CN117160483A - Catalyst for treating exhaust emissions from methanol fuel engines and preparation method and application thereof - Google Patents

Abstract

The application provides a catalyst for treating methanol fuel automobile exhaust, which comprises a first active component part containing noble metal and a second active component part containing one or more of zirconium oxide materials of manganese, titanium and copper, wherein the first active component part is coated on a carrier; a first active component is coated on a first layer of the carrier, and a second active component is coated on an upper layer of the first active component; or the first active component is coated in the first layer back region of the carrier and the second active component is coated in the first layer front region of the carrier; the first layer front area is a tail gas inlet end part, and the first layer rear area is a tail gas outlet end part. The catalyst has obviously lower formic acid yield than the reference catalyst at low temperature, increases the low-temperature activity of formic acid, does not detect cyanide, and avoids the problem of cyanide generated by the reaction of formic acid and ammonia.

Description

Catalyst for treating exhaust emissions from methanol fuel engines and preparation method thereof application

Technical field

The invention belongs to the field of exhaust gas treatment for methanol-fueled engine vehicles, and specifically relates to a catalyst for treating exhaust gases emitted from methanol-fueled engine vehicles.

Background technique

As the number of cars continues to increase, vehicle exhaust emissions have had a serious impact on the environment and human health. Formaldehyde and formic acid are the main harmful substances in vehicle exhaust from methanol-fueled engines. They are potentially harmful to air quality and human health. Therefore, it is of great significance to develop efficient catalysts for exhaust gas treatment of methanol-fueled vehicles, especially catalysts used to reduce formaldehyde and formic acid emissions during cold starts.

Currently, traditional catalysts containing precious metals are mainly used as catalysts for converting formaldehyde and formic acid in the exhaust of methanol-fueled vehicles. Precious metals such as platinum, palladium and rhodium have high catalytic activity and stability and can effectively degrade formaldehyde and formic acid. These precious metals are usually coated on carriers such as honeycomb ceramics to form catalysts.

However, there are the following problems in the existing technology: First, the cost of noble metal catalysts is relatively high. Secondly, precious metal catalysts have certain limitations on the catalytic activity of formaldehyde and formic acid in the exhaust of methanol-fueled vehicles. Especially during cold start, when the vehicle exhaust and after-treatment temperatures are low, the activity of the catalyst for formic acid will be reduced or even completely ineffective. Finally, when a methanol-fueled engine is started, the fuel remaining in the engine gaps is oxidized to produce a large amount of formaldehyde and formic acid. For methanol-fueled engines that use urea aqueous solution and ammonia-containing antifreeze after-treatment systems, the formic acid emissions are related to the after-treatment (mainly Mixers and selective catalytic reduction catalysts, etc.) contact and react with residual ammonia to generate cyanide, causing potential harm to the environment and human health. In summary, the existing technology in the development of methanol fuel vehicle exhaust catalysts has problems such as low catalytic activity and high cost, and the post-processing of methanol lean-burn engines may cause the reaction of formic acid and ammonia to generate cyanide. Therefore, it is necessary to develop a new catalyst that can solve the above problems while reducing formaldehyde and formic acid emissions.

Contents of the invention

In order to solve the above technical problems, the present invention provides a catalyst for treating methanol fuel vehicle exhaust. By coating different catalysts in sections, the first active component and the second active component are used in conjunction with each other without reducing the catalyst's efficiency. While improving methanol conversion performance, it reduces the coating amount of active components containing precious metals, overcomes the reduced activity of the catalyst for formic acid and formaldehyde, and overcomes the problem that discharged formic acid contacts and reacts with residual ammonia to generate cyanide. .

The invention provides a catalyst for treating methanol fuel automobile exhaust. The catalyst includes a first active component containing precious metals coated on a carrier, and a zirconium oxide material containing one or more of manganese, titanium and copper. a second active component; the first active component is coated on the first layer of the carrier, and the second active component is coated on the upper layer of the first active component; or the first active component is coated on The rear area of the first layer of the carrier, the second active component is coated on the front area of the first layer of the carrier; the front area of the first layer is the exhaust gas inlet end part, and the rear area of the first layer The area is the exhaust end part of the exhaust gas.

As some embodiments of the present invention, the carrier is selected from honeycomb ceramics and metal carriers.

As some embodiments of the present invention, the noble metal of the first active component containing noble metal is one or more metal oxides containing Pt, Rh, and Pd.

As some embodiments of the present invention, the second active component of the zirconia material containing one or more types of manganese, titanium and copper is a high-porosity porous material.

