A catalyst, its preparation and use in the treatment of sulfur-containing volatile organic compounds

Abstract

The application discloses a catalyst, a preparation method thereof and application of the catalyst in treatment of volatile organic matters containing sulfur. The catalyst comprises a honeycomb carrier and a catalytic material coated on the surface of the carrier; the catalytic material comprises an active component, an auxiliary agent, a sulfur conversion agent and a matrix; the active component is selected from at least one of platinum, palladium, osmium, iridium, ruthenium and rhodium in a coordination unsaturated oxidation state; the mass of the matrix is 5-30% of the mass of the catalyst; and the mass of the active component is 0.3-5% of the mass of the matrix. The catalyst has high catalytic activity and stability under high air speed conditions; the preparation process is simple, the manufacturing cost is low; the catalyst has good hydrogen sulfide resistance, small resistance drop and long service life.

Description

Technical Field

[0001] This application relates to a catalyst, its preparation method, and its application in treating sulfur-containing volatile organic compounds, belonging to the field of catalytic purification and environmental protection of air pollutants. Background Technology

[0002] Volatile organic compounds (VOCs) are widely present in industries such as chemical, petroleum, paint, printing and dyeing, and food, and are one of the main causes of air pollution. Compared to vehicle exhaust, they originate from fixed point sources, but their harmfulness should not be underestimated. They can cause irreversible damage to humans and other organisms, and can spread through the food chain, posing a significant threat to human health. Therefore, the treatment of industrial waste gas and the control of VOC emissions have always been a matter of widespread concern, and governments worldwide have attached great importance to them. Technologies used to treat sulfur-containing industrial waste gas mainly include activated carbon adsorption, direct combustion, catalytic combustion, high-temperature incineration, absorption, condensation, and plasma low-temperature catalytic oxidation. Catalytic combustion is a simple system structure applicable to various VOC pollution control methods.

[0003] For treating sulfur-containing industrial waste gas, sulfur poisoning of catalysts is a significant factor affecting catalyst lifespan. For catalysts used in the combustion of volatile organic compounds containing hydrogen sulfide, active sites are easily eroded by sulfur during the catalytic reaction, leading to catalyst deactivation. Hydrogen sulfide not only competes with VOCs molecules for adsorption active sites but also reacts with catalyst components to oxidize and form sulfates that coat the catalyst surface, damaging the catalyst structure, reducing active sites, causing catalyst poisoning, and inhibiting catalytic activity. Therefore, catalytic combustion technology faces the challenge of designing and developing hydrogen sulfide-resistant catalysts. Chinese patent CN89105594.0 discloses a "catalyst for the incineration of sulfur-containing organic waste gas and its preparation method," which uses sulfuric acid-treated natural mordenite as a carrier, V2O5 as the active component, and noble metals such as platinum and palladium as auxiliary materials. This catalyst has a good effect on the oxidation of sulfur-containing organic compounds and also shows good purification effects on CO, low-carbon alkanes, and oxygen-containing organic compounds. Chinese patent CN105709854A discloses a metal-based catalytic combustion catalyst and its preparation method. However, the metal-based catalyst cannot operate stably for extended periods under high water vapor and high SO2 conditions. Chinese patent CN102553585A discloses a sulfur-resistant catalyst for gas deoxygenation, its preparation method, and its application. Mo is added to the catalyst, requiring pre-sulfurization to ensure its sulfur resistance; however, the catalyst's activity is low. Summary of the Invention

[0004] In view of the poor hydrogen sulfide resistance and instability of currently disclosed combustion catalysts, this application provides a combustion catalyst with simple preparation process, high catalytic activity, and hydrogen sulfide resistance, as well as a preparation method.

[0005] According to one aspect of this application, a catalyst is provided, the catalyst comprising a honeycomb support and a catalytic material coated on the surface of the support;

[0006] The catalytic material includes an active component, an auxiliary agent, a sulfur conversion agent, and a matrix;

[0007] The active component is selected from at least one of platinum, palladium, osmium, iridium, ruthenium, and rhodium.

[0008] The active component is in a coordinated unsaturated oxidation state.

[0009] The mass of the matrix is ​​5-30 wt% of the mass of the catalyst.

[0010] The mass of the active component is 0.3 to 5 wt% of the mass of the matrix.

[0011] The additive is selected from at least one of iron oxide, copper oxide, lanthanum oxide, tin oxide, nickel oxide, zinc oxide, praseodymium oxide, chromium oxide, manganese oxide, cerium oxide, yttrium oxide, and neodymium oxide;

[0012] The mass of the additive is 1-30 wt% of the mass of the matrix.

