CN1128669C - Automobile tail gas cleaning catalyst and its preparation method - Google Patents
Automobile tail gas cleaning catalyst and its preparation method Download PDFInfo
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Abstract
The present invention relates to a catalyst for purifying automobile exhaust gas. The catalyst for purifying automobile exhaust gas comprises a ceramic carrier and catalytic active components, wherein the ceramic carrier is prepared from gamma-Al2O3 and modified rare earth metal, and the ceramic carrier is coated with onle layer of gamma-Al2O3 and one layer of rare earth metal oxide; the catalytic active components comprises transition metal oxide and noble metal palladium, the transition metal oxide is coated on the coating layer of the rare earth matel oxide, and the noble metal is coated on the coating layer of the transition metal oxide. The present invention also relates to a preparation method of the catalyst for purifying automobile exhaust gas.
Description
The present invention relates to a kind of cleaning catalyst for tail gases of automobiles and preparation method thereof.
Along with industrialized process automobile increases exponentially, automobile exhaust gas has become a main source of contaminated environment.In recent years, along with the attention to environmental protection, people recognize that more and more waste gas that automobile discharges is to harmfulness that environment caused.According to estimates in U.S.'s air pollution 60% from various automobiles, 17% from industrial pollution.The waste gas that automobile is discharged mainly is carbon monoxide (CO), unburned hydrocarbon (HC) and nitrogen oxide (NO
x).Nitrogen oxide mainly is NO and NO
2Nitrogen oxide is well-known destruction atmospheric ozone (O
3) material of layer, and ozone layer is the solar ultraviolet filter.The destruction of ozone layer can cause the earth to accept more ultraviolet ray.It is believed that cutaneum carcinoma is relevant with too much reception ultraviolet irradiation.Just because of vehicle exhaust is so serious to the pollution of environment, so countries in the world require more and more higher to the discharge standard of the harmful substance contents in the vehicle exhaust.For example, the every km CO of Europe ECE-8301 standard-required running car discharge capacity must not be higher than 3.16 grams, THC and nitrogen oxide emission must not be higher than 1.13 grams, the every km CO of ECE-8302 standard-required running car discharge capacity must not be higher than 2.50 grams, and THC and nitrogen oxide emission must not be higher than 0.50 gram.The automobile exhaust purifier that catalyst is equipped with in employing is one of the method for automobile exhaust pollution that reduces or eliminates that generally adopts at present, and the key of this method is a catalyst.
For the catalyst that is used for purifying vehicle exhaust, people have carried out a large amount of research and developments, have had a large amount of patent documentations to be seen in report.Generally be to use the carrier of ceramic-like material at existing cleaning catalyst for tail gases of automobiles, use noble metal (as platinum, rhodium, palladium), transition metal and rare earth metal as active component as catalyst.
Chinese patent application 97120101.3 discloses " a kind of ternary composite metal oxide catalyst that is used for automobile exhaust gas purifying and preparation method thereof ", this catalyst comprises honeycomb ceramic carrier, aluminum oxide coating layer and catalytic active component are wherein attached to the γ-Al on the honeycomb ceramic carrier hole wall surface
2O
3Coating contains Y
2O
3And ZrO
2, the catalyst activity structure is divided into inside and outside two layers, all contains precious metal palladium.According to this catalyst, wherein the consumption of noble metal (oxide) is in every kilogram ceramic monolith, between the 8-75 gram.
Chinese patent application 92113299.9 discloses a kind of " noble metal catalyst for purifying waste gas exhausted from IC engine and preparation ", and this catalyst adopts ceramic honey comb and α-Al
2O
3As carrier, adopt Pt, Pd, at least a among Rh and the Ru as the activity of such catalysts component, the consumption of active component is in every liter of ceramic monolith, between the 0.4-2.0 gram.Claim that according to this patent application its catalyst is 90-98% to the clean-up effect of CO, at 85-95%, service life is more than 40,000 kilometers to the clean-up effect of hydrocarbon (CH).But do not demonstrate the test data of the above-mentioned performance of this catalyst in the specification of this application, and the catalyst of this application there is not clean-up effect to nitrogen oxide.
