CN106540754A - A kind of catalyst for catalytic combustion and its preparation method and application - Google Patents

Abstract

The present invention relates to a kind of catalyst for catalytic combustion and its preparation method and application.The catalyst is made up of with coating and active component ceramic fibre carrier.In described catalyst, ceramic fibre carrier is before being coated with coating through acid treatment and hydrothermal treatment consists.The coating of catalyst is the combination of one or more metal-oxides or CNT, and coating and active component are loaded using infusion process.The features such as catalyst of the present invention has firm coating, noble metal active component utilization rate height, good hydrothermal stability, high temperature resistant, simple preparation method.The catalyst for catalytic combustion can be used for methane catalytic combustion process or other Hydrocarbon and VOC, H₂, CO gases catalysis burning subtractive process.

Description

A kind of catalytic combustion catalyst and its preparation method and application

technical field

The invention belongs to the field of catalytic combustion catalysts, in particular to a catalytic combustion catalyst and its preparation method and application. The catalyst is used in energy utilization and environmental protection technologies.

Background technique

Catalytic combustion is a technology that uses a catalyst to perform flameless combustion at a low light-off temperature, and oxidizes and decomposes organic waste gas into carbon dioxide and water. The essence of catalytic combustion is a violent oxidation reaction involving active oxygen. The active components of the catalyst activate air oxygen. When the activated oxygen molecules come into contact with the reactant molecules, energy transfer occurs, and the reactant molecules are activated, thereby accelerating the oxidation reaction. Catalytic combustion has the advantages of low ignition temperature, high purification efficiency, and adaptability to a wide range of oxygen concentrations. It has attracted widespread attention in terms of organic waste gas treatment, energy recovery, and power generation.

The core of catalytic combustion technology is to choose a suitable catalyst. Due to the high temperature of catalytic combustion, a large amount of water vapor is generated during the combustion reaction process, and there are small amounts of impurities such as chlorine and sulfur. Therefore, catalytic combustion technology has high requirements for catalysts, which require catalysts to have good low-temperature activity, high-temperature stability, large specific surface area, and high activity. High dispersion of components, anti-sintering and anti-chlorine and sulfur poisoning ability. In practical applications, the active components of combustion catalysts are noble metals such as Pd and Pt, as well as transition metal oxides and rare earth oxides. The commonly used carrier materials are γ-Al ₂ O ₃ , α-Al ₂ O ₃ , molecular sieve, silica gel, cordierite, etc., and they are mostly spherical, cylindrical, strip-shaped, irregular particles, and ring-shaped. Selecting new catalyst supports and improving the hydrothermal stability of catalysts are still research hotspots.

Ceramic fiber is a kind of fibrous lightweight refractory material, which has the advantages of light weight, high temperature resistance, good thermal stability, low thermal conductivity, small specific heat and mechanical vibration resistance, so it is widely used in machinery, metallurgy, chemical industry, petroleum, ceramics, Glass, electronics and other industries have been widely used. The thermal shock resistance and mechanical flexibility of catalytic ceramic fibers are superior to ceramic honeycomb carrier materials, and can be shaped according to the shape of the reactor to meet different needs. The diffusion resistance of ceramic fiber catalysts is very small, and fiber catalysts have higher efficiency than granular catalysts for diffusion-controlled reactions. At home and abroad, research has been carried out on replacing cordierite with ceramic fiber as the catalyst carrier for automobile exhaust purification, and it has shown excellent catalytic performance and hydrothermal stability. But its application in the field of combustion catalysts has not been reported yet.

Contents of the invention

The object of the present invention is to provide a catalytic combustion catalyst and a preparation method thereof.

Yet another object of the present invention is to use ceramic fibers as a carrier for catalytic combustion reactions.

The catalyst includes a treated ceramic fiber carrier, a coating and a noble metal active component, and the coating is a metal oxide or carbon nanotube.

