide catalytic particles include noble metals, titanium, cerium, cobalt, nickel and molybdenum.

[0094] The carbon monoxide catalyst provided by the embodiment of the present invention comprises a carrier for supporting metal particles to increase the surface area and active sites of the catalyst; both the metal catalytic particles and the metal oxide catalytic particles are used to catalyze carbon monoxide to produce environmentally friendly compounds. Precious metals are used to reduce the activation energy of carbon monoxide oxidation, thereby catalyzing oxidation; titanium is used to improve the stability of precious metal catalysis; and cerium, cobalt, nickel, and molybdenum are used to improve the precious metal's resistance to poisoning. Due to the high acid stability of the selected carrier and metal, the carbon monoxide catalyst has high sulfur and water resistance, resulting in high catalytic stability in sintering flue gas purification. The carbon monoxide catalyst has high activity and a temperature applicable range, starting catalytic oxidation at 120°C, and the catalytic efficiency at 220°C can reach over 90%.

[0095] In the embodiment, the carbon monoxide catalyst provided by the embodiment of the present invention promotes the catalytic principle of the redox reaction of the target gas. Therefore, the carbon monoxide catalyst provided by the embodiment of the present invention can also be used for the catalysis of other combustible gases such as methane, ethanol, hydrogen, and low-volatile organic compounds.

[0096] In some embodiments, the loading amount of the metal catalytic particles is: 90 kg / m 3 ~150kg / m 3 In this metal loading range, the catalyst has a high adsorption capacity for carbon monoxide and is not prone to agglomeration during the catalytic process. For example, the loading of the metal catalytic particles can be 90 kg / m 3 , 100kg / m 3 、110kg / m 3 , 120kg / m 3 、130kg / m 3 、140kg / m 3 、150kg / m 3 Typical but non-limiting loads or ranges between any two loads.

[0097] In some embodiments, the particle size of the metal catalytic particles ranges from 1 nm to 100 nm. Within this particle size range, the catalyst exhibits optimal catalytic efficiency and stability. For example, the particle size of the metal catalytic particles can be 1 nm, 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, or any other typical but non-limiting particle size, or a range between any two particle sizes.

[0098] In some embodiments, the loading of metal oxide particles is: 90 kg / m 3 ~150kg / m 3 In this metal loading range, the catalyst has a high adsorption capacity for carbon monoxide and is not prone to agglomeration during the catalytic process. For example, the loading of metal oxide particles can be 90 kg / m 3 , 100kg / m 3 、110kg / m 3 , 120kg / m 3 、130kg / m 3 、140kg / m 3 、150kg / m 3 Typical but non-limiting loads or ranges between any two loads.

[0099] In some embodiments, the particle size of the metal oxide catalytic particles ranges from 1 nm to 100 nm. Within this particle size range, the catalytic efficiency and loading stability of the catalyst are optimal. For example, the particle size of the metal oxide catalytic particles can be 1 nm, 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, or other typical but non-limiting particle sizes, or a range between any two particle sizes.

[0100] In some embodiments, the noble metal includes one or more of gold, silver, ruthenium, rhodium, palladium, osmium, iridium, and platinum. These noble metals are active components for catalyzing carbon monoxide and can effectively catalyze carbon monoxide.

[0101] In some embodiments, the support includes one or more of cordierite, honeycomb ceramics, glass fiber, porous carbon material, and hierarchical porous carbon material.

[0102] In some embodiments, the mass fraction of each metal element in the carbon monoxide catalyst includes: 0.5% to 1.0% of precious metals, 0.5% to 1.0% of titanium, 0.5% to 1.0% of cerium, 0.5% to 1.0% of cobalt, 0.5% to 1.0% of nickel, and 0.5% to 1.0% of molybdenum. For example, the mass fraction of the precious metal can be 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, or other typical but non-limiting mass fractions or a range between any two mass fractions; the mass fraction of titanium can be 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, or other typical but non-limiting mass fractions or a range between any two mass fractions; the mass fraction of cerium can be 0.5%. The mass fractions of cobalt can be 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, or any other typical but non-limiting mass fractions, or a range between any two mass fractions; the mass fraction of nickel can be 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, or any other typical but non-limiting mass fractions, or a range between any two mass fractions; and the mass fraction of molybdenum can be 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, or any other typical but non-limiting mass fractions, or a range between any two mass fractions. Within this mass fraction range, the carbon monoxide catalyst exhibits high sulfur and water tolerance, resulting in high catalytic stability in sintering flue gas purification. The carbon monoxide catalyst has a high activity and temperature range, starting catalytic oxidation at 120°C and achieving a catalytic efficiency exceeding 90% at 220°C.

[0103]

The first preparation method of carbon monoxide catalyst

[0104] A second object of the present invention is to provide a method for preparing a carbon monoxide catalyst. As shown in FIG1 , the method comprises the following steps:

[0105] S1. Prepare a first powder by using a first noble metal salt solution, a cerium nitrate solution and a first titanium dioxide suspension.

[0106] S2. Prepare a second powder using a first cobalt salt solution, a first metal ammonium salt solution, and a first carbonate solution.

[0107] S3. Prepare a catalytic particle aqueous solution using the first powder and the second powder.

[0108] S4. Prepare a carbon monoxide catalyst using an aqueous solution of catalytic particles, a first binder solution, a first thickener solution, a first dispersant solution, and a water retaining agent.

[0109] The second purpose of the embodiment of the present invention provides a method for preparing a carbon monoxide catalyst, which comprises first preparing an aqueous solution of catalytic particles, and then mixing the aqueous solution with a first loading slurry, and then mixing the first loading slurry with a first carrier to prepare a carbon monoxide catalyst. Preparing the catalytic particles first can reduce the molecular distance between the catalytically active components (metal catalytic particles, metal oxide catalytic particles), so that more active sites can be catalyzed under the same conditions; and, under the premise of the same catalytic effect, the loading amount of the first carrier can be reduced, and the catalytically active components can be evenly distributed on the carrier, ultimately allowing the carbon monoxide catalyst to have a larger specific surface area and loading strength; the catalyst is formulated into a first loading slurry, and the first carrier is subjected to a first loading treatment and then calcined, so that the catalytic particles are loaded on the first carrier. Wherein, the catalytic particles are metal catalytic particles; or, metal catalytic particles and metal oxide catalytic particles.

[0110] The metal elements in the catalytic particles prepared by the method for preparing a carbon monoxide catalyst provided in the second embodiment of the present invention include: noble metal elements, cerium elements and titanium elements.

[0111] [S1] In some embodiments, in step S1 above, the step of preparing the first powder includes: performing a first mixing process on a first precious metal salt solution, a cerium nitrate solution, and a first titanium dioxide suspension to obtain a first mixed solution; and performing a first drying process and a first calcination process on the first mixed solution to obtain a first powder. In this case, the first powder is prepared to reduce the molecular distance between catalytically active components (metal catalytic particles and metal oxide catalytic particles) in the first powder.

[0112] In some embodiments, the first precious metal salt solution comprises one or more of nitrates, chlorates, and chlorides of gold, silver, ruthenium, rhodium, palladium, osmium, iridium, and platinum. These precious metal salts are readily soluble in water to form a homogeneous aqueous solution. These precious metal salts are readily soluble in water to form a homogeneous aqueous solution.

[0113] In some embodiments, the first precious metal salt solution has a precious metal salt concentration of 10 g / L to 15 g / L. Within this concentration range, stable catalytic efficiency and production cost can be balanced. For example, the concentration of the precious metal salt can be 10 g / L, 11 g / L, 12 g / L, 13 g / L, 14 g / L, 15 g / L, or other typical but non-limiting concentrations, or a range between any two concentrations. Within this concentration range, stable catalytic efficiency and production cost can be balanced.

[0114] In some specific embodiments, the method for preparing the first noble metal salt solution includes the steps of: mixing a noble metal salt and water in a specified mass ratio to obtain the first noble metal salt solution.

[0115] In some embodiments, in step S1 above, the molar concentration of the cerium nitrate solution is 0.5 mol / L to 1.0 mol / L. In this case, a nitrate of cerium is selected, and nitrate radicals are easily roasted to generate nitrogen oxide gas and removed during roasting. Under this cerium nitrate concentration range, while ensuring that the cerium nitrate is completely dissolved, the cerium nitrate has good dispersibility in the first mixed solution. Exemplarily, the molar concentration of the cerium nitrate solution can be a typical but non-restrictive molar concentration such as 0.5 mol / L, 0.6 mol / L, 0.7 mol / L, 0.8 mol / L, 0.9 mol / L, 1.0 mol / L, or a range between any two molar concentrations.

