CN105056970B - A kind of preparation method of diesel vehicle catalyst type particle purifying device - Google Patents
A kind of preparation method of diesel vehicle catalyst type particle purifying device Download PDFInfo
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- CN105056970B CN105056970B CN201510505841.2A CN201510505841A CN105056970B CN 105056970 B CN105056970 B CN 105056970B CN 201510505841 A CN201510505841 A CN 201510505841A CN 105056970 B CN105056970 B CN 105056970B
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- 239000003054 catalyst Substances 0.000 title claims abstract description 159
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- 238000002360 preparation method Methods 0.000 title description 16
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- MCMNRKCIXSYSNV-UHFFFAOYSA-N ZrO2 Inorganic materials O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 claims abstract description 40
- 229910018879 Pt—Pd Inorganic materials 0.000 claims abstract description 35
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Substances [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 claims abstract description 29
- RCFVMJKOEJFGTM-UHFFFAOYSA-N cerium zirconium Chemical group [Zr].[Ce] RCFVMJKOEJFGTM-UHFFFAOYSA-N 0.000 claims abstract description 18
- 229910000510 noble metal Inorganic materials 0.000 claims abstract description 16
- 229910052763 palladium Inorganic materials 0.000 claims abstract description 16
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- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 52
- NWAHZABTSDUXMJ-UHFFFAOYSA-N platinum(2+);dinitrate Chemical compound [Pt+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O NWAHZABTSDUXMJ-UHFFFAOYSA-N 0.000 claims description 45
- GPNDARIEYHPYAY-UHFFFAOYSA-N palladium(ii) nitrate Chemical compound [Pd+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O GPNDARIEYHPYAY-UHFFFAOYSA-N 0.000 claims description 43
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 claims description 33
- 239000002002 slurry Substances 0.000 claims description 30
- 230000003197 catalytic effect Effects 0.000 claims description 26
- KDLHZDBZIXYQEI-UHFFFAOYSA-N palladium Substances [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 claims description 23
- WWHFPJVBJUJTEA-UHFFFAOYSA-N n'-[3-chloro-4,5-bis(prop-2-ynoxy)phenyl]-n-methoxymethanimidamide Chemical compound CONC=NC1=CC(Cl)=C(OCC#C)C(OCC#C)=C1 WWHFPJVBJUJTEA-UHFFFAOYSA-N 0.000 claims description 22
- 239000000203 mixture Substances 0.000 claims description 18
- QGUAJWGNOXCYJF-UHFFFAOYSA-N cobalt dinitrate hexahydrate Chemical compound O.O.O.O.O.O.[Co+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O QGUAJWGNOXCYJF-UHFFFAOYSA-N 0.000 claims description 17
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- 238000011068 loading method Methods 0.000 description 13
- MWUXSHHQAYIFBG-UHFFFAOYSA-N Nitric oxide Chemical compound O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 description 12
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- 238000000576 coating method Methods 0.000 description 11
- UFMZWBIQTDUYBN-UHFFFAOYSA-N cobalt dinitrate Chemical compound [Co+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O UFMZWBIQTDUYBN-UHFFFAOYSA-N 0.000 description 11
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- JCXJVPUVTGWSNB-UHFFFAOYSA-N nitrogen dioxide Inorganic materials O=[N]=O JCXJVPUVTGWSNB-UHFFFAOYSA-N 0.000 description 10
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- DHEQXMRUPNDRPG-UHFFFAOYSA-N strontium nitrate Chemical compound [Sr+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O DHEQXMRUPNDRPG-UHFFFAOYSA-N 0.000 description 8
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- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 4
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- ITHZDDVSAWDQPZ-UHFFFAOYSA-L barium acetate Chemical compound [Ba+2].CC([O-])=O.CC([O-])=O ITHZDDVSAWDQPZ-UHFFFAOYSA-L 0.000 description 3
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- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
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- IWOUKMZUPDVPGQ-UHFFFAOYSA-N barium nitrate Chemical compound [Ba+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O IWOUKMZUPDVPGQ-UHFFFAOYSA-N 0.000 description 2
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- 238000010998 test method Methods 0.000 description 2
- MGWGWNFMUOTEHG-UHFFFAOYSA-N 4-(3,5-dimethylphenyl)-1,3-thiazol-2-amine Chemical compound CC1=CC(C)=CC(C=2N=C(N)SC=2)=C1 MGWGWNFMUOTEHG-UHFFFAOYSA-N 0.000 description 1
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- 210000000621 bronchi Anatomy 0.000 description 1
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- CETPSERCERDGAM-UHFFFAOYSA-N ceric oxide Chemical compound O=[Ce]=O CETPSERCERDGAM-UHFFFAOYSA-N 0.000 description 1
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- DZUDZSQDKOESQQ-UHFFFAOYSA-N cobalt hydrogen peroxide Chemical compound [Co].OO DZUDZSQDKOESQQ-UHFFFAOYSA-N 0.000 description 1
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Abstract
The invention discloses a kind of catalyst purified for PM in exhaust gas from diesel vehicle, the catalyst is expressed from the next: Pt-Pd/Co2O3/CeO2‑ZrO2；Wherein, CeO2‑ZrO2It is cerium zirconium compound oxide carrier；Co2O3It is the auxiliary component of catalyst；Pt, Pd are the active components of noble metal catalyst；Wherein, Co2O3Weight percent content is the 5%-10% of vehicle weight；Both Pt, Pd noble metals total weight percent content is the 1%-2% of vehicle weight, wherein Pt:Pd=2:1-1:2；Wherein Pt, Pd additional amount are in terms of precious metal atom quality.The initiation temperature of catalyst soot of the invention is very low, and anti-aging property is good, can be realized activity of the catalyst under regenerative process high temperature environment.
Description
Technical Field
The invention belongs to the technical field of catalyst preparation and coating, and particularly belongs to the technical field of oxidation type catalyst preparation and wall flow type carrier coating.
Background
The diesel vehicle engine is the first choice power of large and medium-sized commercial vehicles due to high fuel economy, high power performance and good durability. Meanwhile, as the technology of miniaturization and lightening of the diesel vehicle is mature day by day, the proportion of the light diesel vehicle in the market is larger and larger. However, high Particulate Matter (PM) emissions from diesel vehicles are a major obstacle to meeting strict emission regulations, and particulate matter pollution directly harms human health, once PM is inhaled into a human body, the PM directly enters the bronchus, interferes with gas exchange in the lung, and causes diseases including asthma, bronchitis, cardiovascular diseases and the like. Therefore, how to effectively purify the PM in the diesel exhaust becomes a problem to be solved urgently at present.