[0013] The sulfur conversion agent is selected from cobalt oxide, lanthanum oxide, iron oxide, molybdenum oxide, vanadium oxide, nickel oxide, tungsten oxide, copper oxide, calcium oxide, and zinc oxide;

[0014] The mass of the sulfur conversion agent is 5-50 wt% of the mass of the matrix.

[0015] The matrix is ​​selected from at least one of alumina, titanium oxide, cerium oxide, zirconium oxide, yttrium oxide, neodymium oxide, tin oxide, and chromium oxide;

[0016] The honeycomb carrier is selected from cordierite honeycomb ceramics and metal honeycomb.

[0017] According to another aspect of this application, a method for preparing the above-mentioned catalyst is provided, comprising the following steps:

[0018] (1) The honeycomb carrier is impregnated with a coating slurry containing a matrix, binder, surfactant and water, dried, and calcined to obtain A;

[0019] (2) Immerse A in a solution containing solvent X containing sulfur conversion agent precursor, dry II, and calcine II to obtain B;

[0020] (3) Impregnate III with B in a solution containing the active component precursor and the auxiliary agent precursor in solvent Y, dry III, and calcine III to obtain C;

[0021] (4) Reduce C under a hydrogen atmosphere to obtain the catalyst.

[0022] Wherein, A is a honeycomb carrier supporting the matrix, B is a honeycomb carrier sequentially loaded with the matrix and sulfur conversion agent, and C is a honeycomb carrier sequentially loaded with the matrix, sulfur conversion agent, auxiliary agent and active component.

[0023] The binder is selected from at least one of silica sol, aluminum sol, titanium sol, and zirconium sol;

[0024] The surfactant is selected from at least one of polyethylene glycol, glycerol, carboxymethyl cellulose, polyvinyl alcohol, and polyacryl alcohol;

[0025] In the coating slurry, the mass content of the matrix is ​​5~50 wt%;

[0026] In the coating slurry, the mass content of the binder is 1~30 wt%;

[0027] In the coating slurry, the surfactant content is 0.05~3wt% by mass;

[0028] The coating slurry also contains a pH adjuster;

[0029] The pH adjuster is selected from at least one of formic acid, acetic acid, hydrochloric acid, citric acid, phosphoric acid, nitric acid, ammonia, sodium carbonate, and sodium hydroxide.

[0030] The pH adjuster adjusts the pH of the coating slurry to between 2 and 10;

[0031] The coating slurry is ball-milled;

[0032] The ball milling is carried out in a ball milling jar.

[0033] The rotational speed of the ball mill is 200~500 r / min;

[0034] The ball milling time is 1~20 hours;

[0035] The solid content in the coating slurry is 5-50%;

[0036] The immersion time for I is 5-60 seconds;

[0037] The drying process I is hot air drying, with a gas flow rate of 0.2~2m / s;

[0038] The temperature of the drying process I is 100~160℃;

[0039] The drying time for step I is 1-15 minutes;

[0040] The temperature of the calcination I is 400~900℃;

[0041] The roasting time for the first stage is 1 to 10 hours.

[0042] The sulfur conversion agent precursor is selected from at least one of cobalt nitrate, lanthanum nitrate, ferric nitrate, ammonium molybdate, ammonium metavanadate, nickel nitrate, ammonium paratungstate, copper nitrate, calcium nitrate, and zinc nitrate.

[0043] The solvent X is selected from at least one of water, ethanol, and methanol;

[0044] In the solution containing solvent X of the sulfur conversion agent precursor, the mass content of the sulfur conversion agent precursor is 1~50 wt%;

[0045] The immersion time for the second stage is 10~1800s;

[0046] The drying method II is hot air drying, with a gas flow rate of 0.2~2m / s;

[0047] The temperature of the drying II process is 100~160℃;

[0048] The drying time for step II is 1-15 minutes;

[0049] The temperature of calcination II is 400~900℃;

[0050] The roasting time for the second stage is 1 to 10 hours.

[0051] The active component precursor is selected from at least one of chloroplatinic acid, palladium nitrate, osmium chloride, chloroiridic acid, ruthenium chloride, and rhodium chloride.