[0116] In some embodiments, in the above step S1, the method for preparing the first titanium dioxide suspension includes the steps of: pre-treating the first titanium dioxide and mixing it with water to obtain the first titanium dioxide suspension.

[0117] In some specific embodiments, the step of pretreating titanium dioxide includes: heating to 700°C~800°C at a heating rate of 3°C / min~°C / min under air atmosphere, and calcining for 3h~4h to obtain pretreated titanium dioxide.

[0118] In some specific embodiments, a muffle furnace is used to perform calcination pretreatment on titanium dioxide.

[0119] In some embodiments, in step S1 above, the first titanium dioxide content in the first titanium dioxide suspension is 500 g / L to 800 g / L. Within this content range, the titanium dioxide can encapsulate the precious metal ions, reducing the distribution of the precious metal ions in the aqueous phase, improving the coating efficiency, and ensuring the overall catalytic performance of the catalyst. For example, the first titanium dioxide content in the first titanium dioxide suspension can be 500 g / L, 600 g / L, 700 g / L, 800 g / L, or other typical but non-limiting contents, or a range between any two contents.

[0120] In some embodiments, the first mixing process step includes:

[0121] At a temperature of 25°C to 60°C, the first titanium dioxide suspension is stirred for 30 minutes to 45 minutes, and then the first precious metal salt solution and the cerium nitrate solution are added to the first titanium dioxide suspension while stirring to obtain a first mixed solution; wherein the adding method includes dropwise addition.

[0122] In some embodiments, the first drying step includes: stirring the first mixed solution for 5 hours to 10 hours, and then drying the mixed solution at 120° C. to 130° C. for 10 hours to 12 hours.

[0123] In some specific embodiments, in the first drying step, drying is performed in a forced air drying oven.

[0124] In some embodiments, the first calcination step includes: grinding the first mixture after the first drying treatment into powder, heating it to 500°C~600°C at a heating rate of 3°C / min~5°C / min and calcining it for 1.5h~2h, and then cooling it to room temperature to obtain a first powder.

[0125] In some specific embodiments, during the first calcining step, the first mixture is ground into powder using an agate mortar.

[0126] In some specific embodiments, in the first calcination step, the powdered first mixture is calcined in a muffle furnace.

[0127] [S2] In some embodiments, in step S2 above, preparing the second powder includes: subjecting the first cobalt salt solution, the first metal ammonium salt solution, and the first carbonate solution to a second mixing process to obtain a second mixed solution; and subjecting the second mixed solution to a second drying process and a second calcination process to obtain a second powder. In this case, the second powder is prepared to reduce the molecular distance between the catalytically active components (metal catalytic particles and metal oxide catalytic particles) in the second powder.

[0128] In some embodiments, in step S2, the concentration of cobalt ions in the first cobalt salt solution is 0.02 g / L to 0.10 g / L. Within this concentration range, the cobalt ions have good dispersibility.

[0129] In some specific embodiments, the first cobalt salt solution includes an organic acid cobalt salt solution, which includes at least one of a cobalt acetate solution, a cobalt formate solution, and a cobalt oxalate solution. These cobalt salt solutions can improve the catalyst's resistance to poisoning while not introducing other impurities.

[0130] In some specific embodiments, the method for preparing the cobalt acetate solution comprises the steps of:

[0131] The mass and / or volume of cobalt acetate and solvent are obtained according to the concentration of the cobalt acetate solution; wherein the solvent includes anhydrous ethanol and deionized water; the deionized water and anhydrous ethanol are combined to increase the solubility and dissolution dispersion of cobalt acetate, facilitate the reaction of cobalt acetate with alkali, and make it easier to wash after precipitation.

[0132] Cobalt acetate and anhydrous ethanol are mixed, and then mixed with deionized water to obtain a cobalt acetate solution.

[0133] In some embodiments, in step S2, the mass fraction of the first metal ammonium salt in the first metal ammonium salt solution is 0.1% to 0.5%. Within this mass fraction range, the first metal ammonium salt can have good dispersibility. Exemplarily, the mass fraction of the first metal ammonium salt can be 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, or other typical but non-limiting mass fractions, or a range between any two mass fractions.

[0134] In some specific embodiments, the preparation method of the first metal ammonium salt solution includes: mixing the first metal ammonium salt with water, and stirring for at least 30 minutes to obtain the first metal ammonium salt solution.

[0135] In some specific embodiments, the metal ammonium salt in the first metal ammonium salt solution includes one or more of ammonium molybdate, ammonium tungstate, and ammonium metavanadate. In this case, the metal element in the catalytic particles produced by the method for producing a carbon monoxide catalyst provided in the second objective of the present invention further includes at least one of molybdenum, tungsten, and vanadium.

[0136] In some embodiments, in step S2, the first carbonate solution has a concentration of 1 mol / L to 1.5 mol / L. Within this concentration range, the carbonate has good dispersibility and stability. For example, the first carbonate solution may have a concentration of 1 mol / L, 2 mol / L, 3 mol / L, 4 mol / L, 5 mol / L, or any other typical but non-limiting concentration, or a range between any two concentrations.

[0137] In some specific embodiments, in the carbonate solution, the carbonate includes one or more of sodium carbonate, potassium carbonate, and lithium carbonate.

[0138] In some embodiments, in the above step S2, the second mixing treatment step includes: mixing the first cobalt salt solution and the first metal ammonium salt solution, and then adding a carbonate solution dropwise until the pH reaches 10 to obtain a suspension;

[0139] The suspension was stirred for 3 to 4 hours, allowed to stand for aging for more than 2 hours, filtered, and the filtrate was washed until neutral to obtain a paste.

[0140] In some embodiments, in the above step S2, the second drying step includes: drying the paste at a temperature of 120°C to 130°C for 9h to 10h.

[0141] In some specific embodiments, in the second drying step, a drying oven is used to dry the paste.

[0142] In some embodiments, in the above step S2, the second calcination treatment step includes: heating the paste after the second drying treatment to 400°C~500°C in an air atmosphere at a heating rate of 3°C / min~5°C / min, calcining for 2h~3h, and then cooling to room temperature to obtain a second powder.

[0143] [S3] In some embodiments, in step S3 above, preparing the catalytic particle aqueous solution includes: mixing the first and second powders, performing a first ball milling process, performing a third drying process, and then performing a third calcination process, and grinding and screening to obtain catalytic particles; and mixing the catalytic particles with water to obtain the catalytic particle aqueous solution. In this case, ball milling the first and second powders can further reduce the molecular distance between the catalytic particles and increase the loading of the catalytic particles.

[0144] In some embodiments, in step S3, the mass ratio of the first powder to the second powder is 6:(1-2). Within this mass ratio range, the catalytic properties of the precious metal can be maximized. For example, the mass ratio of the first powder to the second powder can be 1:1, 1:2, 1:3, or any other typical but non-limiting mass ratio, or a range between any two mass ratios.

[0145] In some embodiments, in the above step S3, the step of mixing the first powder and the second powder includes: mixing the first powder, the second powder and deionized water to obtain a powder mixture.

[0146] In some specific embodiments, the mass ratio of the total mass of the first and second powders in the powder mixture to deionized water is (2-10):1. Exemplary, typical but non-limiting mass ratios such as 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, and 9:1 can be used, or any range between these two mass ratios. Within this mass ratio range, the resulting powder mixture is easily subjected to the first ball milling reaction and produces a nanoscale product.

[0147] In some embodiments, in the above step S3, the first ball milling treatment includes the steps of: ball milling the powder mixture clockwise for 60 min to 80 min and counterclockwise for 60 min to 80 min at a rotation speed of 400 r / min to obtain a ball-milled product.

[0148] In some specific embodiments, the particle size of the grinding balls during the first ball milling process is no greater than 1 mm. In some specific embodiments, the grinding balls during the first ball milling process include at least one of zirconia balls, alumina balls, and agate balls. In some specific embodiments, the ball milling temperature during the first ball milling process is 25°C to 30°C. In this case, the product obtained after ball milling the first and second powders has a nanometer-scale particle size. After subsequent drying, calcination, and further grinding, dry nano-scale catalytic particles (1 nm to 100 nm) can be obtained.