Currently, a particulate filter (DPF), which is an effective means for solving PM in exhaust gas discharged from diesel vehicles, is composed of a filter element for collecting exhaust particles and a regeneration system for periodically burning or oxidizing the particles accumulated in the filter element. The technology traps PM in exhaust gas with DPF and then regenerates DPF by oxidizing the collected PM, thereby removing soot particles from diesel exhaust with efficiency exceeding 90%. Generally, the PM ignition temperature is generally 550-650 ℃, which is higher than the normal exhaust temperature of the diesel engine. Therefore, to burn the PM, the reaction activation energy of the PM is reduced by adding a catalyst on the surface of the fuel oil or the filter body, so that the ignition temperature of the PM is reduced, and the PM is oxidized at the normal exhaust temperature, namely, the PM is passively regenerated; secondly, the exhaust temperature of the diesel engine or the temperature of the filter body is increased by adopting a heating technology to reach the PM ignition temperature, so that the PM deposited in the filter body can be combusted, namely, the active regeneration is realized. Currently, regeneration of PM is achieved by coating the DPF with a catalyst such that the PM burns at normal exhaust temperatures, and this catalyst coated particulate trap is known as a CDPF, using the most widespread, yet passive, regeneration technology.
At present, researchers at home and abroad have more researches on CDPF catalysts, especially on noble metal and non-noble metal catalystsMuch research has been done. Single Pt noble metal catalyst Pt/MnO as studied in U.S. patent (US20090285736)2:CeO2＝1:1、Pt/MnO2:CeO2CaO is 4:4:1, which has a low PM light-off temperature, but has poor high temperature aging resistance. Although the cost of the non-noble metal catalyst is low, the fresh and aging activity of the catalyst is not high, so that the ignition temperature of PM is high, and the significance of the passive regeneration process of PM is low. Therefore, how to ensure that the catalyst can cause the PM to ignite at a lower temperature and the catalyst has high-temperature aging resistance is the key for determining the continuous regeneration of the PM and also the key for determining whether the technology can be widely used for purifying the PM in the tail gas of the diesel vehicle in China.
Disclosure of Invention
The invention aims to overcome the defects that the CDPF catalyzes PM to have higher ignition temperature, poor use effect and easy aging and invalidation in the prior art, and provides a catalyst for catalyzing PM to ignite, and CDPF equipment using the catalyst to promote PM purification in diesel vehicle exhaust emission.
The invention also provides a preparation method and a coating method of the catalyst and the CDPF, so as to prepare the catalyst type particulate matter trap conveniently.
In order to achieve the above purpose, the invention provides the following technical scheme:
a catalyst for PM purification in diesel vehicle exhaust, the catalyst being represented by the formula:
Pt-Pd/Co2O3/CeO2-ZrO2
wherein, CeO2-ZrO2Is a cerium-zirconium composite oxide carrier; co2O3Is an auxiliary component of the catalyst; pt and Pd are active components of the noble metal catalyst.
Wherein, Co2O3The weight percentage content of the carrier is 5 to 1 percent of the weight of the carrier0 percent; the total weight percentage content of the Pt and the Pd noble metals is 1-2% of the weight of the carrier, wherein the Pt and the Pd are 2:1-1: 2. Wherein the adding amount of Pt and Pd is calculated by the mass of noble metal atom.
The CDPF coated with the catalyst has the excellent characteristics of high activity, good stability and high trapping efficiency, and can effectively reduce particulate matters discharged from the tail gas of the diesel vehicle, thereby reducing the harm of the tail gas to the environment and human beings and meeting the discharge standard of five light diesel vehicles in China. Experiments prove that the carbon smoke ignition temperature of the catalyst is very low, the ageing resistance is further enhanced, and the activity of the catalyst in a high-temperature environment in the regeneration process can be realized.
Further, it is preferable that Co is contained in the catalyst component2O3The content of (B) is 5-10%, preferably about 8% by weight of the carrier.
Further, the content of the noble metal in the catalyst component is preferably 1% to 2%, more preferably about 1.5% by weight of the carrier. Preferably, in the noble metal component, Pt and Pd are 2:1 to 1:2 (by weight). Preferably, Pt and Pd are 2: 1.
It is another object of the present invention to provide a method for preparing the above catalyst material.
The preparation method of the catalyst comprises the following steps:
(1) the platinum and palladium raw material compounds are taken according to the proportion and mixed evenly.
(2) Adding cobalt compound in proportion to prepare red solution.
(3) Test of CeO2-ZrO2And (3) calculating the specific pore volume of the cerium-zirconium carrier powder, and calculating the dosage ratio of the carrier and the red solution in the step (2) according to the mass and the specific pore volume of the carrier powder, wherein the calculation formula is as follows:
the total volume of the solution is equal to the mass of the carrier powder multiplied by the specific pore volume
And (3) taking the carrier powder according to the calculation result, adding the carrier powder into the red solution obtained in the step (2), and stirring to obtain light yellow fine powder.
(4) Drying the yellow powder obtained in the step (3), and then roasting at 500-650 ℃ to obtain Pt-Pd/Co2O3/CeO2-ZrO2A catalyst powder.
The above Pt-Pd/Co2O3/CeO2-ZrO2The noble metal composite oxide catalyst has Pt and Pd in the ratio of 2:1-1:2, and the active components Pt and Pd are added in the form of platinum nitrate and palladium nitrate, and their total content is 1-2 wt%, preferably 1.5 wt% of the carrier in the catalyst. Co2O3Is added in the form of cobalt nitrate hexahydrate, and its content is 5% -10%, preferably 8% of weight percentage of carrier in the catalyst.
It is another object of the present invention to provide a particulate trap/catalytic converter employing the above catalyst composition.
The catalyst, the auxiliary agent and the binder are uniformly mixed to obtain catalyst slurry, the catalyst slurry is coated on a carrier of a ceramic material, the carrier is dried and roasted to obtain a CDPF catalytic unit, and the CDPF catalytic unit is packaged to obtain the complete catalytic converter.
Further, the catalyst slurry consists of: the above catalyst powder (Pt-Pd/Co)2O3/CeO2-ZrO2) Acetic acid, a binder (high viscosity), a dispersant (PVA, ZS-182) and water. The dispersing agent is one or two of PVA and ZS-182. Wherein, the acetic acid is used as an auxiliary agent, and the weight of the acetic acid is 5 to 8 percent of the weight of the catalyst powder, preferably 6 percent. The weight of the binder is 5-8%, preferably 6% of the weight of the catalyst powder; the weight of the dispersant is 0.5% to 1%, preferably 0.6%, of the weight of the catalyst powder. The amount of water used is calculated on the basis of the solids content of the slurry, which is generally defined as 15% to 25% solids content of the slurry.
The PVA is polyvinyl alcohol. The ZS-182 is an ethoxylated alkylphenol type surfactant.