Described ceramic fiber can be commercially available ceramic fiber cloth, felt, paper, can be processed into desired shape according to reaction needs, and in the embodiment of the present invention, ceramic fiber carrier is rolled into a diameter of 1 cm, and a height of 0.5 cm is cylindrical. Placed in a fixed bed reactor for evaluation.

The metal oxide is one or more of metal oxides of aluminum, cerium, zirconium, manganese, cobalt, and titanium, and the preferred metal oxides are MnO ₂ , Co ₃ O ₄ , and ZrO ₂ . The loading amount of the metal oxide coating is 2-50 wt%, preferably 10-30%. The noble metal active component is one or more of palladium, platinum, rhodium, iridium and ruthenium, and the loading amount is 0.1-5 wt%, preferably 0.2-2 wt%.

The preparation method of the catalytic combustion catalyst comprises the following steps: (1) treating the ceramic fiber carrier with acid, soaking the ceramic fiber carrier in an acid solution, repeatedly washing with deionized water until neutral and then drying; (2) hydrothermally treating the ceramic fiber carrier Fiber carrier, the ceramic fiber carrier is treated in a hydrothermal atmosphere and then dried; (3) the loading of the coating adopts the impregnation method, and the processed ceramic fiber carrier is put into aluminum, cerium, zirconium, manganese, cobalt, vanadium, titanium , One or more than two metal oxides or carbon nanotubes in tungsten are immersed in the slurry, then dried at 80-150°C for 6-48h, and finally fired at 400-1200°C for 1-6h, the preferred drying temperature 100-120°C, and the preferred firing temperature is 500-800°C. The loading of the coating can be controlled by adjusting the solid content of the slurry, which is composed of metal oxides or carbon nanotubes mixed with deionized water after ball milling; (4) Loading active components, loading precious metal active The components are also impregnated in excess. The coated ceramic fiber is impregnated in one or more precursor solutions of palladium, platinum, rhodium, iridium, and ruthenium, and then dried and roasted. The drying temperature is 30~ 150°C, drying time is 6-48h, and finally calcined at 200-600°C for 1-6h, the preferred drying temperature is 50-100°C, and the preferred roasting temperature is 250-400°C to obtain a catalytic combustion catalyst.

The precursor described in (4) is preferably one or more of chloride salts of palladium, platinum, rhodium, iridium, and ruthenium.

The acid treatment process is that the ceramic fiber carrier is first treated in 1% to 65% nitric acid/sulfuric acid/phosphoric acid/hydrochloric acid for 0.5 to 48 hours, and then washed and dried to obtain a ceramic fiber carrier from which impurities are removed.

The hydrothermal treatment process is that the ceramic fiber carrier is treated at a temperature of 150-700° C. in an atmosphere of 0.5% to 30% water vapor for 0.5-48 hours, and then dried to obtain a ceramic fiber carrier with good hydrothermal stability. During the treatment, it is preferred The temperature range is 200-500° C., and the preferred mass fraction of water vapor is 4%-20%.

The combustion catalyst with the ceramic fiber as the carrier provided by the invention can be used in the catalytic combustion process of methane or the catalytic combustion removal process of other hydrocarbons, VOC, H ₂ , CO and other gases.

The combustion catalyst with ceramic fiber as carrier provided by the present invention needs to be pretreated at 200-500° C. for 1-4 hours in H ₂ -N ₂ mixed gas flow, or reduced with 2% hydrazine hydrate solution for 24 hours before use.

Compared with the prior art, the catalytic combustion catalyst provided by the invention has advantages and technical effects as follows:

The catalyst of the present invention has the characteristics of firm coating, high utilization rate of noble metal active components, good hydrothermal stability, high temperature resistance, simple preparation method, etc. The coating not only combines firmly with the carrier, increases the specific surface area of the carrier, improves the dispersion of active components It also acts as a co-active ingredient.

