CN115770577A - Preparation method of oxidation type catalyst for purifying automobile exhaust and oxidation type catalyst - Google Patents
Preparation method of oxidation type catalyst for purifying automobile exhaust and oxidation type catalyst Download PDFInfo
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A50/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE in human health protection, e.g. against extreme weather
- Y02A50/20—Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
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Abstract
The invention relates to a preparation method of an oxidation type catalyst for purifying automobile exhaust and the oxidation type catalyst. The preparation method comprises the following steps: the preparation method of the perovskite precursor solution comprises the following steps: dissolving lanthanum nitrate and cerium nitrate solution in deionized water, adding citric acid CA and urea into the solution, and stirring to form a particle suspension to obtain a perovskite precursor solution; preparation of metal ammonia complex solution: adding M-NH into perovskite precursor solution 3 A complex solution, wherein M is any one or any combination of Co, cu and Fe, to obtain a complex-containing solution; spin drying to dryness: transferring the solution containing the complex into a rotary water bath, and evaporating the solutionUntil a hard colloid is formed; and (3) sintering: placing the hard colloid in a muffle furnace under air atmosphere for calcining, and cooling to room temperature to obtain MO-LaCeO 3 A perovskite catalyst.
Description
Technical Field
The invention relates to the technical field of synthesis and preparation of an oxidation catalyst for purifying automobile exhaust, in particular to a preparation method of the oxidation catalyst for purifying the automobile exhaust and the oxidation catalyst for purifying the automobile exhaust.
Background
The exhaust emission of the fuel engine seriously threatens the virtuous circle of the ecological environment, and the purification treatment of the exhaust pollution becomes the hot point of social attention, especially NMHC, CO and CH 4 The emission of harmful substances such as hydrocarbon substances aggravates the greenhouse effect of gases, so that the emission of substances in the tail gas of an engine can be solved by effectively developing the oxidation type catalyst. Most traditional oxidation type catalysts load noble metals to realize the purification and emission of hydrocarbon tail gas, however, factors such as rare reserves, high cost, easy poisoning and inactivation at high temperature and the like seriously restrict the wide use of the catalysts, so that the development of a non-noble metal catalyst material with high-efficiency purification capability has important research value for realizing the catalytic oxidation of hydrocarbon tail gas.
Perovskite materials (ABO) 3 ) Because of the full-coordination space structure of the elements A and B, the catalyst has good high-temperature structural stability and chemical stability, the emission of hydrocarbon tail gas of an engine under a high-temperature condition can be effectively reduced, and the high-temperature reaction activity of a catalytic system is improved.
However, the limited low-temperature catalytic performance of the perovskite material is difficult to meet the oxidation reaction condition of alkanes, and the reaction temperature window can be widened by compounding the perovskite material with other low-temperature active components (metal oxides), so that the catalytic performance of the perovskite material under the low-temperature condition is ensured.
Disclosure of Invention
The transition metal oxide is used as a catalytic reaction auxiliary agent to realize the purification of the hydrocarbon tail gas, and the application is very wide, because the special d-layer orbit of the transition metal element can provide an empty orbit to serve as an electrophilic group or provide a lone pair electron to serve as a nucleophilic group in the chemical reaction process, thereby forming an intermediate product, reducing the reaction activation energy and promoting the catalytic reaction to be carried out.
According to an aspect of the present invention, there is provided a method for preparing an oxidation catalyst for purification of automobile exhaust gas, the method comprising the steps of:
the preparation method of the perovskite precursor solution comprises the following steps: lanthanum nitrate (La (NO) 3 ) 3 ·6H 2 O), cerium nitrate (Ce (NO) 3 ) 3 ) The solution was dissolved in deionized water, and citric acid CA (C) was added to the solution 6 H 8 O 7 ) And urea (CH) 4 N 2 O) stirring to form a particle suspension to obtain a perovskite precursor solution;
preparation of metal ammonia complex solution: adding M-NH into perovskite precursor solution 3 A complex solution, wherein M is any one or any combination of Co, cu and Fe, to obtain a complex-containing solution;
spin-drying to dryness: transferring the solution containing the complex into a rotary water bath kettle, and evaporating the solution until a hard colloid is formed;
and (3) sintering: placing the hard colloid into a muffle furnace in air atmosphere for calcining, and cooling to a roomObtaining MO-LaCeO after warming 3 A perovskite catalyst.