As some embodiments of the present invention, the total amount of precious metals in the first active component containing precious metals is 5 to 150 gpcf. As some embodiments of the present invention, the total amount of precious metals in the first active component containing precious metals is 30 to 90 gpcf.

The total amount of precious metals in the first active component containing precious metals is selected from 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 130, 135, 140, 145, 150, 155, 160gpcf.

As some embodiments of the present invention, the coating amount of the second active component of the zirconia material containing one or more of manganese, titanium and copper is the coating amount of the first active component containing noble metal. 1-40% of covering amount.

The coating amount of the second active component of the zirconia material containing one or more of manganese, titanium and copper is 1, 2, 3 or 4 times the coating amount of the first active component containing noble metal. ,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,20,21,22,23,24,25,26,27,28 , 29, 30, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40%.

As some embodiments of the present invention, the second active component of the zirconia material containing one or more of manganese, titanium and copper contains manganese, titanium and copper in a ratio of: manganese/zirconium (wt%) : 0 to 40%; titanium/zirconium (wt%): 0 to 40%; copper/zirconium (wt%): 0 to 10%.

The manganese ratio is selected from manganese/zirconium (wt%): 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40%.

The titanium ratio is selected from titanium/zirconium (wt%): 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40%.

The copper ratio is selected from copper/zirconium (wt%): 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 20%.

As some embodiments of the present invention, the first active component is coated by top-feed coating or push-down slurry.

Top-loading coating refers to a coating method in which the coating slurry is sucked into the carrier from above.

Push-down slurry coating refers to a coating method in which the coating slurry is squeezed into the carrier from below.

As some embodiments of the invention, the second active ingredient is applied by a sol-gel process or a dipping process.

As some embodiments of the present invention, the second active component is prepared by a sol-gel coating method by mixing one or more precursor salts containing easily hydrolyzable manganese, titanium, and copper with a zirconium-containing material and dissolving in In deionized water, add 0.5 to 5 times the mass of citric acid as the precursor salt, and then add 2% to 30% of the mass of citric acid as polyethylene glycol. After hydrolysis and polycondensation to form a sol, it is dried, and finally heated at a high temperature of 400 to 700°C. The active component is formed after moderate heat treatment.

The amount of citric acid added in the sol-gel coating method is selected from 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, 4.0, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, 5 times.

The amount of polyethylene glycol added in the sol-gel coating method is selected from 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 by mass of citric acid. ,17,18,19,20,20,21,22,23,24,25,26,27,28,29,30%.

The temperature of high and medium heat treatment in the sol-gel coating method is selected from 400, 410, 420, 430, 440, 450, 460, 470, 480, 490, 500, 500, 510, 520, 530, 540, 550, 560 , 570, 580, 590, 600, 610, 620, 630, 640, 650, 660, 670, 680, 690, 700℃.

As some embodiments of the present invention, the second active component is prepared by an impregnation method, which involves soaking one or more precursor salt media containing manganese, titanium, and copper in a zirconium-containing material, allowing the media to penetrate into the surface of the material and The coating is formed and then fired at a high temperature of 400 to 700°C to form the active component.

The medium to high temperature and medium roasting temperatures prepared by the impregnation method are selected from 400, 410, 420, 430, 440, 450, 460, 470, 480, 490, 500, 500, 510, 520, 530, 540, 550, 560, 570, 580, 590, 600, 610, 620, 630, 640, 650, 660, 670, 680, 690, 700℃.

As some embodiments of the present invention, the second active component prepared by the sol-gel method or impregnation method is mixed with deionized water to form a slurry with a solid content of 10-60% w/w, stirred evenly and then ground. The desired second active ingredient slurry is obtained.

The solid content of the slurry is selected from 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60% w/w.

As some embodiments of the present invention, the length of the rear area of the first layer of the carrier is greater than or equal to 1/2 of the length of the carrier; the length of the front area of the first layer of the carrier is less than or equal to the length 1 of the carrier The first half of /2.

The invention provides a method for preparing the catalyst. The method includes the following steps: coating a first active component on the first layer of the carrier, and coating the first layer on the first active component. Coating a second active component on the carrier as the second layer; or coating the first active component on the rear area of the first layer of the carrier, and coating the second active component on the front area of the first layer of the carrier ; The front area of the first layer of the carrier is the exhaust gas inlet end part, and the rear area of the first layer of the carrier is the exhaust gas outlet end part; wherein, the first active component is a first active component containing precious metal, The noble metal is one or more metal oxides containing Pt, Rh, and Pd, and the second active component is a zirconium oxide material containing one or more types of manganese, titanium, or copper.