[0149] In this embodiment, the particle size of the grinding balls is no greater than 1 mm. For example, the particle size can be 1 mm, 10 mm, 15 mm, 20 mm, 500 μm, 100 μm, or any other typical but non-limiting particle size, or a range between any two particle sizes. In this case, the product obtained after ball milling has a nanometer-scale particle size. A subsequent first calcination treatment can produce a dry, nanometer-scale first intermediate product (1 nm to 100 nm).

[0150] In some embodiments, in the above step S3, the third drying step includes: drying the ball-milled material at 120° C. to 130° C. for 10 h to 12 h.

[0151] In some embodiments, in the above step S3, the third calcination treatment step includes: calcining at 400° C. to 500° C. for 1 hour to 2 hours.

[0152] In some embodiments, in step S3, the mesh size of the catalytic particles is 20 to 40. Within this mesh size range, the catalyst has a large specific surface area and good mechanical stability.

[0153] [S4] In some embodiments, in the above step S4, the step of preparing a carbon monoxide catalyst includes: performing a third mixing treatment with a solution including a catalytic particle aqueous solution, a first binder solution, a first thickener solution, a first dispersant solution and a water retaining agent to obtain a first loaded slurry; performing a first loading treatment on the first loaded slurry and the first carrier, and then performing a fourth calcination treatment to obtain a carbon monoxide catalyst.

[0154] In some embodiments, in step S4, the mass ratio of the aqueous solution of catalytic particles, the first binder solution, the first thickener solution, the first dispersant solution, and the water-retaining agent is: (1-5): (0.5-4): (0.5-3): (0.5-2): 1. For example, the mass ratio can be a typical but non-limiting range such as 1:1:1:1, 1:0.5:0.5:1, or 5:4:2:1:1, or any range between any two mass ratios. Within this mass ratio range, the slurry is more stable, thereby improving the loading amount, loading uniformity, and mechanical stability of the catalyst active components.

[0155] In some embodiments, in step S4, the mass ratio of the catalytic particles to water in the aqueous solution of the catalytic particles is 1:(0.3-3). Within this mass ratio range, the catalytic particles can be uniformly dispersed in the first loading slurry. For example, the mass ratio of the catalytic particles to water can be 1:0.3, 1:0.5, 1:0.7, 1:0.9, 1:1, 1:1.1, 1:1.3, 1:1.5, 1:1.7, 1:1.9, 1:2, 1:2.1, 1:2.3, 1:2.5, 1:2.7, 1:2.9, 1:3, or other typical but non-limiting mass ratios, or ranges between any two mass ratios.

[0156] In some embodiments, in step S4 above, the mass fraction of the first binder in the first binder solution is 1% to 15%. For example, the mass fraction of the first binder can be 1%, 5%, 10%, 15%, 20%, or any other typical but non-limiting mass fractions, or a range between any two mass fractions. Within this mass fraction range, the binder can be well dispersed in the first loading slurry.

[0157] In some specific embodiments, the first binder includes one or more of calcium silicate, sodium silicate, calcium aluminate, phenolic resin, diatomaceous earth, aluminum sol, silica sol, kaolin, attapulgite, sodium silicate, bentonite, montmorillonite, and pseudo-boehmite.

[0158] In some specific embodiments, the method for preparing the first binder solution includes the following steps: mixing a specified amount of the first binder with water and stirring for at least 30 minutes to obtain the first binder solution; preparing a binder solution having a mass fraction of 1% to 15% using deionized water as the solvent, and stirring at 100 to 150 rpm for 30 minutes before adding the binder solution. This speed and stirring time ensures that the binder and deionized water are thoroughly mixed and dispersed in the load slurry.

[0159] In some embodiments, the mass fraction of the first thickener in the first thickener solution is 1% to 20%. For example, the mass fraction of the first thickener can be 1%, 5%, 10%, 15%, 20%, or any other typical but non-limiting mass fractions, or a range between any two mass fractions. Within this mass fraction range, the first thickener can be well dispersed in the first loading slurry.

[0160] In some specific embodiments, the first thickener includes one or more of hydroxymethyl cellulose, hydroxymethylpropyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, hydroxyethyl methyl cellulose, cellulose ether, and starch.

[0161] In some specific embodiments, the method for preparing the first thickener solution includes the steps of: mixing a specified amount of the first thickener with water, and stirring for at least 30 minutes to obtain the first thickener solution.

[0162] In some embodiments, the first dispersant solution comprises a first dispersant concentration of 1% to 15% by mass, and a water concentration of 80% to 99% by mass. For example, the first dispersant concentration may be 1%, 5%, 10%, 15%, or any other typical but non-limiting concentration, or a range between any two concentrations. Within this concentration range, the dispersant is well dispersed in the first loading slurry.

[0163] In some specific embodiments, the first dispersant includes one or more of polyacrylic acid, polypropylene, polystyrene, polyethylene wax, polyethylene ether, polyethylene ester, polyvinyl acetate, polyethylene, polyacrylamide, sodium polyacrylate, polyethylene glycol, and polyvinyl alcohol.

[0164] In some specific embodiments, the preparation method of the first dispersant solution includes the steps of: weighing 1% to 15% of dispersant powder and 85% to 99% of deionized water, wherein the deionized water does not contain other trace elements, mixing and stirring at a constant temperature, standing at room temperature and stirring at a constant temperature again; after cooling to room temperature, a first dispersant solution with a mass concentration of 1% to 15% is formed.

[0165] In some embodiments, the water-retaining agent includes one or more of glycerol, lignin, sodium alginate, polyacrylamide, sodium polyacrylate, potassium polyacrylate, and ammonium polyacrylate.

[0166] In some embodiments, the third mixing step includes: first mixing the first binder solution and the first dispersant solution in a specified ratio, adding the catalytic particle aqueous solution and stirring, then adding the first thickener solution and water-retaining agent and stirring, and finally adjusting the pH to 4-10 to obtain a first loaded slurry. In this case, mixing the first binder and the first dispersant first ensures that they are thoroughly mixed and evenly distributed. Adding the catalytic particle aqueous solution allows the catalyst particles to be evenly dispersed in the slurry under the action of the first dispersant. Finally, adding the water-retaining agent allows for water retention after the slurry stabilizes. Adding the thickener after the catalytic particles and before the water-retaining agent allows the catalytic particles to be evenly dispersed in the loaded slurry, while also allowing the thickener itself to be evenly dispersed in the loaded slurry. Thus, preparing the slurry in this order can improve the loading amount, loading uniformity, and mechanical stability of the catalytic active component in the first carrier.

[0167] In the embodiments, the pH of the first support slurry is 4-10. In exemplary embodiments, the pH can be 4, 5, 6, 7, 8, 9, 10, or any range between two mass fractions, which are typical but non-limiting. The pH of the first support slurry directly affects the catalytic performance of the carbon monoxide catalyst. Within this pH range, the loading of precious metals and other metals on the first support is high, and the active sites are correspondingly high. The high loading of other metals improves sulfur and water resistance, resulting in high catalytic stability in sintering flue gas purification.

[0168] In some embodiments, an acid solution or a base solution is used to adjust the pH value.

[0169] In some specific embodiments, the acid solution is one or more of citric acid solution, tartaric acid solution, hydrochloric acid solution, oxalic acid solution, lactic acid solution, trichloroacetic acid solution, monochloroacetic acid solution, and arginine solution.

[0170] In some specific embodiments, the alkaline solution is one or more of hydrazine hydrate, sodium hydroxide solution, sodium carbonate solution, sodium bicarbonate solution, and ammonia solution.

[0171] In some specific embodiments, the first binder solution and the first dispersant solution are mixed and stirred at a stirring rate of 50 rpm to 400 rpm for 1 to 2 hours. At this stirring rate and time, the first binder solution and the first dispersant solution are evenly mixed to form a homogeneous solution.

[0172] In some specific embodiments, the stirring rate of the aqueous solution containing the catalytic particles is 50 r / min to 400 r / min, and the stirring time is 0.5 h to 1 h. At this stirring rate and time, the catalytic particles can be evenly dispersed, thereby improving the catalytic stability.

[0173] In some specific embodiments, the first thickener solution and the water-retaining agent are stirred at a stirring rate of 50 to 400 rpm for 2 to 3 hours. This stirring rate and time ensure uniform mixing of the components (first binder, first dispersant, catalytic particles, first thickener, and water-retaining agent) in the first loading slurry.