[0052] The auxiliary agent precursor is selected from at least one of ferric nitrate, copper nitrate, lanthanum nitrate, tin chloride, nickel nitrate, zinc nitrate, praseodymium nitrate, chromium nitrate, manganese nitrate, cerium nitrate, yttrium nitrate, and neodymium nitrate;

[0053] The solvent Y is selected from at least one of water, ethanol, and methanol;

[0054] In the solvent Y containing the active component precursor and the auxiliary agent precursor, the mass concentration of the active component precursor is 0.1~2wt%, and the mass concentration of the auxiliary agent precursor is 0.5~40wt%.

[0055] The immersion time for the third stage is 10~1800s;

[0056] The drying method III is hot air drying, with a gas flow rate of 0.2~2m / s;

[0057] The temperature of the drying III process is 100~160℃;

[0058] The drying time for step III is 1-15 minutes;

[0059] The temperature of calcination III is 400~900℃;

[0060] The roasting time for the third stage is 1 to 10 hours.

[0061] The hydrogen atmosphere also contains nitrogen.

[0062] The reduction temperature is 300~600℃;

[0063] The restoration time is 1 to 4 hours.

[0064] After each impregnation, compressed air must be used to blow out any excess solution from the pores of the honeycomb carrier.

[0065] According to another aspect of this application, an application of the above-described catalyst is provided for treating sulfur-containing volatile organic compounds.

[0066] The beneficial effects that this application can produce include:

[0067] (1) The hydrogen sulfide-resistant combustion catalyst of the present invention has high catalytic activity and stability under high space velocity conditions;

[0068] (2) The hydrogen sulfide-resistant combustion catalyst of the present invention has a simple preparation process and low manufacturing cost;

[0069] (3) The hydrogen sulfide-resistant combustion catalyst of the present invention has good hydrogen sulfide resistance, low catalyst resistance drop, and long service life. Attached Figure Description

[0070] Figure 1 To evaluate the stability of the catalyst in Comparative Example 1 under SO2 and H2S conditions.

[0071] Figure 2 This is a stability evaluation of Example 1 and Comparative Example 1.

[0072] Figure 3 shows the coordination state of the surface-active component Pt in Example 1. Figure 3a X-ray photoelectron spectroscopy; Figure 3b It is a near-band edge structure for X-ray absorption; Figure 3c X-ray absorption wavelet transform spectrum; Figure 3d To extend the fine spectrum of X-ray absorption at the edge; Figure 3e Fitting of fine X-ray absorption spectra. Detailed Implementation

[0073] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.

[0074] Unless otherwise specified, all raw materials used in the embodiments of this application were purchased through commercial channels.

[0075] Example 1:

[0076] Weigh 60g of titanium dioxide, 24g of silica sol, 2ml of concentrated ammonia, and 0.5g of polyethylene glycol and add them to 140g of deionized water, with a pH of 8-9. Add this mixture to a ball mill jar and ball mill at 500 rpm for 2 hours to obtain a coating slurry. Immerse a 15×15×25mm 200-mesh honeycomb ceramic carrier in the coating slurry for 20 seconds, and blow out excess slurry from the pores of the honeycomb carrier using compressed air. Then, pass the carrier through a hot air bath (temperature 120°C). o C, with a gas flow rate of 0.8 m / s in the pores, dry for 100 s, repeating the above process until the coating mass accounts for 20%~22% of the total mass of the honeycomb carrier before coating, 500 o The honeycomb carrier loaded with M1 was obtained by calcination at C for 4 hours. 100g of a mixed aqueous solution of cobalt nitrate hexahydrate (24.17%) and nickel nitrate hexahydrate (12.98%) was prepared as impregnation solution A. The honeycomb carrier loaded with M1 was immersed in impregnation solution A for 60 seconds. Excess impregnation solution was blown out of the pores of the honeycomb carrier using compressed air. Then, it was subjected to hot air (temperature 120°C). o C, gas flow rate in the pores 0.8 m / s) drying for 100 s, 500 o C calcination for 4 hours yielded a honeycomb carrier loaded with M2. 100g of a mixed aqueous solution of chloroplatinic acid (3mg / ml) and ferric nitrate (16.87%) was prepared as impregnation solution B. The honeycomb carrier loaded with M2 was immersed in impregnation solution B for 60 seconds. Excess impregnation solution was blown out of the pores of the honeycomb carrier using compressed air. Then, it was subjected to hot air (temperature 120°C). o C, gas flow rate in the pores 0.8 m / s) drying for 100 s, 500 o Calcination at C for 4 hours yielded a Pt-based metal-M3 / M2 / M1-supported honeycomb substrate. The prepared Pt-based metal-M3 / M2 / M1 honeycomb substrate was then subjected to calcination at 450 °C under a 10 vol.% H2-90 vol.% N2 atmosphere. o The reduced monolithic catalyst was obtained by reducing C for 2 hours.

