CN102000570A - A Pd/Ce0.8Zr0.2O2/cordierite honeycomb ceramic monolithic catalyst and its preparation method and application - Google Patents

Abstract

The invention discloses a Pd/Ce _0.8 Zr _0.2 O ₂ /cordierite honeycomb ceramic monolithic catalyst and its preparation method and application. The catalyst uses cordierite honeycomb ceramic corroded by hydrochloric acid as the first carrier, and the cerium-zirconium composite oxide is The second carrier uses noble metal Pd as the active component; firstly, the cerium-zirconium composite coating is prepared on the cordierite carrier by the impregnation method, and then the carrier is immersed in the plating solution, and the active component of palladium chloride and sodium hypophosphite is used. Redox reaction and autocatalysis of palladium directly reduce palladium on cordierite honeycomb ceramics coated with cerium-zirconium composite coating; this preparation method can not only improve the oxygen storage performance of the catalyst, improve high temperature resistance and realize nano-palladium particles Evenly loaded on the carrier, the active site will not be embedded, and the amount of palladium is small, which is beneficial to improve the utilization rate of palladium, the process is simple, the preparation cycle is short, and the production cost is low; the monolithic catalyst prepared by the method has the advantages of With high activity and stability, it can completely catalyze the oxidation of toluene into harmless CO ₂ and H ₂ O at 220-300°C.

Description

A Pd/Ce0.8Zr0.2O2/cordierite honeycomb ceramic monolithic catalyst and its preparation method and application

technical field

The invention relates to a noble metal Pd/Ce _0.8 Zr _0.2 O ₂ /cordierite honeycomb ceramic monolithic catalyst and a preparation method thereof. The catalyst is used for catalytic combustion treatment of toluene.

Background technique

Nowadays, benzene, toluene, xylene, ethyl acetate, Acetone, methanol, formaldehyde and other waste gases containing volatile organic compounds (VOCs) (Volatile Organic Compounds). Most of these harmful gases are flammable and explosive, and their massive discharge not only has a serious impact on the local ecological environment but also on the earth's environment. It is one of the reasons for atmospheric photochemical smog, greenhouse effect and ozone layer destruction. At the same time, volatile organic waste gas is a pollutant that endangers human health. It is often distributed in the air along with peculiar smell and stench. Harmful effects, even acute and chronic poisoning, carcinogenic and mutagenic.

Catalytic combustion method is one of the most effective methods for dealing with volatile organic waste gases (VOCs). It is an efficient and environmentally friendly energy utilization and waste gas treatment technology. Flameless combustion decomposes into carbon dioxide and water.