The catalyst uses ceramic fiber as a carrier, and it is treated with acid and hydrothermal method before use to improve the hydrothermal stability of the catalyst. Due to the unique elasticity, heat resistance and shock resistance of the ceramic fiber, the catalyst can be formed into various shapes and has Good hydrothermal stability.

Description of drawings

Figure 1 is a microscopic picture of a ceramic fiber carrier.

Fig. 2 is a microscope picture of a ceramic fiber carrier loaded with 30wt% coating.

detailed description

Unless otherwise indicated, all numbers appearing in the description and claims of the present invention, such as values such as active components, calcination temperature and time, gas conversion rate, etc., should not be understood as absolute precise values, and these values are in the art Within the range of error understood by those of ordinary skill and allowed by known techniques. While every effort has been made to ensure accuracy in the examples given herein, any measured value will inevitably contain errors necessarily resulting from the standard deviation found in various measuring techniques. The above content will be further described below with several embodiments. It should be noted that these embodiments do not limit the above content in any sense.

The ceramic fiber used in the present invention is a commercially available ceramic fiber cloth, which can be processed into a desired shape according to the needs of the reaction. In the embodiment of the present invention, the ceramic fiber carrier is rolled into a cylindrical shape with a diameter of 1 cm and a height of 0.5 cm. The evaluation was carried out in a bed reactor.

Example 1: The ceramic fiber carrier was treated in 25% nitric acid for 12 hours, then washed and dried. Under the air atmosphere of 5% steam, hydrothermal treatment at 500° C. for 24 hours, after drying, a ceramic fiber carrier with good hydrothermal stability after removal of impurities is obtained. 1 g of the treated ceramic fiber carrier was immersed in a mixed slurry with a molar ratio of _TiO2 and ZrO2 of ₂ :1, blown with compressed air to remove excess slurry, dried at 150 °C for 7 h, and then calcined at 800 °C for 2 h. The loading amount of the coating on the ceramic fiber catalyst carrier is 10wt%. Configure a mixed solution of H ₂ PtCl ₆ with a concentration of 6mgPt/ml and PdCl ₂ with a concentration of 6mgPd/ml as the active component impregnation solution, and put the ceramic fiber carrier coated with titanium oxide and zirconia into the active component impregnation solution after immersion Take it out, blow off the residual solution in the pores with compressed air, then dry it in an oven at 80°C for 10 hours, and roast it in air at 400°C for 5 hours to prepare a catalytic combustion catalyst with a noble metal content of 0.4wt%.

Example 2: The ceramic fiber carrier was treated in 5% sulfuric acid for 24 hours, and then washed and dried. Under the air atmosphere of 10% steam, hydrothermal treatment at 700° C. for 8 hours, and after drying, a ceramic fiber carrier with good hydrothermal stability after removal of impurities is obtained. 1 g of the treated ceramic fiber carrier was immersed in a mixed slurry with a molar ratio of CeO2 and _MnO2 of ₈ :1, blown with compressed air to remove excess slurry, dried at 100 °C for 18 h, and then calcined at 600 °C for 2 h. The loading amount of the coating on the ceramic fiber catalyst carrier is 20wt%. Configure the H ₂ PtCl ₆ solution with a concentration of 3mgPt/ml as the active component immersion solution, put the ceramic fiber carrier coated with cerium oxide and manganese oxide into the active component immersion solution and take it out after immersion, blow out the pores with compressed air The remaining solution was dried in an oven at 50° C. for 20 hours, and then calcined at 500° C. in air for 2 hours to obtain a catalytic combustion catalyst with an active component content of 0.1 wt %.

