Carbon monoxide catalytic combustion catalyst, and preparation method and application thereof

Abstract

This invention discloses a carbon monoxide catalytic combustion catalyst and its preparation method. The preparation method includes the following steps: (1) loading an organotitanium and an active metal precursor onto titanium dioxide; or loading an organotitanium, an active metal precursor, and an auxiliary metal precursor onto titanium dioxide; the active metal is at least one of Pt, Pd, and Au, and the auxiliary metal is at least one of Cu, Mn, Co, and Ce; (2) sequentially drying, calcining under an inert atmosphere, and calcining in air to obtain the carbon monoxide catalytic combustion catalyst. The catalyst of this invention exhibits high anti-poisoning stability in the catalytic oxidation reaction of carbon monoxide. This invention also discloses the application of the carbon monoxide catalytic combustion catalyst in the catalytic degradation of carbon monoxide in industrial flue gas.

Description

Technical Field

[0001] This invention relates to the field of waste gas purification and treatment technology, and in particular to a carbon monoxide catalytic combustion catalyst, its preparation method, and its application. Background Technology

[0002] Currently, pollutants affecting air quality such as fine particulate matter, inhalable particulate matter, ozone, sulfur dioxide, and nitrogen oxides in flue gas have been effectively controlled, while the impact of carbon monoxide on air quality is gradually becoming apparent. As a toxic and harmful gas, carbon monoxide emissions into the atmosphere not only cause environmental pollution but also harm human health. Reducing the emission concentration of carbon monoxide from stationary sources (steel, power, cement, and other industries) is an effective way to further improve air quality.

[0003] Catalytic combustion is a highly efficient technology for removing carbon monoxide, characterized by high conversion rates and wide applicability. However, flue gas contains a small amount of SO2 (≤35 mg / m³). 3 Water vapor, dust, and other pollutants can all cause a decrease in catalyst activity, making it crucial to improve the catalyst's resistance to poisoning for the industrial application of this technology.

[0004] Encapsulated catalysts possess a unique structure where precious metal nanoparticles are encapsulated within a support material coating, thus protecting the precious metals. This type of catalyst has been reported to improve catalyst activity and selectivity, inhibit catalyst sintering, reduce coking during the reaction process, and enhance catalyst resistance to poisoning.

[0005] Chinese patents CN 112387275 B and CN 113996290 A disclose a method for preparing an anti-sintering noble metal catalyst by inducing the encapsulation of noble metal nanoparticles on a TiO2 support using melamine under an oxidizing atmosphere. The catalyst requires the introduction of melamine under nitrogen at 600°C and air at 800°C to form an encapsulation structure. Calcination under air at 800°C is a necessary condition.

[0006] Chinese patent CN 117599781 A discloses a noble metal@TiO2 / TiO2 catalyst, its preparation method, and its applications. This method uses a titanium dioxide support synthesized via supercritical hydrothermal synthesis to load the noble metal, which is then calcined to obtain an encapsulated structure. This catalyst exhibits unique advantages in sulfur resistance and stability. However, the supercritical hydrothermal synthesis of the support requires stringent conditions, limiting its industrial application.

[0007] Reports indicate that high-temperature reduction treatment of supported noble metal catalysts can also yield encapsulated structures. However, these structures are prone to degradation under high-temperature oxygen conditions, causing the encapsulation to disappear and limiting their application scenarios.

[0008] Therefore, no encapsulated catalyst that is low in cost, stable under oxygen conditions, and has good sulfur and water resistance can be used for the catalytic combustion of carbon monoxide has been disclosed in the prior art. Summary of the Invention

[0009] This invention provides a carbon monoxide catalytic combustion catalyst and its preparation method, which exhibits high resistance to poisoning in the catalytic oxidation reaction of carbon monoxide.

[0010] The technical solution of the present invention is as follows: A method for preparing a carbon monoxide catalytic combustion catalyst includes the following steps: (1) Loading organotitanium and active metal precursors onto titanium dioxide; or loading organotitanium, active metal precursors and auxiliary metal precursors onto titanium dioxide; The active metal is at least one of Pt and Pd, and the auxiliary metal is at least one of Cu, Mn, Co, and Ce; (2) After drying, inert atmosphere calcination and air calcination in sequence, carbon monoxide catalytic combustion catalyst is obtained.