In some embodiments, the perovskite precursor solution is prepared by the steps of: in the perovskite precursor solution, the total concentration of La and Ce metal element ions is 0.9-0.11mol/L, the molar ratio of the metal elements to the contents of chelating agent citric acid and urea is (1-1.2) to (1.5-1.8), and the pH value of the precursor solution is adjusted to 6-8 by using an ammonia water solution.
In some embodiments, in the step of preparing the metal ammine complex solution, M-NH is added to the solution 3 The solution concentration is 0.09-0.11mol/L, and the molar ratio of the addition amount of the metal ammonia complex to the perovskite in the perovskite precursor solution is 1 (0.04-1).
In some embodiments, the step of spin drying is: and putting the perovskite precursor solution into a rotary water bath stirrer with the temperature of 70-80 ℃ and the rotating speed of 100-120rpm, and evaporating and drying for 10-12h to obtain a viscous colloidal precursor.
In some embodiments, the step of sintering is: placing the colloidal precursor after rotary steaming and drying in a muffle furnace for calcining, heating to 200-300 ℃ at the speed of 3-5 ℃/min in the first stage, preserving heat for 1-1.5h, heating to 350-450 ℃ at the speed of 1-3 ℃/min in the second stage, preserving heat for 1-2h, heating to 550-650 ℃ at the speed of 8-10 ℃/min in the third stage, preserving heat for 1.5-2h, and finally naturally cooling to the normal temperature of 18-28 ℃ to obtain the final perovskite catalyst.
In some embodiments, the prepared perovskite catalyst powder is compacted and then screened through a 40-60 mesh screen.
In some embodiments, perovskite samples are weighed and placed in a catalyst sample activity evaluation instrument for testing, and the space velocity is 60000h -1 The tail gas component concentration of the natural gas engine is respectively CH 4 5000ppm，NO x 500ppm，O 2 50000ppm; diesel engine exhaust gas component concentration (DOC) CO 6000ppm, c 3 H 6 266.7ppm，C 3 H 8 133.3ppm，NO x 1000ppm，O 2 4362ppm; the concentration of the tail gas component (ASC) of the diesel engine is NH respectively 3 500ppm，O 2 375ppm，CO 2 500ppm，H 2 O5 percent and the oxidation efficiency of the hydrocarbon organic matters is 90 to 98 percent.
In some embodiments, the temperature of the test is 50-700 ℃ and the ramp rate is 5-8 ℃/min.
According to another aspect of the present invention, there is provided an oxidation catalyst for automobile exhaust gas purification, which is prepared by the preparation method described above,
the oxidation catalyst adopts LaCeO 3 Perovskite is used as a catalytic support carrier, and transition metal oxide is used as an active additive.
In some embodiments, the area occupation ratio of the transition metal compound uniformly loaded on the surface of the perovskite carrier is 0% -40% by regulating and controlling the load content of the transition metal element species (Co, zr, cu) and the transition metal compound.
The invention utilizes the methods of electrostatic adsorption and low-temperature roasting to perform the process on LaCeO 3 Transition metal oxides (Co, cu and Fe) are loaded on the surface of the perovskite catalytic carrier, and the porous composite catalyst material is synthesized and used for effectively purifying carbonaceous substances in the tail gas of motor vehicles. By adjusting the components, content and loading form of the transition metal oxide, the defect of insufficient activity of the perovskite catalyst in a low-temperature region, namely low-temperature ignition performance, is overcome. Meanwhile, the perovskite catalyst loaded with the metal oxide has obviously increased specific surface area, makes up the defects of few pores and compact structure of the perovskite material, ensures effective adsorption of gas components and full contact reaction with an interface and an active site, and provides a reaction space for transfer and combination of active oxygen in the structure.
Drawings
These and/or other aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the preferred embodiments, taken in conjunction with the accompanying drawings of which:
fig. 1 is a flowchart of a method for preparing an oxidation catalyst for automobile exhaust gas purification according to an embodiment of the present invention;
FIG. 2 is a scanning electron micrograph of a catalyst according to example 1 of the present invention;
FIG. 3 is a scanning electron micrograph of a catalyst according to example 2 of the present invention.
Detailed Description
The technical scheme of the invention is further specifically described by the following embodiments and the accompanying drawings. In the specification, the same or similar reference numerals denote the same or similar components. The following description of the embodiments of the present invention with reference to the accompanying drawings is intended to explain the general inventive concept of the present invention and should not be construed as limiting the invention.
