CN115920884B - Three-way catalyst for reducing THC emission and preparation method thereof - Google Patents
Three-way catalyst for reducing THC emission and preparation method thereof Download PDFInfo
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- CN115920884B CN115920884B CN202211369473.XA CN202211369473A CN115920884B CN 115920884 B CN115920884 B CN 115920884B CN 202211369473 A CN202211369473 A CN 202211369473A CN 115920884 B CN115920884 B CN 115920884B
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- 239000003054 catalyst Substances 0.000 title claims abstract description 90
- 238000002360 preparation method Methods 0.000 title claims abstract description 14
- 239000011248 coating agent Substances 0.000 claims abstract description 165
- 238000000576 coating method Methods 0.000 claims abstract description 165
- 229910000510 noble metal Inorganic materials 0.000 claims abstract description 50
- RCFVMJKOEJFGTM-UHFFFAOYSA-N cerium zirconium Chemical compound [Zr].[Ce] RCFVMJKOEJFGTM-UHFFFAOYSA-N 0.000 claims abstract description 40
- 239000006104 solid solution Substances 0.000 claims abstract description 40
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims abstract description 36
- 229910052593 corundum Inorganic materials 0.000 claims abstract description 36
- 229910001845 yogo sapphire Inorganic materials 0.000 claims abstract description 36
- 159000000009 barium salts Chemical class 0.000 claims abstract description 9
- 238000011068 loading method Methods 0.000 claims abstract description 9
- 238000001035 drying Methods 0.000 claims description 38
- 239000000243 solution Substances 0.000 claims description 31
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Substances [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 claims description 25
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 22
- 239000008367 deionised water Substances 0.000 claims description 20
- 229910021641 deionized water Inorganic materials 0.000 claims description 20
- 239000006255 coating slurry Substances 0.000 claims description 17
- TZCXTZWJZNENPQ-UHFFFAOYSA-L barium sulfate Chemical compound [Ba+2].[O-]S([O-])(=O)=O TZCXTZWJZNENPQ-UHFFFAOYSA-L 0.000 claims description 16
- 238000000498 ball milling Methods 0.000 claims description 15
- 238000002156 mixing Methods 0.000 claims description 15
- 239000000047 product Substances 0.000 claims description 11
- 239000010970 precious metal Substances 0.000 claims description 7
- 239000011265 semifinished product Substances 0.000 claims description 6
- AYJRCSIUFZENHW-DEQYMQKBSA-L barium(2+);oxomethanediolate Chemical compound [Ba+2].[O-][14C]([O-])=O AYJRCSIUFZENHW-DEQYMQKBSA-L 0.000 claims description 4
- 238000000034 method Methods 0.000 claims description 4
- 230000000630 rising effect Effects 0.000 claims description 4
- 229910002637 Pr6O11 Inorganic materials 0.000 claims description 2
- PLDDOISOJJCEMH-UHFFFAOYSA-N neodymium oxide Inorganic materials [O-2].[O-2].[O-2].[Nd+3].[Nd+3] PLDDOISOJJCEMH-UHFFFAOYSA-N 0.000 claims description 2
- 238000012545 processing Methods 0.000 abstract description 3
- 239000000203 mixture Substances 0.000 abstract description 2
- KDLHZDBZIXYQEI-UHFFFAOYSA-N palladium Substances [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 description 47
- 239000010948 rhodium Substances 0.000 description 24
- 239000002002 slurry Substances 0.000 description 20
- 239000000919 ceramic Substances 0.000 description 15
- 238000010438 heat treatment Methods 0.000 description 15
- 239000007789 gas Substances 0.000 description 13
- 229910052763 palladium Inorganic materials 0.000 description 11
- MRELNEQAGSRDBK-UHFFFAOYSA-N lanthanum oxide Inorganic materials [O-2].[O-2].[O-2].[La+3].[La+3] MRELNEQAGSRDBK-UHFFFAOYSA-N 0.000 description 10
- KTUFCUMIWABKDW-UHFFFAOYSA-N oxo(oxolanthaniooxy)lanthanum Chemical compound O=[La]O[La]=O KTUFCUMIWABKDW-UHFFFAOYSA-N 0.000 description 10
- GPNDARIEYHPYAY-UHFFFAOYSA-N palladium(ii) nitrate Chemical compound [Pd+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O GPNDARIEYHPYAY-UHFFFAOYSA-N 0.000 description 10
- 239000011148 porous material Substances 0.000 description 10
- AYJRCSIUFZENHW-UHFFFAOYSA-L barium carbonate Chemical compound [Ba+2].[O-]C([O-])=O AYJRCSIUFZENHW-UHFFFAOYSA-L 0.000 description 8
- 230000000052 comparative effect Effects 0.000 description 7
- 229910052703 rhodium Inorganic materials 0.000 description 7
- 239000011247 coating layer Substances 0.000 description 5
- 229930195733 hydrocarbon Natural products 0.000 description 5
- 150000002430 hydrocarbons Chemical class 0.000 description 5
- NWAHZABTSDUXMJ-UHFFFAOYSA-N platinum(2+);dinitrate Chemical compound [Pt+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O NWAHZABTSDUXMJ-UHFFFAOYSA-N 0.000 description 5
- VXNYVYJABGOSBX-UHFFFAOYSA-N rhodium(3+);trinitrate Chemical compound [Rh+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O VXNYVYJABGOSBX-UHFFFAOYSA-N 0.000 description 5
- 238000012360 testing method Methods 0.000 description 5
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 4
- 229910002091 carbon monoxide Inorganic materials 0.000 description 4
- UHOVQNZJYSORNB-UHFFFAOYSA-N Benzene Chemical compound C1=CC=CC=C1 UHOVQNZJYSORNB-UHFFFAOYSA-N 0.000 description 3
- 239000004215 Carbon black (E152) Substances 0.000 description 3
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- 230000003197 catalytic effect Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000000746 purification Methods 0.000 description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 1
- 238000009825 accumulation Methods 0.000 description 1
- 238000003915 air pollution Methods 0.000 description 1
- 230000000711 cancerogenic effect Effects 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 231100000315 carcinogenic Toxicity 0.000 description 1
- 238000006555 catalytic reaction Methods 0.000 description 1