[0011] When the loading of active metal is too low, the catalytic activity of the catalyst is low; when the loading of active metal is too high, the improvement on the catalytic activity of the catalyst is minimal and the cost is too high.

[0012] Preferably, the loading of active metal, based on raw materials, is 0.3%wt to 1.5%wt.

[0013] Preferably, the precursor of the active metal is at least one of the nitrate, chlorate, and chloride salts of the active metal.

[0014] Additive metals can improve catalyst activity to some extent, but excessive loading will inhibit the catalyst's catalytic activity.

[0015] Preferably, the loading of the auxiliary metal is 0wt% to 5wt% based on the raw material.

[0016] Preferably, the precursor of the active metal is at least one of the nitrate, acetate, and chloride salts of the auxiliary metal.

[0017] After calcination in an inert atmosphere and in air, organotitanium forms a TiOx coating on the surface of the active metal and the auxiliary metal. This coating can exist stably under oxygen-containing high-temperature conditions, giving the catalyst good sulfur and water resistance.

[0018] Preferably, the loading of organotitanium is 1.0wt% to 5.0wt% based on the raw material.

[0019] When the loading of organotitanium is too low, an effective coating layer cannot be formed; when the loading of organotitanium is too high, the coating layer is too thick, which will inhibit the catalytic activity of the catalyst.

[0020] More preferably, the loading of organotitanium is 1.5wt% to 2.0wt% based on the raw material.

[0021] Preferably, the organotitanium is at least one of di(2-hydroxypropionic acid)diammonium hydroxide titanium and (triethanolamine)isopropoxide titanium (IV).

[0022] Preferably, step (1) includes: An impregnation solution is prepared by mixing and dissolving organic titanium and active metal precursors, and titanium dioxide is impregnated into the impregnation solution in an equal volume. Alternatively, an impregnation solution can be prepared by mixing and dissolving organic titanium, an active metal precursor, and an auxiliary metal precursor, and then impregnating an equal volume of titanium dioxide into the impregnation solution.

[0023] Preferably, the inert atmosphere is at least one of nitrogen, argon, and helium.

[0024] Preferably, the inert atmosphere calcination temperature is 350℃~450℃, and the calcination time is 2~5h.

[0025] Further preferred, the inert atmosphere calcination temperature is 380℃~410℃, and the calcination time is 3~5h.

[0026] Preferably, the air calcination temperature is 350℃~450℃ and the calcination time is 2~5h.

[0027] Further preferred, the air calcination temperature is 380℃~410℃, and the calcination time is 3~5h.

[0028] Preferably, the heating rate during the inert atmosphere roasting stage and the air roasting stage is 3~7℃ / min.

[0029] The preparation method of this invention involves supporting organotitanium, calcining in an inert atmosphere, and calcining in air to form a special encapsulation structure on the catalyst surface. This encapsulation structure remains stable under oxygen-containing high-temperature conditions, resulting in a catalyst with high carbon monoxide catalytic oxidation activity and good sulfur and water resistance. This catalyst can be applied to the catalytic combustion of carbon monoxide under complex flue gas conditions.

[0030] The present invention also provides a carbon monoxide catalytic combustion catalyst, which is prepared by the above preparation method.

[0031] The present invention also provides the application of the aforementioned carbon monoxide catalytic combustion catalyst in the catalytic degradation of carbon monoxide in industrial flue gas.

[0032] Preferably, the application includes: filling the carbon monoxide catalytic combustion catalyst into a fixed-bed reactor, introducing industrial flue gas containing carbon monoxide, with a total gas flow rate of 10~200 ml / min and a total volume hourly space velocity of 10000~50000 ml / (g cat·h); and a reaction temperature of 80~200℃.