Go toThe binder is mainly used for improving the strength of the catalyst, and can be one or more of silica sol, aluminum sol and high viscosity. The adhesive is most applied by silica sol and aluminum sol, and has stable and reliable quality and excellent adhesive effect. In the present invention, it is preferable to use a high viscosity as a binder, and a high viscosity pseudoboehmite, which is an alumina monohydrate, of the formula Al2O3·nH2O (n is 0.08-0.62), non-toxic, tasteless and odorless white powder, good peptization performance, strong cohesiveness, high specific surface area, large pore volume and the like, and the high viscosity is purchased from Shandong aluminum industry.
The dispersing agent in the catalyst slurry comprises PVA and ZS-182, wherein the ratio of the PVA to the ZS-182 is 1: 1-2: 1. In particular, it is preferred that the weight of PVA is 1% of the weight of the catalyst powder and the weight of ZS-182 is 0.6% of the weight of the catalyst powder. Experiments prove that the dispersing agent in the catalyst slurry can well disperse the catalyst particles in the slurry, and is beneficial to coating the catalyst slurry on the DPF carrier and dispersing the catalyst active component.
Another object of the present invention is to provide a method for preparing a particle trap using the above catalyst composition.
A method of producing the above catalytic converter, comprising the steps of:
(1) taking high viscosity, acetic acid and water, and grinding into thick liquid. Adding Pt-Pd/Co2O3/CeO2-ZrO2And (3) grinding the catalyst powder raw material, the dispersing agent and water again, and controlling the particle size of the pulp to be 0.3-0.8 mu m.
(2) And (2) coating the slurry obtained in the step (1) on a ceramic carrier, controlling the sizing time to be 50-55 seconds, and blowing off the redundant slurry.
(3) And (3) drying the ceramic carrier loaded with the catalyst material obtained in the step (2), roasting at 600-650 ℃ to obtain a CDPF catalytic unit, and packaging to obtain the complete catalytic converter.
The catalytic converter packaged by the invention has very low ignition temperature for catalyzing soot, has excellent ageing resistance, and can realize the activity of the catalyst in a high-temperature environment in the regeneration process.
Compared with the prior art, the invention has the beneficial effects that:
1. the catalyst provided by the invention has the advantages of low ignition temperature of carbon smoke, good ageing resistance and capability of realizing the activity of the catalyst in a high-temperature environment in the regeneration process.
2. The catalyst has high activity, good stability and high trapping efficiency, and can effectively reduce particulate matters discharged from the tail gas of the diesel vehicle, thereby reducing the harm of the tail gas to the environment and human beings and meeting the emission standard of the light diesel vehicle in China.
3. The catalyst of the invention has high soot loading capacity and low regeneration equilibrium point temperature.
Description of the drawings:
FIG. 1 is a diagram of Pt-Pd (2: 1)/8% Co2O3/CeO2-ZrO2Pressure drop profile during CDPF loading for formulation 18g/L slurry coating.
FIG. 2 is a diagram of Pt-Pd (2: 1)/8% Co2O3/CeO2-ZrO2Backpressure performance curves for CDPF at different soot loadings for 18g/L slurry 18g/L coating dose of formulation.
FIG. 3 is a diagram of Pt-Pd (2: 1)/8% Co2O3/CeO2-ZrO2Pressure drop profile during CDPF regeneration at 18g/L coating level of formulation 18g/L slurry.
FIG. 4 is a diagram of Pt-Pd (2: 1)/8% Co2O3/CeO2-ZrO2CDPF front and rear end NO in CDPF regeneration process with 18g/L slurry formulation 18g/L coating amountxAnd NO2A curve of variation.
Detailed Description
More specifically, a preferred process for preparing a catalyst powder according to the present invention comprises the steps of:
(1) platinum nitrate and palladium nitrate solute are mixed according to 1% -2% of the weight of the carrier in the target catalyst, wherein the ratio of element Pt: pd 2:1-1:2, heating to 80-90 ℃ to remove acid, preferably to 85 ℃ to remove acid.
(2) Cobalt nitrate is measured according to the amount of cobalt oxide accounting for 5% -8% of the weight of the carrier in the target catalyst, and deionized water is added to prepare a cobalt nitrate solution. Adding the red solution into the solution obtained in the step (1), and then uniformly mixing platinum, palladium and cobalt nitrate to obtain a red solution.
(3) Test of CeO2-ZrO2And (2) calculating and adjusting the specific pore volume of the prepared solution, wherein the total volume of the solution is equal to the mass of the carrier powder multiplied by the specific pore volume, then adding the cerium-zirconium carrier powder into the adjusted solution, and stirring for 2-3 hours to obtain light yellow fine powder.
(4) Drying the light yellow fine powder in an oven at 60-80 ℃ for 1-2 hours, and at 100-120 ℃ for 12-24 hours.
(5) Putting the dried catalyst powder obtained in the step (4) into a muffle furnace, and roasting at the temperature of 500-650 ℃ for 3-4 hours to obtain Pt-Pd/Co2O3/CeO2-ZrO2A catalyst powder. It can also be calcined by mesh belt furnace.
More specifically, a preferred method of making a catalyst-type particle trap (CDPF) of the present invention comprises the steps of:
(1) according to Pt-Pd/Co2O3/CeO2-ZrO2Taking 6% of the catalyst powder (powder) material, and grinding with acetic acid and deionized water for 8-10min to obtain the binder.
(2) Adding catalyst powder, dispersing agents PVA and ZS-172 accounting for 0.5-1% of the weight of the catalyst powder, and water accounting for 15-20% of solid content into the binder, and grinding together. And (4) controlling the pulp grinding until the grain diameter of the pulp is 0.3-0.8 mu m to obtain the pulp.
(3) The slurry and the ceramic carrier are coated on a semi-automatic coating machine. The sizing time was controlled to 50-55s, and then excess slurry was blown off with 40KPa pressure to obtain a catalyst slurry coated support.
(4) And drying the carrier coated with the catalyst slurry at the temperature of 100-120 ℃ for 8-10 hours, and roasting at the temperature of 600-650 ℃ for 2-3 hours to obtain the CDPF catalytic unit, and packaging to obtain the complete catalytic converter.
Overall, the method of the invention for producing a catalytic converter comprises the following overall steps: a preparation method of a catalytic converter for purifying PM in diesel vehicle tail gas comprises the following steps:
① platinum nitrate and palladium nitrate are added according to the percentage content of 1-2.0 percent of the weight of the prepared catalyst carrier, wherein the content of noble metal is 10g/ft3And Pt: pd 2:1-1:2, respectively placing the materials into beakers, and heating platinum nitrate and nitric acid in a water bath at 85 ℃ to drive acid.