[0077] Example 2:

[0078] Weigh 60g of zirconium dioxide, 24g of zirconium sol, 1ml of concentrated nitric acid, and 0.5g of polyvinyl alcohol and add them to 140g of deionized water, with a pH of 3-4. Add this mixture to a ball mill jar and ball mill at 500 rpm for 2 hours to obtain a coating slurry. Immerse a 15×15×25mm 200-mesh honeycomb ceramic carrier in the coating slurry for 20 seconds, and blow out excess slurry liquid from the pores of the honeycomb carrier with compressed air. Then, pass the carrier through a hot air bath (temperature 120°C). o C, with a gas flow rate of 0.8 m / s in the pores, dry for 100 s, repeating the above process until the coating mass accounts for 20%~22% of the total mass of the honeycomb carrier before coating, 500 o The honeycomb carrier loaded with M1 was obtained by calcination at C for 4 hours. 100g of a mixed aqueous solution of 20.26% copper nitrate triple solution and 16.87% ferric nitrate nonahydrate was prepared as impregnation solution A. The honeycomb carrier loaded with M1 was immersed in impregnation solution A for 60 seconds. Excess impregnation solution was blown out of the pores of the honeycomb carrier using compressed air. Then, it was subjected to hot air (temperature 120°C). o C, gas flow rate in the pores 0.8 m / s) drying for 100 s, 500 o C calcination for 4 hours yielded a honeycomb carrier loaded with M2. 100g of a mixed aqueous solution of chloroplatinic acid (3mg / ml) and zinc nitrate hexahydrate (12.18%) was prepared as impregnation solution B. The honeycomb carrier loaded with M2 was immersed in impregnation solution B for 60 seconds. Excess impregnation solution was blown out of the pores of the honeycomb carrier using compressed air. Then, it was subjected to hot air (temperature 120°C). o C, gas flow rate in the pores 0.8 m / s) drying for 100 s, 500 o Calcination at C for 4 hours yielded a Pt-based metal-M3 / M2 / M1-supported honeycomb substrate. The prepared Pt-based metal-M3 / M2 / M1 honeycomb substrate was then subjected to calcination at 450 °C under a 10 vol.% H2-90 vol.% N2 atmosphere. o The reduced monolithic catalyst was obtained by reducing C for 2 hours.

[0079] Example 3:

[0080] Weigh 60g of alumina, 24g of aluminum sol, 1.5ml of concentrated nitric acid, and 0.5g of polyvinyl alcohol and add them to 140g of deionized water, with a pH of 3-4. Add this mixture to a ball mill jar and ball mill at 500 rpm for 2 hours to obtain a coating slurry. Immerse a 15×15×25mm 200-mesh honeycomb ceramic carrier in the coating slurry for 20 seconds, and blow out excess slurry from the pores of the honeycomb carrier with compressed air. Then, pass the carrier through a hot air bath (temperature 120°C). o C, with a gas flow rate of 0.8 m / s in the pores, dry for 100 s, repeating the above process until the coating mass accounts for 20%~22% of the total mass of the honeycomb carrier before coating, 500o The honeycomb carrier loaded with M1 was obtained by calcination at C for 4 hours. 100g of a mixed aqueous solution of 24.17% cobalt nitrate hexahydrate and 17.55% chromium nitrate nonahydrate was prepared as impregnation solution A. The honeycomb carrier loaded with M1 was immersed in impregnation solution A for 60 seconds. Excess impregnation solution was blown out of the pores of the honeycomb carrier using compressed air. Then, it was subjected to hot air (temperature 120°C). o C, gas flow rate in the pores 0.8 m / s) drying for 100 s, 500 o C was calcined for 4 hours to obtain the honeycomb carrier loaded with M2. 100g of a mixed aqueous solution of chloroplatinic acid (3mg / ml) and tin tetrachloride pentahydrate (7.75%) was prepared as impregnation solution B. The honeycomb carrier loaded with M2 was immersed in impregnation solution B for 60 seconds. Excess impregnation solution was blown out of the pores of the honeycomb carrier using compressed air. Then, it was subjected to hot air (temperature 120°C). o C, gas flow rate in the pores 0.8 m / s) drying for 100 s, 500 o Calcination at C for 4 hours yielded a Pt-based metal-M3 / M2 / M1-supported honeycomb substrate. The prepared Pt-based metal-M3 / M2 / M1 honeycomb substrate was then subjected to calcination at 450 °C under a 10 vol.% H2-90 vol.% N2 atmosphere. o The reduced monolithic catalyst was obtained by reducing C for 2 hours.

