Smoking smoke purification catalyst as well as preparation method and application thereof

Abstract

The invention provides a smoke purification catalyst as well as a preparation method and application thereof. The smoke purification catalyst comprises an active metal and an active compound, the active metal comprises Pt and Pd; the active compound comprises modified aluminum oxide, a modified cerium-zirconium oxygen storage material and a molecular sieve. The flue gas purification catalyst provided by the invention has excellent catalytic activity and high-temperature-resistant stability through synergistic cooperation of the active metal and the active compound component, has a remarkable purification effect on CO and hydrocarbon, has the purification efficiency of 99% or more and can still reach 98% or more after aging treatment, and has a good purification effect on high-concentration flue gas in a smoking working condition. Long-term stable operation can be achieved, and the overall purification efficiency is 95% or above.

Description

Technical Field

[0001] The invention belongs to the technical field of gas purification, and relates to a flue gas purification catalyst, and in particular to a fumigation flue gas purification catalyst and a preparation method and application thereof. Background Art

[0002] With the improvement of living standards, modern people pay more and more attention to physical health and family environmental protection issues. In the family space, the indoor space is small and the ventilation conditions are poor, making the smoke in the family space more complicated and difficult to deal with.

[0003] Household smokers process food by slowly burning or incompletely burning smoke materials to produce smoke. When in use, they need to generate smoke. The use environment is generally in an oxygen-deficient state. In addition, the smoke circulation is slow, and the CO emission concentration can reach more than 1000ppm. In general, CO concentrations in the environment exceed 35ppm, which may cause headaches, fatigue, accelerated heartbeats and other safety issues. Such high concentrations of CO emissions from household smokers are bound to seriously affect health and may even cause carbon monoxide poisoning and coma. At the same time, the charcoal used in the smoker will also emit hydrocarbon gases with irritating odors when producing smoke, which are not suitable for human inhalation. Therefore, it is urgent to control the emission of CO and irritating odor gases in the smoke.

[0004] For example, CN118384896A, CN118341446A, etc. disclose catalysts for CO removal and purification. At present, the existing catalysts for flue gas removal and purification have the following problems: (1) they can only treat CO in flue gas, and have poor treatment effects on hydrocarbon gases with pungent odors; (2) the catalysts usually contain a high content of active precious metals, and the cost of such catalysts is often high, which is not suitable for home environments; (3) the high-temperature activity of the catalyst is poor, and the temperature condition of more than 500°C is often required for fumigation. The catalyst will cause performance degradation if it is exposed to high-temperature water vapor for a long time, making it difficult to use for a long time; (4) the catalyst has poor sulfur resistance and is easily poisoned by sulfur. Meat contains a certain amount of sulfur, so the catalyst is required to have a high resistance to sulfur poisoning. Poor sulfur resistance also shortens the service life of the catalyst.

[0005] Based on the deficiencies of existing catalysts, the present invention provides a fumigation flue gas purification catalyst and a preparation method and application thereof. Summary of the invention

[0006] The object of the present invention is to provide a fumigation flue gas purification catalyst and a preparation method and application thereof, so as to catalytically purify high-concentration CO and hydrocarbons in a fumigation working environment.

[0007] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0008] In a first aspect, the present invention provides a fumigation flue gas purification catalyst, the fumigation flue gas purification catalyst comprising: an active metal and an active compound;

[0009] The active metals include Pt and Pd;

[0010] The active compound comprises modified alumina, modified cerium-zirconium oxygen storage material and molecular sieve.

[0011] The flue gas purification catalyst provided by the present invention uses Pt and Pd as active metals, modified alumina, modified cerium-zirconium oxygen storage materials and molecular sieves as active compound components to carry out catalytic conversion with active metals. The modified alumina has suitable acidity and sulfur resistance, and can be used as a carrier to carry active metals. The modified cerium-zirconium oxygen storage material can provide oxygen adsorption active sites, stabilize the active metal load, and improve the catalytic efficiency and stability of the active metal. The molecular sieve has a good adsorption and storage effect on odorous hydrocarbon molecules due to its unique pore structure. Through the coordinated coordination of the catalyst components, the catalytic activity and long-term operation stability of the catalyst are significantly improved, and it has an excellent purification effect for high-concentration smoke.

[0012] Preferably, the smoke-gas purification catalyst comprises: 0.1-0.5wt% of active metal, 60-70wt% of modified alumina, 10-20wt% of modified cerium-zirconium oxygen storage material, and 10-15wt% of molecular sieve.

[0013] In the fumigation flue gas purification catalyst, the content of active metal is 0.1-0.5wt%, for example, it can be 0.1wt%, 0.15wt%, 0.2wt%, 0.25wt%, 0.3wt%, 0.35wt%, 0.4wt%, 0.45wt% or 0.5wt%, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0014] In the fumigated flue gas purification catalyst, the content of modified alumina is 60-70wt%, for example, it can be 60wt%, 61wt%, 62wt%, 63wt%, 64wt%, 65wt%, 66wt%, 67wt%, 68wt%, 69wt% or 70wt%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0015] In the smoked flue gas purification catalyst, the content of the modified cerium-zirconium oxygen storage material is 10-20wt%, for example, it can be 10wt%, 11wt%, 12wt%, 13wt%, 14wt%, 15wt%, 16wt%, 17wt%, 18wt%, 19wt% or 20wt%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0016] In the smoke-gas purification catalyst, the content of molecular sieve is 10-15wt%, for example, it can be 10wt%, 10.5wt%, 11wt%, 11.5wt%, 12wt%, 12.5wt%, 13wt%, 13.5wt%, 14wt%, 14.5wt% or 15wt%, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0017] Preferably, the mass ratio of Pt to Pd is 1:(0.1-1), for example, it can be 1:0.1, 1:0.2, 1:0.3, 1:0.4, 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9 or 1:1, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0018] Preferably, the modified alumina includes Ti, Si and Zr modified alumina.