② cobalt oxide as the second active ingredient, Co2O3Adding cobalt nitrate in the weight percentage of 5-8% of the weight of the prepared catalyst carrier, dissolving the cobalt nitrate in deionized water to prepare cobalt nitrate solution, then adding the cobalt nitrate solution into the beaker in the step ①, and then mixing the platinum, palladium and cobalt nitrate with acid removed to form red solution.
③ test for CeO2-ZrO2The specific pore volume of the cerium-zirconium carrier powder is adjusted ②, the volume of the prepared solution is equal to the mass of the carrier powder multiplied by the specific pore volume, then the cerium-zirconium carrier powder is added into the adjusted solution volume in step ②, and the mixture is stirred for 2 to 3 hours, thus obtaining light yellow fine powder.
④ placing the powder obtained in step ③ into an oven, standing at 60-80 deg.C for 2 hr, and drying at 120 deg.C for 24 hr;
⑤ placing the dried catalyst powder from step ④ into a muffle furnace, and calcining at 650 deg.C for 3-4 hours to obtain Pt-Pd/Co2O3/CeO2-ZrO2A catalyst powder.
⑥ adding high-viscosity and equal amount of acetic acid and water into 6% of the catalyst powder, and grinding for 8-10 min.
⑦ adding a certain amount of catalyst powder obtained in the step ⑤ into the binder obtained in the step ⑥, dispersing agents PVA and ZS-172 accounting for 0.5-1% of the weight of the catalyst powder, and water according to a certain solid content, and grinding together, wherein the particle size of the pulp is controlled to be 0.3-0.8 mu m.
⑧ the slurry obtained in step ⑦ and the ceramic carrier were coated on a semi-automatic coater, the control was to run for 50-55 seconds and then blow off the excess slurry with 40KPa pressure.
⑨ the CDPF catalytic unit is prepared by drying the catalyst carrier obtained in step ⑧ at 100-120 deg.C for 8-10 hours and calcining at 600-650 deg.C for 2-3 hours.
⑩ packaging the catalytic unit obtained in step ⑨ to obtain a complete catalytic converter
The term in part in the present invention is to be interpreted as follows:
"specific pore volume" refers to the sum of the true pore volumes per weight of the interior of the catalyst particles.
The term "driving off the acid" means that the solution is heated to volatilize and discharge an excess of the acid component, and platinum nitrate and palladium nitrate used in the present invention contain an excess of the nitric acid component, and the excess of the nitric acid component is volatilized and discharged by heating.
The invention adopts cerium-zirconium composite oxide as catalyst carrier material, loads active component noble metal on the catalyst carrier material by an isometric impregnation method, forms catalyst powder by drying and roasting, then prepares slurry by adding a certain amount of high viscosity, dispersant and deionized water, coats the slurry on a ceramic substrate to form an integral catalyst, and then prepares a complete catalytic converter by packaging.
When the prepared catalyst is used for carrying out small sample activity evaluation (namely evaluating the performance of the catalyst by the ignition temperature of soot in the presence of the catalyst), the obtained Pt-Pd/Co2O3/CeO2-ZrO2 catalyst powder and soot discharged by an engine are loosely mixed and loaded into a fixed bed reactor, and the reaction temperature is controlled within the range of 25-700 ℃ for temperature programming test; with NO, NO2、O2Is an oxidizing gas, N2For balancing gas, the total flow of the gas is controlled to be 1000mL/min, and the space velocity is 30000h-1(ii) a The soot discharged by the engine can be effectively oxidized, and the emission of PM is reduced.
When the packaged catalyst is applied to bench testing (namely, real emission testing after a real diesel vehicle is installed with the catalyst is simulated), the obtained complete CDPF catalytic converter is installed on a diesel engine bench, proper working conditions are selected for soot loading, and the loading working conditions are selected as follows: 1500rpm 311Nm, airspeed 48000h-1CDPF inlet temperature 300 deg.C, smoke density 0.966FSN 17.06mg/m3Simultaneously testing the back pressure in the loading process; selecting a proper working condition to perform passive regeneration (reducing the reaction activation energy of PM by adding a catalyst on the surface of a DPF carrier so as to reduce the light-off temperature of the PM), and selecting the working condition of the passive regeneration: 1300rpm 350Nm and space velocity 36000h-1CDPF inlet temperature 430 deg.C, smoke degree 0.457FSN, soot loading level 5.1g/L, regeneration time 50 min; the catalyst can effectively react with the activity of the catalyst by regenerating the temperature of the equilibrium point, effectively oxidize soot knocked by the engine and reduce the emission of PM.
According to the invention, a precursor cobalt nitrate hexahydrate of a second active component cobalt dioxide is added, and the main active component and the secondary active component of the catalyst are optimized, so that the synergistic catalytic effect among the active components is exerted. Experiments prove that the catalyst provided by the invention effectively improves the performance of the catalyst, can ignite PM discharged by an engine at a lower temperature, has the lowest temperature of 252 ℃, has the bench test regeneration balance point temperature of 350-360 ℃, and also has the advantages of high PM trapping efficiency and good aging resistance in a high-temperature environment generated in the regeneration process.
The present invention will be described in further detail with reference to test examples and specific embodiments. It should be understood that the scope of the above-described subject matter is not limited to the following examples, and any techniques implemented based on the disclosure of the present invention are within the scope of the present invention. The percentages not specifically stated in the present invention are percentages by weight.
The following examples are commercially available for each chemical starting material and reagent. For example, acetic acid is purchased from Hedgehog chemical reagent plant, high viscosity is purchased from Shandong aluminum industry, ZS-172 is purchased from Shanghai Yikelong chemical reagent plant, cobalt nitrate hexahydrate is purchased from Hedgehog chemical reagent plant, barium acetate is purchased from Hedgehog chemical reagent plant, platinum nitrate is purchased from Heley (Heraeus) of Shanghai, palladium nitrate is purchased from Hedgey (Heraeus) of Shanghai, cerium zirconium composite oxide is purchased from Rodia, France, cerium zirconium aluminum composite oxide is purchased from Gangjing science and technology company, Zhou.