The invention utilizes the methods of electrostatic adsorption and low-temperature roasting to perform the process on LaCeO 3 Transition metal oxides (Co, cu and Fe) are loaded on the surface of the perovskite catalytic carrier, and the porous composite catalyst material is synthesized and used for effectively purifying carbonaceous substances in the tail gas of motor vehicles. By adjusting the components, content and loading form of the transition metal oxide, the defect of insufficient activity of the perovskite catalyst in a low-temperature region, namely low-temperature ignition performance, is overcome. Meanwhile, the perovskite catalyst loaded with the metal oxide has obviously increased specific surface area, makes up the defects of few pores and compact structure of the perovskite material, ensures effective adsorption of gas components and full contact reaction with an interface and an active site, and provides a reaction space for transfer and combination of active oxygen in the structure.
According to the present general inventive concept, there is provided a method of preparing an oxidation catalyst for purification of automobile exhaust gas, the method comprising the steps of:
the preparation method of the perovskite precursor solution comprises the following steps: lanthanum nitrate (La (NO) 3 ) 3 ·6H 2 O), cerium nitrate (Ce (NO) 3 ) 3 ) The solution was dissolved in deionized water, and citric acid CA (C) was added to the solution 6 H 8 O 7 ) And urea (CH) 4 N 2 O) stirring to form a particle suspension to obtain a perovskite precursor solution;
preparation of metal ammonia complex solution: adding M-NH into perovskite precursor solution 3 A complex solution, wherein M is any one or any combination of Co, cu and Fe, to obtain a complex-containing solution;
spin drying to dryness: transferring the solution containing the complex into a rotary water bath kettle, and evaporating the solution until a hard colloid is formed;
and (3) sintering: placing the hard colloid in a muffle furnace under air atmosphere for calcining, and cooling to room temperature to obtain MO-LaCeO 3 A perovskite catalyst.
In some embodiments, the perovskite precursor solution is prepared by the steps of: in the perovskite precursor solution, the total concentration of La and Ce metal element ions is 0.9-0.11mol/L, the molar ratio of the metal elements to the contents of chelating agent citric acid and urea is (1-1.2) to (1.5-1.8), and the pH value of the precursor solution is adjusted to 6-8 by using an ammonia water solution.
In some embodiments, in the step of preparing the metal ammine complex solution, M-NH is added to the solution 3 The concentration of the solution is 0.09-0.11mol/L, and the molar ratio of the addition amount of the metal ammonia complex to the perovskite in the perovskite precursor solution is 1 (0.04-1).
In some embodiments, the step of spin drying is: and putting the perovskite precursor solution into a rotary water bath stirrer with the temperature of 70-80 ℃ and the rotating speed of 100-120rpm, and evaporating and drying for 10-12h (h) to obtain a viscous colloidal precursor.
In some embodiments, the step of sintering is: and placing the colloidal precursor subjected to rotary steaming and drying in a muffle furnace for calcining, heating to 200-300 ℃ at the speed of 3-5 ℃/min in the first stage, preserving heat for 1-1.5h, heating to 350-450 ℃ at the speed of 1-3 ℃/min in the second stage, preserving heat for 1-2h, heating to 550-650 ℃ at the speed of 8-10 ℃/min in the third stage, preserving heat for 1.5-2h, and finally naturally cooling to the normal temperature of 18-28 ℃ in air to obtain the final perovskite catalyst.
In some embodiments, the prepared perovskite catalyst powder is compacted and then screened through a 40-60 mesh screen.
In some embodiments, perovskite samples are weighed and placed in a catalyst sample activity evaluation instrument for testing, and the space velocity is 60000h -1 The tail gas component concentration of the natural gas engine is CH respectively 4 5000ppm，NO x 500ppm，O 2 50000ppm; diesel engine tail gas compositionConcentration (DOC) CO 6000ppm, C 3 H 6 266.7ppm，C 3 H 8 133.3ppm，NO x 1000ppm，O 2 4362ppm; the concentration of the tail gas component (ASC) of the diesel engine is NH respectively 3 500ppm，O 2 375ppm，CO 2 500ppm，H 2 O5 percent and the oxidation efficiency of the hydrocarbon organic matters is 90 to 98 percent.
In some embodiments, the temperature of the test is 50-700 ℃ and the ramp rate is 5-8 ℃/min (minutes).