[0019] Preferably, the composition of the modified alumina is expressed as Ti a Si b Zr c -mAl2O3, wherein a:b:c:m is (1-10):(1-10):(1-10):(70-90).

[0020] The a:b:c:m is (1-10):(1-10):(1-10):(70-90), for example, it can be 10:10:10:70, 5:10:10:75, 10:5:10:75, 10:10:5:75, 5:5:10:80, 5:10:5:80, 10:5:5:80, 5:5:5:85, 1:4:10:85, 10:4:1:85, 1:3:6:90, 6:3:1:90, 2:4:4:90 or 3:3:4:90, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0021] Preferably, the modified cerium-zirconium oxygen storage material includes La and Pr modified cerium-zirconium oxygen storage material.

[0022] Preferably, the composition of the modified cerium-zirconium oxygen storage material is expressed as Ce d Zr e La f Pr g O x , where d:e:f:g is (40-60):(30-50):(1-10):(1-10).

[0023] The d:e:f:g is (40-60):(30-50):(1-10):(1-10), for example, it can be 40:40:10:10, 40:45:5:10, 40:45:10:5, 40:50:5:5, 45:35:10:10, 45:40:5:10, 45:45:5:5, 45:50:1:4, 50:30:10:10, 50:40:5:5, 55:30:5:10, 55:40:1:4, 60:30:5:5 or 60:35:4:1, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0024] The range of x is 140-260.

[0025] Preferably, the molecular sieve comprises any one of ZSM-5, β molecular sieve, 5A molecular sieve or SSZ-13, or a combination of at least two thereof. Typical but non-limiting combinations include a combination of ZSM-5 and β molecular sieve, a combination of β molecular sieve and 5A molecular sieve, a combination of 5A molecular sieve and SSZ-13, a combination of ZSM-5, β molecular sieve and 5A molecular sieve, a combination of β molecular sieve, 5A molecular sieve and SSZ-13, or a combination of ZSM-5, β molecular sieve, 5A molecular sieve and SSZ-13.

[0026] Preferably, the fumigation flue gas purification catalyst further comprises: a rare earth additive.

[0027] Preferably, the rare earth additive includes any one of La, Ce or Y or a combination of at least two of them. Typical but non-limiting combinations include a combination of La and Ce, a combination of Ce and Y, a combination of La and Y, or a combination of La, Ce and Y.

[0028] Preferably, in the fumigation flue gas purification catalyst, the content of the rare earth additive is 0.5-5wt%, for example, it can be 0.5wt%, 1wt%, 1.5wt%, 2wt%, 2.5wt%, 3wt%, 3.5wt%, 4wt%, 4.5wt% or 5wt%, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0029] Preferably, the fumigation flue gas purification catalyst further comprises: a binder.

[0030] Preferably, the binder is boehmite and / or pseudo-boehmite.

[0031] Preferably, in the smoke-gas purification catalyst, the content of the binder is 1-7wt%, for example, it can be 1wt%, 2wt%, 3wt%, 4wt%, 5wt%, 6wt% or 7wt%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0032] Preferably, the pore volume of the smoke-gas purification catalyst is ≥0.8 mL / g, for example, it can be 0.8 mL / g, 1.0 mL / g, 1.5 mL / g, 2.0 mL / g, 3.0 mL / g or 5.0 mL / g, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0033] Preferably, the specific surface area of ​​the smoke-fed flue gas purification is ≥140m 2 / g, for example, it can be 140m 2 / g, 145m 2 / g, 150m 2 / g, 160m 2 / g, 180m 2 / g or 200m 2 / g, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0034] In a second aspect, the present invention provides a method for preparing the smoke-gas purification catalyst according to the first aspect, the preparation method comprising the following steps:

[0035] (1) mixing modified alumina, active metal salt, rare earth additive and modified cerium-zirconium oxygen storage material to obtain a mixture, and then sequentially mixing the mixture with a reducing agent, a complexing agent and a molecular sieve to obtain an active component slurry;

[0036] (2) mixing the active component slurry obtained in step (1) with a binder and cellulose to obtain a coating slurry;

[0037] (3) The coating slurry obtained in step (2) is sequentially calcined and reduced to obtain a catalyst coating.

[0038] The preparation method of the catalyst provided by the present invention comprises the following steps: firstly mixing modified alumina, active metal salt, rare earth additive and modified cerium zirconium oxygen storage material, adding reducing agent and complexing agent, wherein the reducing agent reduces the active metal and forms a platinum-palladium alloy state, the complexing agent combines the noble metal and the carrier material together, the rare earth additive plays the role of dispersing and stabilizing the active metal, and then adding molecular sieve to obtain the active component of the core-shell structure of the molecular sieve wrapped platinum-palladium alloy, and then adjusting the viscosity of the active component slurry, and then calcining and reducing to obtain a catalyst with high catalytic purification activity. In the present invention, the obtained coating slurry can be applied to the carrier used to form a catalyst coating for use.

[0039] Preferably, the active metal salt in step (1) comprises any one of nitrate, hydrochloride, acetate or acetylacetonate of the active metal, or a combination of at least two thereof. Typical but non-limiting combinations include a combination of nitrate and hydrochloride, a combination of hydrochloride and acetate, a combination of acetate and acetylacetonate, a combination of nitrate, hydrochloride and acetate, a combination of hydrochloride, acetate and acetylacetonate, or a combination of nitrate, hydrochloride, acetate and acetylacetonate.