Chinese patent application 96119452.9 discloses a kind of " the atmospheric cleaning catalyst and the method for making of carried noble metal particle ", and this catalyst as carrier, is coated with the Al that contains metal oxide containing precious metals with porous honeycomb ceramic on this carrier
2O
3Coating in every liter of described catalyst, contains the Al of noble metal and metal oxide
2O
3The weight of coating is the 60-180 gram, and the consumption of precious metals pt and Pd is the 0.8-1.4 gram.Do not use rare earth metal and transition metal in this catalyst, because the applicant of this patent application thinks the ABO that contains rare earth metal and transition metal
3Perovskite structure catalyst sulfur resistance and anti-high heat aging performance are poor.Although the content of noble metal is in every liter of catalyst in the catalyst of this application, in the scope of 0.8-1.4 gram, the laboratory tests data of catalyst have only been provided in this application file.And this Preparation of catalysts method more complicated.
Above-mentioned catalyst has all used noble metal as the activity of such catalysts component.Along with the shortage of noble metal resource, recently people study the catalyst of the purifying automobile tail gas that do not use noble metal.
Chinese patent application 85109694.8 discloses honeycomb combustion catalyst of non-precious metal, it comprises uses two carriers and copper, vanadium, manganese, cobalt, the oxide of nickel or the mixed oxide of several compositions in the above-mentioned element, contains the oxide of rare earth element such as lanthanum, cerium, praseodymium, samarium, neodymium, yttrium or its mixture simultaneously as active component.
Chinese patent application 93105063.9 also discloses and Chinese patent application 85109694.8 akin exhausted gases purification catalyst.It comprises the complex carrier of honeybee shape ceramic material and aluminum oxide coating layer, the active component of the mixture of one or more in the oxide of transition metal zirconium, cobalt, nickel, manganese, copper, chromium and the oxide of rare earth element, to activating oxide hydrogen, carbon monoxide, hydrocarbon compound have carried out reduction to be handled.Can think that like this some metallic element activating oxides are converted into metallic element probably.
EP0393517A2 discloses catalytic oxidation and the reduction converter that is used to transform I. C. engine waste gas, and it can be reduced into elemental nitrogen and oxygen with unburned hydrocarbon and carbon monoxide completing combustion and with nitrogen oxide.As catalyst, described converter uses and is selected from Cr, Mn, and Fe, Co, Ni, Cu, Zn, Sn, Ba, the metal oxide of La and Ce, specification have only provided a chemical composition (weight %) and have been: Cu26%, Cr21%; The catalyst of BaO=11%.But when this converter is contained in the mobile muffler exit, must use heater, so that the waste gas that makes this converter that desire is transformed reacts.
But these non-precious metal catalysts are relatively poor at aspects such as low-temperature startup performance, the efficient of removing pernicious gas composition in the tail gas and life of catalyst, can not satisfy the needs as cleaning catalyst for tail gases of automobiles.
An object of the present invention is for the shortcoming that overcomes prior art provides that a kind of bullion content is low, the life-span is long and carbon monoxide, hydrocarbon and nitrogen oxide (NO
x) cleaning catalyst for tail gases of automobiles that transformation efficiency is high.
Second purpose of the present invention provides the method for the above-mentioned catalyst of preparation.
The invention provides a kind of catalyst that is used for purifying vehicle exhaust, comprise with γ-Al
2O
3With rare-earth metal modified porous ceramics carrier and catalytic active component, it is characterized in that described modified ceramic carrier comprises one deck γ-Al that applies on ceramic monolith matrix and the matrix
2O
3Coating and at described γ-Al
2O
3The one deck that applies on the coating is selected from the rare-earth metal oxide coating of lanthanum or cerium or its mixture; Described catalytic active component is the oxide and the noble metal of transition metal, and wherein said transition metal is cobalt, nickel, manganese, barium and zirconium, and described noble metal is a palladium; Wherein the mixed oxide of transition metal is coated on the described rare-earth metal oxide coating, and described noble metal is coated on the mixed oxide coatings of described transition metal.