As some embodiments of the present invention, the carrier is selected from honeycomb ceramics and metal carriers.

As some embodiments of the present invention, the total amount of precious metals in the first active component containing precious metals is 5 to 150 gpcf. As some embodiments of the present invention, the total amount of precious metals in the first active component containing precious metals is 30 to 90 gpcf.

As some embodiments of the present invention, the coating amount of the second active component of the zirconia material containing one or more of manganese, titanium and/or copper is the first active component containing noble metal. 1-40% of partial coating amount.

As some embodiments of the present invention, the second active component of the zirconium oxide material containing one or more types of manganese, titanium and/or copper contains manganese, titanium and copper in a ratio of: manganese/zirconium respectively. (wt%): 0 to 40%; titanium/zirconium (wt%): 0 to 40%; copper/zirconium (wt%): 0 to 10%.

As some embodiments of the present invention, the first active component in the step (1) is coated by top-feed coating or push-down slurry; the second active component in the step (2) Coating by sol-gel method or dipping method.

As some embodiments of the present invention, the second active component in step (2) is prepared by a sol-gel coating method, which is one or more easily hydrolyzable compounds containing manganese, titanium, and copper. The precursor salt and the zirconium-containing material are mixed and dissolved in deionized water, 0.5 to 5 times the mass of the precursor salt is added in citric acid, and then 2% to 30% of the mass of citric acid polyethylene glycol is added. After hydrolysis and polycondensation to form a sol After drying and finally heat treatment at a high temperature of 400 to 700°C, the active component is formed.

As some embodiments of the present invention, the second active component is prepared by an impregnation method, which involves soaking one or more precursor salt media containing manganese, titanium, and copper in a zirconium-containing material, and then permeating the media It reaches the surface of the material and forms a coating, and then is fired at a high temperature of 400 to 700°C to form active components.

As some embodiments of the present invention, the second active component prepared by the sol-gel method or impregnation method is mixed with deionized water to form a slurry with a solid content of 10-60%, stirred evenly and then ground to obtain Desired second active ingredient slurry.

As some embodiments of the present invention, the length of the rear area of the first layer of the carrier is greater than or equal to 1/2 of the length of the carrier; the length of the front area of the first layer of the carrier is less than or equal to the length of the carrier length 1/2.

The invention also provides the use of the catalyst in catalytically treating methanol fuel automobile exhaust.

As mentioned above, the catalyst of the present invention for treating exhaust gas emitted by methanol-fueled engine vehicles and its preparation method and application have the following beneficial effects:

1. Coat the first active component containing precious metal on the first layer or the rear area of the first layer of honeycomb ceramics. This technical means can meet the degradation efficiency of methanol, formaldehyde and formic acid in the medium and high exhaust temperature range, thereby meeting the catalyst activity requirements.

2. Coat the second layer or the front area of the first layer of the honeycomb ceramic with one or more zirconium oxide materials containing manganese, titanium or copper as the second active component. This technical means can reduce the demand for precious metals and reduce the cost of catalysts. The second active component can form a layer of high-porosity component on the surface of the first active component or carrier, which absorbs at low temperatures and releases formaldehyde and formic acid at high temperatures. This further improves the catalyst's degradation efficiency of formaldehyde and formic acid.

Through the structure of the above catalyst, it is also possible to prevent the formic acid produced by the cold start of the methanol lean-burn engine from contacting the residual ammonia gas in the post-processing (mainly the mixer and selective catalytic reduction catalyst, etc.) and reacting to generate cyanide. That is, the presence of the second active component can adsorb formaldehyde and formic acid at low temperatures and release formaldehyde and formic acid at high temperatures. Avoid contact between formic acid and ammonia at low temperatures and prevent the formation of cyanide, thus effectively reducing potential harm to the environment and human health.

3. A synergistic effect occurs between the second active component and the first active component of the catalyst of the present invention, which increases the conversion efficiency of methanol, formaldehyde and formic acid at medium and high temperatures.

In summary, the technical solution of this application is to coat the first layer or the rear area of the honeycomb ceramics with the first active component, and to coat the second layer or the front area of the first layer with the second catalytic component. Test to improve the catalytic activity of the catalyst, reduce costs, and avoid the reaction of formic acid and ammonia to form cyanide. Through the joint action of the first active component and the second active component, it is possible to effectively reduce costs, significantly reduce formaldehyde and formic acid emissions when the emission temperature is lower than 300°C, and produce no cyanide in methanol lean-burn engine emissions.