[0033] Preferably, the industrial flue gas has a carbon monoxide concentration of 1000-10000 ppm, a sulfur dioxide concentration of 0-150 ppm, and a water vapor volume concentration of 0-15%.

[0034] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The carbon monoxide catalytic combustion catalyst of the present invention has high activity and strong water and sulfur resistance in carbon monoxide catalytic combustion.

[0035] (2) The catalyst preparation method of the present invention is simple, the raw materials are inexpensive, and it is easy to prepare on a large scale, and has good industrial application prospects. Attached Figure Description

[0036] Figure 1 CO-DRIFT spectra of the catalysts prepared in Example 1, Comparative Example 1, Comparative Example 2, and Comparative Example 3; Figure 2 Electron micrograph of the catalyst prepared in Example 1; Figure 3 Electron micrograph of the catalyst prepared in Comparative Example 1; As can be clearly seen from the electron microscope images, Example 1 has a distinct encapsulation layer, while Comparative Example 1 does not have a corresponding encapsulation layer.

[0037] Figure 4 The graphs show the stability test results of the catalysts prepared in Example 1, Comparative Example 1, and Comparative Example 2. Detailed Implementation

[0038] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be noted that the embodiments described below are intended to facilitate the understanding of the present invention and do not limit it in any way.

[0039] Example 1 0.5 g of palladium nitrate solution (10% Pd concentration) and 0.123 g of diammonium di(2-hydroxypropionic acid) hydroxide titanium dioxide were weighed and dissolved in 4.5 g of deionized water. After stirring for 30 min, an impregnation solution was obtained. 10 g of titanium dioxide was weighed and the impregnation solution was added dropwise to the surface of titanium dioxide while stirring. After the addition was complete, the catalyst was left to stand for 10 h and then dried in an oven at 80 °C for 10 h. Subsequently, the catalyst was placed in a tube furnace and calcined at 400 °C for 4 h under nitrogen atmosphere. Finally, the catalyst was calcined in a muffle furnace at 400 °C under air atmosphere for 4 h to obtain 0.5Pd-Ti-N400-Air-400.

[0040] Example 2 Weigh 0.5 g of platinum nitrate solution (10% Pt concentration) and 0.123 g of diammonium di(2-hydroxypropionic acid) hydroxide titanium dioxide, dissolve them in 4.5 g of deionized water, and stir for 30 min to obtain an impregnation solution. Weigh 10 g of titanium dioxide and add the impregnation solution dropwise onto the surface of titanium dioxide while stirring. After the addition is complete, let the catalyst stand for 10 h, then dry it in an oven at 80 °C for 10 h. Subsequently, place the catalyst in a tube furnace and calcine it at 400 °C for 4 h under nitrogen atmosphere. Finally, calcine the catalyst in a muffle furnace at 400 °C under air atmosphere for 4 h to obtain 0.5Pt-Ti-N400-Air-400.

[0041] Example 3 Weigh 0.5 g of palladium nitrate solution (10% Pd concentration) and 0.123 g of titanium isopropoxide (IV) (aminotriethanol) and dissolve them in 4.5 g of deionized water. After stirring for 30 min, an impregnation solution is obtained. Weigh 10 g of titanium dioxide and add the impregnation solution dropwise onto the surface of the titanium dioxide while stirring. After the addition is complete, the catalyst is left to stand for 10 h and then dried in an oven at 80 °C for 10 h. Subsequently, the catalyst is placed in a tube furnace and calcined at 400 °C for 4 h under nitrogen atmosphere. Finally, the catalyst is calcined in a muffle furnace at 400 °C under air atmosphere for 4 h to obtain 0.5Pd-Ti. （另一种前驱体） -N400-Air-400.

[0042] Example 4 0.5 g of palladium nitrate solution (10% Pd concentration) and 0.123 g of diammonium di(2-hydroxypropionic acid) hydroxide titanium dioxide were weighed and dissolved in 4.5 g of deionized water. After stirring for 30 min, an impregnation solution was obtained. 10 g of titanium dioxide was weighed and the impregnation solution was added dropwise to the surface of the titanium dioxide while stirring. After the addition was complete, the catalyst was left to stand for 10 h and then dried in an oven at 80 °C for 10 h. Subsequently, the catalyst was placed in a tube furnace and calcined at 400 °C for 4 h under helium. Finally, the catalyst was calcined in a muffle furnace at 400 °C under air for 4 h to obtain 0.5Pd-Ti-He400-Air-400.