At present, most of the catalytic combustion monolithic catalysts use cordierite honeycomb ceramics as the substrate. Cordierite honeycomb ceramics have the advantages of low pressure drop, low thermal expansion coefficient, large geometric surface area, high mechanical strength and high resistance to thermal vibration (heat resistance temperature 1400 ° C) and so on. ; The surface of cordierite honeycomb ceramics is often coated with a coating as the second carrier. Among the many coating materials, the CeO ₂ -ZrO ₂ composite has been studied a lot, mainly because of the excellent performance of the composite. Excellent oxygen storage and release performance, good high temperature thermal stability and excellent low temperature catalytic performance. Therefore, CeO ₂ -ZrO ₂ composite oxide is considered to be the coating material with the most potential application value at present. Noble metals such as Pd and Pt have high catalytic activity, good thermal stability, low light-off temperature, and relatively low requirements on reactor materials. Therefore, loading such active components on carriers has good industrial application prospects. . The impregnation method is often used for the loading of noble metal active components. Although the active components are relatively uniformly dispersed in the catalyst prepared by this method, the concentration of the active components is large, and it is difficult to control the loading of the active components. Zhang Qingbao et al. reported in Acta Catalytica Sinica 29(4) 373-378 that the soluble salts of Ce, Zr and Pd were used as precursors, and the Pd/Ce _0.8 Zr _0.2 O ₂ /substrate was prepared by a one-time simultaneous dip coating method. The main disadvantage of the monolithic catalyst is that the specific surface area of the prepared catalyst is only 5.9m ² /g, and the active component Pd is easy to be embedded, which is not conducive to improving the utilization rate of palladium, and the loading of palladium is not easy to control. The dot is also evident from its reported SEM image. People such as Li Yushan have reported adopting electroless plating method to prepare palladium powder catalyst on Al-Ce-Zr-Fe-Mn powder composite oxide in Industrial Catalysis 14 (7) 57-59, be applied to automobile exhaust gas purification catalyst, but this This powder catalyst is not suitable for monolithic catalysts with large diameters. In the declared patent, Li Yongfeng and others reported the preparation of platinum palladium powder catalyst directly on the cordierite honeycomb ceramics by electroless plating, which was applied to the catalytic combustion of toluene. In the catalyst prepared by this method, between the platinum palladium noble metal and the cordierite honeycomb ceramics, there is no CeO ₂ -ZrO ₂ composite oxide coating with good oxygen storage and release performance and high temperature thermal stability as the second carrier, which is easy to sinter at high temperature , affecting catalyst activity, etc. In the patent (Application No. 200710029199.0), it is reported that electroless palladium plating is carried out on cordierite honeycomb ceramics corroded by strong alkali. The key step is to immerse the cordierite ceramic carrier treated by strong alkali into NaH ₂ PO ₂ Put it in the stock solution for a period of time, then soak it into the Pd solution for palladium plating, repeat the above operation twice, and add CeO ₂ , NiCl ₂ 6H ₂ O powder particle additives to the Pd solution for modification to improve the palladium The adsorption capacity and uniformity of dispersion. Its main disadvantage is that CeO ₂ particles are insoluble in acid and alkali, so CeO ₂ has poor suspension in the plating solution and is easy to precipitate to the bottom of the solution, and Pd is easily adsorbed on CeO ₂ particles and co-precipitates, resulting in the loss of Pd and CeO ₂ , reduce the loading of Pd and CeO ₂ on the cordierite ceramic carrier; and this method does not form the second carrier containing CeO ₂ coating. And the present invention first uses the impregnation method to coat CeO ₂ -ZrO ₂ coatings on the cordierite honeycomb ceramics corroded by hydrochloric acid as the second carrier, and then uses PdCl ₂ and reducing agent in the same solution simultaneously as the plating solution for chemical Palladium plating has a simpler process and is more conducive to improving the utilization rate of palladium. The method of the present invention prepares Pd/Ce _0.8 Zr _0.2 O ₂ /cordierite honeycomb ceramic monolithic catalyst and applies it to the catalytic combustion treatment of toluene, which has not been reported yet.

Contents of the invention

The object of the present invention is to provide a Pd/Ce _0.8 Zr _0.2 O ₂ /cordierite honeycomb ceramic monolithic catalyst and its preparation method and application. The catalyst is mainly used for the catalytic combustion treatment of toluene.

The present invention adopts the combination of impregnation method and electroless plating method to prepare a noble metal Pd/Ce _0.8 Zr _0.2 O ₂ /cordierite honeycomb ceramic monolithic catalyst, and the monolithic catalyst uses the cordierite honeycomb ceramic corroded by hydrochloric acid as the first carrier , the cerium-zirconium composite oxide prepared by the impregnation method is used as the second carrier, and the noble metal Pd loaded on the electroless plating is used as the active component. The molar ratio of cerium and zirconium is 4:1, the loading of _CeO2 - _ZrO2 coating is 1.0-6.0wt%, the loading of noble metal Pd is 0.06-0.6wt%, and the specific surface area is ^6.56-18.23m2 /g.