[0081] Example 4:

[0082] Weigh 60g of titanium dioxide, 24g of silica sol, 2ml of concentrated ammonia, and 0.5g of polyethylene glycol and add them to 140g of deionized water, with a pH of 8-9. Add this mixture to a ball mill jar and ball mill at 500 rpm for 2 hours to obtain a coating slurry. Immerse a 15×15×25mm 200-mesh honeycomb ceramic carrier in the coating slurry for 20 seconds, and blow out excess slurry from the pores of the honeycomb carrier using compressed air. Then, pass the carrier through a hot air bath (temperature 120°C). o C, with a gas flow rate of 0.8 m / s in the pores, dry for 100 s, repeating the above process until the coating mass accounts for 20%~22% of the total mass of the honeycomb carrier before coating, 500 o The honeycomb carrier loaded with M1 was obtained by calcination at C for 4 hours. 100g of a mixed aqueous solution of ferric nitrate (33.73%) and ammonium molybdate (4.54%) was prepared as impregnation solution A. The honeycomb carrier loaded with M1 was immersed in impregnation solution A for 60 seconds. Excess impregnation solution was blown out of the pores of the honeycomb carrier using compressed air. Then, it was subjected to hot air (temperature 120°C). o C, gas flow rate in the pores 0.8 m / s) drying for 100 s, 500 oC was calcined for 4 hours to obtain the honeycomb carrier loaded with M2. 100g of a mixed aqueous solution of chloroplatinic acid (3mg / ml) and tin tetrachloride pentahydrate (7.75%) was prepared as impregnation solution B. The honeycomb carrier loaded with M2 was immersed in impregnation solution B for 60 seconds. Excess impregnation solution was blown out of the pores of the honeycomb carrier using compressed air. Then, it was subjected to hot air (temperature 120°C). o C, gas flow rate in the pores 0.8 m / s) drying for 100 s, 500 o Calcination at C for 4 hours yielded a Pt-based metal-M3 / M2 / M1-supported honeycomb substrate. The prepared Pt-based metal-M3 / M2 / M1 honeycomb substrate was then subjected to calcination at 450 °C under a 10 vol.% H2-90 vol.% N2 atmosphere. o The reduced monolithic catalyst was obtained by reducing C for 2 hours.

[0083] Example 5:

[0084] Weigh 60g of cerium dioxide, 24g of aluminum sol, 2ml of concentrated nitric acid, and 0.5g of polyethylene glycol and add them to 140g of deionized water, with a pH of 2-3. Add this mixture to a ball mill jar and ball mill at 500 rpm for 2 hours to obtain a coating slurry. Immerse a 15×15×25mm 200-mesh honeycomb ceramic carrier in the coating slurry for 20 seconds, and blow out excess slurry liquid from the pores of the honeycomb carrier with compressed air. Then, pass the carrier through a hot air bath (temperature 120°C). o C, with a gas flow rate of 0.8 m / s in the pores, dry for 100 s, repeating the above process until the coating mass accounts for 20%~22% of the total mass of the honeycomb carrier before coating, 500 o The honeycomb carrier loaded with M1 was obtained by calcination at C for 4 hours. 100g of a mixed aqueous solution of 24.17% cobalt nitrate hexahydrate and 7.75% tin tetrachloride pentahydrate was prepared as impregnation solution A. The honeycomb carrier loaded with M1 was immersed in impregnation solution A for 60 seconds. Excess impregnation solution was blown out of the pores of the honeycomb carrier using compressed air. Then, it was subjected to hot air (temperature 120°C). o C, gas flow rate in the pores 0.8 m / s) drying for 100 s, 500 o C calcination for 4 hours yielded a honeycomb carrier loaded with M2. 100g of a mixed aqueous solution of chloroplatinic acid (3mg / ml) and copper nitrate trihydrate (10.13%) was prepared as impregnation solution B. The honeycomb carrier loaded with M2 was immersed in impregnation solution B for 60 seconds. Excess impregnation solution was blown out of the pores of the honeycomb carrier using compressed air. Then, it was subjected to hot air (temperature 120°C). o C, gas flow rate in the pores 0.8 m / s) drying for 100 s, 500 oCalcination at C for 4 hours yielded a Pt-based metal-M3 / M2 / M1-supported honeycomb substrate. The prepared Pt-based metal-M3 / M2 / M1 honeycomb substrate was then subjected to calcination at 450 °C under a 10 vol.% H2-90 vol.% N2 atmosphere. o The reduced monolithic catalyst was obtained by reducing C for 2 hours.