[0043] Example 5 0.5 g of palladium nitrate solution (10% Pd concentration) and 0.123 g of diammonium di(2-hydroxypropionic acid) hydroxide titanium dioxide were weighed and dissolved in 4.5 g of deionized water. After stirring for 30 min, an impregnation solution was obtained. 10 g of titanium dioxide was weighed and the impregnation solution was added dropwise to the surface of the titanium dioxide while stirring. After the addition was complete, the catalyst was left to stand for 10 h and then dried in an oven at 80 °C for 10 h. Subsequently, the catalyst was placed in a tube furnace and calcined at 400 °C for 4 h under argon atmosphere. Finally, the catalyst was calcined in a muffle furnace at 400 °C under air atmosphere for 4 h to obtain 0.5Pd-Ti-Ar400-Air-400.

[0044] Example 6 0.5 g of palladium nitrate solution (10% Pd concentration) and 0.246 g of diammonium di(2-hydroxypropionic acid) hydroxide titanium dioxide were weighed and dissolved in 4.5 g of deionized water. After stirring for 30 min, an impregnation solution was obtained. 10 g of titanium dioxide was weighed and the impregnation solution was added dropwise to the surface of titanium dioxide while stirring. After the addition was complete, the catalyst was left to stand for 10 h and then dried in an oven at 80 °C for 10 h. Subsequently, the catalyst was placed in a tube furnace and calcined at 400 °C for 4 h under nitrogen atmosphere. Finally, the catalyst was calcined in a muffle furnace at 400 °C under air atmosphere for 4 h to obtain 0.5Pd-2Ti-N400-Air-400.

[0045] Example 7 0.3 g of palladium nitrate solution (10% Pd concentration) and 0.123 g of di(2-hydroxypropionic acid)diammonium hydroxide titanium dioxide were weighed and dissolved in 4.5 g of deionized water. After stirring for 30 min, an impregnation solution was obtained. 10 g of titanium dioxide was weighed and the impregnation solution was added dropwise to the surface of titanium dioxide while stirring. After the addition was complete, the catalyst was left to stand for 10 h and then dried in an oven at 80 °C for 10 h. Subsequently, the catalyst was placed in a tube furnace and calcined at 400 °C for 4 h under nitrogen atmosphere. Finally, the catalyst was calcined in a muffle furnace at 400 °C under air atmosphere for 4 h to obtain 0.3Pd-Ti-N400-Air-400.

[0046] Example 8 1 g of palladium nitrate solution (10% Pd concentration) and 0.123 g of di(2-hydroxypropionic acid)diammonium hydroxide titanium dioxide were weighed and dissolved in 4.5 g of deionized water. After stirring for 30 min, an impregnation solution was obtained. 10 g of titanium dioxide was weighed and the impregnation solution was added dropwise to the surface of the titanium dioxide while stirring. After the addition was complete, the catalyst was left to stand for 10 h and then dried in an oven at 80 °C for 10 h. Subsequently, the catalyst was placed in a tube furnace and calcined at 400 °C for 4 h under nitrogen atmosphere. Finally, the catalyst was calcined in a muffle furnace at 400 °C under air atmosphere for 4 h to obtain 1Pd-Ti-N400-Air-400.

[0047] Example 9 0.5 g of palladium nitrate solution (10% Pd concentration) and 0.123 g of diammonium di(2-hydroxypropionic acid) hydroxide titanium dioxide were weighed and dissolved in 4.5 g of deionized water. After stirring for 30 min, an impregnation solution was obtained. 10 g of titanium dioxide was weighed and the impregnation solution was added dropwise to the surface of the titanium dioxide while stirring. After the addition was complete, the catalyst was left to stand for 10 h and then dried in an oven at 80 °C for 10 h. Subsequently, the catalyst was placed in a tube furnace and calcined at 350 °C for 4 h under nitrogen atmosphere. Finally, the catalyst was calcined in a muffle furnace at 400 °C under air atmosphere for 4 h to obtain 0.5Pd-Ti-N350-Air-400.