[0174] In some embodiments, in step S4, the first loading treatment step includes applying the first loading slurry to the pretreated first carrier using a vacuum coater. The second loading slurry is then applied to the second carrier using a coating method. Vacuum coating can increase coating strength, control loading volume, and avoid excessive slurry waste.

[0175] In some specific embodiments, the first carrier is one or more of cordierite, honeycomb ceramics, glass fiber, porous carbon material, and hierarchical porous carbon material.

[0176] In some specific embodiments, the step of pretreating the first carrier includes: rinsing the first carrier with distilled water, placing it in acetic acid with a volume concentration of 5% to 25%, sealing it with a cover, and heating and soaking it at a constant temperature of 60° C. to 80° C. for 3 h to 4 h;

[0177] After taking it out, dry it at room temperature for 1.5h~3.5h, then dry it at 60℃~120℃ for 4h~10h;

[0178] The pretreated first carrier is then calcined in a muffle furnace at 350° C. to 450° C. for 4 to 6 hours and cooled to room temperature to obtain the pretreated first carrier.

[0179] In some embodiments, in step S4 above, the fourth calcination step includes drying the slurry obtained by the first loading treatment at 90°C to 110°C for 12 to 14 hours until the dehydration rate of the slurry is no less than 90%, then heating the slurry to 350°C to 400°C at a heating rate of 2°C / min to 32°C / min and calcining the slurry for 1.5 to 2 hours to obtain a carbon monoxide catalyst. In this case, the slurry is first dried at low temperature and then calcined at high temperature, resulting in a carbon monoxide catalyst with a smooth surface and no cracks.

[0180] [Preparation method of the second carbon monoxide catalyst]

[0181] A third object of the present invention is to provide another method for preparing a carbon monoxide catalyst. As shown in FIG2 , the preparation method comprises the following steps:

[0182] S01. Prepare a third mixed solution comprising a second noble metal salt solution and a second titanium dioxide suspension.

[0183] S02. Prepare a fourth mixed solution using a second cobalt salt solution and a second metal ammonium salt solution.

[0184] S03. Prepare a fifth mixed solution using the third mixed solution and the fourth mixed solution.

[0185] S04. Prepare a carbon monoxide catalyst using the fifth mixed solution, the second dispersant solution, the second binder solution, the second thickener solution and the second carrier.

[0186] Another method for preparing a carbon monoxide catalyst provided by an embodiment of the present invention, the method prepares a third mixed liquid and a fourth mixed liquid respectively, and then uses them to prepare a fifth mixed liquid, so that the metal ions in the fifth mixed liquid are very evenly dispersed, which is convenient for subsequent preparation of a second loaded slurry with a dispersant, a binder, and a thickener, and then the second loaded slurry is subjected to a second loading treatment and then calcined, so that the catalytic particles are loaded on the second carrier. This method simplifies the preparation process and eliminates the need for material loss caused by multiple calcinations; and in the prepared carbon monoxide catalyst, the catalytic particles can be evenly loaded on the carrier, and finally a carbon monoxide catalyst with a nanometer particle size is prepared. The metal elements in the carbon monoxide catalyst prepared by the another method for preparing a carbon monoxide catalyst provided by an embodiment of the present invention include: precious metal elements and titanium elements.

[0187] [S01] In some embodiments, in the above step S01, the step of preparing the third mixed liquid includes: performing a fourth mixing treatment on the second precious metal salt solution and the second titanium dioxide suspension to obtain the third mixed liquid.

[0188] In some embodiments, in step S01, the second precious metal salt in the second precious metal salt solution includes one or more of nitrates, chlorates, and chlorides of gold, silver, ruthenium, rhodium, palladium, osmium, iridium, and platinum. These precious metal salts are readily soluble in water to form a homogeneous aqueous solution.

[0189] In some specific embodiments, the second precious metal salt solution has a concentration of 10 g / L to 15 g / L. Exemplary concentrations include 10 g / L, 11 g / L, 12 g / L, 13 g / L, 14 g / L, 15 g / L, and other typical but non-limiting concentrations, or any range between these two concentrations. Within this concentration range, stable catalytic efficiency and production costs are both achieved.

[0190] In some specific embodiments, the method for preparing the second noble metal salt solution includes the steps of: mixing a noble metal salt and water in a specified mass ratio to obtain the second noble metal salt solution.

[0191] In some embodiments, in the above step S01, the method for preparing the second titanium dioxide suspension includes the steps of: pre-treating the second titanium dioxide and mixing it with water to obtain the second titanium dioxide suspension.

[0192] In some specific embodiments, the step of pretreating the second titanium dioxide includes: heating to 700°C-800°C at a heating rate of 5°C / min-10°C / min under air atmosphere, and calcining for 3h-4h to obtain the pretreated second titanium dioxide.

[0193] In some specific embodiments, the second titanium dioxide is pre-treated by calcination in a muffle furnace.

[0194] In some embodiments, in step S01, the second titanium dioxide suspension has a titanium dioxide content of 500 g / L to 800 g / L. For example, the content can be 500 g / L, 600 g / L, 700 g / L, 800 g / L, or any other typical but non-limiting content, or a range between any two of these contents. Within this content range, the distribution of the precious metal in the aqueous phase can be reduced, coating efficiency can be improved, and the overall catalytic performance of the catalyst can be ensured.

[0195] In some embodiments, in the above step S01, the fourth mixing step includes:

[0196] At a temperature of 20°C to 45°C, the second titanium dioxide suspension is stirred for 30 minutes to 45 minutes, and then the second precious metal salt solution is added while stirring, and stirring is continued for 30 minutes to 35 minutes to obtain a third mixed solution; wherein the second precious metal salt solution is added dropwise.

[0197] In the fourth mixing step, the second titanium dioxide is stirred for 30 to 45 minutes to uniformly disperse the titanium dioxide in the second titanium dioxide suspension; and the stirring is continued for 30 to 35 minutes to uniformly stir the second titanium dioxide suspension and the second precious metal salt solution.

[0198] [S02] In some embodiments, in the above step S02, the step of preparing the fourth mixed solution includes: performing a fifth mixing treatment on the second cobalt salt solution and the second metal ammonium salt solution, adjusting the pH value to 10~12, and obtaining the fourth mixed solution.

[0199] In some embodiments, in step S02, the concentration of cobalt in the second cobalt salt solution is between 0.05 g / L and 0.15 g / L. For example, the concentration can be 0.05 g / L, 0.1 g / L, 0.15 g / L, or any other typical but non-limiting concentration, or a range between any two concentrations. In this case, the second cobalt salt solution provides the cobalt required for preparing the carbon monoxide catalyst.

[0200] In some embodiments, in step S02, the second cobalt salt solution includes organic acid cobalt salts such as cobalt acetate solution, cobalt formate solution, and cobalt oxalate solution. These cobalt salt solutions can improve the catalyst's resistance to poisoning while not introducing other impurities.

[0201] In some specific embodiments, the method for preparing the cobalt acetate solution comprises the steps of:

[0202] Obtaining the mass and / or volume of the cobalt acetate and 50% ethanol solution according to the concentration of the cobalt acetate solution;

[0203] Cobalt acetate and 50% ethanol solution are mixed to obtain a cobalt acetate solution.

[0204] In some embodiments, in step S02, the mass fraction of the second metal ammonium salt in the second metal ammonium salt solution is 0.1% to 0.5%. Within this mass fraction range, the second metal ammonium salt can have good dispersibility.

[0205] In some specific embodiments, the preparation method of the second metal ammonium salt solution includes: mixing a specified amount of the second metal ammonium salt with water and stirring for 30 minutes to 45 minutes to obtain the second metal ammonium salt solution.

[0206] In some specific embodiments, the second metal ammonium salt in the second metal ammonium salt solution includes one or more of ammonium molybdate, ammonium tungstate, and ammonium metavanadate. In this case, the metal element in the catalytic particles produced by the second carbon monoxide catalyst preparation method provided in the third aspect of the present invention further includes at least one of molybdenum, tungsten, and vanadium.

[0207] In some specific embodiments, the step of preparing the second metal ammonium salt solution comprises:

[0208] After mixing the second metal ammonium salt and water in a specified ratio, stirring for 25 min to 30 min in a water bath at a temperature of 60° C. to 65° C., a second metal ammonium salt solution is obtained.