According to another aspect of the present invention, there is provided an oxidation catalyst for automobile exhaust gas purification, which is prepared by the preparation method described above,
the oxidation catalyst adopts LaCeO 3 The perovskite is used as a catalytic support carrier, and the transition metal oxide is used as an active additive.
In some embodiments, the area occupation ratio of the transition metal compound uniformly loaded on the surface of the perovskite carrier is 0% -40% by regulating and controlling the load content of the transition metal element species (Co, zr, cu) and the transition metal compound.
Example 1
1. Preparing a perovskite precursor solution: 12.99g lanthanum nitrate (La (NO) was weighed 3 ) 3 ·6H 2 O), 13.02g of cerium nitrate (Ce (NO) 3 ) 3 ·6H 2 O), dissolved in 500mL of deionized water (18 M.OMEGA.) to prepare a transparent solution with a total concentration of metal element ions of 0.1mol/L, and then 9.45g of citric acid CA (C) was added to the transparent solution 6 H 8 O 7 ) 3.6g Urea (CH) 4 N 2 O) and evenly stirring to finally obtain a clear solution of the perovskite precursor, and adjusting the pH value of the solution of the perovskite precursor to 6.5 by using an ammonia water solution;
2. preparation of metal ammonia complex solution: weighing 1.5 mu mol of transition metal ammine complex M-NH 3 (M = Co, cu, fe) is added to the above clarified solution, the molar ratio of the added amount of the metal ammine complex solution to the perovskite precursor being 1;
3. spin drying to dryness: transferring the solution into a rotary water bath kettle at the rotation speed of 110rpm/min and the temperature of 75 ℃, and placing the solution in a drying oven at the temperature of 110 ℃ for drying for 11h to obtain a viscous colloidal precursor after the solution is evaporated to form a gel with poor fluidity;
4. and (3) sintering: calcining the rotary evaporated and dried colloidal precursor in a muffle furnace, heating to 250 ℃ at a speed of 4 ℃/min in the first stage, preserving heat for 1h, heating to 400 ℃ at a speed of 2 ℃/min in the second stage, preserving heat for 1h, heating to 600 ℃ at a speed of 9 ℃/min in the third stage, preserving heat for 1.5h, and finally naturally cooling to 23 ℃ at normal temperature to obtain LaCeO 3 A perovskite catalyst;
5. activity evaluation: compacting the prepared catalyst powder, sieving by a 50-mesh sieve, weighing 2mL of sample, placing in a catalyst small sample activity evaluation instrument, and standing for 60000h -1 The catalyst evaluation tests of different tail gases are completed under the conditions of airspeed, 50-700 ℃ and 6 ℃/min heating rate, and the tail gas component concentrations of the natural gas engine are respectively CH 4 5000ppm，NO x 500ppm，O 2 10000ppm; diesel engine exhaust gas component concentration (DOC) CO 6000ppm, c 3 H 6 266.7ppm，C 3 H 8 133.3ppm，NO x 1000ppm，O 2 4362ppm; the concentration of the tail gas component (ASC) of the diesel engine is NH respectively 3 500ppm，O 2 375ppm，CO 2 500ppm，H 2 O5 percent and the oxidation efficiency of the hydrocarbon organic matters reaches 98 percent.