Example 3: The ceramic fiber carrier was treated in 3% hydrochloric acid for 20 hours, and then washed and dried. Under the air atmosphere of 30% steam, hydrothermal treatment at 400° C. for 2 hours, after drying, a ceramic fiber carrier with good hydrothermal stability after removal of impurities is obtained. Immerse 1 g of the treated ceramic fiber carrier in a mixed slurry with a molar ratio of Al ₂ O ₃ and Co ₃ O ₄ of 5:1, blow it with compressed air to remove excess slurry, and dry it at 120°C for 20 hours. ℃ calcination for 2 hours, the loading amount of the coating on the ceramic fiber catalyst carrier is: 8wt%. Configure a RuCl mixed solution with a concentration of _60mgRu /ml as the active component impregnation solution, put the ceramic fiber carrier coated with alumina and cobalt oxide into the active component impregnation solution and take it out after immersion, blow out the pores with compressed air The residual solution was then dried in an oven at 120° C. for 24 hours, and then calcined at 600° C. in air for 3 hours to obtain a catalytic combustion catalyst with a precious metal content of 2 wt %.

Example 4: The ceramic fiber carrier was treated in 10% phosphoric acid for 0.5 h, and then washed and dried. Under the air atmosphere of 9% steam, hydrothermal treatment at 200° C. for 5 hours, and after drying, a ceramic fiber carrier with good hydrothermal stability after removal of impurities was obtained. 1 g of the treated ceramic fiber carrier was immersed in a mixed slurry with a molar ratio of _TiO2 and CeO2 of ₄ :1, blown with compressed air to remove excess slurry, dried at 90 °C for 15 h, and then calcined at 600 °C for 4 h. The loading amount of the coating on the ceramic fiber catalyst carrier is 30wt%. Configure the mixed solution of H ₂ PtCl ₆ with a concentration of 12mgPt/ml and RhCl ₂ of 12mgRh/ml as the active component impregnation solution, and put the ceramic fiber carrier coated with titanium oxide and cerium oxide into the active component impregnation solution after immersion Take it out, blow off the residual solution in the pores with compressed air, then dry it in an oven at 150°C for 10h, and roast it in air at 250°C for 1h to prepare a catalytic combustion catalyst with a noble metal content of 0.8wt%.

Example 5: The ceramic fiber carrier was treated in 30% sulfuric acid for 1 hour, and then washed and dried. Under the air atmosphere of 0.5% steam, hydrothermal treatment at 150° C. for 48 hours, after drying, a ceramic fiber carrier with good hydrothermal stability after removal of impurities was obtained. Immerse ₁ g of the treated ceramic fiber carrier in a mixed slurry of _Al2O3 , _MnO2 and ZrO2 with a molar ratio of ₁ :1:5, blow with compressed air to remove excess slurry, and dry at 100 °C for 12 h Afterwards, calcination at 500° C. for 3 h, and the loading amount of the coating on the ceramic fiber catalyst carrier is 5 wt %. Configure a mixed solution of _H2PtCl6 with a concentration of _100mgPt /ml and _RuCl2 of 50mgRu/ml as the active component impregnation solution, and put the ceramic fiber carrier coated with alumina, manganese oxide and zirconia into the active component impregnation solution Take it out after dipping in the medium, blow off the residual solution in the pores with compressed air, then dry it in an oven at 90°C for 15 hours, and roast it in air at 250°C for 3 hours to prepare a catalytic combustion catalyst with a noble metal content of 5wt%.

Example 6: The ceramic fiber carrier was treated in 60% nitric acid for 0.5 h, and then washed and dried. Under the air atmosphere of 15% steam, hydrothermal treatment at 600° C. for 1 hour, and after drying, a ceramic fiber carrier with good hydrothermal stability after removal of impurities is obtained. Immerse ₁ g of the treated ceramic fiber carrier in a mixed slurry with a molar ratio of ZrO2 and Co3O4 of ₁₀ : ₁ , blow with compressed air to remove excess slurry, dry at 120 °C for 15 h, and then bake at 700 °C 1h, the loading amount of the coating on the ceramic fiber catalyst carrier is 50wt%. Configure a mixed solution of H ₂ PtCl ₆ with a concentration of 6mgPt/ml and PdCl ₂ of 9mgPd/ml as the active component impregnation solution, and put the ceramic fiber carrier coated with zirconia and cobalt oxide into the active component impregnation solution after immersion Take it out, blow off the residual solution in the pores with compressed air, then dry it in an oven at 80°C for 10 hours, and roast it in air at 400°C for 5 hours to prepare a catalytic combustion catalyst with a noble metal content of 0.5wt%.