[0040] Preferably, the reducing agent in step (1) comprises any one of hydrazine hydrate, methanol, ethanol, ethylene glycol, propanol or glycerol, or a combination of at least two thereof. Typical but non-limiting combinations include a combination of hydrazine hydrate and methanol, a combination of ethanol and ethylene glycol, a combination of propanol and glycerol, a combination of hydrazine hydrate, methanol and ethylene glycol, or a combination of ethanol, propanol and glycerol.

[0041] Preferably, the pH of the mixture in step (1) is 3-6, for example, 3, 3.5, 4, 4.5, 5, 5.5 or 6, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0042] Preferably, the amount of the reducing agent in step (1) is 3-5 times the molar amount of the active metal, for example, it can be 3 times, 3.5 times, 4 times, 4.5 times or 5 times, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0043] Preferably, the complexing agent in step (1) comprises any one of citric acid, ascorbic acid, oxalic acid or ethylenediaminetetraacetic acid, or a combination of at least two thereof. Typical but non-limiting combinations include a combination of citric acid and ascorbic acid, a combination of ascorbic acid and oxalic acid, a combination of oxalic acid and ethylenediaminetetraacetic acid, a combination of citric acid, ascorbic acid and oxalic acid, or a combination of ascorbic acid, oxalic acid and ethylenediaminetetraacetic acid.

[0044] Preferably, the amount of the complexing agent in step (1) is 3-5 times the molar amount of the active metal, for example, it can be 3 times, 3.5 times, 4 times, 4.5 times or 5 times, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0045] Preferably, the amount of cellulose in step (2) is 0.1-0.5wt% of the smoke gas purification catalyst, for example, it can be 0.1wt%, 0.2wt%, 0.3wt%, 0.4wt% or 0.5wt%, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0046] Preferably, the calcination temperature in step (3) is 450-550°C, for example, 450°C, 460°C, 480°C, 500°C, 520°C, 540°C or 550°C, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0047] Preferably, the calcination time in step (3) is 1-3 h, for example, 1 h, 1.5 h, 2 h, 2.5 h or 3 h, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0048] Preferably, the reduction in step (3) is carried out under a hydrogen atmosphere.

[0049] Preferably, the reduction temperature in step (3) is 300-500°C, for example, 300°C, 320°C, 340°C, 350°C, 360°C, 380°C, 400°C, 420°C, 440°C, 450°C, 460°C, 480°C or 500°C, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0050] Preferably, the reduction time in step (3) is 0.5-2 h, for example, 0.5 h, 0.8 h, 1 h, 1.2 h, 1.5 h, 1.8 h or 2 h, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0051] In a third aspect, the present invention provides an application of the fumigation fume purification catalyst according to the first aspect, wherein the fumigation fume purification catalyst is applied to a fumigator.

[0052] Compared with the prior art, the present invention has the following beneficial effects:

[0053] The flue gas purification catalyst provided by the present invention has excellent catalytic activity and high temperature stability through the synergistic coordination of active metal and active compound components, and has a significant purification effect on CO and hydrocarbons, with a purification efficiency of more than 99%, which can still reach more than 98% after aging treatment. For high-concentration flue gas in fumigation conditions, it can operate stably for a long time, and the overall purification efficiency is more than 95%. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 This is a graph showing the ignition temperature characteristic of the smoke-gas purification catalyst provided in Example 1. DETAILED DESCRIPTION

[0055] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0056] In a specific embodiment, the modified alumina and modified cerium-zirconium oxygen storage materials used are purchased commercial products.

[0057] Example 1

[0058] This embodiment provides a smoke-gas purification catalyst, and the smoke-gas purification catalyst comprises:

[0059] Pt 0.2wt%, Pd 0.06wt%, modified alumina 69.74wt%, modified cerium-zirconium oxygen storage material 10wt%, molecular sieve 10wt%, rare earth additive cerium 3wt%, rare earth additive lanthanum 2wt%, binder 5wt%.

[0060] The mass ratio of Pt to Pd is 1:0.3.

[0061] The composition of the modified alumina is expressed as Ti 10 Si5Zr5-80Al2O3.

[0062] The composition of the modified cerium-zirconium oxygen storage material is expressed as Ce 40 Zr 50 Lp5V x , x is 196.7.

[0063] The molecular sieve is ZSM-5 molecular sieve.

[0064] The preparation method of the fumigation flue gas purification catalyst comprises the following steps:

[0065] (1) Weigh the modified alumina into a bucket and stir evenly;

[0066] (2) Weigh the Pt nitrate solution, dilute it 5 times, weigh the rare earth additive cerium nitrate and add it to the solution. After it is completely dissolved, add it to a bucket and stir it;

[0067] (3) Weigh the Pd nitrate solution, dilute it 5 times, weigh the rare earth additive lanthanum nitrate and add it to the solution. After it is completely dissolved, add it to a bucket and stir it;

[0068] (4) Weighing the modified cerium-zirconium oxygen storage material and adding it into a bucket, adjusting the resulting slurry to a pH of 5;

[0069] (5) Weigh 5% of the reducing agent hydrazine hydrate in the slurry and add it to the slurry, stirring;

[0070] (6) Weigh 5% of the complexing agent citric acid in the slurry and add it to the slurry and stir evenly;

[0071] (7) Weigh ZSM-5 molecular sieve into a bucket and stir evenly;

[0072] (8) Weigh pseudo-boehmite into a bucket and stir, add cellulose, and stir until the coating viscosity is reached. The amount of cellulose added is 0.4 wt% of the catalyst;

[0073] (9) The slurry obtained after stirring was dried at 100°C, calcined at 500°C for 2 h, and finally reduced at 300°C for 1 h in a hydrogen atmosphere to obtain a catalyst.

[0074] Example 2

[0075] This embodiment provides a smoke-gas purification catalyst, and the smoke-gas purification catalyst comprises:

[0076] Pt 0.4wt%, Pd 0.05wt%, modified alumina 61.55wt%, modified cerium-zirconium oxygen storage material 20wt%, molecular sieve 10wt%, rare earth additive cerium 3wt%, rare earth additive lanthanum 1wt%, binder 4wt%.