[0209] In some embodiments, in the above step S02, the fifth mixing process step includes:

[0210] In a water bath at a temperature of 60° C. to 65° C. and under stirring, the second metal ammonium salt solution and the second cobalt salt solution are mixed to obtain a fourth mixed solution; wherein the second metal ammonium salt solution is added to the second cobalt salt solution by slow dropwise addition.

[0211] In some specific embodiments, the step of adjusting the pH value to 10-12 comprises:

[0212] When the pH value of the solution is adjusted to 10-12 with aqueous ammonia, stirring is continued for 30-40 minutes to obtain a fourth mixed solution.

[0213] [S03] In some embodiments, in the above step S03, the step of preparing the fifth mixed liquid includes: performing a sixth mixing treatment on the third mixed liquid and the fourth mixed liquid to obtain the fifth mixed liquid.

[0214] In some embodiments, in the above step S03, the sixth mixing process includes:

[0215] obtaining a mass ratio of the third mixed liquid to the fourth mixed liquid;

[0216] The third mixed liquid and the fourth mixed liquid are mixed to obtain a fifth mixed liquid.

[0217] In some embodiments, in step S03, the mass ratio of the third mixed liquid to the fourth mixed liquid is (0.5-3):1. For example, the mass ratio can be typical but non-limiting mass ratios such as 0.5:1, 1:1, 2:1, 3:1, or any range between two mass ratios. In this case, the mass ratio of the third mixed liquid to the fourth mixed liquid within this range can ensure catalyst activity, improve catalytic efficiency, and enhance stability.

[0218] [S04] In some embodiments, in the above step S04, the step of preparing a carbon monoxide catalyst includes: subjecting the fifth mixed liquid, the second dispersant solution, the second binder solution and the second thickener solution to a seventh mixing treatment to obtain a second loaded slurry; then subjecting the second loaded slurry and the second carrier to a second loading treatment, and then subjecting the second loaded slurry to a fifth calcination treatment to obtain a carbon monoxide catalyst.

[0219] In some embodiments, in the above step S04, the seventh mixing process includes:

[0220] Obtaining mass fractions of the fifth mixed solution, the second dispersant solution, the second binder solution, and the second thickener solution: 1 wt% to 5 wt% of the second dispersant solution, 1 wt% to 5 wt% of the second binder solution, 1 wt% to 5 wt% of the second thickener solution, and the remainder being the fifth mixed solution;

[0221] The second binder solution and the second dispersant solution are first mixed according to the above ratio, and then the fifth mixed solution and the second thickener solution are added respectively. After mixing, the pH value of the solution is adjusted to 4-10 to obtain a second loaded slurry.

[0222] In some specific embodiments, the pH value is adjusted to 4-10 using an acid solution or an alkaline solution.

[0223] In the embodiments, the pH of the second support slurry is between 4 and 10. In exemplary embodiments, the pH value can be 4, 5, 6, 7, 8, 9, 10, or any range between two mass fractions. The pH value of the second support slurry has a direct impact on the catalytic performance of the carbon monoxide catalyst. Within this pH range, the loading of precious metals and other metals on the second support is high, and the active sites are correspondingly high. The high loading of other metals improves sulfur and water resistance, resulting in high catalytic stability in sintering flue gas purification.

[0224] In some specific embodiments, the acid solution is one or more of citric acid solution, tartaric acid solution, hydrochloric acid solution, oxalic acid solution, lactic acid solution, trichloroacetic acid solution, monochloroacetic acid solution, and arginine solution.

[0225] In some specific embodiments, the alkaline solution is one or more of hydrazine hydrate, sodium hydroxide solution, sodium carbonate solution, sodium bicarbonate solution, and ammonia solution.

[0226] In some embodiments, in step S04, the second dispersant solution comprises a second dispersant with a mass fraction of 1% to 15% and a water mass fraction of 85% to 99%. The mass fraction of the second dispersant can be typical but non-limiting mass fractions such as 1%, 3%, 5%, 7%, 9%, 11%, 13%, 15%, or any range between these two mass fractions. Within this mass fraction range, the dispersant can be well dispersed in the second loading slurry.

[0227] In some specific embodiments, the method for preparing the second dispersant solution includes the following steps: weighing 1% to 15% of dispersant powder and 85% to 99% of deionized water, mixing and stirring at a constant temperature, allowing to stand at room temperature, and then stirring at a constant temperature again; after cooling to room temperature, forming a second dispersant solution with a mass concentration of 1% to 15%. The purpose of the deionized water is to ensure that no unnecessary elements and impurities are introduced during the preparation process.

[0228] In some specific embodiments, the second dispersant includes one or more of polyacrylic acid, polypropylene, polystyrene, polyethylene wax, polyethylene ether, polyethylene ester, polyvinyl acetate, polyethylene, polyacrylamide, sodium polyacrylate, polyethylene glycol, and polyvinyl alcohol.

[0229] In some embodiments, in step S04, the mass fraction of the second binder in the second binder solution is 1% to 20%. The mass fraction of the second binder can be typical but non-limiting mass fractions such as 1%, 5%, 10%, 15%, 20%, or any range between two mass fractions. Within this mass fraction range, the binder can be well dispersed in the second loading slurry.

[0230] In some specific embodiments, the second binder includes one or more of calcium silicate, sodium silicate, calcium aluminate, phenolic resin, diatomaceous earth, aluminum sol, silica sol, kaolin, attapulgite, sodium silicate, bentonite, montmorillonite, and pseudo-boehmite.

[0231] In some specific embodiments, the method for preparing the second binder solution includes the steps of: mixing the second binder with water, and stirring for at least 30 minutes to obtain the second binder solution.

[0232] In some embodiments, in step S04, the mass fraction of the second thickener in the second thickener solution is 1% to 20%. The mass fraction of the second thickener can be typical but non-limiting mass fractions such as 1%, 5%, 10%, 15%, 20%, or any range between two mass fractions. Within this mass fraction range, the thickener can be well dispersed in the solution.

[0233] In some specific embodiments, the second thickener includes one or more of hydroxymethyl cellulose, hydroxymethylpropyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, hydroxyethyl methyl cellulose, cellulose ether, and starch.

[0234] In some specific embodiments, the method for preparing the second thickener solution includes the steps of: adding the thickener into deionized water, maintaining the mass fraction of the thickener at 1% to 20%, and stirring at room temperature for 30 minutes to 45 minutes.

[0235] In some embodiments, in step S04, the second loading treatment step includes applying the second loading slurry to the pretreated second support using a vacuum coater. Applying the second loading slurry to the second support using a vacuum coating method allows for better control of loading, increased loading strength, and the formation of regular channels. Furthermore, the carbon monoxide catalyst obtained by calcination after vacuum coating has a particle size of 50 nm to 200 nm, representing a nanoscale catalyst material.

[0236] In some embodiments, in the above step S04, the second carrier is one or more of cordierite, honeycomb ceramics, glass fiber, porous carbon material, and hierarchical porous carbon material.

[0237] In some specific embodiments, the step of pretreating the second carrier includes: rinsing the first carrier with distilled water and then placing it in acetic acid with a volume concentration of 5% to 25%, sealing it with a cover, and heating and soaking it at a constant temperature of 60° C. to 80° C. for 3 h to 4 h;

[0238] After taking it out, dry it at room temperature for 1.5h~3.5h, then dry it at 60℃~800℃ for 4h~10h;

[0239] The pretreated second carrier is then calcined in a muffle furnace at 350° C. to 450° C. for 4 to 6 hours and cooled to room temperature to obtain the pretreated second carrier.

[0240] In some embodiments, in step S04 above, the fifth calcination step includes drying the slurry obtained after the second loading treatment at 90°C to 110°C for 12 to 14 hours until the dehydration rate of the slurry is no less than 90%, then heating the slurry to 350°C to 400°C at a heating rate of 2°C / min to 20°C / min and calcining the slurry for 1.5 to 2 hours to obtain a carbon monoxide catalyst. In this case, the slurry is first dried at low temperature and then calcined at high temperature, resulting in a carbon monoxide catalyst with a smooth surface and no cracks.

[0241]

application

[0242] A fourth object of an embodiment of the present invention is to provide an application of the carbon monoxide catalyst provided by the first object of the present invention or the carbon monoxide catalyst prepared by the preparation method provided by the second object of the present invention or the third object of the present invention in the field of removing carbon monoxide pollutants.