Example 7: The ceramic fiber carrier was treated in 8% sulfuric acid for 48 hours, and then washed and dried. Under the air atmosphere of 20% steam, hydrothermal treatment at 150° C. for 36 hours, after drying, a ceramic fiber carrier with good hydrothermal stability after removal of impurities was obtained. Immerse 1 g of the treated ceramic fiber carrier in a mixed slurry with a molar ratio of Al ₂ O ₃ and Co ₃ O ₄ of 4:1, blow it with compressed air to remove excess slurry, and dry it at 100°C for 20 h, 400 ℃ calcination for 5 hours, and the loading amount of the coating on the ceramic fiber catalyst carrier is 5wt%. Prepare a PdCl solution with a concentration of _40mgPd /ml as the active component impregnation solution, put the ceramic fiber carrier coated with alumina and cobalt oxide into the active component impregnation solution, take it out after immersion, and blow off the residue in the pores with compressed air. The solution was then dried in an oven at 80° C. for 12 hours, and then calcined at 600° C. in air for 1 hour to obtain a catalytic combustion catalyst with an active component content of 1.3 wt %.

Example 8: The ceramic fiber carrier was treated in 20% phosphoric acid for 30 hours, and then washed and dried. Under the air atmosphere of 8% steam, hydrothermal treatment at 400° C. for 16 hours, after drying, a ceramic fiber carrier with good hydrothermal stability after removal of impurities was obtained. Immerse 1g of the treated ceramic fiber carrier in the carbon nanotube slurry, blow it with compressed air to remove the excess slurry, dry it at 110°C for 24h, and then bake it at 300°C for 2h. The loading capacity of the coating on the ceramic fiber catalyst carrier is 7wt%. Configure a mixed solution of PdCl ₂ with a concentration of 19mgPd/ml and RhCl ₂ of 2mgRh/ml as the active component impregnation solution, put the ceramic fiber carrier coated with carbon nanotubes into the active component impregnation solution and take it out after immersion. The residual solution in the pores was blown away by air, then dried in an oven at 80° C. for 20 hours, and calcined at 200° C. in air for 4 hours to obtain a catalytic combustion catalyst with an active component content of 0.7 wt %.

Example 9: The ceramic fiber carrier was treated in 10% nitric acid for 32 hours, and then washed and dried. Under the air atmosphere of 9% steam, hydrothermal treatment at 300° C. for 10 h, and after drying, a ceramic fiber carrier with good hydrothermal stability after removal of impurities is obtained. Immerse 1 g of the treated ceramic fiber carrier in a mixed slurry with a molar ratio of _Al2O3 and ZrO2 of ₂ : ₃ , blow with compressed air to remove excess slurry, dry at 120 °C for 12 h, and then bake at 400 °C 3h, the loading amount of the coating on the ceramic fiber catalyst carrier is 15wt%. Configuration concentration is the PdCl solution of _18mgPd /ml and the RuCl of _15mgRu /ml as the active component impregnating solution, puts the ceramic fiber carrier coated with alumina and zirconia into the active component impregnating solution and takes out after soaking, and use The residual solution in the pores was blown off with compressed air, then dried in an oven at 80°C for 18 hours, and calcined at 550°C in air for 5 hours to obtain a catalytic combustion catalyst with an active component content of 1.1 wt%.