Example 1
Pt-Pd(1:1)/8％Co2O3/CeO2-ZrO2Preparation of the catalyst
Weighing 0.475g of 29.77 mass percent platinum nitrate solution, performing acid removal in a water bath kettle at 80 ℃ until the solution is completely removed, weighing 0.475g of 15.58 mass percent palladium nitrate solution, performing acid removal under the same conditions until the solution is completely removed, adding 5g of deionized water to dissolve the platinum nitrate and the palladium nitrate, and finally uniformly mixing the platinum nitrate and the palladium nitrate. 14.49g of cobalt nitrate hexahydrate is put into 20g of deionized water, and after the cobalt nitrate hexahydrate is completely dissolved, the cobalt nitrate hexahydrate is added into a mixed solution of platinum nitrate and palladium nitrate, and the mixture is stirred to be uniformly mixed. And pouring the mixed solution into a loaded plastic barrel, adding 50g of cerium-zirconium carrier powder into the loaded plastic barrel, then washing the residual solution with the remaining 5g of water, and stirring for 1-3 hours to obtain yellow fine powder. The resulting powder was placed in an oven, left at 60-80 ℃ for 2 hours, and then dried at 120 ℃ for 24 hours. Drying the powderPlacing the powder into a muffle furnace, and roasting at the temperature of 500-600 ℃ for 3-4 hours to obtain Pt-Pd (1:1)/8 percent Co2O3/CeO2-ZrO2A catalyst powder.
Example 2
Pt-Pd(1:2)/8％Co2O3/CeO2-ZrO2Preparation of the catalyst
Weighing 0.32g of 29.77% platinum nitrate solution by mass fraction, carrying out acid removal in a water bath kettle at 80 ℃ until the solution is completely removed, weighing 0.63g of 15.58% palladium nitrate solution by mass fraction, carrying out acid removal under the same conditions until the solution is completely removed, adding 5g of deionized water to dissolve the platinum nitrate and the palladium nitrate, and finally mixing the platinum nitrate and the palladium nitrate uniformly. 14.49g of cobalt nitrate hexahydrate is put into 20g of deionized water, and after the cobalt nitrate hexahydrate is completely dissolved, the cobalt nitrate hexahydrate is added into a mixed solution of platinum nitrate and palladium nitrate, and the mixture is stirred to be uniformly mixed. And pouring the mixed solution into a loaded plastic barrel, adding 50g of cerium-zirconium carrier powder into the loaded plastic barrel, then washing the residual solution with the remaining 5g of water, and stirring for 1-3 hours to obtain yellow fine powder. The resulting powder was placed in an oven, left at 60-80 ℃ for 2 hours, and then dried at 120 ℃ for 24 hours. The dried powder is put into a muffle furnace and roasted for 3 to 4 hours at the temperature of 500-600 ℃ to obtain Pt-Pd (1:2)/8 percent Co2O3/CeO2-ZrO2A catalyst powder.
Example 3
Pt-Pd(2:1)/8％Co2O3/CeO2-ZrO2Preparation of the catalyst
Weighing 0.63g of 29.77% platinum nitrate solution by mass fraction, carrying out acid removal in a water bath kettle at 80 ℃ until the solution is completely acidified, weighing 0.32g of 15.58% palladium nitrate solution by mass fraction, carrying out acid removal under the same conditions until the solution is completely acidified, adding 5g of deionized water to dissolve platinum nitrate and palladium nitrate, and finally mixing the platinum nitrate and the palladium nitrate uniformly. 14.49g of hexahydrate of cobalt nitrate in 20g of deionized water,after the cobalt nitrate hexahydrate is completely dissolved, adding the cobalt nitrate into the mixed solution of the platinum nitrate and the palladium nitrate, and stirring to uniformly mix the cobalt nitrate and the platinum nitrate. And pouring the mixed solution into a loaded plastic barrel, adding 50g of cerium-zirconium carrier powder into the loaded plastic barrel, then washing the residual solution with the remaining 5g of water, and stirring for 1-3 hours to obtain yellow fine powder. The resulting powder was placed in an oven, left at 60-80 ℃ for 2 hours, and then dried at 120 ℃ for 24 hours. The dried powder is put into a muffle furnace and roasted for 3 to 4 hours at the temperature of 500-600 ℃ to obtain Pt-Pd (2:1)/8 percent Co2O3/CeO2-ZrO2A catalyst powder.
Taking high viscosity, acetic acid and water, and grinding into thick liquid. Adding the obtained catalyst powder raw material, a dispersing agent and water, and grinding the mixture into thick liquid again, wherein the particle size of the thick liquid is controlled to be 0.3-0.8 mu m. And coating the slurry on a ceramic carrier, controlling the sizing time to be 50-55 seconds, and blowing off the redundant slurry. And drying the ceramic carrier loaded with the catalyst material, roasting at 600-650 ℃ to obtain a CDPF catalytic unit, and packaging to obtain the complete catalytic converter.
The pressure drop characteristic curve during the loading process is tested, and the result is shown in figure 1. The back pressure characteristics were tested at different soot loadings and the results are shown in figure 2. The pressure drop profile during regeneration was tested and the results are shown in figure 3. The results of testing the change curves of NOx and NO2 at the front and rear ends of CDPF during regeneration are shown in FIG. 4.
Remarking: fig. 1 illustrates that the pressure drop increases during soot loading, and is controlled to be within the pressure drop range of the engine when the loading is at a certain amount, in order to see how much the CDPF is loaded for soot. Figure 2 shows that the pressure drops for the different soot loading tests are within the specified range for the engine in order to demonstrate that the 18g/L slurry loading is appropriate. Fig. 3 illustrates that under this condition, the pressure drop is decreasing, i.e. soot has already started to regenerate. Fig. 4 illustrates that the NOx amount in the front and rear ends during regeneration is almost constant, while the rear end of NO2 is more concentrated than the front end, illustrating that the precious metals also play a role in the NO → NO2 conversion during regeneration.
Example 4
Pt-Pd(2:1)/10％Co2O3/CeO2-ZrO2Preparation of the catalyst
Weighing 0.63g of 29.77% platinum nitrate solution by mass fraction, carrying out acid removal in a water bath kettle at 80 ℃ until the solution is completely acidified, weighing 0.32g of 15.58% palladium nitrate solution by mass fraction, carrying out acid removal under the same conditions until the solution is completely acidified, adding 5g of deionized water to dissolve platinum nitrate and palladium nitrate, and finally mixing the platinum nitrate and the palladium nitrate uniformly. 18.11g of cobalt nitrate hexahydrate is put into 20g of deionized water, and after the cobalt nitrate hexahydrate is completely dissolved, the cobalt nitrate hexahydrate is added into a mixed solution of platinum nitrate and palladium nitrate, and the mixture is stirred to be uniformly mixed. And pouring the mixed solution into a loaded plastic barrel, adding 50g of cerium-zirconium carrier powder into the loaded plastic barrel, then washing the residual solution with the remaining 5g of water, and stirring for 1-3 hours to obtain yellow fine powder. The resulting powder was placed in an oven, left at 60-80 ℃ for 2 hours, and then dried at 120 ℃ for 24 hours. The dried powder is put into a muffle furnace and roasted for 3 to 4 hours at the temperature of 500-600 ℃ to obtain Pt-Pd (2:1)/10 percent Co2O3/CeO2-ZrO2A catalyst powder.