[0077] The mass ratio of Pt to Pd is 1:0.13.

[0078] The composition of the modified alumina is expressed as Ti5Si 10 Zr5-80Al2O3.

[0079] The composition of the modified cerium-zirconium oxygen storage material is expressed as Ce 45 Zr 45 Lp5V x , x is 196.7.

[0080] The molecular sieve is a β molecular sieve.

[0081] The preparation method of the fumigation flue gas purification catalyst comprises the following steps:

[0082] (1) Weigh the modified alumina into a bucket and stir evenly;

[0083] (2) Weigh the Pt nitrate solution, dilute it 5 times, weigh the rare earth additive cerium nitrate and add it to the solution. After it is completely dissolved, add it to a bucket and stir it;

[0084] (3) Weigh the Pd nitrate solution, dilute it 5 times, weigh the rare earth additive lanthanum nitrate and add it to the solution. After it is completely dissolved, add it to a bucket and stir it;

[0085] (4) Weighing the modified cerium-zirconium oxygen storage material and adding it into a bucket, adjusting the resulting slurry to a pH of 5;

[0086] (5) Weigh 5% of the reducing agent hydrazine hydrate in the slurry and add it to the slurry, stirring;

[0087] (6) Weigh 5% of the complexing agent ascorbic acid in the slurry and add it to the slurry and stir evenly;

[0088] (7) Weigh the molecular sieve and put it into a bucket, stirring evenly;

[0089] (8) Weigh pseudo-boehmite into a bucket and stir, add cellulose, and stir until the coating viscosity is reached. The amount of cellulose added is 0.3 wt% of the catalyst;

[0090] (9) The slurry obtained after stirring was dried at 100°C, calcined at 500°C for 2 h, and finally reduced at 300°C for 2 h in a hydrogen atmosphere to obtain a catalyst.

[0091] Example 3

[0092] This embodiment provides a smoke-gas purification catalyst, and the smoke-gas purification catalyst comprises:

[0093] Pt 0.2wt%, Pd 0.2wt%, modified alumina 64.6wt%, modified cerium-zirconium oxygen storage material 15wt%, molecular sieve 10wt%, rare earth additive cerium 3wt%, rare earth additive lanthanum 2wt%, binder 5wt%.

[0094] The mass ratio of Pt to Pd is 1:1.

[0095] The composition of the modified alumina is expressed as Ti 10 Si 10 Zr 10 -70Al2O3.

[0096] The composition of the modified cerium-zirconium oxygen storage material is expressed as Ce 40 Zr 50 Lp5V x , x is 196.7.

[0097] The molecular sieve is SSZ-13 molecular sieve.

[0098] The preparation method of the fumigation flue gas purification catalyst comprises the following steps:

[0099] (1) Weigh the modified alumina into a bucket and stir evenly;

[0100] (2) Weigh the Pt nitrate solution, dilute it 5 times, weigh the rare earth additive cerium nitrate and add it to the solution. After it is completely dissolved, add it to a bucket and stir it;

[0101] (3) Weigh the Pd nitrate solution, dilute it 5 times, weigh the rare earth additive lanthanum nitrate and add it to the solution. After it is completely dissolved, add it to a bucket and stir it;

[0102] (4) Weighing the modified cerium-zirconium oxygen storage material and adding it into a bucket, adjusting the resulting slurry to a pH of 5;

[0103] (5) Weigh 5% of the reducing agent ethylene glycol and add it to the slurry, stirring;

[0104] (6) Weigh 5% of the complexing agent oxalic acid in the slurry and add it to the slurry and stir evenly;

[0105] (7) Weigh the molecular sieve and put it into a bucket, stirring evenly;

[0106] (8) Weigh pseudo-boehmite into a bucket and stir, add cellulose, and stir until the coating viscosity is reached. The amount of cellulose added is 0.4 wt% of the catalyst;

[0107] (9) The slurry obtained after stirring was dried at 100°C, calcined at 500°C for 2 h, and finally reduced at 400°C for 1 h in a hydrogen atmosphere to obtain a catalyst.

[0108] Example 4

[0109] This embodiment provides a smoke-gas purification catalyst, and the smoke-gas purification catalyst comprises:

[0110] Pt 0.3wt%, Pd 0.2wt%, modified alumina 59.5wt%, modified cerium-zirconium oxygen storage material 20wt%, molecular sieve 10wt%, rare earth additive cerium 2wt%, rare earth additive lanthanum 1wt%, binder 7wt%.

[0111] The mass ratio of Pt to Pd is 1:0.7.

[0112] The composition of the modified alumina is expressed as Ti5Si3Zr2-90Al2O3.

[0113] The composition of the modified cerium-zirconium oxygen storage material is expressed as Ce 60 Zr 30 Lp5V x , x is 196.7.

[0114] The molecular sieve is SSZ-13 molecular sieve.

[0115] The preparation method of the fumigation flue gas purification catalyst comprises the following steps:

[0116] (1) Weigh the modified alumina into a bucket and stir evenly;

[0117] (2) Weigh the Pt nitrate solution, dilute it 5 times, weigh the rare earth additive cerium nitrate and add it to the solution. After it is completely dissolved, add it to a bucket and stir it;

[0118] (3) Weigh the Pd nitrate solution, dilute it 5 times, weigh the rare earth additive lanthanum nitrate and add it to the solution. After it is completely dissolved, add it to a bucket and stir it;

[0119] (4) Weighing the modified cerium-zirconium oxygen storage material and adding it into a bucket, adjusting the resulting slurry to a pH of 5;

[0120] (5) Weigh 5% of the reducing agent ethanol into the slurry and add it to the slurry, stirring;

[0121] (6) Weigh 5% of the complexing agent oxalic acid in the slurry and add it to the slurry and stir evenly;

[0122] (7) Weigh the molecular sieve and put it into a bucket, stirring evenly;

[0123] (8) Weigh pseudo-boehmite into a bucket and stir, add cellulose, and stir until the coating viscosity is reached. The amount of cellulose added is 0.4 wt% of the catalyst;

[0124] (9) The slurry obtained after stirring was dried at 100°C, calcined at 500°C for 2 h, and finally reduced at 500°C for 0.5 h in a hydrogen atmosphere to obtain a catalyst.