Example 10: The ceramic fiber carrier was treated in 15% hydrochloric acid for 6 hours, and then washed and dried. Under the air atmosphere of 30% steam, hydrothermal treatment at 200° C. for 5 hours, after drying, a ceramic fiber carrier with good hydrothermal stability after removal of impurities is obtained. 1 g of the treated ceramic fiber carrier was immersed in a mixed slurry with a molar ratio of _TiO2 and CeO2 of ₅ :1, blown with compressed air to remove excess slurry, dried at 150 °C for 8 h, and then fired at 450 °C for 3 h. The loading amount of the coating on the ceramic fiber catalyst carrier is 18wt%. Configuration concentration is the PdCl of 3mgPd/ _ml2 and the _PtCl2 solution of 21mgPt/ml as the active component impregnating liquid, puts the ceramic fiber carrier that has been coated with titanium oxide and cerium oxide into active component impregnating liquid and takes out after dipping, with The residual solution in the pores was blown away by compressed air, then dried in an oven at 80°C for 12 hours, and calcined at 600°C in air for 1 hour to obtain a catalytic combustion catalyst with an active component content of 0.8 wt%.

Example 11: The ceramic fiber carrier was treated in 12% hydrochloric acid for 3 hours, and then washed and dried. Under the air atmosphere of 10% steam, hydrothermal treatment at 350° C. for 6 hours, and after drying, a ceramic fiber carrier with good hydrothermal stability after removal of impurities is obtained. Immerse 1 g of the treated ceramic fiber carrier in a mixed slurry with a molar ratio of MnO ₂ and Co ₃ O ₄ of 1:1, blow with compressed air to remove excess slurry, dry at 110 °C for 12 h, and then bake at 350 °C 4h, the loading amount of the coating on the ceramic fiber catalyst carrier is 20wt%. Configuration concentration is the PtCl of 20mgPd/ml ₂ and the RuCl solution of _40mgRu /ml as active component impregnating solution, the ceramic fiber carrier that has been coated with manganese oxide and cobalt oxide is put into the active component impregnating solution and takes out after dipping, with The residual solution in the pores was blown away by compressed air, then dried in an oven at 100° C. for 18 hours, and calcined at 600° C. in air for 2 hours to obtain a catalytic combustion catalyst with an active component content of 2 wt%.

Example 12: The ceramic fiber carrier was treated in 5% phosphoric acid for 40 hours, and then washed and dried. Under the air atmosphere of 30% steam, hydrothermal treatment at 500° C. for 3 hours, and after drying, a ceramic fiber carrier with good hydrothermal stability after removal of impurities is obtained. Immerse 1 g of the treated ceramic fiber carrier in a mixed slurry with a molar ratio of _Al2O3 and _TiO2 of ₁ :3, blow with compressed air to remove excess slurry, dry at 80°C for 24h, and then bake at 500°C 2h, the loading amount of the coating on the ceramic fiber catalyst carrier is 18wt%. Configure the PdCl solution with a concentration of _9mgPd /ml as the active component impregnation solution, put the ceramic fiber carrier coated with alumina and titanium oxide into the active component impregnation solution and take it out after immersion, blow off the residual in the pores with compressed air The solution was then dried in an oven at 80° C. for 12 hours, and then calcined at 600° C. in air for 2 hours to obtain a catalytic combustion catalyst with an active component content of 0.3 wt %.

Comparative Example 1: Immerse 1g of cordierite honeycomb ceramic carrier in a mixed slurry with a molar ratio of CeO2 and _MnO2 of ₈ :1, blow with compressed air to remove excess slurry, dry at 150°C for 7h, and then dry at 800°C After firing for 2 hours, the loading amount of the coating on the cordierite honeycomb ceramic catalyst carrier is 20wt%. Configure the H ₂ PtCl ₆ solution with a concentration of 15mgPt/ml as the active component impregnation solution, put the cordierite honeycomb ceramic carrier coated with cerium oxide and manganese oxide into the active component impregnation solution, take it out after immersion, and blow it with compressed air. Remove the residual solution in the pores, then dry in an oven at 50° C. for 20 hours, and bake at 500° C. in air for 2 hours to prepare a catalytic combustion catalyst with an active component content of 0.5 wt % cordierite honeycomb ceramics as a carrier.