The specific preparation steps of the invention are as follows:

(1) Surface pretreatment of the cordierite honeycomb ceramic carrier: heat and boil the cordierite honeycomb ceramic carrier in 10wt% dilute hydrochloric acid solution for 30 minutes, take it out, rinse it with distilled water, and dry it at 120° C. for 1 hour;

(2) Preparation of cerium-zirconium composites by impregnation method: Ce(NO ₃ ) ₃ 6H ₂ O and Zr(NO ₃ ) ₄ 5H ₂ O are mixed in a molar ratio of 4:1, and the total molar number of metal ions is 1.2 times Add citric acid into the mixed solution of cerium and zirconium, stir for 60 minutes in a water bath at 40°C, then immerse the honeycomb ceramic carrier treated in step (1) into the mixed solution for 3 hours, take out and blow off the remaining solution in the holes , air-dried naturally, dried at 120°C for 2h, baked in a muffle furnace at 400°C for 1h, and repeated the above process twice to obtain a Ce _0.8 Zr _0.2 O ₂ /cordierite honeycomb ceramic carrier;

(3) Sensitization and activation treatment of Ce _0.8 Zr _0.2 O ₂ /cordierite honeycomb ceramic carrier: impregnate the cordierite honeycomb ceramic carrier treated in step (2) to a concentration of 1-10.0g/L SnCl ₂ and 30mL/ In the sensitization solution of L hydrochloric acid for 5-10 minutes, take it out and wash it with distilled water; then immerse it in the activation solution of PdCl ₂ with a concentration of 0.05-0.10g/L and 1mL/L hydrochloric acid for 5-10 minutes, take it out and wash it with distilled water ;

(4) Preparation of electroless palladium plating solution: the electroless plating solution consists of 0.05～0.50g/L of PdCl ₂ , sodium hypophosphite of 5.0g/L, 38wt% concentrated hydrochloric acid of 23mL/L, 25wt% ammoniacal liquor of 80mL/L and Ammonium chloride composition of 13.5g/L;

(5) Electroless palladium plating: immerse the honeycomb ceramic carrier treated in step (3) into the chemical plating solution, heat at a constant temperature of 30°C for 30-60min, then at a constant temperature of 40°C for 30-60min, then at a constant temperature of 50°C for 30-60min, Finally, keep the temperature at 60°C until no bubbles are generated, take it out and wash it with distilled water, and finally dry it at 120°C for 2 hours, and bake it at 120-900°C for 3 hours to obtain the required Pd/Ce _0.8 Zr _0.2 O ₂ /cordierite honeycomb ceramic monolith catalyst.

The loading amount of the CeO ₂ -ZrO ₂ coating prepared in the step (2) is 1.0-6.0 wt%.

The loaded amount of noble metal Pd in the monolithic catalyst prepared in the step (5) is 0.06-0.60wt%.

The cordierite honeycomb ceramics used above are commercial products with a cell density of 400 cells/in ² and a cell wall thickness of 0.1 mm.

The Pd/Ce _0.8 Zr _0.2 O ₂ /cordierite honeycomb ceramic monolithic catalyst prepared by the invention is suitable for catalytic combustion treatment of toluene.

The present invention has the following outstanding advantages and beneficial effects:

The present invention adopts impregnation method and electroless plating method to prepare a monolithic catalyst of noble metal Pd/Ce _0.8 Zr _0.2 O ₂ /cordierite honeycomb ceramics, uses cordierite honeycomb ceramics corroded by hydrochloric acid as the first carrier, and cerium-zirconium composite compound As the second carrier, the noble metal Pd is the active component. The monolithic catalyst not only has a firm coating layer, but also has good catalytic activity, good high temperature resistance and thermal stability, and is suitable for industrial application.

Catalytic combustion method to remove toluene With the help of this integral catalyst, toluene is decomposed into carbon dioxide and water by flameless combustion at a relatively low temperature. The catalyst prepared by this invention can completely convert toluene into CO ₂ at 220°C-300°C And H ₂ O, is an efficient and environmentally friendly waste gas treatment technology.