[0243] The following is further explained with reference to embodiments. Example 1

[0244] Example 1 provides a method for preparing a carbon monoxide catalyst, comprising the steps of:

[0245] (1) Preparation of catalytic particles

[0246] 1) Preparation of the first powder:

[0247] ① First, titanium dioxide pretreatment: weigh an appropriate amount of TiO2 into a porcelain boat and use a muffle furnace to perform calcination pretreatment in an air atmosphere at a heating rate of 3°C / min. Sinter at 700°C for 4 hours. The obtained TiO2 is recorded as TiO2 (700°C).

[0248] ② Preparation of the first noble metal salt solution: Select platinum nitrate and palladium nitrate as the first noble metal salt, and prepare a first noble metal salt solution with a concentration of 10 g / L.

[0249] ③ Preparation of cerium nitrate solution: Weigh 18.1 g of cerium nitrate and dissolve it in deionized water to make a 0.5 mol / L solution for later use.

[0250] ④ Preparation of the first titanium dioxide suspension: Weigh 1200 g of the pretreated first titanium dioxide into a beaker, add 2400 ml of deionized water, and stir to form a uniform suspension.

[0251] ⑤ First mixing treatment: heat the first titanium dioxide suspension to 60°C in a water bath; then add the prepared cerium nitrate solution dropwise to the first titanium dioxide suspension, stir for 10 minutes, and then add the prepared first precious metal salt solution dropwise to the suspension according to a ratio based on a Pt mass fraction of 0.7% in the final catalyst to obtain a first mixed solution.

[0252] ⑥ After continuing to stir the first mixed liquid for 5 hours, place it in a blast drying oven and dry it at 120°C for 12 hours; then place it in an agate mortar and carefully grind it into powder. Then place the powder in a muffle furnace and heat it to 500°C in an air atmosphere at a heating rate of 3°C / min. After calcining for 2 hours, cool it to room temperature to obtain the first powder.

[0253] 2) Preparation of the second powder:

[0254] ① Prepare the cobalt acetate solution (first cobalt salt solution): Weigh 800 g of cobalt acetate into a beaker. Add 4000 ml of anhydrous ethanol to the weighed cobalt acetate and stir continuously in a water bath for 10 minutes. Add 3000 ml of deionized water to the beaker, heat to 60°C in a water bath, and continue stirring for 30 minutes to obtain the cobalt acetate solution.

[0255] ②Preparing an ammonium molybdate solution (a first metal ammonium salt solution): mixing ammonium molybdate with water to obtain an ammonium molybdate solution.

[0256] ③ Prepare sodium carbonate solution (first carbonate solution): Weigh 689 g of sodium carbonate and dissolve it in 6500 ml of deionized water using a beaker. Then transfer the solution to a volumetric flask. Rinse the beaker three times and transfer the liquid to the volumetric flask. Finally, bring the volume of the volumetric flask to a constant volume. The prepared 1 mol / L sodium carbonate solution is ready for use.

[0257] ④ Second mixing treatment: add the ammonium molybdate solution to the cobalt acetate solution, heat it in a water bath at 60°C and continue stirring for 30 minutes; then slowly add the sodium carbonate solution dropwise to the cobalt acetate solution, and measure the pH value of the suspension. When the pH value reaches 10, stop adding the sodium carbonate solution dropwise to obtain a second mixed solution.

[0258] ⑤ After continuing to stir the second mixed liquid for 3 hours, let it stand and age for 2 hours, then filter and wash the suspension until it is neutral; place the washed paste in a drying oven at 120°C and dry it for 10 hours; after being fully dried, place it in a muffle furnace and heat it to 400°C in an air atmosphere at a heating rate of 3°C min-1. After calcining for 3 hours, cool it to room temperature to obtain the second powder.

[0259] 3) Preparation of catalytic particles

[0260] The first powder and the second powder are mixed in a mass ratio of 1:1, placed in a ball mill, and an appropriate amount of deionized water is added and stirred to obtain a mixture;

[0261] The mixture was ball milled in a clockwise direction for 60 minutes and then counterclockwise for 60 minutes at a speed of 400 rpm in a ball mill. After ball milling, the milled material was removed and fully dried at 120°C for 12 hours. It was then calcined in a muffle furnace at 400°C for 2 hours. The catalytic particles were then ground and sieved to obtain particles with a mesh size of 20-40.

[0262] (2) Mixing the catalytic particles with water to obtain a catalytic particle aqueous solution.

[0263] (3) Preparation of the first loading slurry:

[0264] ① Prepare a first thickener solution: weigh 13 g of carboxymethyl cellulose and 130 g of deionized water, mix the carboxymethyl cellulose and water to obtain a first thickener solution with a mass fraction of 10%.

[0265] ② Prepare the first dispersant solution: weigh 15.6 g of polyvinyl alcohol powder and 156 g of deionized water, mix the polyvinyl alcohol and water to obtain a first dispersant solution with a mass fraction of 10%.

[0266] ③ First, pour 2450g of deionized water into the mixing bucket. Turn on the mixer and stir for 5 minutes. Then, slowly add 1300g of the binder solution and continue stirring for 10 minutes. Weigh 1170g of the prepared catalytic particle aqueous solution and slowly pour it into the mixing bucket. Then, pour the prepared first dispersant solution and first thickener solution into the mixing bucket in sequence, stirring for 30 minutes each time. Adjust the pH of the slurry to 6 with ammonia water and stir at room temperature for 6 hours. Observe the slurry constantly. After stirring, you will obtain a first-loaded slurry with high solids content, good fluidity, and stable viscosity.

[0267] (4) Preparation of carbon monoxide catalyst

[0268] 1) Pretreatment of the First Carrier: Cordierite was selected as the first carrier. The cordierite was rinsed with distilled water and then placed in 10% acetic acid. The solution was sealed and heated at 80°C for 3 hours. After removal, the solution was dried at room temperature for 2 hours, then dried at 80°C for 6 hours, and then calcined in a muffle furnace at 400°C for 2 hours. The solution was then cooled to room temperature to obtain the pretreated cordierite.

[0269] 2) Coating: Place the first load slurry in the slurry storage tank, weigh the pre-treated cordierite and place it in the coating equipment. Set the purge pressure of the coating equipment to 0.4MPa, and coat the slurry completely and evenly on the inner wall. Blow off the excess slurry into the slurry recovery tank. (The loading capacity of the catalytic particles on the honeycomb carrier (dry basis) is 100kg / m 3 ~150kg / m 3 , each component is evenly loaded along the pore direction)

[0270] 3) Drying and calcining: Place the coated cordierite in an oven and dry it at 120°C for 12 hours. It must be completely dried with a dehydration rate of 90%. There should be no cracks or scaling after drying.

[0271] After drying, the product was calcined in a muffle furnace at a heating rate of 2°C / min to 350°C, maintained for 2 hours, and then cooled. After calcination, the product was slowly cooled to room temperature to obtain a carbon monoxide catalyst. Example 2

[0272] The preparation method of the carbon monoxide catalyst provided in Example 2 has the same steps as those in Example 1, except that:

[0273] The first carrier is glass fiber. Example 3

[0274] The preparation method of the carbon monoxide catalyst provided in Example 3 has the same steps as those in Example 1, except that:

[0275] The first loading slurry was adjusted to pH 4 using citric acid. Example 4

[0276] The preparation method of the carbon monoxide catalyst provided in Example 4 is basically the same as that in Example 1, except that:

[0277] The pH of the first loading slurry was adjusted to 5.5 using citric acid. Example 5

[0278] The preparation method of the carbon monoxide catalyst provided in Example 5 is basically the same as that in Example 1, except that:

[0279] The pH of the first loading slurry was adjusted to 7.5 using ammonia acid. Example 6

[0280] The preparation method of the carbon monoxide catalyst provided in Example 6 has the same steps as those in Example 1, except that:

[0281] The first loading slurry was adjusted to a pH of 9 using aqueous ammonia.

[0282] In order to verify the progress of the embodiments of the present invention, the carbon monoxide catalysts prepared in Examples 1 to 6 were selected to conduct catalytic experiments on carbon monoxide in industrial flue gas, along with existing copper-manganese-based catalysts and iron-magnesium-cobalt catalysts. The experimental apparatus used is shown in Figure 3. The experimental conditions were 260°C and a space velocity of 17000 h / min. -1 .