[0125] Example 5

[0126] This embodiment provides a smoke-gas purification catalyst, and the smoke-gas purification catalyst comprises:

[0127] Pt 0.2wt%, Pd 0.3wt%, modified alumina 69.5wt%, modified cerium-zirconium oxygen storage material 10wt%, molecular sieve 10wt%, rare earth additive cerium 3wt%, rare earth additive lanthanum 2wt%, binder 5wt%.

[0128] The mass ratio of Pt to Pd is 1:1.5.

[0129] The composition of the modified alumina is expressed as Ti 10 Si5Zr5-80Al2O3.

[0130] The composition of the modified cerium-zirconium oxygen storage material is expressed as Ce 40 Zr 50 Lp5V x , x is 196.7.

[0131] The molecular sieve is ZSM-5 molecular sieve.

[0132] That is, compared with Example 1, the content of Pd in ​​the fumigation flue gas purification catalyst is controlled to be 0.3wt%, the mass ratio of Pt to Pd is 1:1.5, and the rest is the same as Example 1.

[0133] The preparation method of the fumigation flue gas purification catalyst is the same as that of Example 1.

[0134] Example 6

[0135] This embodiment provides a smoke-gas purification catalyst, and the smoke-gas purification catalyst comprises:

[0136] Pt 0.2wt%, Pd 0.06wt%, modified alumina 69.74wt%, modified cerium-zirconium oxygen storage material 10wt%, molecular sieve 10wt%, rare earth additive cerium 3wt%, rare earth additive lanthanum 2wt%, binder 5wt%.

[0137] The mass ratio of Pt to Pd is 1:0.3.

[0138] The composition of the modified alumina is expressed as Ti 10 Zr 10 -80Al2O3.

[0139] The composition of the modified cerium-zirconium oxygen storage material is expressed as Ce 40 Zr 50 Lp5V x , x is 196.7.

[0140] The molecular sieve is ZSM-5 molecular sieve.

[0141] That is, the fumigation flue gas purification catalyst, compared with Example 1, replaces the modified alumina with Ti in equal amounts. 10 Zr 10 -80Al2O3, and the rest are the same as in Example 1.

[0142] The preparation method of the fumigation flue gas purification catalyst is the same as that of Example 1.

[0143] Example 7

[0144] This embodiment provides a smoke-gas purification catalyst, and the smoke-gas purification catalyst comprises:

[0145] Pt 0.2wt%, Pd 0.06wt%, modified alumina 69.74wt%, modified cerium-zirconium oxygen storage material 10wt%, molecular sieve 10wt%, rare earth additive cerium 3wt%, rare earth additive lanthanum 2wt%, binder 5wt%.

[0146] The mass ratio of Pt to Pd is 1:0.3.

[0147] The composition of the modified alumina is expressed as Ti 10 Si 10 -80Al2O3.

[0148] The composition of the modified cerium-zirconium oxygen storage material is expressed as Ce 40 Zr 50 Lp5V x , x is 196.7.

[0149] The molecular sieve is ZSM-5 molecular sieve.

[0150] That is, the fumigation flue gas purification catalyst, compared with Example 1, replaces the modified alumina with Ti in equal amounts. 10 Si 10 -80Al2O3, and the rest are the same as in Example 1.

[0151] The preparation method of the fumigation flue gas purification catalyst is the same as that of Example 1.

[0152] Example 8

[0153] This embodiment provides a smoke-gas purification catalyst, and the smoke-gas purification catalyst comprises:

[0154] Pt 0.2wt%, Pd 0.06wt%, modified alumina 69.74wt%, modified cerium-zirconium oxygen storage material 10wt%, molecular sieve 10wt%, rare earth additive cerium 3wt%, rare earth additive lanthanum 2wt%, binder 5wt%.

[0155] The mass ratio of Pt to Pd is 1:0.3.

[0156] The composition of the modified alumina is expressed as Ti 10 Si5Zr5-80Al2O3.

[0157] The composition of the modified cerium-zirconium oxygen storage material is expressed as Ce 40 Zr 50 La 10 O x , x is 195.

[0158] The molecular sieve is ZSM-5 molecular sieve.

[0159] That is, the fumigation flue gas purification catalyst, compared with Example 1, replaces the modified cerium zirconium oxygen storage material with Ce 40 Zr 50 La 10 O x , the rest are the same as in Example 1.

[0160] The preparation method of the fumigation flue gas purification catalyst is the same as that of Example 1.

[0161] Example 9

[0162] This embodiment provides a smoke-gas purification catalyst, and the smoke-gas purification catalyst comprises:

[0163] Pt 0.2wt%, Pd 0.06wt%, modified alumina 69.74wt%, modified cerium-zirconium oxygen storage material 10wt%, molecular sieve 10wt%, rare earth additive cerium 3wt%, rare earth additive lanthanum 2wt%, binder 5wt%.

[0164] The mass ratio of Pt to Pd is 1:0.3.

[0165] The composition of the modified alumina is expressed as Ti 10 Si5Zr5-80Al2O3.

[0166] The composition of the modified cerium-zirconium oxygen storage material is expressed as Ce 40 Zr 50 Pr 10 O x , x is 198.3.