The present invention also provides the method for preparing above-described catalyst, may further comprise the steps:
1) stir down aluminium colloidal sol and deionized water with 1: the weight ratio of 7-10 mixes, and makes the aqueous solution of aluminium colloidal sol;
2) select a kind of porous ceramic monolith matrix, in the aqueous solution that step 1) makes, soaked 5-15 minute, take out after-blow and remove redundant moisture in the ceramic monolith matrix, under 120-300 ℃ temperature, make its drying then;
3) with step 2) repeat at least twice, then with carrier 400-700 ℃ temperature roasting 3-8 hour, obtain having γ-carrier of Al2O3 coating;
4) soluble-salt with lanthanum or cerium or its mixture is dissolved in the aqueous solution that makes its soluble-salt in the deionized water, the carrier that step 3) is obtained soaked 5-10 minute in the described aqueous solution then, obtained the modified ceramic carrier at 120-180 ℃ at 500-900 ℃ of roasting 4-8 hour after making its bone dry;
5) mixture with the soluble-salt of transition metal is dissolved in the aqueous solution that makes its soluble-salt in the deionized water, the modified ceramic carrier that then step 4) is obtained soaked 5-10 minute in the described aqueous solution, 120-180 ℃ make its bone dry after at 400-600 ℃ of roasting 6-8 hour;
6) soluble-salt with palladium is dissolved in the aqueous solution that makes its soluble-salt in the deionized water, the modified ceramic carrier with transition metal oxide coating that then step 5) is obtained soaked 5-10 minute in the described aqueous solution, 120-180 ℃ make its bone dry after in 400-600 ℃ nitrogen atmosphere reductase 12-4 hour, obtain catalyst.
Brief Description Of Drawings:
Air-fuel ratio attribute testing result before the catalyst ageing that Fig. 1 makes for the embodiment of the invention 3.
Initiation temperature attribute testing result before the catalyst ageing that Fig. 2 makes for the embodiment of the invention 3.
The air-fuel ratio attribute testing result who (is equivalent to 50,000 kms that travel) after the catalyst ageing that Fig. 3 makes for the embodiment of the invention 3.
The initiation temperature attribute testing result who (is equivalent to 50,000 kms that travel) after the catalyst ageing that Fig. 4 makes for the embodiment of the invention 3.
In order to reach purpose of the present invention, the invention provides a kind of catalyst for the vehicle exhaust purification, comprise with γ-Al2O
3With porous ceramics carrier and the catalytic active component of rare earth metal modification, it is characterized in that described modified ceramic carrier comprises one deck γ-Al that applies on ceramic monolith matrix and the matrix2O
3Coating and at described γ-Al2O
3The one deck that applies on the coating is selected from the rare-earth oxide coating of lanthanum or cerium or its mixture; Described catalytic active component is oxide and the noble metal of transition metal, and wherein said transition metal is cobalt, nickel, manganese, barium and zirconium, and described noble metal is palladium; Wherein the mixed oxide of transition metal is coated on the described rare-earth oxide coating, and described noble metal is coated on the mixed oxide coatings of described transition metal.
According to catalyst of the present invention, wherein said carrier matrix can be arbitrarily carrier as known in the art, the preferred porous ceramics that adopts, for example hole density be 200-600 hole/square inch, content more than or equal to 92%, water absorption rate is that the cordierite of 20-30% is ceramic.
In the catalyst of the present invention, in every liter of described porous ceramics carrier matrix, γ-Al2O
3The amount of coating is the 3.5-7 gram, is preferably the 4.5-6 gram; In every liter of described porous ceramics carrier matrix, the amount of described rare-earth oxide coating is the 17.5-35 gram, is preferably the 22-30 gram.
In the catalyst of the present invention, employed rare-earth oxide can be the oxide for independent lanthanum, or the oxide of cerium, or the mixed oxide of lanthanum and cerium. The present inventor finds that by research the use of thulium lanthanum and cerium not only can be played and stablize γ-Al2O
3Crystal formation and the effect that improves its high-temperature stability, can also make catalyst in use can reach rapidly its " flash-point " temperature, that is catalyst is started rapidly under very low temperature. In addition, lanthanum and cerium also have the function that absorbs oxygen and discharge oxygen, are conducive to the reduction of CO and hydrocarbon and the reduction of nitrogen oxide. In these areas, the effect of lanthanum is more obvious. Therefore, in the catalyst of the present invention, as the oxide of thulium, preferably use the oxide of lanthanum, particularly preferably use the mixed oxide of lanthanum and cerium. When using the mixed oxide of lanthanum and cerium, the weight ratio of lanthanum and cerium is 4-1 in the mixture: 1.
In the catalyst of the present invention, in every liter of described porous ceramics carrier matrix, the consumption of described cobalt oxide is the 3-6 gram, is preferably the 4-5 gram, the consumption of manganese oxide is the 1-2.5 gram, be preferably the 1.5-2 gram, barytic consumption is the 1.5-2.5 gram, is preferably the 1.8-2.3 gram, zirconic consumption is the 1.5-2.5 gram, be preferably the 1.8-2.3 gram, the consumption of nickel oxide is 0.1-1.0 grams, is preferably the 0.5-0.8 gram.