Example 5
Pt-Pd(2:1)/8％Co2O3Preparation of CeO2-ZrO2-Al2O3 catalyst
Weighing 0.63g of 29.77% platinum nitrate solution by mass fraction, carrying out acid removal in a water bath kettle at 80 ℃ until the solution is completely acidified, weighing 0.32g of 15.58% palladium nitrate solution by mass fraction, carrying out acid removal under the same conditions until the solution is completely acidified, adding 5g of deionized water to dissolve platinum nitrate and palladium nitrate, and finally mixing the platinum nitrate and the palladium nitrate uniformly. 14.49g of cobalt nitrate hexahydrate is put into 20g of deionized water, and after the cobalt nitrate hexahydrate is completely dissolved, the cobalt nitrate hexahydrate is added into a mixed solution of platinum nitrate and palladium nitrate, and the mixture is stirred to be uniformly mixed. Pouring the mixed solution into a load plastic bucket, and adding 50g of cerium-zirconium-aluminum carrier powder into the load plastic bucketThen, the residual solution was washed with the remaining 5g of water and stirred for 1 to 3 hours to obtain a yellow fine powder. The resulting powder was placed in an oven, left at 60-80 ℃ for 2 hours, and then dried at 120 ℃ for 24 hours. The dried powder is put into a muffle furnace and roasted for 3 to 4 hours at the temperature of 500-600 ℃ to obtain Pt-Pd (2:1)/8 percent Co2O3CeO2-ZrO2-Al2O3 catalyst powder.
Comparative example 1
Pt-Pd(2:1)/CeO2-ZrO2Preparation of the catalyst
(1) Weighing 0.63g of 29.77 percent platinum nitrate solution by mass fraction, carrying out acid removal in a water bath kettle at 80 ℃ until the solution is completely acidified, weighing 0.32g of 15.58 percent palladium nitrate solution by mass fraction, carrying out acid removal under the same condition until the solution is completely acidified, adding 5g of deionized water to dissolve the platinum nitrate and the palladium nitrate, and finally mixing the platinum nitrate and the palladium nitrate uniformly.
(2) And (2) pouring the mixed solution in the step (1) into a loaded plastic barrel, adding 50g of cerium-zirconium carrier powder into the loaded plastic barrel, then washing the residual liquid in the step (2) with the residual 5g of water, and stirring for 1-3 hours to obtain yellow fine powder.
(4) Putting the powder obtained in the step (3) into an oven, staying at 60-80 ℃ for 2 hours, and then drying at 120 ℃ for 24 hours.
(5) Putting the dried powder in the step (4) into a muffle furnace, and roasting at the temperature of 500-600 ℃ for 3-4 hours to obtain Pt-Pd (2:1)/CeO2-ZrO2A catalyst powder.
Comparative example 2
Pt-Pd(2:1)/8％BaO/CeO2-ZrO2Preparation of the catalyst
(1) Weighing 0.63g of 29.77 percent platinum nitrate solution by mass fraction, carrying out acid removal in a water bath kettle at 80 ℃ until the solution is completely acidified, weighing 0.32g of 15.58 percent palladium nitrate solution by mass fraction, carrying out acid removal under the same condition until the solution is completely acidified, adding 5g of deionized water to dissolve the platinum nitrate and the palladium nitrate, and finally mixing the platinum nitrate and the palladium nitrate uniformly.
(2) And 6.16g of barium acetate is put into 20g of deionized water, and after the barium nitrate is completely dissolved, the barium acetate is added into the mixed solution of the platinum nitrate and the palladium nitrate, and the mixture is stirred to be uniformly mixed.
(3) And (3) pouring the mixed solution in the step (2) into a loaded plastic barrel, adding 50g of cerium-zirconium carrier powder into the loaded plastic barrel, then washing the residual liquid in the step (2) with the residual 5g of water, and stirring for 1-3 hours to obtain yellow fine powder.
(4) Putting the powder obtained in the step (3) into an oven, staying at 60-80 ℃ for 2 hours, and then drying at 120 ℃ for 24 hours.
(5) Putting the dried powder in the step (4) into a muffle furnace, and roasting at the temperature of 500-600 ℃ for 3-4 hours to obtain Pt-Pd (2:1)/8 percent BaO/CeO2-ZrO2A catalyst powder.
Comparative example 3
Pt-Pd(2:1)/8％K2O/CeO2-ZrO2Preparation of the catalyst
(1) Weighing 0.63g of 29.77 percent platinum nitrate solution by mass fraction, carrying out acid removal in a water bath kettle at 80 ℃ until the solution is completely acidified, weighing 0.32g of 15.58 percent palladium nitrate solution by mass fraction, carrying out acid removal under the same condition until the solution is completely acidified, adding 5g of deionized water to dissolve the platinum nitrate and the palladium nitrate, and finally mixing the platinum nitrate and the palladium nitrate uniformly.
(2) 8.6g of potassium nitrate is put into 20g of deionized water, and after the potassium nitrate is completely dissolved, the potassium nitrate is added into the mixed solution of platinum nitrate and palladium nitrate, and the mixture is stirred to be uniformly mixed.
(3) And (3) pouring the mixed solution in the step (2) into a loaded plastic barrel, adding 50g of cerium-zirconium carrier powder into the loaded plastic barrel, then washing the residual liquid in the step (2) with the residual 5g of water, and stirring for 1-3 hours to obtain yellow fine powder.
(4) Putting the powder obtained in the step (3) into an oven, staying at 60-80 ℃ for 2 hours, and then drying at 120 ℃ for 24 hours.
(5) Putting the dried powder in the step (4) into a muffle furnace, and roasting at the temperature of 500-600 ℃ for 3-4 hours to obtain Pt-Pd (2: 1)/8% K2O/CeO2-ZrO2A catalyst powder.
Comparative example 4
Pt-Pd(2:1)/8％SrO/CeO2-ZrO2Preparation of the catalyst
(1) Weighing 0.63g of 29.77 percent platinum nitrate solution by mass fraction, carrying out acid removal in a water bath kettle at 80 ℃ until the solution is completely acidified, weighing 0.32g of 15.58 percent palladium nitrate solution by mass fraction, carrying out acid removal under the same condition until the solution is completely acidified, adding 5g of deionized water to dissolve the platinum nitrate and the palladium nitrate, and finally mixing the platinum nitrate and the palladium nitrate uniformly.
(2) And (3) adding 8.17g of strontium nitrate into 20g of deionized water, adding the strontium nitrate into the platinum nitrate and palladium nitrate mixed solution after the strontium nitrate is completely dissolved, and stirring to uniformly mix the strontium nitrate and the platinum nitrate and the palladium nitrate.