[0167] The molecular sieve is ZSM-5 molecular sieve.

[0168] That is, the fumigation flue gas purification catalyst, compared with Example 1, replaces the modified cerium zirconium oxygen storage material with Ce 40 Zr 50 Pr 10 O x , the rest are the same as in Example 1.

[0169] The preparation method of the fumigation flue gas purification catalyst is the same as that of Example 1.

[0170] Example 10

[0171] This embodiment provides a smoke-gas purification catalyst, and the smoke-gas purification catalyst comprises:

[0172] Pt 0.2wt%, Pd 0.06wt%, modified alumina 69.74wt%, modified cerium-zirconium oxygen storage material 10wt%, molecular sieve 10wt%, rare earth additive cerium 3wt%, rare earth additive lanthanum 2wt%, binder 5wt%.

[0173] The mass ratio of Pt to Pd is 1:0.3.

[0174] The composition of the modified alumina is expressed as Ti 10 Si5Zr5-80Al2O3.

[0175] The composition of the modified cerium-zirconium oxygen storage material is expressed as Ce 40 Zr 50 5Y5 x , x is 195.

[0176] The molecular sieve is ZSM-5 molecular sieve.

[0177] That is, the fumigation flue gas purification catalyst, compared with Example 1, replaces the modified cerium zirconium oxygen storage material with Ce 40 Zr 50 5Y5 x , the rest are the same as in Example 1.

[0178] The preparation method of the fumigation flue gas purification catalyst is the same as that of Example 1.

[0179] Embodiment 11

[0180] This embodiment provides a smoke-gas purification catalyst, and the smoke-gas purification catalyst comprises:

[0181] Pt 0.2wt%, Pd 0.06wt%, modified alumina 79.74wt%, modified cerium-zirconium oxygen storage material 5wt%, molecular sieve 5wt%, rare earth additive cerium 3wt%, rare earth additive lanthanum 2wt%, binder 5wt%.

[0182] The mass ratio of Pt to Pd is 1:0.3.

[0183] The composition of the modified alumina is expressed as Ti 10 Si5Zr5-80Al2O3.

[0184] The composition of the modified cerium-zirconium oxygen storage material is expressed as Ce 40 Zr 50 Lp5V x , x is 196.7.

[0185] The molecular sieve is ZSM-5 molecular sieve.

[0186] That is, in the fumigated flue gas purification catalyst, compared with Example 1, the composition contents of modified alumina, modified cerium-zirconium oxygen storage material and molecular sieve are adjusted to 79.74wt%, 5wt% and 5wt%, respectively, and the rest are the same as Example 1.

[0187] The preparation method of the fumigation flue gas purification catalyst is the same as that of Example 1.

[0188] Example 12

[0189] This embodiment provides a smoke-gas purification catalyst, and the smoke-gas purification catalyst comprises:

[0190] Pt 0.2wt%, Pd 0.06wt%, modified alumina 44.74wt%, modified cerium-zirconium oxygen storage material 25wt%, molecular sieve 20wt%, rare earth additive cerium 3wt%, rare earth additive lanthanum 2wt%, binder 5wt%.

[0191] The mass ratio of Pt to Pd is 1:0.3.

[0192] The composition of the modified alumina is expressed as Ti 10 Si5Zr5-80Al2O3.

[0193] The composition of the modified cerium-zirconium oxygen storage material is expressed as Ce 40 Zr 50 Lp5V x , x is 196.7.

[0194] The molecular sieve is ZSM-5 molecular sieve.

[0195] That is, in the fumigated flue gas purification catalyst, compared with Example 1, the composition contents of modified alumina, modified cerium-zirconium oxygen storage material and molecular sieve are adjusted to 44.74wt%, 25wt% and 20wt%, respectively, and the rest are the same as Example 1.

[0196] The preparation method of the fumigation flue gas purification catalyst is the same as that of Example 1.

[0197] Example 13

[0198] This embodiment provides a smoke-gas purification catalyst, and the smoke-gas purification catalyst comprises:

[0199] Pt 0.2wt%, Pd 0.06wt%, modified alumina 69.74wt%, modified cerium-zirconium oxygen storage material 15wt%, molecular sieve 10wt%, binder 5wt%.

[0200] The mass ratio of Pt to Pd is 1:0.3.

[0201] The composition of the modified alumina is expressed as Ti 10 Si5Zr5-80Al2O3.

[0202] The composition of the modified cerium-zirconium oxygen storage material is expressed as Ce 40 Zr 50 Lp5V x , x is 196.7.

[0203] The molecular sieve is ZSM-5 molecular sieve.

[0204] That is, compared with Example 1, the fumigation flue gas purification catalyst does not add rare earth additives, and the rare earth additives are replaced by modified cerium-zirconium oxygen storage materials in equal amounts, and the rest are the same as Example 1.

[0205] Embodiment 14

[0206] This embodiment provides a smoke-gas purification catalyst, and the smoke-gas purification catalyst comprises:

[0207] Pt 0.2wt%, Pd 0.06wt%, modified alumina 69.74wt%, modified cerium-zirconium oxygen storage material 10wt%, molecular sieve 10wt%, rare earth additive cerium 3wt%, rare earth additive lanthanum 2wt%, binder 5wt%.

[0208] The mass ratio of Pt to Pd is 1:0.3.

[0209] The composition of the modified alumina is expressed as Ti 10 Si5Zr5-80Al2O3.

[0210] The composition of the modified cerium-zirconium oxygen storage material is expressed as Ce 40 Zr 50 Lp5V x , x is 196.7.

[0211] The molecular sieve is ZSM-5 molecular sieve.

[0212] That is, the composition of the fumigation flue gas purification catalyst is the same as that of Example 1.