Description of drawings

Figure 1 shows a graph showing changes in methanol conversion rate, formic acid and cyanide production with temperature on a catalyst methanol lean-burn engine bench in Examples and Reference Examples of the present invention.

Detailed ways

The present invention will be further described below with reference to specific examples. It should be understood that these examples are only used to illustrate the present invention and are not intended to limit the scope of protection of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

It should be understood that the terms used in the embodiments of the present invention are for describing specific embodiments, and are not intended to limit the scope of the present invention; in the description and claims of the present invention, unless the context clearly indicates otherwise, the singular form "a ”, “a” and “the” include the plural form. When the examples give numerical ranges, it should be understood that, unless otherwise stated in the present invention, both endpoints of each numerical range and any value between the two endpoints can be selected.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. In addition to the specific methods, equipment, and materials used in the embodiments, those skilled in the art can also use methods, equipment, and materials described in the embodiments of the present invention based on their understanding of the prior art and the description of the present invention. Any methods, equipment and materials similar or equivalent to those in the prior art may be used to implement the present invention.

Unless otherwise stated, the experimental methods, detection methods, and preparation methods disclosed in the present invention all adopt conventional techniques in this technical field and related fields.

Preparation Example 1 Preparation method of methanol fuel automobile exhaust catalyst of the present invention

The structure of the catalyst of the present application includes a first layer and/or a second layer coated on honeycomb ceramics. The first layer is coated with a traditional catalyst containing precious metals, and the second layer is coated with one or more catalysts containing manganese, titanium and copper. A kind of zirconium oxide material, or the back area of the first layer is coated with a traditional catalyst containing precious metals, and the front area of the first layer is coated with one or more zirconium oxide materials containing manganese, titanium and copper. The front area of the first layer is the exhaust gas inlet end part, and the rear area of the first layer is the exhaust gas outlet part. The specific preparation method is as follows:

Step 1: Prepare coatings containing precious metal traditional catalysts. Stir and mix a metal solution with a precious metal ratio of Pt/Rh/Pd = 5:2:1 in a total amount of 50 gpcf (grams per cubic foot) and a metal oxide material containing cerium and aluminum, and then grind it to form a slurry.

Step 2: Apply the first coat or first coat back area. Apply the slurry obtained in step 1 evenly on the rear area of the first layer of honeycomb ceramics using a push-down slurry method. The coating length is 1/2 the length of the carrier.

Step 3: Set paint. The coating is fixed on the rear area of the first layer of honeycomb ceramics through a sintering process under an air atmosphere of 500°C/2h.

Step 4: Prepare the slurry of zirconia material containing manganese and titanium. Take 2C ₄ H ₆ MnO ₄ ·4H ₂ O: 1Ti(NO ₃ ) ₂ : 7Zr(NO ₃ ) ₄ (C ₄ H ₆ MnO ₄ ·4H ₂ O and Ti(NO ₃ ) ₂ and Zr(NO ₃ ) ₄ The molar ratio is 2:1:7) as the precursor, using the solution-sol method. First, dissolve the above precursor in deionized water, and add citric acid with 2 times the mass of manganese and titanium ions (the mass of citric acid is manganese and titanium). 2 times the sum of the mass of elements), then add 10% polyethylene glycol by mass of citric acid, and stir at 80°C until the solution becomes transparent. Finally, it was dried at 110°C for 2 hours, transferred to a muffle furnace at 500°C, and roasted in an air atmosphere for 5 hours. The manganese- and titanium-containing zirconia materials prepared by the solution-sol method were mixed with deionized water to form a water-based coating with a solid content of 35%.

Step 5: Apply the first coat of front area. Apply the slurry obtained in step 4 evenly on the front area of the first layer of honeycomb ceramics using a push-down slurry method. The coating length is 1/2 of the carrier length, and the coating amount is 20% of the coating amount of the first active component.

Step 6: Set paint. The coating is fixed on the front area of the first layer of honeycomb ceramics through a sintering process under an air atmosphere of 500°C/2h.

Preparation Example 2

Repeat steps 1, 2 and 3 of Example 1 to prepare a honeycomb ceramic carrier catalyst containing the first layer back zone with the same precious metal concentration ratio.