In the catalyst of the present invention, in every liter of described porous ceramics carrier matrix, the consumption of described palladium is the 0.3-2.0 gram, is preferably the 0.6-1.6 gram.
For the vehicle exhaust cleaning catalyst, generally all contain γ-Al2O
3And thulium, people think that thulium itself also is a kind of catalytic active component. The present inventor finds by years of researches, for containing γ-Al2O
3With the catalyst of thulium, especially when it was used for the vehicle exhaust cleaning catalyst, thulium only was to play to stablize γ-Al2O
3And make it at high temperature still keep its original crystalline structure and active effect. In addition, in the catalyst of the present invention, the transition metal coating is by thulium coating and γ-Al2O
3Keep apart, therefore, in the preparation process of catalyst, transition metal not can with Al2O
3React, thereby make transition metal give full play to its catalytic activity, thereby greatly reduce the consumption of noble metal. Therefore, according to catalyst of the present invention, in every liter of described porous ceramics carrier matrix, the consumption of described palladium is the 0.3-2.0 gram, is preferably the 0.6-1.6 gram.
The present invention also provides the preparation method of above-mentioned catalyst, and the method may further comprise the steps:
1) stir lower with aluminium colloidal sol and deionized water with 1: the weight ratio of 7-10 mixes, and makes the aqueous solution of aluminium colloidal sol;
2) select to select a kind of porous ceramic monolith matrix, in step 1) soaked 5-15 minute in the aqueous solution that makes, take out after-blow except unnecessary moisture in the ceramic monolith matrix, then under 120-300 ℃ temperature, make its drying;
3) with step 2) repeat at least twice, then with carrier 400-700 ℃ temperature roasting 3-8 hour, obtain having γ-carrier of Al2O3 coating;
4) soluble-salt with lanthanum or cerium or its mixture is dissolved in the aqueous solution that makes its soluble-salt in the deionized water, the carrier that step 3) is obtained soaked 5-10 minute in the described aqueous solution then, obtained the modified ceramic carrier at 120-180 ℃ at 500-900 ℃ of roasting 4-8 hour after making its bone dry;
5) mixture with the soluble-salt of transition metal is dissolved in the aqueous solution that makes its soluble-salt in the deionized water, the modified ceramic carrier that then step 4) is obtained soaked 5-10 minute in the described aqueous solution, 120-180 ℃ make its bone dry after at 400-600 ℃ of roasting 6-8 hour;
6) soluble-salt with palladium is dissolved in the aqueous solution that makes its soluble-salt in the deionized water, the modified ceramic carrier with transition metal oxide coating that then step 5) is obtained soaked 5-10 minute in the described aqueous solution, 120-180 ℃ make its bone dry after in 400-600 ℃ nitrogen atmosphere reductase 12-4 hour, obtain catalyst.
According to method of the present invention, wherein selected porous ceramics carrier matrix is the cordierite ceramic of 200-600 hole/square inch for hole density.
In the method for the present invention, the soluble-salt of described lanthanum or cerium can be its soluble-salt arbitrarily, but is preferably its nitrate or its acetate.Can use the soluble-salt of lanthanum or cerium respectively, or use the mixture of the soluble-salt of lanthanum and cerium, but preferably use the mixture of the soluble-salt of lanthanum and cerium.When the mixture of the soluble-salt that uses lanthanum and cerium, the weight ratio of lanthanum and cerium is 4-1: 1.
In the method for the present invention, nitrate or acetate that described soluble palladium salt is palladium.
According to method of the present invention, adopt the method for heating using microwave, high-frequency radio frequency heating or FAR INFRARED HEATING that immersion is had γ-Al
2O
3The ceramic monolith matrix carry out drying at 120-300 ℃.
With non-limiting example the present invention is described in more detail below.
Embodiment 1
In one 5 liters band stirred vessels, add 2100ml deionized water, 300 gram aluminium colloidal sols, stirring obtains the uniform aluminium colloidal sol aqueous solution.(Jingtu Industry Co., Ltd., Shanxi Prov. produces with 500g porous ceramics carrier, hole density is 300-400 hole/square inch, proportion is 650 grams per liters, and water absorption rate is 30% (weight)) in the resulting aluminium colloidal sol aqueous solution, soaked 10 minutes, blow down the aqueous solution unnecessary in the carrier then; With microwave drier 120 ℃ of dryings 2 hours.Dried carrier was soaked in the aforesaid aluminium colloidal sol aqueous solution 10 minutes once more, with microwave drier 120 ℃ of dryings 1 hour.Described immersion-dry run repeats once again.Dried carrier is heated to 650 ℃, is incubated 3 hours, obtain having γ-Al
2O
3The carrier of coating is in every liter of carrier matrix, γ-Al
2O
3The amount of coating is 5 grams.