Comparative Example 2: Immerse 1 g of the treated cordierite honeycomb ceramic carrier in a mixed slurry with a molar ratio of _Al2O3 and Co3O4 _{of 4} : ₁ , blow with compressed air to remove excess slurry, 100 After drying at °C for 20 hours, it was fired at 400°C for 5 hours, and the loading amount of the coating on the cordierite honeycomb ceramic carrier was 5 wt%. Prepare a PdCl solution with a concentration of _40mgPd /ml as the active component impregnation solution, put the ceramic fiber carrier coated with alumina and cobalt oxide into the active component impregnation solution, take it out after immersion, and blow off the residue in the pores with compressed air. The solution was then dried in an oven at 80° C. for 12 hours, and then calcined at 600° C. in air for 1 hour to prepare a catalytic combustion catalyst with an active component content of 3 wt % supported by cordierite honeycomb ceramics.

The catalysts prepared by the above-mentioned Examples 1-6 and Comparative Example 1 of the present invention are packed in a fixed-bed catalytic combustion reactor, the loading amount of the catalyst is 0.5g, and the catalyst needs to be mixed with 10% H ₂ -N ₂ Pretreatment at 200-500°C for 1-4 hours, or reduction with 2% hydrazine hydrate solution for 24 hours. The CO content in the inlet gas is 0.02%, the CO ₂ content is 6%, the Air content is 10%, the H ₂ O steam content is 9%, the SO ₂ content is 20ppm, N ₂ is used as the balance gas, and the gas space velocity is 110,000h ^-1 . In the range of reaction temperature 0-200°C, the initial activity of the catalyst and the hydrothermal stability at 200°C were investigated (t=50h). The results are shown in Table 1. From the experimental data in the table, it can be found that the activity curve of Examples 1-6 moves to the low temperature direction compared with Comparative Example 1, and has good hydrothermal stability compared with Comparative Example 1. The reaction time is 50h. The conversion rate of CO was still above 90% after the end, while the conversion rate of CO in Comparative Example 1 began to decline continuously after 10 hours, and dropped to about 60% after 50 hours.

Table 1 Catalyst CO removal performance table

Example T ₁₀ /℃ T ₅₀ /℃ T ₉₀ /℃ t=50h/% 1 92.6 110.3 133.7 100 2 91.5 117.2 138.5 93 3 81.8 103.8 110.7 91 4 78.3 93.4 120.3 97 5 88.2 105.3 111.5 100 6 95.4 118.1 127.8 90 Comparative example 1 97.8 125.3 148.5 62

The catalysts prepared by the above-mentioned examples 7-12 of the present invention and comparative example 2 are packed in a fixed-bed catalytic combustion reactor, and the simulated coal mine ventilation gas is passed into. Pretreatment in %H ₂ -N ₂ mixed gas flow at 200-500°C for 1-4 hours, or reduction with 2% hydrazine hydrate solution for 24 hours. The methane content in the inlet gas is 0.2%, HCl 10ppm, the rest is air, and the gas space velocity is 20000h ^-1 . In the range of reaction temperature 0-500°C, the stability of the initial activity of the catalyst at 500°C for 50h was investigated, and the results are shown in Table 2. The activity data in the table is not much different from the comparative examples, but from the stability data, the examples have good hydrothermal stability and chlorine resistance.

Visible by above _- mentioned experiment, catalytic combustion catalyst of the present invention, with ceramic fiber as carrier, under the experimental condition of low concentration CO and CH Catalytic combustion, the performance of catalyst has been evaluated, and the result shows that the catalyst disclosed in this patent not only has It has excellent catalytic activity and hydrothermal stability, and also has good anti-toxic properties such as sulfur/chlorine resistance.