[0283] As shown in Figure 3, a gas path is drawn from the desulfurized flue gas pipeline. Its power is provided by an air pump, its flow rate is controlled by a rotameter, and its temperature is controlled by a heating coil. The first ball valve is opened and the second ball valve is closed. The drawn gas passes through the pipeline and enters the catalytic tower, where the temperature is maintained at 200°C to 220°C. The catalytic tower is filled with the carbon monoxide catalyst prepared in Example 1 or an existing copper-manganese-based catalyst or iron-magnesium-cobalt catalyst. The carbon monoxide in the drawn gas is catalytically oxidized to carbon dioxide, producing the treated gas.

[0284] During the measurement, the gas treated with the integral carbon monoxide catalyst is passed into the flue gas analyzer to measure the carbon monoxide content in the treated gas. After the reading of the flue gas analyzer stabilizes, the carbon monoxide content is recorded and then discharged.

[0285] Close the first ball valve and open the second ball valve to allow the exhaust gas to enter the flue gas analyzer directly. Measure the carbon monoxide content of the exhaust gas and record the carbon monoxide content after the flue gas analyzer reading stabilizes. Finally, calculate the carbon monoxide catalytic efficiency based on the carbon monoxide content of the flue gas before and after treatment.

[0286] The experimental results of Example 1 and the existing copper-manganese-based catalyst and iron-magnesium-cobalt catalyst are compared and shown in Table 1 below.

[0287] Table 1

[0288]

[0289] As can be seen from Table 1 above, the carbon monoxide catalyst prepared by the preparation method in Example 1 of the present application has high catalytic efficiency for carbon monoxide and low deactivation rate, and no or negligible agglomeration phenomenon occurs during the catalytic process.

[0290] During the preparation process, the effect of the pH value of the first loaded slurry on the catalytic performance of the carbon monoxide catalyst is shown in Figure 4 of the specification. As can be seen from Figure 4, the pH value of the first loaded slurry has a direct impact on the catalytic performance of the final carbon monoxide catalyst. When the pH value of the first loaded slurry is 6, the catalytic efficiency of the prepared carbon monoxide catalyst is the most stable. This is because, in the carbon monoxide catalyst loaded with the first loaded slurry at this pH value, the loading amount of precious metals and other metals in the carrier is high, and the active sites are correspondingly high. The high loading amount of other metals makes it highly resistant to sulfur and water, and its catalytic stability is high in sintering flue gas purification. The carbon monoxide catalyst has a high activity and temperature applicable range, starting catalytic oxidation at 120°C, and the catalytic efficiency at 220°C can reach over 90%. Example 7

[0291] Example 7 provides a method for preparing a carbon monoxide catalyst, comprising the steps of:

[0292] (1) Preparation of the second loading slurry

[0293] 1) Preparation of the third mixed solution

[0294] ① Prepare the second precious metal salt solution: Select 5 g of precious metal and prepare a 10 g / L precious metal solution in a 500 mL volumetric flask for later use.

[0295] ② Second titanium dioxide pretreatment: In air atmosphere, heat to 700°C~800°C at a heating rate of 5°C / min~10°C / min, and calcine for 3h~4h to obtain pretreated titanium dioxide.

[0296] ③Preparing a second titanium dioxide suspension: mixing the pretreated second titanium dioxide with water and stirring to obtain a second titanium dioxide suspension.

[0297] ④ Fourth mixing treatment: After stirring the second titanium dioxide suspension at 40° C. for 30 minutes, the second noble metal salt solution is added dropwise while stirring, and stirring is continued for 30 to 35 minutes to obtain a third mixed solution.

[0298] 2) Preparation of the fourth mixed solution

[0299] ① Preparation of cobalt acetate solution: Weigh 700 g of cobalt acetate, dissolve it in 50% ethanol solution, and stir it in water at 60°C for 10 minutes to obtain a cobalt acetate solution.

[0300] ② Preparation of ammonium molybdate solution: Weigh 140 g of ammonium molybdate, mix with water and stir in a water bath at 60° C. for 30 min until uniform to obtain an ammonium molybdate solution.

[0301] ③ Fifth mixing treatment: in a water bath at a temperature of 60° C. to 65° C. and under stirring, the second metal ammonium salt solution and the second cobalt salt solution are mixed to obtain a fourth mixed solution.

[0302] 3) Preparing a fifth mixed solution: Slowly add aqueous ammonia to the fourth mixed solution, and detect the pH value thereof to be 10-12. Continue stirring the suspension for 30 minutes to obtain a fifth mixed solution.

[0303] 4) Preparing a sixth mixed solution: uniformly mix the third mixed solution and the fifth mixed solution at a mass ratio of 1:1 to obtain a sixth mixed solution.

[0304] 5) Preparation of the second loading slurry

[0305] ① Prepare the second dispersant solution: weigh 20 g of polyvinyl alcohol powder and 180 g of deionized water, mix the polyvinyl alcohol powder and deionized water to obtain a second dispersant solution with a mass fraction of 10%.

[0306] ② Prepare a second binder solution: weigh 20 g of sodium silicate and 180 g of deionized water, mix the sodium silicate and deionized water, and stir for at least 30 minutes to prepare a second binder solution with a mass fraction of 10%.

[0307] ③ Prepare the second thickener solution: weigh 20 g of carboxymethyl cellulose and 180 g of deionized water, mix the carboxymethyl cellulose and deionized water to obtain a second thickener solution with a mass fraction of 10%.

[0308] ④ First, pour 2400g of deionized water into the mixing bucket. Turn on the mixer and stir for 5 minutes. Then, slowly add 1300g of the second binder solution and continue stirring for 10 minutes. Weigh 1170g of the prepared sixth mixed solution and slowly pour it into the mixing bucket. Pour the prepared second dispersant solution and second thickener solution into the mixing bucket in sequence, stirring for 30 minutes each time. Adjust the pH of the slurry to 6 with ammonia water and stir at room temperature for 6 hours. Observe the slurry state at all times. After stirring, you will obtain a second loaded slurry with high solids content, good fluidity, and stable viscosity.

[0309] (2) Preparation of carbon monoxide catalyst

[0310] 1) Pretreatment of the second carrier: A glass fiber of 150 mm × 150 mm × 150 mm was selected and calcined in a muffle furnace at 400° C. for 2 h, and then cooled to room temperature to obtain a pretreated second carrier.

[0311] 2) Coating: Place the second loading slurry into the slurry storage tank, weigh the pre-treated glass fiber and place it in the coating equipment. Set the purge pressure of the coating equipment to 0.35MPa, and coat the slurry completely and evenly on the inner wall. Blow off the excess slurry into the slurry recovery tank. (The loading amount of catalytic particles on the glass fiber (dry basis) is 100kg / m 3 ~150kg / m 3 , each component is evenly loaded along the pore direction)

[0312] 3) Drying and calcining: Place the coated glass fiber in an oven and dry it at 120°C for 12 hours. It must be completely dried with a dehydration rate of 90%. There should be no cracks or peeling after drying.

[0313] After drying, the product was calcined in a muffle furnace at a heating rate of 2°C / min to 350°C, maintained for 2 hours, and then cooled. After calcination, the product was slowly cooled to room temperature to obtain a carbon monoxide catalyst. Example 8

[0314] The preparation method of the carbon monoxide catalyst provided in Example 8 has the same steps as those in Example 7, except that:

[0315] The first loading slurry was adjusted to pH 4 using citric acid. Example 9

[0316] The preparation method of the carbon monoxide catalyst provided in Example 9 is substantially the same as that in Example 7, except that:

[0317] The pH of the first loading slurry was adjusted to 5.5 using citric acid. Example 10

[0318] The preparation method of the carbon monoxide catalyst provided in Example 10 is substantially the same as that in Example 7, except that:

[0319] The pH of the first loading slurry was adjusted to 7.5 using ammonia acid. Example 11

[0320] The preparation method of the carbon monoxide catalyst provided in Example 11 has the same steps as those in Example 7, except that:

[0321] The first loading slurry was adjusted to a pH of 9 using ammonia acid.

[0322] To demonstrate the advancements of the present invention, catalytic experiments were conducted on carbon monoxide in industrial flue gas using the carbon monoxide catalysts prepared in Examples 7-11, existing hopcalite catalysts, and iron-magnesium-cobalt catalysts. The carbon monoxide catalytic testing procedures were identical to those described in the first method for preparing the carbon monoxide catalyst. The molar ratio of copper to manganese in the hopcalite catalyst was between 2.2 and 3:1.