[0213] The preparation method of the fumigation flue gas purification catalyst is the same as that of Example 1, except that the reduction temperature in step (9) is controlled to be 400° C., and the rest is the same as that of Example 1.

[0214] Embodiment 15

[0215] This embodiment provides a smoke-gas purification catalyst, and the smoke-gas purification catalyst comprises:

[0216] Pt 0.2wt%, Pd 0.06wt%, modified alumina 69.74wt%, modified cerium-zirconium oxygen storage material 10wt%, molecular sieve 10wt%, rare earth additive cerium 3wt%, rare earth additive lanthanum 2wt%, binder 5wt%.

[0217] The mass ratio of Pt to Pd is 1:0.3.

[0218] The composition of the modified alumina is expressed as Ti 10 Si5Zr5-80Al2O3.

[0219] The composition of the modified cerium-zirconium oxygen storage material is expressed as Ce 40 Zr 50 Lp5V x , x is 196.7.

[0220] The molecular sieve is ZSM-5 molecular sieve.

[0221] That is, the composition of the fumigation flue gas purification catalyst is the same as that of Example 1.

[0222] The preparation method of the fumigation flue gas purification catalyst is the same as that of Example 1, except that the reduction temperature in step (9) is controlled to be 500° C., and the rest is the same as that of Example 1.

[0223] Comparative Example 1

[0224] This comparative example provides a smoke-gas purification catalyst. Compared with Example 1, the composition of the smoke-gas purification catalyst does not contain Pt, and the mass of Pt is replaced by Pd. The rest is the same as that of Example 1.

[0225] Comparative Example 2

[0226] This comparative example provides a smoke-gas purification catalyst. Compared with Example 1, the composition of the smoke-gas purification catalyst does not contain Pd, and the mass of Pd is replaced by Pt. The rest is the same as that of Example 1.

[0227] Comparative Example 3

[0228] This comparative example provides a fumigation flue gas purification catalyst. Compared with Example 1, the composition of the fumigation flue gas purification catalyst does not contain molecular sieves, and the molecular sieves are replaced by modified cerium zirconium oxygen storage materials. The rest is the same as Example 1.

[0229] Comparative Example 4

[0230] This comparative example provides a smoke-generated flue gas purification catalyst. Compared with Example 1, the composition of the smoke-generated flue gas purification catalyst does not contain modified cerium-zirconium oxygen storage material, and the modified cerium-zirconium oxygen storage material is replaced by modified alumina and molecular sieve in an equal mass ratio of modified alumina to molecular sieve of 1:1. The rest is the same as Example 1.

[0231] Comparative Example 5

[0232] This comparative example provides a fumigation flue gas purification catalyst. Compared with Example 1, the composition of the fumigation flue gas purification catalyst is the same as that of Example 1, in which the modified alumina is replaced by Al2O3, that is, the alumina is not modified.

[0233] Comparative Example 6

[0234] This comparative example provides a fume purifying catalyst. Compared with Example 1, the composition of the fume purifying catalyst is as follows: the modified cerium zirconium oxygen storage material is replaced by Ce 50 Zr 50 O x , that is, the cerium-zirconium oxygen storage material is not modified, and the rest is the same as in Example 1.

[0235] Performance Characterization

[0236] The catalytic purification performance of the catalysts provided in the examples and comparative examples was tested in the initial state (ie, fresh state) and after hydrothermal aging treatment (ie, hydrothermal aging state).

[0237] The method of hydrothermal aging treatment is: hydrothermal aging at 750°C for 50 hours.

[0238] ① Add the catalyst into the fixed bed reactor for catalytic reaction. The reaction conditions are: reaction gas is 200ppm CO, 100ppm C3H6, 2vol.% O2, 10vol.% CO2, 10vol.% H2O, N2 is the balance gas, and the space velocity is 100000h -1 , the reaction pressure is 0.1MPa; the concentration changes of CO and hydrocarbons before and after the reaction are measured by Fourier transform infrared spectrometer, and the conversion rate is calculated. The results are listed in Table 1 and Table 2. The ignition temperature characteristic curve of the catalyst provided in Example 1 is shown in Figure 1 shown.

[0239] Table 1

[0240]

[0241]

[0242] Table 2

[0243]

[0244]

[0245] ② The catalyst was loaded into a household smoker for operation. The concentration changes of CO and non-methane hydrocarbons in the flue gas before and after purification were measured by Fourier transform infrared spectrometer. The fresh catalyst was used to continuously smoke meat for 2000 hours for testing, and the conversion rate was calculated. The results are listed in Table 3.

[0246] The operating parameters of the household fumigator are: CO concentration 500ppm, non-methane hydrocarbon concentration 50ppm, operating temperature 500-700℃, flue gas flow rate 1m / s, and air volume at the fumigator outlet 50m 3 / h.

[0247] Table 3

[0248]

[0249]

[0250] It can be seen from Table 1 and Table 2 that the smoke-fed flue gas purification catalyst provided by the present invention effectively reduces the ignition temperature of the flue gas components, maintains the purification efficiency of CO and non-methane total hydrocarbons at above 99.9% under the high temperature condition of 500°C, and after long-term high-temperature aging treatment, the purification efficiency of the catalyst can still be maintained at above 98.3%, with excellent purification performance. Compared with Example 1, in Examples 6-7, the performance of the aged catalyst slightly decreased by using two elements of modified alumina; in Examples 8-10, the performance of the aged catalyst slightly decreased by using cerium-zirconium oxygen storage materials modified by different elements; in Examples 11-12, after adjusting the composition content of modified alumina, modified cerium-zirconium oxygen storage materials and molecular sieves in the catalyst, the purification performance of the fresh catalyst and the aged catalyst decreased; in Example 13, no rare earth additive was added, which affected the state of the active metal and caused the catalyst performance to decrease; in Examples 14-15, it can be seen that the increase in the reduction temperature slightly increased the ignition temperature of the flue gas components.