In one 500 milliliters band stirred vessels, add 150ml deionized water, 21.9 gram lanthanum nitrates, 5.8 gram cerous nitrates, stirring obtains its uniform aqueous solution.With above obtain have γ-Al
2O
3The carrier of coating is soaked in the nitrate aqueous solution of described rare earth metal, and the described aqueous solution is absorbed equably by described carrier fully.Make its bone dry at 130 ℃ then, dried carrier is warming up to 800 ℃, be incubated 5 hours, obtain the catalyst active carrier of modification.
6.0 gram cobalt nitrates, 2.2 gram manganese nitrates, 2.1 gram barium nitrates, 4.8 gram zirconium nitrates and 1.8 gram nickel nitrates are dissolved in 100 ml deionized water, and stirring obtains its uniform mixture solution.The catalyst active carrier of the above-mentioned modification that obtains was soaked in the described aqueous solution 5-10 minute, and the described aqueous solution is absorbed equably by described carrier fully.Make its bone dry at 130 ℃ then, dried carrier is warming up to 500 ℃, be incubated 5 hours.
1.17 gram palladium nitrates fully are dissolved in the uniform aqueous solution that obtains palladium nitrate in 100 ml deionized water.The catalyst active carrier of the above-mentioned modification with transition metal oxide coating that obtains was soaked in the described aqueous solution 5-10 minute, and the described aqueous solution is absorbed equably by described carrier fully.Make its bone dry at 130 ℃ then, dried carrier was reduced 3 hours at 500 ℃ in nitrogen atmosphere, obtain catalyst of the present invention.
Embodiment 2
In one 5 liters band stirred vessels, add 2850ml deionized water, 300 gram aluminium colloidal sols, stirring obtains the uniform aluminium colloidal sol aqueous solution.(Jingtu Industry Co., Ltd., Shanxi Prov. produces with 500g porous ceramics carrier, hole density is 300-400 hole/square inch, proportion is 650 grams per liters, and water absorption rate is 30% (weight)) in the resulting aluminium colloidal sol aqueous solution, soaked 15 minutes, blow down the aqueous solution unnecessary in the carrier then; With microwave drier 120 ℃ of dryings 1 hour.Dried carrier was soaked in the aforesaid aluminium colloidal sol aqueous solution 10 minutes once more, with microwave drier 150 ℃ of dryings 1 hour.Described immersion-drying repeats secondary again.Dried carrier is heated to 650 ℃, is incubated 4 hours, obtain having γ-Al
2O
3The carrier of coating is in every liter of carrier matrix, γ-Al
2O
3The amount of coating is 5.5 grams.
In one 500 milliliters band stirred vessels, add 150ml deionized water, 23.9 gram lanthanum nitrates, 11.9 gram cerous nitrates, stirring obtains its uniform aqueous solution.With above obtain have γ-Al
2O
3The carrier of coating is soaked in the nitrate aqueous solution of described rare earth metal, and the described aqueous solution is absorbed equably by described carrier fully.Make its bone dry at 130 ℃ then, dried carrier is warming up to 700 ℃, be incubated 5 hours, obtain the catalyst active carrier of modification of the present invention.
7.5 gram cobalt nitrates, 2.8 gram manganese nitrates, 2.3 gram barium nitrates, 4.6 gram zirconium nitrates and 1.6 gram nickel nitrates are dissolved in 100 ml deionized water, and stirring obtains its uniform mixture solution.The catalyst active carrier of the above-mentioned modification that obtains was soaked in the described aqueous solution 5-10 minute, and the described aqueous solution is absorbed equably by described carrier fully.Make its bone dry at 130 ℃ then, dried carrier is warming up to 500 ℃, be incubated 5 hours.
1.67 gram palladium nitrates fully are dissolved in the uniform aqueous solution that obtains palladium nitrate in 100 ml deionized water.The catalyst active carrier of the above-mentioned modification with transition metal oxide coating that obtains was soaked in the described aqueous solution 5-10 minute, and the described aqueous solution is absorbed equably by described carrier fully.Make its bone dry at 130 ℃ then, dried carrier was reduced 3 hours at 500 ℃ in nitrogen atmosphere, obtain catalyst of the present invention.