[0323] The experimental results of Example 7 and the existing hopcalite catalyst and iron-magnesium-cobalt catalyst are compared and shown in Table 2 below.

[0324] Table 2

[0325]

[0326] As can be seen from Table 2 above, the carbon monoxide catalyst prepared by the preparation method in Example 7 of the present application has high catalytic efficiency for carbon monoxide and low deactivation rate, and no or negligible agglomeration phenomenon occurs during the catalytic process.

[0327] During the preparation process, the effect of the pH value of the second loaded slurry on the catalytic performance of the carbon monoxide catalyst is shown in Figure 5 of the specification. As can be seen from Figure 5, the pH value of the second loaded slurry has a direct impact on the catalytic performance of the final carbon monoxide catalyst. When the pH value of the second loaded slurry is 6.0, the catalytic efficiency of the prepared carbon monoxide catalyst is the most stable. This is because, in the carbon monoxide catalyst obtained by loading the second loaded slurry at this pH value, the loading amount of precious metals and other metals in the carrier is high, and the active sites are correspondingly high. The high loading amount of other metals makes it highly resistant to sulfur and water, and its catalytic stability is high in sintering flue gas purification. The carbon monoxide catalyst has a high activity and temperature applicable range, starting catalytic oxidation at 120°C, and the catalytic efficiency at 220°C can reach over 90%.

[0328] The above description is merely a preferred embodiment of the carbon monoxide catalyst, preparation method and application thereof of the present invention, and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention shall be included in the scope of protection of the present invention.

Claims

1. A carbon monoxide catalyst, characterized in that The carbon monoxide catalyst comprises a carrier and metal catalytic particles supported in the carrier; or metal catalytic particles and metal oxide catalytic particles; The metal in the metal catalytic particles or metal oxide catalytic particles includes noble metals, titanium, cerium, cobalt, nickel and molybdenum; The carrier includes one or more of cordierite, honeycomb ceramics, glass fiber, porous carbon material, and hierarchical porous carbon material; The mass fractions of the metal elements in the carbon monoxide catalyst include: 0.5% to 1.0% of noble metals, 0.5% to 1.0% of titanium, 0.5% to 1.0% of cerium, 0.5% to 1.0% of cobalt, 0.5% to 1.0% of nickel, and 0.5% to 1.0% of molybdenum.

2. The carbon monoxide catalyst according to claim 1, characterized in that The loading amount of the metal catalytic particles is: 90kg / m 3 ~150kg / m 3 ; And / or, the particle size of the carbon monoxide catalyst is in the range of 50 nm to 200 nm; And / or, the loading amount of the metal oxide particles is: 90 kg / m 3 ~150kg / m 3 ; And / or, the particle size of the metal catalytic particles is in the range of 1 nm to 100 nm; And / or, the particle size of the metal oxide catalytic particles is in the range of 1 nm to 100 nm; And / or, the mesh size of the catalytic particles is 20-40 mesh.

3. The carbon monoxide catalyst according to claim 1 or 2, characterized in that The precious metal includes one or more of gold, silver, ruthenium, rhodium, palladium, osmium, iridium and platinum.

4. A method for preparing a carbon monoxide catalyst as claimed in claim 3, characterized in that: The preparation method comprises the following steps: A first powder is prepared by using a first noble metal salt solution, a cerium nitrate solution and a first titanium dioxide suspension; preparing a second powder by using a first cobalt salt solution, a first metal ammonium salt solution, and a first carbonate solution; preparing a catalytic particle aqueous solution by using the first powder and the second powder; The carbon monoxide catalyst is prepared by using the catalytic particle aqueous solution, the first binder solution, the first thickener solution, the first dispersant solution and the water retaining agent.

5. The method for preparing a carbon monoxide catalyst according to claim 4, wherein: The steps of preparing the first powder include: performing a first mixing process on a first noble metal salt solution, a cerium nitrate solution, and a first titanium dioxide suspension to obtain a first mixed solution; performing a first drying process and a first calcination process on the first mixed solution to obtain the first powder; And / or, the step of preparing the second powder includes: performing a second mixing process on the first cobalt salt solution, the first metal ammonium salt solution, and the first carbonate solution to obtain a second mixed solution; performing a second drying process and a second calcination process on the second mixed solution to obtain the second powder; And / or, the step of preparing the catalytic particle aqueous solution includes: mixing the first powder and the second powder, performing a first ball milling process, performing a third drying process, and then performing a third roasting process, and grinding and screening to obtain catalytic particles; mixing the catalytic particles with water to obtain the catalytic particle aqueous solution; And / or, the steps of preparing the carbon monoxide catalyst include: performing a third mixing treatment using the catalytic particle aqueous solution, a first binder solution, a first thickener solution, a first dispersant solution and a water retaining agent to obtain a first loaded slurry; performing a first loading treatment on the first loaded slurry and a first carrier, and then performing a fourth calcination treatment to obtain the carbon monoxide catalyst.

6. The method for preparing a carbon monoxide catalyst according to claim 5, characterized in that: The metal elements in the catalytic particles include: noble metal elements, cerium elements and titanium elements; and / or, in the first precious metal salt solution, the precious metal salt comprises one or more of nitrates, chlorates, and chlorides of gold, silver, ruthenium, rhodium, palladium, osmium, iridium, and platinum; and / or, in the first noble metal salt solution, the noble metal salt concentration is 10 g / L to 15 g / L; and / or, the molar concentration of the cerium nitrate solution is 0.5 mol / L to 1.0 mol / L; And / or, the titanium dioxide content in the first titanium dioxide suspension is 500 g / L to 800 g / L; and / or, the concentration of cobalt ions in the first cobalt salt solution is 0.02 g / L to 0.10 g / L; and / or, in the first metal ammonium salt solution, the mass fraction of the first metal ammonium salt is 0.1% to 0.5%; and / or, the concentration of the first carbonate solution is 1 mol / L to 1.5 mol / L; and / or, in the aqueous solution of catalytic particles, the mass ratio of catalytic particles to water is 1:(0.3-3); and / or, in the first ball milling process, the particle size of the grinding balls is not greater than 1 mm; and / or, in the first ball milling process, the particle size of the grinding balls is not greater than 1 mm; and / or, in the first ball milling process, the grinding balls include at least one of zirconia balls, alumina balls, and agate balls; And / or, in the first ball milling process, the ball milling temperature is 25° C. to 30° C.; and / or, in the first binder solution, the mass fraction of the first binder is 1% to 15%; And / or, in the first thickener solution, the mass fraction of the first thickener is: 1% to 20%; And / or, in the first dispersant solution, the mass fraction of the first dispersant is 1% to 20%.

7. The method for preparing a carbon monoxide catalyst according to claim 5 or 6, characterized in that: The third mixing step comprises: mixing the first binder solution and the first dispersant solution in a specified ratio, adding the catalytic particle aqueous solution and stirring, adding the first thickener solution and the water-retaining agent and stirring, and finally adjusting the pH value to 4-10 to obtain the first loaded slurry; And / or, the fourth calcination treatment step includes: drying the slurry obtained by the first loading treatment at 90°C~110°C for 12h~14h until the dehydration rate of the slurry is not less than 90%, heating it to 350°C~400°C at a heating rate of 2°C / min~32°C / min, and calcining it for 1.5h~2h to obtain the carbon monoxide catalyst.

8. The method for preparing a carbon monoxide catalyst according to claim 5 or 6, characterized in that: The first cobalt salt solution includes an organic acid cobalt salt solution; and / or, in the first metal ammonium salt solution, the first metal ammonium salt comprises one or more of ammonium molybdate, ammonium tungstate, and ammonium metavanadate; And / or, the metal elements in the catalytic particles further include: at least one of molybdenum, tungsten, and vanadium; And / or, in the first carbonate solution, the carbonate includes one or more of sodium carbonate, potassium carbonate, and lithium carbonate.

9. The method for preparing a carbon monoxide catalyst according to claim 5 or 6, characterized in that: The mass ratio of the first powder to the second powder is 6:(1~2); And / or, the mass ratio of the catalytic particle aqueous solution, the first binder solution, the first thickener solution, the first dispersant solution and the water retaining agent is: (1-5): (0.5-4): (0.5-3): (0.5-2):

1.

10. Use of the carbon monoxide catalyst according to any one of claims 1 to 3 or the carbon monoxide catalyst prepared by the preparation method according to any one of claims 4 to 9 in the field of removing carbon monoxide pollutants.

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