Step 4: Prepare a slurry of zirconium oxide material containing manganese and titanium in the same proportion as in Example 1. Dissolve manganese nitrate and titanium nitrate in deionized water, and use the impregnation method to impregnate the zirconia powder. Then it was dried at 110°C for 2 hours, transferred to a muffle furnace at 650°C, and roasted in an air atmosphere for 2 hours. The manganese-titanium-containing zirconia material prepared by the impregnation method was configured into a water-based coating with a solid content of 35%.

Repeat steps 5 and 6 of Example 1. Finally, the catalyst is obtained.

Reference ratio:

Repeat the above steps 1, 2 and 3 to obtain the same precious metal concentration ratio, and the coating amount is the same as the total amount of the first active component and the second active component of the finished catalyst according to the embodiment preparation method of the present application.

Catalyst performance evaluation: The catalyst prepared above was packaged and placed on a methanol lean-burn engine bench to test the catalyst steady-state methanol conversion efficiency and formic acid and cyanide emission values in accordance with the requirements of GB17691-2018 regulations. The results obtained are shown in Figure 1.

Example 3 Catalytic effects of catalysts prepared in Examples 1, 2 and Reference Examples

It can be seen from the engine bench test results in Figure 1:

1. The catalysts obtained after coating the second active component prepared by two different methods in Preparation Examples 1 and 2 have basically the same conversion performance on pollutants.

2. The methanol conversion performance of the three catalyst samples is basically the same, and the methanol conversion performance of the catalyst of the present invention in the low-temperature section is slightly better. It shows that the catalysts of Preparation Examples 1 and 2 can achieve the same catalytic performance requirements at a lower cost.

3. The amount of formic acid generated by the catalyst of the present invention at low temperature is significantly lower than that of the reference catalyst, indicating that the coated first layer of front zone components increases the low-temperature activity of the catalyst towards formic acid.

4. The catalyst of the present invention basically does not detect the formation of cyanide, indicating that the coated first layer of front zone components avoids the problem of cyanide generated by the reaction between formic acid and ammonia.

5. The precious metal proportion and coating amount of the first active component prepared by two different methods in Preparation Examples 1 and 2 are lower than the precious metal proportion and coating amount of the catalyst of the reference ratio. However, the methanol conversion efficiency of the catalysts in the two examples is different from that of the reference ratio. Basically the same. This shows that there is a synergistic effect between the second active component and the first active component of the present invention, ensuring the conversion efficiency of methanol.

In summary, the preparation method of this catalyst is simple and low-cost. It is suitable for the catalytic degradation of formaldehyde and formic acid emitted during cold start of methanol lean-burn engines. It avoids the reaction of formic acid and ammonia to generate cyanide, and can be produced and applied on a large scale.

The above are only preferred embodiments of the present invention, and do not limit the present invention in any form or substance. It should be pointed out that for those of ordinary skill in the art, without departing from the methods of the present invention, they will also Several improvements and additions can be made, and these improvements and additions should also be considered as the protection scope of the present invention. Those skilled in the art who are familiar with the art can make slight changes, modifications and equivalent changes based on the technical content disclosed above without departing from the spirit and scope of the invention. Equivalent embodiments; at the same time, any equivalent changes, modifications and evolutions made to the above embodiments based on the essential technology of the present invention still fall within the scope of the technical solution of the present invention.

Claims (10)

1. A catalyst for treating methanol fuel automobile exhaust, characterized in that the catalyst comprises a first active component part coated with a noble metal-containing material and a second active component part of a zirconia material containing one or more of manganese, titanium and copper on a carrier;

a first active component is coated on a first layer of the carrier, and a second active component is coated on an upper layer of the first active component;

or the first active component is coated in a first layer rear region of the carrier and the second active component is coated in a first layer front region of the carrier;

the first layer front area is a tail gas inlet end part, and the first layer rear area is a tail gas outlet end part.

2. The catalyst of claim 1, wherein the support is selected from the group consisting of honeycomb ceramics, metal supports;

or the noble metal of the first active component containing noble metal is one or more metal oxides containing Pt, rh, and Pd;

or the second active component of the zirconia material containing one or more of manganese, titanium, and copper is a high porosity porous material;

or the total amount of noble metal of the first noble metal-containing active component is 5 to 150gpcf, preferably 30 to 90gpcf;

or the second active component of the one or more manganese, titanium and/or copper containing zirconia materials is coated in an amount of 1 to 40% of the coating amount of the first active component containing a noble metal;

or the proportion of manganese, titanium and copper in the second active component of the zirconia material containing one or more of manganese, titanium and/or copper is respectively as follows: manganese/zirconium (wt%): 0-40%; titanium/zirconium (wt%): 0-40%; copper/zirconium (wt%): 0-10%.