[0048] Example 10 0.5 g of palladium nitrate solution (10% Pd concentration) and 0.123 g of diammonium di(2-hydroxypropionic acid) hydroxide titanium dioxide were weighed and dissolved in 4.5 g of deionized water. After stirring for 30 min, an impregnation solution was obtained. 10 g of titanium dioxide was weighed and the impregnation solution was added dropwise to the surface of the titanium dioxide while stirring. After the addition was complete, the catalyst was left to stand for 10 h and then dried in an oven at 80 °C for 10 h. Subsequently, the catalyst was placed in a tube furnace and calcined at 450 °C for 4 h under nitrogen atmosphere. Finally, the catalyst was calcined in a muffle furnace at 400 °C under air atmosphere for 4 h to obtain 0.5Pd-Ti-N400-Air-450.

[0049] Example 11 0.5 g of palladium nitrate solution (10% Pd concentration) and 0.123 g of diammonium di(2-hydroxypropionic acid) hydroxide titanium dioxide were weighed and dissolved in 4.5 g of deionized water. After stirring for 30 min, an impregnation solution was obtained. 10 g of titanium dioxide was weighed and the impregnation solution was added dropwise to the surface of the titanium dioxide while stirring. After the addition was complete, the catalyst was left to stand for 10 h and then dried in an oven at 80 °C for 10 h. Subsequently, the catalyst was placed in a tube furnace and calcined at 400 °C for 4 h under nitrogen atmosphere. Finally, the catalyst was calcined in a muffle furnace at 350 °C under air for 4 h to obtain 0.5Pd-Ti-N400-Air-350.

[0050] Example 12 0.5 g of palladium nitrate solution (10% Pd concentration) and 0.123 g of di(2-hydroxypropionic acid)diammonium hydroxide titanium dioxide were weighed and dissolved in 4.5 g of deionized water. After stirring for 30 min, an impregnation solution was obtained. 10 g of titanium dioxide was weighed and the impregnation solution was added dropwise to the surface of the titanium dioxide while stirring. After the addition was complete, the catalyst was left to stand for 10 h and then dried in an oven at 80 °C for 10 h. Subsequently, the catalyst was placed in a tube furnace and calcined at 400 °C for 4 h under nitrogen atmosphere. Finally, the catalyst was calcined in a muffle furnace at 450 °C under air atmosphere for 4 h to obtain 0.5Pd-Ti-N400-Air-450.

[0051] Example 13 Weigh 0.5 g of platinum nitrate solution (10% Pt concentration), 0.123 g of diammonium di(2-hydroxypropionic acid) hydroxide titanium dioxide, dissolve in 4.5 g of deionized water, and add 0.25 g of cobalt nitrate hexahydrate. Stir for 30 min to obtain an impregnation solution. Weigh 10 g of titanium dioxide and add the impregnation solution dropwise onto the surface of titanium dioxide while stirring. After the addition is complete, let the catalyst stand for 10 h, then dry it in an oven at 80 °C for 10 h. Subsequently, place the catalyst in a tube furnace and calcine at 400 °C for 4 h under nitrogen atmosphere. Finally, calcine the catalyst in a muffle furnace at 400 °C under air for 4 h to obtain 0.5Pt-Ti-0.5Co-N400-Air-400.

[0052] Example 14 Weigh 0.5 g of platinum nitrate solution (10% Pt concentration), 0.123 g of diammonium di(2-hydroxypropionic acid) hydroxide titanium dioxide, dissolve in 4.5 g of deionized water, and add 0.151 g of cerium nitrate hexahydrate. Stir for 30 min to obtain an impregnation solution. Weigh 10 g of titanium dioxide and add the impregnation solution dropwise onto the surface of titanium dioxide while stirring. After the addition is complete, let the catalyst stand for 10 h, then dry it in an oven at 80 °C for 10 h. Subsequently, place the catalyst in a tube furnace and calcine at 400 °C for 4 h under nitrogen atmosphere. Finally, calcine the catalyst in a muffle furnace at 400 °C under air for 4 h to obtain 0.5Pt-Ti-0.5Ce-N400-Air-400.