Embodiment 3
Repeat the step identical with embodiment 1, just the consumption of lanthanum nitrate is 31.9 grams, the consumption of cerous nitrate is 15.9 grams, the consumption of cobalt nitrate is 8.0 grams, the consumption of manganese nitrate is 3.3 grams, and the consumption of barium nitrate is 2.6 grams, and the consumption of zirconium nitrate is 4.3 grams, the consumption of nickel nitrate is 1.4 grams, and the consumption of palladium nitrate is 2.00 grams.
Embodiment 4
Repeat the step identical with embodiment 1, just the consumption of lanthanum nitrate is 37.9 grams, the consumption of cerous nitrate is 13.9 grams, the consumption of cobalt nitrate is 9.0 grams, the consumption of manganese nitrate is 3.8 grams, and the consumption of barium nitrate is 2.8 grams, and the consumption of zirconium nitrate is 4.0 grams, the consumption of nickel nitrate is 1.2 grams, and the consumption of palladium nitrate is 2.33 grams.
Repeat the step identical with embodiment 2, just the consumption of lanthanum nitrate is 29.9 grams, the consumption of cerous nitrate is 11.9 grams, the consumption of cobalt nitrate is 9.5 grams, the consumption of manganese nitrate is 4.2 grams, and the consumption of barium nitrate is 3.0 grams, and the consumption of zirconium nitrate is 3.8 grams, the consumption of nickel nitrate is 0.7 gram, and the consumption of palladium nitrate is 2.66 grams.
Embodiment 6
Repeat the step identical with embodiment 2, just the consumption of lanthanum nitrate is 49.9 grams, the consumption of cerous nitrate is 0, the consumption of cobalt nitrate is 11.0 grams, the consumption of manganese nitrate is 4.7 grams, and the consumption of barium nitrate is 3.1 grams, and the consumption of zirconium nitrate is 3.5 grams, the consumption of nickel nitrate is 0.5 gram, and the consumption of palladium nitrate is 3.00 grams.
Test example 1
The catalyst of 1.4 liters of embodiment 3 preparation is made the purifying vehicle exhaust catalytic converter, under the following experimental condition Tsing-Hua University's automotive research automotive catalyst benchmark test platform on test:
1, initiation temperature test: the catalytic converter inlet temperature is 200-550 ℃, air-fuel ratio A/F=14.55, air speed SV=40,000/h
2, air-fuel ratio characteristic: 535 ℃ of catalytic converter inlet temperatures, air-fuel ratio A/F=12.5-16.0, air speed SV=40,000/h
3, quick aging: 760 ℃ of catalytic converter inlet temperatures, 60 seconds at the uniform velocity, 5 seconds oil-breaks, air speed SV=60,000/h (50,000 kms are equivalent to drive a vehicle)
4, test sequence is: earlier raw catelyst is carried out catalytically active assessment, and carry out initiation temperature attribute testing and air-fuel ratio attribute testing, carry out quick aging (62.5 hours then, 50,000 kms are equivalent to drive a vehicle), again the catalytic activity of the catalyst after aging is estimated, and carried out initiation temperature attribute testing and air-fuel ratio attribute testing.
The key instrument that test is adopted is:
1, exhaust gas analyzer is the EIFC-4089 that Japanese willow our company produces
2, the air-fuel ratio instrument is the TL-7113-A1 that Japanese NGK company produces
3, dynamometer machine is the CW160 that Hunan instrument dynamic test instrument plant produces
4, development engine is the 492/100Q that group produces in the north
5, test is No. 90 unleaded gases with fuel, and its RON method octane number is 91.2, MON
The method octane number is 79.3, and lead content is less than 2.5mg/L
Result of the test:
1, aging preceding catalytic converter air-fuel ratio attribute testing the results are shown in Figure 1
2, aging preceding Temperature of Catalytic Converter attribute testing the results are shown in Figure 2
3, catalytic converter (50,000 kms are equivalent to travel) the air-fuel ratio characteristic examination after aging
Test and the results are shown in Figure 3
4, catalytic converter (50,000 kms are equivalent to travel) the initiation temperature characteristic after aging
Result of the test is seen Fig. 4
5, aging front and back main performance contrast sees the following form:
| The highest transformation efficiency (%) | Initiation temperature (℃) | |||||
| CO | THC | NO | CO | THC | NO | |
| Before aging | 97.3 | 93.5 | 98.0 | 360 | 355 | 355 |
| After aging | 96.4 | 90.8 | 93.3 | 417 | 410 | 413 |
| Deterioration factor | 1.01 | 1.03 | 1.05 | |||
As can be seen from the test results, catalyst of the present invention is lower to the initiation temperature of CO, hydrocarbon and nitrogen oxide, and the deterioration factor before and after the catalyst ageing is lower, and to the purification efficiency of three kinds of pernicious gases also than higher.Satisfy existing standard to purifying vehicle exhaust.In addition, also use catalyst of the present invention to carry out road performance test, when travelling 30,000 kms, the purification efficiency of CO, HC is all more than 98%, and the purification efficiency of NOx is more than 90%, when travelling 80,000 kms, the purification efficiency of CO, HC is all more than 90%, and the purification efficiency of NOx is more than 85%.Show that catalyst of the present invention has good waste gas purification effect and long service life.