The preparation method of the present invention can improve the oxygen storage performance, high temperature resistance, thermal stability of the catalyst and realize that the nano-palladium particles are more evenly loaded on the carrier, and the active site will not be embedded (as can be clearly seen from the accompanying drawing 1), and has It is beneficial to improve the utilization rate of palladium and improve the catalytic performance of the catalyst.

Description of drawings

Fig. 1 is an SEM image of the Pd/Ce _0.8 Zr _0.2 O ₂ /cordierite honeycomb ceramic monolithic catalyst prepared in Example 4 of the present invention.

Fig. 2 is a graph showing the influence of loading amount on the catalytic combustion conversion rate of toluene of Pd/Ce _0.8 Zr _0.2 O ₂ /cordierite honeycomb ceramic monolithic catalyst palladium prepared in the present invention.

Fig. 3 is a graph showing the influence of calcination temperature on the catalytic combustion conversion rate of toluene for the Pd/Ce _0.8 Zr _0.2 O ₂ /cordierite honeycomb ceramic monolithic catalyst prepared in the present invention.

Detailed ways

In order to further illustrate the present invention, the following examples are cited, but do not limit the scope of the present invention.

Example 1

(1) Surface pretreatment of honeycomb ceramics: Boil cordierite honeycomb ceramics with a pore density of 400 pores/ ⁱⁿ² and a wall thickness of 0.1 mm in 10 wt% dilute hydrochloric acid solution for 30 minutes, take it out and rinse it with distilled water, and dry it at 120°C for 1 hour ;

(2) Preparation of cerium-zirconium composite by impregnation method: mix 0.16moL/L Ce(NO ₃ ) ₃ ·6H ₂ O, 0.04moL/L Zr(NO ₃ ) ₄ ·5H ₂ O and 0.24moL/L citric acid solution, stirred in a water bath at 40°C for 60min, then dipped the honeycomb ceramic carrier treated in step (1) into the mixed solution for 3h, took out and blown off the remaining solution in the hole, air-dried naturally, dried at 120°C for 2h, and then Baking in a muffle furnace at 400°C for 1 h, and repeating the above process twice to obtain a Ce _0.8 Zr _0.2 O ₂ /cordierite honeycomb ceramic carrier;

(3) Sensitization and activation treatment of Ce _0.8 Zr _0.2 O ₂ /cordierite honeycomb ceramic carrier: impregnate the cordierite honeycomb ceramic carrier treated in step (2) to a concentration of 10.0g/L SnCl ₂ and 30mL/L hydrochloric acid 10min in the sensitizing solution, take it out and wash it with distilled water; then immerse it in the activation solution of 0.10g/L PdCl ₂ and 1mL/L hydrochloric acid for 10min, take it out and wash it with distilled water;

(4) Preparation of electroless palladium plating solution: chemical plating solution consists of 0.10g/L of PdCl ₂ , 5.0g/L of sodium hypophosphite, 23mL/L of 38wt% concentrated hydrochloric acid, 80mL/L of 25wt% ammonia and 13.5g /L ammonium chloride composition;

(5) Electroless palladium plating: immerse the honeycomb ceramic carrier treated in step (3) into the chemical plating solution, heat at a constant temperature of 30°C for 40 minutes, then at a constant temperature of 40°C for 40 minutes, then at a constant temperature of 50°C for 40 minutes, and finally at a constant temperature of 60°C until no Bubbles are generated, take it out and wash it with distilled water, and finally dry it at 120°C for 2 hours, and bake it at 500°C for 3 hours to obtain a 0.06wt% Pd/Ce _0.8 Zr _0.2 O ₂ /cordierite honeycomb ceramic monolithic catalyst;

(6) Evaluation of catalytic combustion performance of the monolithic catalyst: Cut the rectangular parallelepiped Pd/Ce _0.8 Zr _0.2 O ₂ /cordierite honeycomb ceramic monolithic catalyst with a size of 15mm×15mm×25mm into a rectangular parallelepiped of 7mm×7mm×15mm, and then The catalyst is loaded into a catalytic reactor.