[0251] As can be seen from Table 3, the fumigation fume purification catalyst provided by the present invention is used in the actual working conditions of a household fumigator, and also produces excellent purification effects. After continuous long-term operation for 2000 hours, it can still maintain a CO purification rate of more than 97.0% and a non-methane total hydrocarbon purification rate of more than 95.0%. As mentioned above, compared with Example 1, the purification effect in Examples 6-15 is slightly reduced.

[0252] Compared with Example 1, it can be seen from Comparative Examples 1-6 that the provided catalyst lacks any component, the purification performance of the catalyst is significantly reduced, and the purification effect is not ideal. The components in the smoke gas purification catalyst provided by the present invention cooperate with each other and have a significantly excellent purification effect.

[0253] In summary, the flue gas purification catalyst provided by the present invention has excellent catalytic activity and high temperature stability through the synergistic combination of active metal and active compound components, and has significant purification effects on CO and hydrocarbons, with a purification efficiency of more than 99%, which can still reach more than 98% after aging treatment. For high-concentration flue gas in fumigation conditions, it can operate stably for a long time, and the overall purification efficiency is more than 95%.

[0254] The applicant declares that the above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention shall fall within the protection scope and disclosure scope of the present invention.

Claims

1. A smoke-gas purification catalyst, characterized in that: The fumigation flue gas purification catalyst comprises: an active metal and an active compound; The active metals include Pt and Pd; The active compound comprises modified alumina, modified cerium-zirconium oxygen storage material and molecular sieve.

2. The smoke-gas purification catalyst according to claim 1, characterized in that: The smoke-gas purification catalyst comprises: 0.1-0.5wt% of active metal, 60-70wt% of modified alumina, 10-20wt% of modified cerium-zirconium oxygen storage material, and 10-15wt% of molecular sieve; Preferably, the mass ratio of Pt to Pd is 1:(0.1-1); Preferably, the modified alumina includes Ti, Si and Zr modified alumina; Preferably, the composition of the modified alumina is expressed as Ti a Si b Zr c -mAl2O3, wherein a:b:c:m is (1-10):(1-10):(1-10):(70-90); Preferably, the modified cerium-zirconium oxygen storage material comprises La and Pr modified cerium-zirconium oxygen storage material; Preferably, the composition of the modified cerium-zirconium oxygen storage material is expressed as Ce d Zr e La f Pr g O x , wherein d:e:f:g is (40-60):(30-50):(1-10):(1-10); Preferably, the molecular sieve includes any one of ZSM-5, β molecular sieve, 5A molecular sieve or SSZ-13, or a combination of at least two thereof.

3. The smoke-gas purification catalyst according to claim 1 or 2, characterized in that: The fumigation flue gas purification catalyst further comprises: a rare earth additive, wherein the rare earth additive comprises any one of La, Ce or Y or a combination of at least two thereof; Preferably, the content of the rare earth additive in the fumigation flue gas purification catalyst is 0.5-5wt%.

4. The fumigation flue gas purification catalyst according to any one of claims 1 to 3, characterized in that: The fumigation flue gas purification catalyst further comprises: a binder; Preferably, the binder comprises boehmite and / or pseudo-boehmite; Preferably, in the fumigation flue gas purification catalyst, the content of the binder is 1-7wt%; Preferably, the pore volume of the fumigation flue gas purification catalyst is ≥ 0.8 mL / g; Preferably, the specific surface area of ​​the fumigation flue gas purification catalyst is ≥140m 2 / g.

5. A method for preparing a fumigation flue gas purification catalyst according to any one of claims 1 to 4, characterized in that: The preparation method comprises the following steps: (1) mixing modified alumina, active metal salt, rare earth additive and modified cerium-zirconium oxygen storage material to obtain a mixture, and then sequentially mixing the mixture with a reducing agent, a complexing agent and a molecular sieve to obtain an active component slurry; (2) mixing the active component slurry obtained in step (1) with a binder and cellulose to obtain a coating slurry; (3) The coating slurry obtained in step (2) is sequentially calcined and reduced to obtain a catalyst coating.

6. The preparation method according to claim 5, characterized in that: The active metal salt in step (1) includes any one of the nitrate, hydrochloride, acetate or acetylacetonate of the active metal, or a combination of at least two thereof.

7. The preparation method according to claim 5 or 6, characterized in that: The pH of the mixture in step (1) is 3-6; Preferably, the reducing agent in step (1) comprises any one or a combination of at least two of hydrazine hydrate, methanol, ethanol, ethylene glycol, propanol or glycerol; Preferably, the amount of the reducing agent in step (1) is 3-5 times the molar amount of the active metal; Preferably, the complexing agent in step (1) comprises any one of citric acid, ascorbic acid, oxalic acid or ethylenediaminetetraacetic acid, or a combination of at least two thereof; Preferably, the amount of the complexing agent in step (1) is 3-5 times the molar amount of the active metal; Preferably, the amount of cellulose used in step (2) is 0.1-0.5 wt % of the smoke-gas purification catalyst.

8. The preparation method according to any one of claims 5 to 7, characterized in that: The calcination temperature in step (3) is 450-550°C; Preferably, the calcination time in step (3) is 1-3 hours.

9. The preparation method according to any one of claims 5 to 8, characterized in that: The reduction in step (3) is carried out under a hydrogen atmosphere; Preferably, the reduction temperature in step (3) is 300-500°C; Preferably, the reduction time in step (3) is 0.5-2h.

10. An application of the smoke-gas purification catalyst according to any one of claims 1 to 4, characterized in that: The fumigation flue gas purification catalyst is applied to a fumigator.

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