Claims (11)
1, a kind of catalyst that is used for purifying vehicle exhaust comprises with γ-Al
2O
3With rare-earth metal modified porous ceramics carrier and catalytic active component, it is characterized in that described modified ceramic carrier comprises one deck γ-Al that applies on ceramic monolith matrix and the matrix
2O
3Coating and at described γ-Al
2O
3The one deck that applies on the coating is selected from the rare-earth metal oxide coating of lanthanum or cerium or its mixture, in every liter of described porous ceramics carrier matrix, described γ-Al
2O
3The amount of coating is the 3.5-7 gram, and the amount of described rare-earth metal oxide coating is the 17.5-35 gram; Described catalytic active component is the oxide and the noble metal of transition metal, and wherein said transition metal is cobalt, nickel, manganese, barium and zirconium, and described noble metal is a palladium; Wherein the mixed oxide of transition metal is coated on the described rare-earth metal oxide coating, described noble metal is coated on the mixed oxide coatings of described transition metal, in every liter of described porous ceramics carrier matrix, the consumption of described cobalt oxide is the 3-6 gram, the consumption of manganese oxide is the 1-2.5 gram, and barytic consumption is the 1.5-2.5 gram, and zirconic consumption is the 1.5-2.5 gram, the consumption of nickel oxide is the 0.1-1.0 gram, and the consumption of described palladium is the 0.3-2.0 gram.
2, catalyst as claimed in claim 1 is characterized in that described porous ceramics carrier matrix is the cordierite ceramic of 200-600 hole/square inch for hole density.
3, catalyst as claimed in claim 1 is characterized in that in every liter of described porous ceramics carrier matrix, described γ-Al
2O
3The amount of coating is the 4.5-6 gram, and the amount of described rare-earth metal oxide coating is the 20-30 gram.
4, catalyst as claimed in claim 1 is characterized in that described rare-earth oxide is the mixed oxide of lanthanum and cerium, and wherein the weight ratio of lanthanum and cerium is 4-1: 1.
5, catalyst as claimed in claim 1, it is characterized in that in every liter of described porous ceramics carrier matrix, the consumption of described cobalt oxide is the 4-5 gram, the consumption of manganese oxide is the 1.5-2 gram, barytic consumption is the 1.8-2.3 gram, zirconic consumption is the 1.8-2.3 gram, and the consumption of nickel oxide is the 0.5-0.8 gram.
6, catalyst as claimed in claim 1 is characterized in that in every liter of described porous ceramics carrier matrix, and the consumption of described palladium is the 0.6-1.6 gram.
7, prepare the method for the described catalyst of claim 1, may further comprise the steps:
(1) stir down aluminium colloidal sol and deionized water with 1: the weight ratio of 7-10 mixes, and makes the aqueous solution of aluminium colloidal sol;
(2) select a kind of porous ceramic monolith matrix, in the aqueous solution that step 1) makes, soaked 5-15 minute, take out after-blow and remove redundant moisture in the ceramic monolith matrix, under 120-300 ℃ temperature, make its drying then;
(3) with step 2) repeat at least twice, then with carrier 400-700 ℃ temperature roasting 3-8 hour, obtain having γ-carrier of Al2O3 coating;
(4) soluble-salt with lanthanum or cerium or its mixture is dissolved in the aqueous solution that makes its soluble-salt in the deionized water, the carrier that step 3) is obtained soaked 5-10 minute in the described aqueous solution then, obtained the modified ceramic carrier at 120-180 ℃ at 500-900 ℃ of roasting 4-8 hour after making its bone dry;
(5) mixture with the soluble-salt of transition metal is dissolved in the aqueous solution that makes its soluble-salt in the deionized water, the modified ceramic carrier that then step 4) is obtained soaked 5-10 minute in the described aqueous solution, 120-180 ℃ make its bone dry after at 400-600 ℃ of roasting 6-8 hour;
(6) soluble-salt with palladium is dissolved in the aqueous solution that makes its soluble-salt in the deionized water, the modified ceramic carrier with transition metal oxide coating that then step 5) is obtained soaked 5-10 minute in the described aqueous solution, 120-180 ℃ make its bone dry after in 400-600 ℃ nitrogen atmosphere reductase 12-4 hour, obtain catalyst.