Toluene is brought into the reaction furnace by air at a certain flow rate, its concentration is 4.0g/m ³ , and the space velocity is 10000h ^-1 . The concentration of toluene in the reactants and products was analyzed by Agilent GC-6820 gas chromatograph (FID), and the evaluation results are shown in Figure 2.

Example 2

(1) honeycomb ceramic surface pretreatment: operate by the method in embodiment 1;

(2) Preparation of cerium-zirconium composite by impregnation method: operate according to the method in Example 1;

(3) Sensitization and activation treatment of Ce _0.8 Zr _0.2 O ₂ /cordierite honeycomb ceramic carrier: operate according to the method in Example 1;

(4) prepare electroless palladium plating solution: prepare by the method in embodiment 1, PdCl _{Concentration} is 0.10g/L;

(5) Electroless palladium plating: operate according to _the method in embodiment 1, can obtain 0.12wt%Pd/ _Ce0.8Zr0.2O2 /cordierite honeycomb ceramic monolithic catalyst _;

(6) Catalytic combustion performance evaluation of the monolithic catalyst: operate according to the method in Example 1, and the evaluation results are shown in accompanying drawing 2.

Example 3

(1) honeycomb ceramic surface pretreatment: operate by the method in embodiment 1;

(2) Preparation of cerium-zirconium composite by impregnation method: operate according to the method in Example 1;

(3) Sensitization and activation treatment of Ce _0.8 Zr _0.2 O ₂ /cordierite honeycomb ceramic carrier: operate according to the method in Example 1;

(4) prepare electroless palladium plating solution: prepare by the method in embodiment 1, _PdCl Concentration is 0.20g/L;

(5) Electroless palladium plating: operate according to _the method in embodiment 1, can obtain 0.24wt%Pd/ _Ce0.8Zr0.2O2 /cordierite honeycomb ceramic monolithic catalyst _;

(6) Catalytic combustion performance evaluation of the monolithic catalyst: operate according to the method in Example 1, and the evaluation results are shown in accompanying drawing 2.

Example 4

(1) honeycomb ceramic surface pretreatment: operate by the method in embodiment 1;

(2) Preparation of cerium-zirconium composite by impregnation method: operate according to the method in Example 1;

(3) Sensitization and activation treatment of Ce _0.8 Zr _0.2 O ₂ /cordierite honeycomb ceramic carrier: operate according to the method in Example 1;

(4) prepare electroless palladium plating solution: prepare by the method in embodiment 1, _{PdClConcentration} is 0.30g/L;

(5) Electroless palladium plating: according to the method in Example 1, a 0.36wt% Pd/Ce _0.8 Zr _0.2 O ₂ /cordierite honeycomb ceramic monolithic catalyst can be obtained.

(6) Catalytic combustion performance evaluation of the monolithic catalyst: operate according to the method in Example 1, and the evaluation results are shown in accompanying drawing 2.

Example 5

(1) honeycomb ceramic surface pretreatment: operate by the method in embodiment 1;

(2) Preparation of cerium-zirconium composite by impregnation method: operate according to the method in Example 1;

(3) Sensitization and activation treatment of Ce _0.8 Zr _0.2 O ₂ /cordierite honeycomb ceramic carrier: operate according to the method in Example 1;

(4) prepare electroless palladium plating solution: prepare by the method in embodiment 1, _PdCl Concentration is 0.40g/L;

(5) Electroless palladium plating: operate according to _the method in embodiment 1, can obtain 0.48wt%Pd/ _Ce0.8Zr0.2O2 /cordierite honeycomb ceramic monolithic catalyst _;

(6) Catalytic combustion performance evaluation of the monolithic catalyst: operate according to the method in Example 1, and the evaluation results are shown in accompanying drawing 2.