[0085] Example 6:

[0086] Weigh 60g of titanium dioxide, 24g of silica sol, 2ml of concentrated ammonia, and 0.5g of polyethylene glycol and add them to 140g of deionized water, with a pH of 8-9. Add this mixture to a ball mill jar and ball mill at 500 rpm for 2 hours to obtain a coating slurry. Immerse a 15×15×25mm 200-mesh honeycomb ceramic carrier in the coating slurry for 20 seconds, and blow out excess slurry from the pores of the honeycomb carrier using compressed air. Then, pass the carrier through a hot air bath (temperature 120°C). o C, with a gas flow rate of 0.8 m / s in the pores, dry for 100 s, repeating the above process until the coating mass accounts for 20%~22% of the total mass of the honeycomb carrier before coating, 500 o The honeycomb carrier loaded with M1 was obtained by calcination at C for 4 hours. 100g of a mixed aqueous solution of 20.26% copper nitrate trihydrate and 12.18% zinc nitrate hexahydrate was prepared as impregnation solution A. The honeycomb carrier loaded with M1 was immersed in impregnation solution A for 60 seconds. Excess impregnation solution was blown out of the pores of the honeycomb carrier using compressed air. Then, it was subjected to hot air (temperature 120°C). o C, gas flow rate in the pores 0.8 m / s) drying for 100 s, 500 o C calcination for 4 hours yielded a honeycomb carrier loaded with M2. 100g of a mixed aqueous solution of chloroplatinic acid (3mg / ml) and ferric nitrate (16.87%) was prepared as impregnation solution B. The honeycomb carrier loaded with M2 was immersed in impregnation solution B for 60 seconds. Excess impregnation solution was blown out of the pores of the honeycomb carrier using compressed air. Then, it was subjected to hot air (temperature 120°C). o C, gas flow rate in the pores 0.8 m / s) drying for 100 s, 500 o Calcination at C for 4 hours yielded a Pt-based metal-M3 / M2 / M1-supported honeycomb substrate. The prepared Pt-based metal-M3 / M2 / M1 honeycomb substrate was then subjected to calcination at 450 °C under a 10 vol.% H2-90 vol.% N2 atmosphere. o The reduced monolithic catalyst was obtained by reducing C for 2 hours.

[0087] Comparative Example 1:

[0088] Weigh 60g of titanium dioxide, 24g of silica sol, 2ml of concentrated ammonia, and 0.5g of polyethylene glycol and add them to 140g of deionized water, with a pH of 8-9. Add this mixture to a ball mill jar and ball mill at 500 rpm for 2 hours to obtain a coating slurry. Immerse a 15×15×25mm 200-mesh honeycomb ceramic carrier in the coating slurry for 20 seconds, and blow out excess slurry from the pores of the honeycomb carrier using compressed air. Then, pass the carrier through a hot air bath (temperature 120°C). o C, with a gas flow rate of 0.8 m / s in the pores, dry for 100 s, repeating the above process until the coating mass accounts for 20%~22% of the total mass of the honeycomb carrier before coating; 500 o The honeycomb carrier with the loaded coating was obtained by calcination at C for 4 hours. 100g of a chloroplatinic acid aqueous solution with a concentration of 3mg / ml was prepared as an impregnation solution. The honeycomb carrier with the loaded coating was immersed in the impregnation solution for 60 seconds. Excess impregnation solution was blown out of the pores of the honeycomb carrier using compressed air. Then, it was subjected to hot air (temperature 120°C). o C, gas flow rate in the pores 0.8 m / s) drying for 100 s, 500 o Calcination at C for 4 hours yielded a honeycomb carrier supported on a Pt-based metal / coating. The carrier was then calcined at 450 °C under a 10 vol.% H₂-90 vol.% N₂ atmosphere. o The reduced monolithic catalyst was obtained by reducing C for 2 hours.