8, method as claimed in claim 7 is characterized in that described porous ceramics carrier matrix is for having the cordierite ceramic in 200-600 hole per square inch.
9, method as claimed in claim 7 is characterized in that described soluble-salt is nitrate or acetate.
10, method as claimed in claim 7 is characterized in that the described soluble-salt of step 4) is the mixture salt of lanthanum and cerium, and wherein the weight ratio of lanthanum and cerium is 4-1: 1.
11, method as claimed in claim 7 is characterized in that the ceramic monolith matrix that will be impregnated with aluminium colloidal sol carries out drying with the method for heating using microwave, high-frequency radio frequency heating or FAR INFRARED HEATING.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 99105250 CN1128669C (en) | 1999-04-30 | 1999-04-30 | Automobile tail gas cleaning catalyst and its preparation method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 99105250 CN1128669C (en) | 1999-04-30 | 1999-04-30 | Automobile tail gas cleaning catalyst and its preparation method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1272400A CN1272400A (en) | 2000-11-08 |
| CN1128669C true CN1128669C (en) | 2003-11-26 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 99105250 Expired - Fee Related CN1128669C (en) | 1999-04-30 | 1999-04-30 | Automobile tail gas cleaning catalyst and its preparation method |
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| Country | Link |
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| CN (1) | CN1128669C (en) |
Families Citing this family (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100371072C (en) * | 2005-09-30 | 2008-02-27 | 清华大学 | Preparation process of selective reduction catalyst for lean-burn gasoline motor car exhausted gas nitrogen oxide |
| CN100427208C (en) * | 2006-01-19 | 2008-10-22 | 清华大学 | Method for preparing catalyst to purify automobile tail gas |
| US8568675B2 (en) * | 2009-02-20 | 2013-10-29 | Basf Corporation | Palladium-supported catalyst composites |
| CN102513131B (en) * | 2011-12-09 | 2013-09-11 | 十堰市登喜路实业有限公司 | Catalyst for purification of tail gas produced by military diesel offroad vehicle and coating method thereof |
| CN102626633B (en) * | 2012-03-26 | 2014-07-23 | 清华大学 | Supported composite Co3O4 / CeO2-Al2O3 / cordierite catalyst, preparation method and purpose thereof |
| CN104959144B (en) * | 2015-06-30 | 2018-01-02 | 苏磊 | A kind of catalyst and its coating material for purifying vehicle exhaust, preparation method and application |
| CN105195174B (en) * | 2015-10-20 | 2017-03-22 | 浙江通源环保科技有限公司 | Catalyst used for automobile exhaust particle catalytic filter and preparation method for catalyst |
| CN105148675B (en) * | 2015-10-20 | 2017-07-21 | 成都东洋蓝环保设备有限公司 | A kind of vehicle exhaust filter method |
| CN108607552A (en) * | 2018-05-07 | 2018-10-02 | 华北电力大学（保定） | A kind of high-efficient purification auto-exhaust catalyst |
| CN108607579A (en) * | 2018-05-24 | 2018-10-02 | 安徽国能亿盛环保科技有限公司 | Exhaust gas purification catalyst and the exhaust gas purifying method for using this catalyst |
| CN109174077A (en) * | 2018-10-17 | 2019-01-11 | 安徽菲扬新材料有限公司 | A kind of vehicle maintenance service catalyst and preparation method thereof |
| CN110075887B (en) * | 2019-05-31 | 2020-08-07 | 江南大学 | Preparation method and application of palladium supported catalyst for methanol catalytic combustion |
| CN112169787B (en) * | 2019-07-04 | 2023-01-17 | 重庆鲍斯净化设备科技有限公司 | Catalyst for removing hydrocarbon substances by low-temperature combustion and preparation method thereof |
| CN113019363B (en) * | 2021-03-23 | 2022-10-28 | 中自环保科技股份有限公司 | Tail gas treatment catalyst and application thereof |
-
1999
- 1999-04-30 CN CN 99105250 patent/CN1128669C/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| CN1272400A (en) | 2000-11-08 |
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