[0053] Example 15 Weigh 0.5 g of platinum nitrate solution (10% Pt concentration), 0.123 g of diammonium di(2-hydroxypropionic acid) hydroxide titanium dioxide, dissolve in 4.5 g of deionized water, and add 0.261 g of manganese nitrate hexahydrate. Stir for 30 min to obtain an impregnation solution. Weigh 10 g of titanium dioxide and add the impregnation solution dropwise onto the surface of titanium dioxide while stirring. After the addition is complete, let the catalyst stand for 10 h, then dry it in an oven at 80 °C for 10 h. Subsequently, place the catalyst in a tube furnace and calcine at 400 °C for 4 h under nitrogen atmosphere. Finally, calcine the catalyst in a muffle furnace at 400 °C under air for 4 h to obtain 0.5Pt-Ti-0.5Mn-N400-Air-400.

[0054] Example 16 Weigh 0.5 g of platinum nitrate solution (10% Pt concentration), 0.123 g of diammonium di(2-hydroxypropionic acid) hydroxide titanium dioxide, dissolve in 4.5 g of deionized water, and add 0.379 g of copper nitrate hexahydrate. Stir for 30 min to obtain an impregnation solution. Weigh 10 g of titanium dioxide and add the impregnation solution dropwise onto the surface of titanium dioxide while stirring. After the addition is complete, let the catalyst stand for 10 h, then dry it in an oven at 80 °C for 10 h. Subsequently, place the catalyst in a tube furnace and calcine at 400 °C for 4 h under nitrogen atmosphere. Finally, calcine the catalyst in a muffle furnace at 400 °C under air for 4 h to obtain 0.5Pt-Ti-0.5Cu-N400-Air-400.

[0055] Example 17 Weigh 0.5 g of platinum nitrate solution (10% Pt concentration), 0.123 g of diammonium di(2-hydroxypropionic acid) hydroxide titanium dioxide, dissolve in 4.5 g of deionized water, and add 1.5 g of cobalt nitrate hexahydrate. Stir for 30 min to obtain an impregnation solution. Weigh 10 g of titanium dioxide and add the impregnation solution dropwise onto the surface of titanium dioxide while stirring. After the addition is complete, let the catalyst stand for 10 h, then dry it in an oven at 80 °C for 10 h. Subsequently, place the catalyst in a tube furnace and calcine at 400 °C for 4 h under nitrogen atmosphere. Finally, calcine the catalyst in a muffle furnace at 400 °C under air for 4 h to obtain 0.5Pt-Ti-0.5Co-N400-Air-400.

[0056] Comparative Example 1 Weigh 0.5 g of palladium nitrate solution (10% Pd concentration), dissolve it in 4.5 g of deionized water, and stir for 30 min to obtain an impregnation solution. Weigh 10 g of titanium dioxide and add the impregnation solution dropwise onto the surface of the titanium dioxide while stirring. After the addition is complete, let the catalyst stand for 10 h, then dry it in an oven at 80 °C for 10 h. Subsequently, place the catalyst in a tube furnace and calcine it at 400 °C for 4 h under nitrogen atmosphere. Finally, calcine the catalyst in a muffle furnace at 400 °C under air atmosphere for 4 h.

[0057] Comparative Example 2 Weigh 0.5 g of palladium nitrate solution (10% Pd concentration) and 0.123 g of di(2-hydroxypropionic acid)diammonium hydroxide titanium dioxide, dissolve them in 4.5 g of deionized water, and stir for 30 min to obtain an impregnation solution. Weigh 10 g of titanium dioxide and add the impregnation solution dropwise onto the surface of titanium dioxide while stirring. After the addition is complete, let the catalyst stand for 10 h, then dry it in an oven at 80 °C for 10 h. Subsequently, calcine the catalyst in a muffle furnace at 400 °C under air for 4 h.