[0089] The hydrogen sulfide-containing combustion catalysts of Examples 1-6 and Comparative Example 1 were evaluated for activity and stability. Specifically, a fixed-bed reactor was used for catalyst evaluation. The reaction gas composition was: CO=0.1%, O2=6%, CO2=12%, H2S=34ppm, NO=0.03%, H2O=21%, and the reaction space velocity was 50,000 h⁻¹. -1 First, catalyst activity is evaluated within a reaction temperature range of 150-300℃; then, catalyst stability is evaluated at a reaction temperature of 200℃. T50 refers to the temperature corresponding to a carbon monoxide conversion of 50%, and T90 refers to the temperature corresponding to a carbon monoxide conversion of 90%. (Appendix) Figure 1 During the stability evaluation, SO2=34ppm was introduced into the reaction gas from 0-17h; from 17-31h, SO2 was switched to H2S=34ppm.

[0090] The catalyst activity and stability are shown in the table below.

[0091]

[0092] As can be seen from the table, under H2S conditions, the catalysts obtained in Examples 1-6 exhibit significantly better CO catalytic oxidation activity and stability than the catalyst obtained in Comparative Example 1.

[0093] Figure 1Stability evaluation of the catalyst obtained in Comparative Example 1 under SO2 and H2S conditions.

[0094] The reaction conditions were: CO=0.1%, O2=6%, CO2=12%, H2S=34ppm, NO=0.03%, H2O=21%, with SO2=34ppm introduced as the reaction gas from 0 to 17 hours; from 17 to 31 hours, SO2 was switched to H2S=34ppm, and the reaction temperature was 200°C. o C, reaction space velocity 50000h -1 .

[0095] As can be seen from the figure, the catalyst obtained in the comparative example has good CO catalytic oxidation activity under SO2 conditions, but its catalytic activity decreases significantly when switched to H2S conditions, indicating deactivation under H2S conditions.

[0096] Figure 2 Stability evaluation of the catalysts obtained in Example 1 and Comparative Example 1.

[0097] The reaction conditions were as follows: Reactant gas composition: CO=0.1%, O2=6%, CO2=12%, H2S=34ppm, NO=0.03%, H2O=21%; reaction temperature: 200°C. o C, reaction space velocity 50000h -1 .

[0098] As can be seen from the figure, under H2S conditions, the catalyst obtained in Example 1 has good CO catalytic oxidation activity and stability, and the CO conversion rate is still greater than 88% after 150 h of reaction.

[0099] Figure 3: Coordination state of the surface-active component Pt in Example 1. Wherein, Figure 3a The X-ray photoelectron spectroscopy shows that the binding energy of the active species in Pt-OM is relatively high, therefore Pt is in a high valence state; Figure 3b The near-band edge structure of X-ray absorption shows that the height of the white line in the Pt component is much higher than that of metallic Pt, and close to that of the reference sample PtO2. Figure 3c The X-ray absorption wavelet transform spectrum shows that the active Pt component is highly dispersed. The first shell is Pt-O coordination, and the second shell is neither Pt-Pt coordination in nonmetallic Pt nor Pt-O-Pt coordination in PtO2, but Pt-OM coordination. Figure 3d The X-ray absorption extended edge absorption fine spectrum shows that the Pt species are highly dispersed, approximately in a single-atom distribution state, with the main coordination being Pt-O bonds; Figure 3e According to the fine X-ray absorption spectrum fitting, it can be seen that in the Pt active component, Pt atoms are coordinated with an average of 5 oxygen atoms in the first shell, and with 3 Pt-(O)-M and 4 Pt-(O)-Pt in the second shell.

[0100] In summary, it can be seen that Pt exists in a high valence state on the catalyst surface, and the wavelet transform shows obvious Pt-OM bond characteristics (M comes from the support metal oxide MO2).

[0101] The above description is merely a few embodiments of this application and is not intended to limit this application in any way. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A catalyst, characterized in that, The catalyst includes a honeycomb support and a catalytic material coated on the surface of the support; The catalytic material includes an active component, an auxiliary agent, a sulfur conversion agent, and a matrix; The active component is selected from at least one of platinum, palladium, osmium, iridium, ruthenium, and rhodium. The active component is in a coordination-unsaturated oxidation state. The additive is selected from at least one of iron oxide, copper oxide, lanthanum oxide, tin oxide, nickel oxide, zinc oxide, praseodymium oxide, chromium oxide, manganese oxide, cerium oxide, yttrium oxide, and neodymium oxide; The sulfur conversion agent is selected from cobalt oxide, lanthanum oxide, iron oxide, molybdenum oxide, vanadium oxide, nickel oxide, tungsten oxide, copper oxide, calcium oxide, and zinc oxide; The matrix is ​​selected from at least one of alumina, titanium oxide, cerium oxide, zirconium oxide, yttrium oxide, neodymium oxide, tin oxide, and chromium oxide; The mass of the matrix is ​​5-30 wt% of the mass of the catalyst. The mass of the active component is 0.3~5 wt% of the mass of the matrix; The mass of the additive is 1-30 wt% of the mass of the matrix. The mass of the sulfur conversion agent is 5-50 wt% of the mass of the matrix. The honeycomb carrier is selected from cordierite honeycomb ceramic and metal honeycomb; The catalyst is prepared by a method comprising the following steps: (1) The honeycomb carrier is impregnated with a coating slurry containing a matrix, binder, surfactant and water, dried, and calcined to obtain A; (2) Immerse A in a solution containing solvent X containing sulfur conversion agent precursor, dry II, and calcine II to obtain B; (3) Impregnate III with B in a solution containing the active component precursor and the auxiliary agent precursor in solvent Y, dry III, and calcine III to obtain C; (4) Reduce C under a hydrogen atmosphere to obtain the catalyst.