Example 2
1. Preparing a perovskite precursor solution: 12.99g lanthanum nitrate (La (NO) was weighed 3 ) 3 ·6H 2 O), 13.02g of cerium nitrate (Ce (NO) 3 ) 3 ·6H 2 O), dissolving in 500mL of deionized water (18M omega) to prepare a transparent solution with the total concentration of metal element ions of 0.1mol/L, and adding 9.45g of citric acid CA (C) into the solution 6 H 8 O 7 ) 3.6g Urea (CH) 4 N 2 O) and evenly stirring to finally obtain a clear solution, wherein the pH value of the precursor solution is adjusted to 7 by using an ammonia water solution;
2. preparation of metal ammonia complex solution: weighing 3 mu mol of transition metal ammine complex M-NH 3 (M = Co, cu, fe) is added to the above-mentioned clarified solution, and the molar ratio of the amount of the metal ammine complex added to the perovskite precursor in the perovskite precursor solution is 1
3. Spin drying to dryness: transferring the solution into a rotary water bath kettle at the rotation speed of 110rpm/min and the temperature of 75 ℃, and placing the solution in a drying oven at the temperature of 110 ℃ for drying for 11h to obtain a viscous colloidal precursor after the solution is evaporated to form a gel with poor fluidity;
4. and (3) sintering: calcining the colloidal precursor dried by rotary evaporation in a muffle furnace, heating to 200 ℃ at a speed of 4 ℃/min in the first stage, preserving heat for 1h, heating to 350 ℃ at a speed of 2 ℃/min in the second stage, preserving heat for 1.5h, heating to 600 ℃ at a speed of 9 ℃/min in the third stage, preserving heat for 1.5h, and finally naturally cooling to the normal temperature of 23 ℃ to obtain LaCeO 3 A perovskite catalyst;
5. activity evaluation: compacting the prepared catalyst powder, sieving by a 50-mesh sieve, weighing 2mL of sample, placing in a catalyst small sample activity evaluation instrument, and standing for 60000h -1 The catalyst evaluation tests of different tail gases are completed under the conditions of airspeed, 50-700 ℃ and 6 ℃/min heating rate, and the tail gas component concentrations of the natural gas engine are respectively CH 4 5000ppm，NO x 500ppm，O 2 50000ppm; diesel engine exhaust gas component concentration (DOC) CO 6000ppm, c 3 H 6 266.7ppm，C 3 H 8 133.3ppm，NO x 1000ppm，O 2 4362ppm; the concentration of the tail gas component (ASC) of the diesel engine is NH respectively 3 500ppm，O 2 375ppm，CO 2 500ppm，H 2 O5 percent and the oxidation efficiency of hydrocarbon organic matters reaches up to 90 percent.
Referring to fig. 2, it can be seen that the perovskite metal oxide has a relatively good nucleation effect and relatively few core wall damage, and compared to fig. 3, the perovskite metal oxide has a slightly poor nucleation effect and has a core wall damage phenomenon. This also illustrates the reason why example 2 has a lower efficiency of oxidizing the hydrocarbon-based organic material than example 1.
The invention relates to a preparation method of an oxidation type catalyst for purifying automobile exhaust. The oxidized formThe catalyst is LaCeO 3 The perovskite is used as a catalytic support carrier, the transition metal oxide is used as an active assistant and compounded, uniform loading (0% -40%) on the surface of the perovskite carrier is realized by regulating and controlling the types (Co, zr and Cu) of transition metal elements and the loading content, and meanwhile, the temperature rise rate is controlled to optimize the structural form of the metal oxide nucleation process, and finally, the catalytic reaction activity on the component to be oxidized in the automobile exhaust is improved. Roasting in a programmed multi-stage heating mode, wherein the heating rate is controlled at 2 ℃/min, and the temperature is kept constant at the temperature points of 100 ℃, 200 ℃, 300 ℃ and 400 ℃ for 30 min, so that the phenomenon that the nucleation effect of the perovskite metal oxide is influenced by too fast temperature rise is avoided.
Based on the thermal stability of the perovskite structure, the invention is beneficial to improving the microstructure (specific surface area and pore characteristics) of the catalyst and the reaction process of the transfer and release of surface active oxygen groups by doping the transition metal oxide, and solves the problem of poor low-temperature activity of the perovskite material. The invention has simple preparation process, can be widely applied to the fields of catalytic combustion, mobile source pollution emission control and the like, particularly provides technical support for the research and development of clean automobile fuels in China in future, and has important significance for energy conservation and emission reduction.
The present invention will be described in more detail below, but the present invention is not limited to the following examples, and other transition metal ammine complexes may be substituted for the (Co, cu, fe) ammine complexes described below, and the present invention is applicable to hydrocarbon component purification in all engine combustion systems.
The preferred embodiments of the present invention have been described in detail with reference to the accompanying drawings, however, the present invention is not limited to the specific details of the above embodiments, and various simple modifications may be made to the technical solution of the present invention within the technical idea of the present invention, and these simple modifications all fall within the protection scope of the present invention.
It should be noted that the various features described in the above embodiments may be combined in any suitable manner without departing from the scope of the invention. The invention is not described in detail in order to avoid unnecessary repetition.
In addition, any combination of the various embodiments of the present invention is also possible, and the same should be considered as the disclosure of the present invention as long as it does not depart from the spirit of the present invention.
Although a few embodiments of the present general inventive concept have been shown and described, it will be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the general inventive concept, the scope of which is defined in the appended claims and their equivalents.