Example 6

(1) honeycomb ceramic surface pretreatment: operate by the method in embodiment 1;

(2) Preparation of cerium-zirconium composite by impregnation method: operate according to the method in Example 1;

(3) Sensitization and activation treatment of Ce _0.8 Zr _0.2 O ₂ /cordierite honeycomb ceramic carrier: operate according to the method in Example 1;

(4) prepare electroless palladium plating solution: prepare by the method in embodiment 1, _{PdClConcentration} is 0.50g/L;

(5) Electroless palladium plating: operate according to _the method in embodiment 1, can obtain 0.60wt%Pd/ _Ce0.8Zr0.2O2 /cordierite honeycomb ceramic monolithic catalyst _;

(6) Catalytic combustion performance evaluation of the monolithic catalyst: operate according to the method in Example 1, and the evaluation results are shown in accompanying drawing 2.

Example 7

(1) honeycomb ceramic surface pretreatment: operate by the method in embodiment 1;

(2) Preparation of cerium-zirconium composite by impregnation method: operate according to the method in Example 1;

(3) Sensitization and activation treatment of Ce _0.8 Zr _0.2 O ₂ /cordierite honeycomb ceramic carrier: operate according to the method in Example 1;

(4) prepare electroless palladium plating solution: prepare by the method in embodiment 1, _{PdClConcentration} is 0.30g/L;

(5) Electroless palladium plating: operate according to the method in Example 1, and roast at 120°C for 3 hours to obtain a 0.36wt% Pd/Ce _0.8 Zr _0.2 O ₂ /cordierite honeycomb ceramic monolithic catalyst;

(6) Catalytic combustion performance evaluation of the monolithic catalyst: operate according to the method in Example 1, and the evaluation results are shown in FIG. 3 .

Example 8

(1) honeycomb ceramic surface pretreatment: operate by the method in embodiment 1;

(2) Preparation of cerium-zirconium composite by impregnation method: operate according to the method in Example 1;

(3) Sensitization and activation treatment of Ce _0.8 Zr _0.2 O ₂ /cordierite honeycomb ceramic carrier: operate according to the method in Example 1;

(4) prepare electroless palladium plating solution: prepare by the method in embodiment 1, _PdCl Concentration is 0.30g/L;

(5) Electroless palladium plating: operate according to the method in Example 1, and roast at 300°C for 3 hours to obtain a 0.36wt% Pd/Ce _0.8 Zr _0.2 O ₂ /cordierite honeycomb ceramic monolithic catalyst;

(6) Catalytic combustion performance evaluation of the monolithic catalyst: operate according to the method in Example 1, and the evaluation results are shown in accompanying drawing 3.

Example 9

(1) honeycomb ceramic surface pretreatment: operate by the method in embodiment 1;

(2) Preparation of cerium-zirconium composite by impregnation method: operate according to the method in Example 1;

(3) Sensitization and activation treatment of Ce _0.8 Zr _0.2 O ₂ /cordierite honeycomb ceramic carrier: operate according to the method in Example 1;

(4) prepare electroless palladium plating solution: prepare by the method in embodiment 1, _PdCl Concentration is 0.30g/L;

(5) Electroless palladium plating: operate according to the method in Example 1, and roast at 700°C for 3 hours to obtain a 0.36wt% Pd/Ce _0.8 Zr _0.2 O ₂ /cordierite honeycomb ceramic monolithic catalyst;

(6) Catalytic combustion performance evaluation of the monolithic catalyst: operate according to the method in Example 1, and the evaluation results are shown in accompanying drawing 3.

Example 10

(1) honeycomb ceramic surface pretreatment: operate by the method in embodiment 1;

(2) Preparation of cerium-zirconium composite by impregnation method: operate according to the method in Example 1;

(3) Sensitization and activation treatment of Ce _0.8 Zr _0.2 O ₂ /cordierite honeycomb ceramic carrier: operate according to the method in Example 1;

(4) prepare electroless palladium plating solution: prepare by the method in embodiment 1, _{PdClConcentration} is 0.30g/L;

(5) Electroless palladium plating: operate according to the method in Example 1, and roast at 900°C for 3 hours to obtain a 0.36wt% Pd/Ce _0.8 Zr _0.2 O ₂ /cordierite honeycomb ceramic monolithic catalyst;

(6) Catalytic combustion performance evaluation of the monolithic catalyst: operate according to the method in Example 1, and the evaluation results are shown in accompanying drawing 3.