Table 2 Catalyst removal _CH4 performance table

Example T ₁₀ /℃ T ₅₀ /℃ T ₉₀ /℃ t=50h/% 7 221 352 465 >90 8 238 362 481 >90 9 247 371 478 >90 10 253 368 475 >90 11 223 241 458 >90 12 245 381 462 >90 Comparative example 1 252 377 483 >50

Claims (9)

1. A catalytic combustion catalyst, characterized in that the catalyst comprises a treated ceramic fiber carrier, a coating and a noble metal active component, and the coating is a metal oxide or carbon nanotube. 2. catalytic combustion catalyst as claimed in claim 1, is characterized in that, described ceramic fiber carrier is through acid treatment and hydrothermal treatment earlier before coating, coating and precious metal active component adopt impregnation method to load on the ceramic fiber . 3. catalytic combustion catalyst as claimed in claim 2 is characterized in that, when described ceramic fiber support is treated with acid, the acid used is nitric acid, sulfuric acid, phosphoric acid, one or more in hydrochloric acid, acid The concentration is 1%-65%, and the treatment time is 0.5-48 hours; When the ceramic fiber carrier is hydrothermally treated, the water vapor concentration is 0.5%-30%, the treatment temperature is 150-700° C., and the treatment time is 0.5-48 hours. 4. catalytic combustion catalyst as claimed in claim 1, is characterized in that, described coating accounts for 2-50wt% of catalyst gross weight, noble metal active component accounts for 0.1-5wt% of catalyst gross weight, and described metal oxide It is one or more of metal oxides of aluminum, cerium, zirconium, manganese, cobalt and titanium, and the active component of noble metal is one or more of palladium, platinum, rhodium, iridium and ruthenium. 5. a preparation method of the arbitrary described catalytic combustion catalyst of claim 1-4, the method comprises the following steps: (1) acid treatment ceramic fiber carrier, ceramic fiber carrier is put into acid solution and soaked, with deionized water (2) hydrothermally treating the ceramic fiber carrier, drying the ceramic fiber carrier in a hydrothermal atmosphere; (3) loading the coating, putting the processed ceramic fiber carrier into aluminum, cerium , zirconium, manganese, cobalt, vanadium, titanium, tungsten, one or more than two metal oxides or carbon nanotubes in the slurry and then dried and roasted, the slurry is made of metal oxides or carbon nanotubes and Composition after mixing deionized water with ball milling; (4) loading active components, impregnating the coated ceramic fiber in one or more precursor solutions of palladium, platinum, rhodium, iridium, ruthenium, and drying Roasting can obtain catalytic combustion catalyst. 6. The preparation method according to claim 5, characterized in that, the drying temperature in (3) is 80-150°C, the drying time is 6-48h, the roasting temperature is 400-1200°C, and the roasting time is 1-6h (4) The drying temperature is 30-150°C, the drying time is 6-48h, the roasting temperature is 200-600°C, and the roasting time is 1-6h. 7. The application of the catalytic combustion catalyst as claimed in claims 1-4 in the catalytic combustion process of methane or the catalytic combustion removal process of other hydrocarbons and VOC, H ₂ , CO gases. 8. The application as claimed in claim 7, characterized in that the reaction conditions used in the methane catalytic combustion process are: the methane content in the inlet gas is 0.2-1%, the chloride content is 0-30ppm, and the rest is air, gas The space velocity is 5000-40000h ^-1 , and the reaction temperature is within the range of 0-600°C; the reaction conditions used in the catalytic combustion of carbon monoxide are: the CO content in the inlet gas is 0.005-0.5%, and the _CO2 content is 0-10% , the Air content is 5-20%, the H ₂ O vapor content is 0-15%, the sulfide content is 0-30ppm, N ₂ is used as the balance gas, the gas space velocity is 20000-200,000h ^-1 , and the reaction temperature is 0- 300°C range. 9. The application according to claim 8, characterized in that before use, it needs to be pretreated at 200-500°C for 1-4 hours in a 10% H ₂ -N ₂ mixed gas flow, or reduced with 2% hydrazine hydrate solution for 24 hours .