2. The catalyst according to claim 1, characterized in that, In the preparation method, The binder is selected from at least one of silica sol, aluminum sol, titanium sol, and zirconium sol; The surfactant is selected from at least one of polyethylene glycol, glycerol, carboxymethyl cellulose, polyvinyl alcohol, and polyacryl alcohol; In the coating slurry, the mass content of the matrix is ​​5~50 wt%; In the coating slurry, the mass content of the binder is 1~30 wt%; In the coating slurry, the surfactant content is 0.05~3wt% by mass; The coating slurry also contains a pH adjuster; The pH adjuster is selected from at least one of formic acid, acetic acid, hydrochloric acid, citric acid, phosphoric acid, nitric acid, ammonia, sodium carbonate, and sodium hydroxide. The pH adjuster adjusts the pH of the coating slurry to between 2 and 10; The coating slurry is ball-milled; The rotational speed of the ball mill is 200~500 r / min; The ball milling time is 1~20 hours; The immersion time for I is 5-60 seconds; The drying process I is hot air drying, with a gas flow rate of 0.2~2m / s; The temperature of the drying process I is 100~160℃; The drying time for step I is 1-15 minutes; The temperature of the calcination I is 400~900℃; The roasting time for the first stage is 1 to 10 hours.

3. The catalyst according to claim 1, characterized in that, In the preparation method, The sulfur conversion agent precursor is selected from at least one of cobalt nitrate, lanthanum nitrate, ferric nitrate, ammonium molybdate, ammonium metavanadate, nickel nitrate, ammonium paratungstate, copper nitrate, calcium nitrate, and zinc nitrate. The solvent X is selected from at least one of water, ethanol, and methanol; In the solution containing solvent X of the sulfur conversion agent precursor, the mass content of the sulfur conversion agent precursor is 1~50 wt%; The immersion time for the second stage is 10~1800s; The drying method II is hot air drying, with a gas flow rate of 0.2~2m / s; The temperature of the drying II process is 100~160℃; The drying time for step II is 1-15 minutes; The temperature of the second calcination is 400~900℃; The roasting time for the second stage is 1 to 10 hours.

4. The catalyst according to claim 1, characterized in that, In the preparation method, The active component precursor is selected from at least one of chloroplatinic acid, palladium nitrate, osmium chloride, chloroiridic acid, ruthenium chloride, and rhodium chloride. The auxiliary agent precursor is selected from at least one of ferric nitrate, copper nitrate, lanthanum nitrate, tin chloride, nickel nitrate, zinc nitrate, praseodymium nitrate, chromium nitrate, manganese nitrate, cerium nitrate, yttrium nitrate, and neodymium nitrate; The solvent Y is selected from at least one of water, ethanol, and methanol; In the solvent Y containing the active component precursor and the auxiliary agent precursor, the mass concentration of the active component precursor is 0.1~2wt%, and the mass concentration of the auxiliary agent precursor is 0.5~40wt%. The immersion time for the third stage is 10~1800s; The drying method III is hot air drying, with a gas flow rate of 0.2~2m / s; The temperature of the drying III process is 100~160℃; The drying time for step III is 1-15 minutes; The temperature of calcination III is 400~900℃; The roasting time for the third stage is 1 to 10 hours.

5. The catalyst according to claim 1, characterized in that, In the preparation method, The hydrogen atmosphere also contains nitrogen. The reduction temperature is 300~600℃; The restoration time is 1 to 4 hours.

6. The application of the catalyst according to claim 1, characterized in that, Used for treating sulfur-containing volatile organic compounds.

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