Claims (5)

1. Pd/Ce _0.8Zr _0.2O ₂/ cordierite honeycomb ceramic integral catalyzer, it is characterized in that: the cordierite honeycomb ceramic of this integral catalyzer after with hcl corrosion is first carrier, cerium zirconium compound oxide with immersion process for preparing is second carrier, is active component with the precious metals pd in the chemical plating load.

2. described Pd/Ce of claim 1 _0.8Zr _0.2O ₂The preparation method of/cordierite honeycomb ceramic integral catalyzer is characterized in that may further comprise the steps:

(1) to the surface preparation of cordierite honeycomb ceramic carrier: cordierite honeycomb ceramic carrier heated in the dilute hydrochloric acid solution of 10wt% boiled 30 minutes, take out with the clean back 120 ℃ of dry 1h of distilled water flushing;

(2) immersion process for preparing cerium zirconium composite: with Ce (NO ₃) ₃6H ₂O and Zr (NO ₃) ₄5H ₂O mixes for 4:1 in molar ratio, the citric acid of 1.2 times of metal ion total mole numbers is joined in the mixed solution of cerium zirconium, stir 60min under 40 ℃ of water-baths, the cordierite honeycomb ceramic carrier that step (1) was handled is impregnated in this mixed solution then, dipping 3h, solution residual in the hole is blown away in taking-up, natural air drying, 120 ℃ of dry 2h, 400 ℃ of roasting 1h in Muffle furnace, repeat said process again 2 times, make Ce _0.8Zr _0.2O ₂/ cordierite honeycomb ceramic carrier;

(3) Ce _0.8Zr _0.2O ₂The sensitization of/cordierite honeycomb ceramic carrier and activation processing: it is 1～10.0g/L SnCl that the cordierite honeycomb ceramic carrier that step (2) was handled is impregnated into concentration ₂With 5～10min in the sensitizing solution of 30mL/L hydrochloric acid, take out with distilled water and clean; Be immersed in the PdCl that concentration is 0.05～0.10g/L then ₂With 5～10min in the activating solution of the hydrochloric acid of 1mL/L, take out with distilled water and clean;

(4) preparation chemical palladium plating solution: chemical plating fluid is by the PdCl of 0.05～0.50g/L ₂, 5.0g/L 38wt% concentrated hydrochloric acid, the 25wt% ammoniacal liquor of 80mL/L and the ammonium chloride of 13.5g/L of inferior sodium phosphate, 23mL/L form;

(5) chemical palladium-plating: the cordierite honeycomb ceramic carrier that step (3) was handled is immersed in the chemical plating fluid, 30 ℃ of heated at constant temperature 30～60min, 40 ℃ of constant temperature 30～60min again, and then 50 ℃ of constant temperature 30～60min, last 60 ℃ of constant temperature do not produce to there being bubble, take out with distilled water and clean, at last at 120 ℃ of dry 2h, 120～900 ℃ of roasting 3h can obtain required Pd/Ce _0.8Zr _0.2O ₂/ cordierite honeycomb ceramic integral catalyzer.

3. preparation method according to claim 2 is characterized in that: preparation CeO in the described step (2) ₂-ZrO ₂The load capacity of coating is 1.0～6.0wt%.

4. preparation method according to claim 2 is characterized in that: the load capacity of precious metals pd is 0.06～0.60wt% in the integral catalyzer for preparing in the described step (5).

5. the Pd/Ce of the described preparation method of claim 2 preparation _0.8Zr _0.2O ₂/ cordierite honeycomb ceramic integral catalyzer is applicable to the catalytic combustion processing of toluene.

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