(3) And (3) pouring the mixed solution in the step (2) into a loaded plastic barrel, adding 50g of cerium-zirconium carrier powder into the loaded plastic barrel, then washing the residual liquid in the step (2) with the residual 5g of water, and stirring for 1-3 hours to obtain yellow fine powder.
(4) Putting the powder obtained in the step (3) into an oven, staying at 60-80 ℃ for 2 hours, and then drying at 120 ℃ for 24 hours.
(5) The dried powder in the step (4) is put into a muffle furnace and roasted for 3 to 4 hours at the temperature of 500-600 ℃ to obtain Pt-Pd (2:1)/8 percent SrO/CeO2-ZrO2A catalyst powder.
Results of Activity detection
The catalysts in the above examples were subjected to activity evaluation tests. The test conditions are as follows:
the catalyst powder is loosely contacted with soot discharged by an engine according to the ratio of 10:1, and the atmosphere conditions are as follows: 600ppm of Nitric Oxide (NO), 400ppm of nitrogen dioxide (NO)2) 10% oxygen (O)2) The rest of the reaction gas is nitrogenQi (N)2) The volume of the catalyst powder and the soot discharged by the engine is 2ml, and the reaction space velocity is 30000h-1Activating at 180 deg.C for 30min, then continuously heating at a heating rate of 10 deg.C/min and a temperature range of 25-700 deg.C, and recording the CO just generated2Temperature (Ti) of (2), maximum amount of CO produced2Temperature (Tf) and CO2The temperature (Tm) at which the amount of the product became 0 is shown in Table 1.
TABLE 1
| Ti | Tf | Tm | |
| Example 1 | 324.8 | 350.7 | 389.6 |
| Example 2 | 334.2 | 365.1 | 397.8 |
| Example 3 | 309.0 | 318.9 | 353.8 |
| Example 4 | 315.4 | 331.7 | 352.4 |
| Example 5 | 369.5 | 391.4 | 440.8 |
| Comparative example 1 | 350.8 | 396.4 | 438.5 |
| Comparative example 2 | 330.5 | 351.7 | 409.8 |
| Comparative example 3 | 288.7 | 309.6 | 340.5 |
| Comparative example 4 | 336.7 | 354.9 | 414.3 |
Hydrothermal aging experimental conditions of the catalyst are 800 ℃, 16h and 30000h-110% water vapor. Hydrothermal aging experiments were conducted on the catalysts prepared in example 1, example 2, example 3, example 4, example 5, example 6, comparative example 1, comparative example 2, and comparative example 3, respectively. Then, the above soot catalyzed light-off test methods were used to test the Ti, Tf, Tm temperatures, respectively, and the results are shown in table 2.
TABLE 2
| Ti | Tf | Tm | |
| Example 1 hydrothermal aging | 345.2 | 379.4 | 400.2 |
| Example 2 hydrothermal aging | 356.8 | 392.1 | 435.7 |
| Example 3 hydrothermal aging | 312.8 | 335.7 | 350.7 |
| Example 4 hydrothermal aging | 339.8 | 421.5 | 450.3 |
| Example 5 hydrothermal aging | 371.2 | 398.5 | 447.8 |
| Comparative example 1 hydrothermal aging | 361.9 | 400.5 | 442.8 |
| Comparative example 2 hydrothermal aging | 346.1 | 370.5 | 423.8 |
| Comparative example 3 hydrothermal aging | 380.8 | 427.9 | 478.6 |
| Comparative example 4 hydrothermal aging | 375.2 | 401.5 | 449.8 |
The experimental condition of the sulfur resistance of the catalyst is 350 ℃, 15h and 50ppm SO 2. The catalysts prepared in example 1, example 2, example 3, example 4, example 5, example 6, comparative example 1, comparative example 2 and comparative example 3 were subjected to a sulfur resistance test, respectively. Then, the above soot catalyzed light-off test methods were used to test the Ti, Tf, Tm temperatures, respectively, and the results are shown in table 3.
TABLE 3
| Ti | Tf | Tm | |
| Example 1 Sulfur aging | 341.2 | 359.7 | 389.5 |
| Example 2 Sulfur aging | 380.5 | 410.7 | 439.5 |
| Example 3 Sulfur aging | 310.5 | 311.6 | 355.6 |
| Example 4 Sulfur aging | 330.6 | 389.2 | 423.7 |
| Example 5 Sulfur aging | 372.8 | 403.5 | 435.8 |
| Comparative example 1 Sulfur aging | 361.9 | 400.5 | 442.8 |
| Comparative example 2 Sulfur aging | 344.8 | 387.6 | 442.7 |
| Comparative example 3 Sulfur aging | 377.4 | 418.5 | 448.9 |
| Comparative example 4 Sulfur aging | 345.7 | 389.4 | 444.8 |
The above catalyst formulations are compared in terms of carrier material, precious metal content, adjuvant dosage and adjuvant type, and can be found from the three tables:
(1) in example 5, compared with other examples and comparative examples, the hydrothermal aging resistance and the sulfur aging resistance are good, but the fresh catalyst activity is poor, and the ignition temperature of soot is high.
(2) When the catalyst is compared with examples 1, 2 and 3, the activity of the catalyst is better than that of the catalyst at a ratio of 2 to 1, and the sulfur resistance of the catalyst is reduced with the increase of the content of Pd, resulting in the reduction of the activity.
(3) From examples 3 and 4, the catalyst activity was the best when the promoter amount was 8%. When the amount of the additive is increased, the ignition temperature of the soot is reduced, so that the activity of the catalyst is reduced.
(4) The types of the auxiliary have a large influence on the catalytic activity as compared with example 3, comparative example 1, comparative example 2, comparative example 3, and comparative example 4. It can be seen from comparative example 1 that the soot ignition temperature of the unadjuvanted catalyst is higher than that of the additivated catalyst, and the catalyst activity is poor. The comparison of example 3, comparative example 2, comparative example 3 and comparative example 4 shows that the catalyst added with the additive K has good fresh activity, but poor resistance to hydrothermal aging and sulfur aging, and the catalyst has good fresh activity and aging resistance activity and low light-off temperature for soot by comprehensively considering the fresh activity and aging resistance of example 3.
Claims (6)
1. A catalyst for PM purification in diesel vehicle exhaust, the catalyst being represented by the formula:
Pt-Pd/Co2O3/CeO2-ZrO2
wherein,
CeO2-ZrO2is a cerium-zirconium composite oxide carrier;
Co2O3is an auxiliary component of the catalyst;
pt and Pd are active components of the noble metal catalyst;
wherein, Co2O3The weight percentage content is 8% -10% of the carrier weight;
the active component Pt uses a platinum nitrate solution with the mass fraction of 29.77% as a raw material, and the active component Pd uses a palladium nitrate solution with the mass fraction of 15.58% as a raw material; the proportion of Pt to Pd =2:1-1:2 is calculated according to the weight parts of the raw materials;
the total weight percentage content of the raw materials used by the active components Pt and Pd is 1-2% of the weight of the carrier.