3. The catalyst of any one of claims 1 to 2, wherein the first active component is applied by means of upfeed or downslurry;

or the second active component is coated by sol-gel, hydrothermal, co-precipitation or impregnation;

preferably, the second active component is prepared by a sol-gel coating method, which is to mix one or more precursor salts containing manganese, titanium and copper which are easy to hydrolyze with zirconium-containing materials, dissolve the mixture in deionized water, add citric acid with the mass of 0.5 to 5 times of the precursor salts, then add polyethylene glycol with the mass of 2 to 30 percent of the citric acid, form sol through hydrolytic polycondensation, dry the sol, and finally treat the sol at the temperature of 400 to 700 ℃ with the temperature of Wen Zhongre to form the active component;

preferably, the second active component is prepared by an impregnation method, which is to soak one or more precursor salt mediums containing manganese, titanium and copper in a zirconium-containing material, then to allow the mediums to permeate to the surface of the material and form a coating, and then to bake at a high temperature of 400-700 ℃ to form the active component;

preferably, the second active component is prepared by a sol-gel method or an immersion method, and then is mixed with deionized water to prepare slurry with the solid content of 10-60%, and the slurry of the second active component is obtained after uniform stirring and grinding.

4. A catalyst according to any one of claims 1 to 3, wherein the length of the first layer back zone of the support is greater than or equal to 1/2 of the length of the support;

the length of the first layer front region of the carrier is less than or equal to 1/2 of the length of the carrier.

5. A process for preparing the catalyst of any one of claims 1 to 4, comprising the steps of:

coating a first active component on a first layer of the carrier, and coating a second active component as a second layer on top of the first layer coated with the first active component;

or coating a first active component in a first layer back region of the carrier and a second active component in a first layer front region of the carrier;

the front area of the first layer of the carrier is a tail gas inlet end part, and the rear area of the first layer of the carrier is a tail gas outlet end part; wherein the first active component is a noble metal-containing first active component, wherein the noble metal is one or more metal oxides containing Pt, rh, and Pd;

the second active component is a zirconia material containing one or more of manganese, titanium, or copper.

6. The method of claim 5, wherein the support is selected from the group consisting of honeycomb ceramics, metal supports;

or the total amount of noble metal of the first noble metal-containing active component is 5 to 150gpcf, preferably 30 to 90gpcf;

or the coating amount of the zirconia material containing one or more of manganese, titanium and/or copper is 1-40% of the coating amount of the first active component containing noble metal;

or the proportion of manganese, titanium and copper in the second active component of the zirconia material containing one or more of manganese, titanium and/or copper is respectively as follows: manganese/zirconium (wt%): 0-40%; titanium/zirconium (wt%): 0-40%; copper/zirconium (wt%): 0-10%.

7. The method of any one of claims 5 to 6, wherein the first active component is applied by means of an up-feed application or a down-slurry application;

the second active component in the step (2) is prepared by a sol-gel method and an impregnation method.

8. The method according to claim 7, wherein the second active component is prepared by a sol-gel coating method, which comprises mixing one or more precursor salts containing manganese, titanium and copper which are easy to hydrolyze with zirconium-containing materials, dissolving in deionized water, adding citric acid with the mass of 0.5-5 times of the precursor salts, then adding polyethylene glycol with the mass of 2-30% of the citric acid, forming sol by hydrolytic polycondensation, drying, and finally processing at 400-700 ℃ and high Wen Zhongre to form the active component;

the second active component is prepared by an impregnation method, which is to soak one or more precursor salt mediums containing manganese, titanium and copper in a zirconium-containing material, then to make the mediums permeate to the surface of the material to form a coating, and then to bake at a high temperature of 400-700 ℃ to form an active component;

preferably, the second active component is prepared by a sol-gel method or an immersion method, and then is mixed with deionized water to prepare slurry with the solid content of 10-60%, and the slurry of the second active component is obtained after uniform stirring and grinding.

9. The method of any one of claims 5 to 8, wherein the length of the first layer back region of the carrier is greater than or equal to 1/2 the length of the carrier;

the length of the first layer front region of the carrier is less than or equal to 1/2 of the length of the carrier.

10. Use of a catalyst according to any one of claims 1 to 4 for the catalytic treatment of methanol fuel automobile exhaust.