Claims (10)
1. A preparation method of an oxidation type catalyst for purifying automobile exhaust is characterized by comprising the following steps:
the preparation method of the perovskite precursor solution comprises the following steps: lanthanum nitrate (La (NO) 3 ) 3 ·6H 2 O), cerium nitrate (Ce (NO) 3 ) 3 ) The solution was dissolved in deionized water, and citric acid CA (C) was added to the solution 6 H 8 O 7 ) And urea (CH) 4 N 2 O) stirring to form a particle suspension to obtain a perovskite precursor solution;
preparation of metal ammonia complex solution: adding M-NH into perovskite precursor solution 3 A complex solution, wherein M is any one or any combination of Co, cu and Fe, to obtain a complex-containing solution;
spin drying to dryness: transferring the solution containing the complex into a rotary water bath kettle, and evaporating the solution until a hard colloid is formed;
and (3) sintering: placing the hard colloid in a muffle furnace under air atmosphere for calcining, and cooling to room temperature to obtain MO-LaCeO 3 A perovskite catalyst.
2. The method for preparing an oxidation catalyst for purification of automobile exhaust according to claim 1, wherein the perovskite precursor solution is prepared by the steps of: in the perovskite precursor solution, the total concentration of La and Ce metal element ions is 0.9-0.11mol/L, the molar ratio of the metal elements to the contents of chelating agent citric acid and urea is (1-1.2) to (1.5-1.8), and the pH value of the precursor solution is adjusted to 6-8 by using an ammonia water solution.
3. The method of preparing an oxidation catalyst for purification of automobile exhaust according to claim 1, wherein in the step of preparing the metal ammonia complex solution, M-NH 3 The concentration of the solution is 0.09-0.11mol/L, and the molar ratio of the addition amount of the metal ammonia complex to the perovskite in the perovskite precursor solution is 1 (0.04-1).
4. The method for preparing an oxidation catalyst for purification of automobile exhaust according to claim 1, wherein the spin-drying step comprises: and putting the perovskite precursor solution into a rotary water bath stirrer with the temperature of 70-80 ℃ and the rotating speed of 100-120rpm, and evaporating and drying for 10-12h to obtain a viscous colloidal precursor.
5. The method for preparing an oxidation catalyst for purification of automobile exhaust according to claim 4, wherein the sintering step is: placing the colloidal precursor after rotary steaming and drying in a muffle furnace for calcining, heating to 200-300 ℃ at the speed of 3-5 ℃/min in the first stage, preserving heat for 1-1.5h, heating to 350-450 ℃ at the speed of 1-3 ℃/min in the second stage, preserving heat for 1-2h, heating to 550-650 ℃ at the speed of 8-10 ℃/min in the third stage, preserving heat for 1.5-2h, and finally naturally cooling to the normal temperature of 18-28 ℃ to obtain the final perovskite catalyst.
6. The method for preparing an oxidation catalyst for purification of automobile exhaust according to any one of claims 1 to 5, wherein the perovskite catalyst powder obtained by the preparation is compacted and then sieved through a 40-60 mesh screen.
7. The method for preparing an oxidation catalyst for purifying automobile exhaust according to claim 6, wherein the perovskite sample is weighed and placed in a catalyst sample activity evaluation instrument for testing, and the space velocity is 60000h -1 Natural gas engine exhaustThe component concentrations are respectively CH 4 5000ppm，NO x 500ppm，O 2 50000ppm; diesel engine exhaust gas component concentration (DOC) CO 6000ppm, c 3 H 6 266.7ppm，C 3 H 8 133.3ppm，NO x 1000ppm，O 2 4362ppm; the concentration of the tail gas component (ASC) of the diesel engine is NH respectively 3 500ppm，O 2 375ppm，CO 2 500ppm，H 2 O5 percent and the oxidation efficiency of the hydrocarbon organic matters is 90 to 98 percent.
8. The method for preparing an oxidation catalyst for purification of automobile exhaust according to claim 7, wherein the temperature of the test is 50 to 700 ℃ and the rate of temperature rise is 5 to 8 ℃/min.
9. An oxidation catalyst for purification of automobile exhaust gas, characterized in that the oxidation catalyst is prepared by the preparation method according to any one of claims 1 to 8, and the oxidation catalyst is LaCeO 3 The perovskite is used as a catalytic support carrier, and the transition metal oxide is used as an active additive.
10. The oxidation catalyst for automobile exhaust purification according to claim 9, wherein the area percentage of the transition metal compound uniformly supported on the surface of the perovskite carrier is 0% to 40% by controlling the types of the transition metal elements (Co, zr, cu) and the loading content of the transition metal compound.
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