2. The catalyst for PM purification in diesel vehicle exhaust according to claim 1, wherein the noble metal component is in a ratio of Pt: Pd =2:1-1:1, calculated as parts by weight of the raw material.
3. A process for preparing a catalyst according to any one of claims 1-2, comprising the steps of:
(1) taking platinum and palladium raw material compounds according to a proportion and uniformly mixing;
(2) adding a cobalt compound in proportion to prepare a red solution;
(3) test of CeO2-ZrO2And (3) calculating the specific pore volume of the cerium-zirconium carrier powder, and calculating the dosage ratio of the carrier and the red solution in the step (2) according to the mass and the specific pore volume of the carrier powder, wherein the calculation formula is as follows:
total volume of solution = mass of carrier powder x specific pore volume
Adding the carrier powder into the red solution obtained in the step (2) according to the calculation result, and stirring to obtain light yellow fine powder;
(4) drying the yellow powder obtained in the step (3), and then roasting at 500-650 ℃ to obtain Pt-Pd/Co2O3/CeO2-ZrO2A catalyst powder.
4. The method of claim 3, wherein the Pt-Pd/Co is used as a catalyst2O3/CeO2-ZrO2A catalyst,
the active components Pt and Pd are measured and taken in the form of 29.77 percent by mass of platinum nitrate solution and 15.58 percent by mass of palladium nitrate solution, and the sum of the two solutions is 1 to 2 percent of the weight of the carrier in the catalyst;
Co2O3is added in the form of cobalt nitrate hexahydrate, and the content of cobalt oxide is 8-10% of the weight percentage content of the carrier in the catalyst.
5. A catalytic converter comprising the catalyst composition of claim 1 or 2, wherein the catalyst, the promoter and the binder are mixed uniformly to obtain a catalyst slurry, the catalyst slurry is coated on a ceramic material carrier, the carrier is dried and calcined to obtain a CDPF catalytic unit of the particle trap coated with the catalyst, and the CDPF catalytic unit is packaged to obtain a complete catalytic converter.
6. The catalytic converter of claim 5, wherein the catalyst slurry consists of: the catalyst powder, acetic acid, a binder, a dispersant and water;
the dispersing agent is one or two of polyvinyl alcohol PVA and ethoxylated alkylphenol type surfactant ZS-182;
wherein, acetic acid is used as an auxiliary agent, and the weight of the acetic acid is 5 to 8 percent of that of the catalyst powder;
the weight of the binder is 5-8% of the weight of the catalyst powder;
the weight of the dispersant is 1-2% of the weight of the catalyst powder,
the amount of water is such that the solids content of the slurry is limited to 15% to 25%, calculated on the solids content of the slurry.
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| CN106732584B (en) * | 2017-01-24 | 2019-09-06 | 中国石油大学(北京) | A kind of cerium yttrium composite oxides support catalyst of platinum and its preparation method and application |
| CN107866364A (en) * | 2017-10-27 | 2018-04-03 | 南京依柯卡特排放技术股份有限公司 | One kind is used for diesel exhaust purification particle and removes DPF catalyst coating process |
| CN108561211B (en) * | 2018-04-20 | 2019-10-15 | 中自环保科技股份有限公司 | It is a kind of with low back pressure, the DPF of low light-off temperature Catalytic Layer and its preparation process |
| CN109595060A (en) * | 2018-11-07 | 2019-04-09 | 上海创怡环境技术有限公司 | Non-rice habitats mechanically moving tail gas black smoke treatment and purification system and purification method |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2004076829A1 (en) * | 2003-02-26 | 2004-09-10 | Umicore Ag & Co. Kg | Exhaust-gas purification system for the selective catalytic reduction of nitrogen oxides in the lean exhaust gas of internal combustion engines and method of exhaust-gas purification |
| CN101056692A (en) * | 2004-10-14 | 2007-10-17 | 催化溶液公司 | Platinum group metal-free catalysts for reducing the ignition temperature of particulates on a diesel particulate filter |
| CN101564646A (en) * | 2008-04-22 | 2009-10-28 | 赫多特普索化工设备公司 | Method for purification of an exhaust gas from a diesel engine |
| CN102000507A (en) * | 2010-11-05 | 2011-04-06 | 中国石油大学(北京) | Reducing gas injection and quadruple-effect catalysis purification system for diesel vehicle tail gas treatment |
| CN102176957A (en) * | 2008-09-18 | 2011-09-07 | 约翰森·马瑟公开有限公司 | Catalyst and process |
| CN102245295A (en) * | 2008-12-12 | 2011-11-16 | 韩国能源技术研究院 | Dual functional catalysts for decomposition and oxidation of nitrogen monoxide, mixed catalysts for exhaust-gas reducing device including the same, and preparation method thereof |
| CN202707186U (en) * | 2012-06-29 | 2013-01-30 | 四川中自尾气净化有限公司 | Particulate filter regeneration system |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20060107649A1 (en) * | 2002-08-26 | 2006-05-25 | Masayuki Kamikawa | Apparatus and method for clarifying exhaust gas of diesel engine |
-
2015
- 2015-08-17 CN CN201510505841.2A patent/CN105056970B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2004076829A1 (en) * | 2003-02-26 | 2004-09-10 | Umicore Ag & Co. Kg | Exhaust-gas purification system for the selective catalytic reduction of nitrogen oxides in the lean exhaust gas of internal combustion engines and method of exhaust-gas purification |
| CN101056692A (en) * | 2004-10-14 | 2007-10-17 | 催化溶液公司 | Platinum group metal-free catalysts for reducing the ignition temperature of particulates on a diesel particulate filter |
| CN101564646A (en) * | 2008-04-22 | 2009-10-28 | 赫多特普索化工设备公司 | Method for purification of an exhaust gas from a diesel engine |
| CN102176957A (en) * | 2008-09-18 | 2011-09-07 | 约翰森·马瑟公开有限公司 | Catalyst and process |
| CN102245295A (en) * | 2008-12-12 | 2011-11-16 | 韩国能源技术研究院 | Dual functional catalysts for decomposition and oxidation of nitrogen monoxide, mixed catalysts for exhaust-gas reducing device including the same, and preparation method thereof |
| CN102000507A (en) * | 2010-11-05 | 2011-04-06 | 中国石油大学(北京) | Reducing gas injection and quadruple-effect catalysis purification system for diesel vehicle tail gas treatment |
| CN202707186U (en) * | 2012-06-29 | 2013-01-30 | 四川中自尾气净化有限公司 | Particulate filter regeneration system |
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