[0058] Comparative Example 3 Weigh 0.5 g of palladium nitrate solution (10% Pd concentration) and 0.1 g of melamine, dissolve them in 4.5 g of deionized water, and stir for 30 min to obtain an impregnation solution. Weigh 10 g of titanium dioxide and add the impregnation solution dropwise onto the surface of the titanium dioxide while stirring. After the addition is complete, let the catalyst stand for 10 h, then dry it in an oven at 80 °C for 10 h. Subsequently, place the catalyst in a tube furnace and calcine it at 400 °C for 4 h under nitrogen atmosphere. Finally, calcine the catalyst in a muffle furnace at 400 °C under air atmosphere for 4 h.

[0059] Comparative Example 4 0.5 g of palladium nitrate solution (10% Pd concentration) and 0.123 g of diammonium di(2-hydroxypropionic acid) hydroxide titanium dioxide were weighed and dissolved in 4.5 g of deionized water. After stirring for 30 min, an impregnation solution was obtained. 10 g of titanium dioxide was weighed and the impregnation solution was added dropwise to the surface of the titanium dioxide while stirring. After the addition was complete, the catalyst was left to stand for 10 h and then dried in an oven at 80 °C for 10 h. Subsequently, it was calcined in a muffle furnace at 400 °C under air for 4 h. Finally, the catalyst was placed in a tube furnace and calcined at 400 °C under nitrogen for 4 h to obtain 0.5Pd-Ti-Air-400-N400.

[0060] Comparative Example 4 Weigh 0.5 g of platinum nitrate solution (10% Pd concentration) and 0.123 g of diammonium di(2-hydroxypropionic acid) hydroxide titanium dioxide, dissolve them in 4.5 g of deionized water, and stir for 30 min to obtain an impregnation solution. Weigh 10 g of titanium dioxide and add the impregnation solution dropwise onto the surface of titanium dioxide while stirring. After the addition is complete, the catalyst is left to stand for 10 h, and then dried in an oven at 80 °C for 10 h. Subsequently, it is calcined in a muffle furnace at 400 °C under air for 4 h. Finally, the catalyst is placed in a tube furnace and calcined at 400 °C under nitrogen for 4 h to obtain 0.5Pt-Ti-Air-400-N400.

[0061] The samples were tested using a Nicolet 6700 infrared spectrometer. The samples were pretreated in a nitrogen stream at 120 °C and 30 mL / min for 1 hour, and then cooled to 30 °C before recording the background spectrum. At 30 °C, the nitrogen gas was switched to a 1% CO / N2 mixture for 30 minutes, followed by a switch back to nitrogen for 30 minutes, with infrared spectra recorded simultaneously.

[0062] 1970~2090 cm -1 The spectrum represents the characteristic peak range of CO adsorption on the Pd / TiO2 surface. After nitrogen stripping, the CO adsorption characteristic peaks essentially disappeared. Furthermore, almost no obvious CO adsorption characteristic peaks were observed in Example 1, while CO adsorption characteristic peaks reappeared in Comparative Example 1, a weak CO adsorption characteristic peak appeared in Comparative Example 2, and CO adsorption characteristic peaks also reappeared in Comparative Example 3. This spectrum indirectly indicates that an amorphous TiOx thin layer appeared on the surface of Example 1, significantly suppressing CO adsorption. Comparative Example 2 may have partially formed an encapsulation structure. Comparative Examples 1 and 3 did not form an encapsulation structure.

[0063] TEM images of the catalysts prepared in Example 1 and Comparative Example 1 are shown below. Figure 2 and Figure 3As shown in the electron microscope image, it is clear that the catalyst prepared in Example 1 has a distinct coating layer, while the catalyst prepared in Comparative Example 1 does not have a corresponding coating layer.

[0064] Catalyst activity evaluation: 200 mg of the catalysts prepared in Examples 1-17 and Comparative Examples 1-5 were weighed and placed into fixed-bed reactors respectively. A mixed gas of carbon monoxide and air at 8000 ppm was introduced, with a total gas flow rate of 100 ml / min and a total volume hourly space velocity of 30000 ml / (g cat·h). The concentrations of CO and CO2 were measured using a gas chromatograph.

[0065] The conversion rate of the corresponding substance was calculated based on the change in net outlet concentration. Starting from 60℃, the concentration of carbon monoxide in the reactor tail gas was measured under different reaction temperatures. The conversion rate of carbon monoxide was calculated based on the change in carbon monoxide concentration, and the temperature T at which the carbon monoxide conversion rate reached 99% was recorded. 99 The results are recorded in Table 1.

[0066] The conversion rate calculation formula is: w= .

[0067] Table 1 Evaluation of catalyst's sulfur resistance stability: 200 mg of the catalysts prepared in Example 1, Comparative Example 1, and Comparative Example 2 were weighed and placed into fixed-bed reactors respectively. 8000 ppm carbon monoxide, 100 ppm sulfur dioxide, 10% water vapor, and the remainder air were introduced. The total gas flow rate was 100 ml / min. The reaction was carried out continuously at 135 °C, and the catalyst activity was continuously tested. The results are shown in [Figure showing the results]. Figure 4 .

[0068] Comparing the data in Table 1, it can be seen that the catalyst prepared using the technical solution of this invention exhibits higher catalytic activity for carbon monoxide. This may be because the catalyst obtained after inert atmosphere calcination and air calcination has an encapsulated structure, and the noble metal is in a low valence state after inert atmosphere calcination, resulting in higher catalyst activity. Furthermore, from... Figure 4 It can be clearly seen that the catalyst prepared using the technical solution of this invention has excellent water and sulfur resistance in the catalytic carbon monoxide combustion reaction at 135℃, and exhibits excellent stability.

[0069] The embodiments described above provide a detailed explanation of the technical solutions and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, additions, and equivalent substitutions made within the scope of the principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a carbon monoxide catalytic combustion catalyst, characterized in that, Includes the following steps: (1) Loading organotitanium and active metal precursors onto titanium dioxide; or loading organotitanium, active metal precursors and auxiliary metal precursors onto titanium dioxide; The active metal is at least one of Pt and Pd, and the auxiliary metal is at least one of Cu, Mn, Co, and Ce; (2) After drying, inert atmosphere calcination and air calcination in sequence, carbon monoxide catalytic combustion catalyst is obtained.

2. The method for preparing the carbon monoxide catalytic combustion catalyst according to claim 1, characterized in that, In step (1), the loading of active metal is 0.3%wt~1.5%wt based on raw materials.

3. The method for preparing the carbon monoxide catalytic combustion catalyst according to claim 1, characterized in that, In step (1), the loading of the auxiliary metal is 0wt%~5wt% based on the raw materials.

4. The method for preparing the carbon monoxide catalytic combustion catalyst according to claim 1, characterized in that, In step (1), the loading of organic titanium is 1.0wt%~5.0wt% based on raw materials.

5. The method for preparing the carbon monoxide catalytic combustion catalyst according to claim 1 or 4, characterized in that, The organic titanium is at least one of di(2-hydroxypropionic acid)diammonium hydroxide titanium and (triethanolamine)isopropoxide titanium (IV).

6. The method for preparing the carbon monoxide catalytic combustion catalyst according to claim 1, characterized in that, In step (2), the inert atmosphere is at least one of nitrogen, argon, and helium, the inert atmosphere calcination temperature is 350℃~450℃, and the calcination time is 2~5h.

7. The method for preparing the carbon monoxide catalytic combustion catalyst according to claim 1, characterized in that, In step (2), the air roasting temperature is 350℃~450℃ and the roasting time is 2~5h.

8. A carbon monoxide catalytic combustion catalyst, characterized in that, It is prepared by the preparation method according to any one of claims 1 to 7.

9. The application of the carbon monoxide catalytic combustion catalyst of claim 8 in the catalytic degradation of carbon monoxide in industrial flue gas.

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