- 239000008199 coating composition Substances 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000003344 environmental pollutant Substances 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 229910052746 lanthanum Inorganic materials 0.000 description 1
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- 238000006552 photochemical reaction Methods 0.000 description 1
- 229910052697 platinum Inorganic materials 0.000 description 1
- 231100000719 pollutant Toxicity 0.000 description 1
- 125000005575 polycyclic aromatic hydrocarbon group Chemical group 0.000 description 1
- 238000011160 research Methods 0.000 description 1
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- 231100000331 toxic Toxicity 0.000 description 1
- 230000002588 toxic effect Effects 0.000 description 1
- 230000001052 transient effect Effects 0.000 description 1
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Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/10—Internal combustion engine [ICE] based vehicles
- Y02T10/12—Improving ICE efficiencies
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- Exhaust Gas Treatment By Means Of Catalyst (AREA)
Abstract
The invention provides a three-way catalyst for reducing THC emission and a preparation method thereof, wherein the catalyst comprises a carrier and a coating coated on the carrier, the coating comprises a lower coating arranged on the carrier and an upper coating arranged on the lower coating, the lower coating comprises an air inlet section and an air outlet section, the air inlet section comprises noble metal Pd and noble metal Rh, the noble metal Pd and the noble metal Rh are loaded on a cerium-zirconium solid solution, the air outlet section is noble metal Pd, and the noble metal Pd is loaded on barium salt and La 2O3-Al2O3; the upper coating comprises noble metal Pt which is supported on La 2O3-Al2O3 and cerium-zirconium solid solution; the load capacity of noble metal Pd in the gas inlet section of the lower coating is 5-350 g/ft 3, the load capacity of noble metal Rh is 0.1-50 g/ft 3, and the load capacity of noble metal Pd in the gas outlet section is 5-350 g/ft 3; the loading amount of the upper coating noble metal Pt is 0.1-100 g/ft 3. The invention improves the processing capacity of THC by optimizing the composition distribution of the coating and enhances the tail gas purifying performance.
Description
Technical Field
The invention relates to the technical field of catalyst preparation, in particular to a three-way catalyst for reducing THC emission and a preparation method thereof.
Background
The three-way catalyst of the gasoline automobile refers to an automobile catalyst which converts carbon monoxide (CO), hydrocarbon (THC) and oxynitride (NOx) in the original row of automobile exhaust into harmless carbon dioxide (CO 2), water (H 2 O) and nitrogen (N 2) through catalytic reaction; with the development of society, the conservation amount of global motor vehicles is continuously increased, and pollutants in automobile exhaust become one of main sources of urban air pollution, so that the automobile exhaust is harmful to human health and has great damage to ecological environment; many researches show that various THC compounds in automobile exhaust emission are harmful to human bodies, wherein part of organic components such as benzene and other polycyclic aromatic hydrocarbons are cancerogenic substances, and have long-term accumulation effect in human bodies; in addition, the hydrocarbon and the oxynitride can further undergo photochemical reaction under strong light irradiation to form toxic photochemical smog. And unburned hydrocarbons can also directly stimulate the human visual and olfactory organs, causing hypofunction.
In the existing gasoline engine with three-effect catalyst, 60-80% of unburned hydrocarbon (THC) is produced in cold start stage, so that combustion and emission control of THC in cold start process is one of the key links of emission control of the existing automobile engine.
Disclosure of Invention
Aiming at the defects in the prior art, the invention provides a three-way catalyst for reducing THC emission and a preparation method thereof.
The technical scheme adopted by the invention is as follows:
A three-way catalyst for reducing THC emissions, wherein: the catalyst comprises a carrier and a coating coated on the carrier, wherein the coating comprises a lower coating arranged on the carrier and an upper coating arranged on the lower coating, the lower coating comprises an air inlet section and an air outlet section, the air inlet section comprises noble metal Pd and noble metal Rh, the noble metal Pd and the noble metal Rh are loaded on a cerium-zirconium solid solution, the air outlet section is noble metal Pd, and the noble metal Pd is loaded on barium salt and La 2O3-Al2O3; the upper coating comprises noble metal Pt, wherein the noble metal Pt is supported on La 2O3-Al2O3 and cerium-zirconium solid solution; the loading capacity of the precious metal Pd in the gas inlet section of the lower coating is 5-350 g/ft 3, the loading capacity of the precious metal Rh is 0.1-50 g/ft 3, and the loading capacity of the precious metal Pd in the gas outlet section is 5-350 g/ft 3; the loading of the upper coating noble metal Pt is 0.1-100 g/ft 3.
Preferably, the three-way catalyst for reducing THC emissions, wherein: the cerium-zirconium solid solution comprises ZrO 2 and CeO 2, wherein the content of CeO 2 is 30-80 wt%.
Preferably, the three-way catalyst for reducing THC emissions, wherein: the cerium-zirconium solid solution also comprises one or more of La 2O3、Y2O3、Pr6O11、Nd2O3, and the content of the cerium-zirconium solid solution is 1-15 wt%.
Preferably, the three-way catalyst for reducing THC emissions, wherein: the La 2O3-Al2O3 comprises the following components: 1 to 10 weight percent of La 2O3 and 90 to 99 weight percent of Al 2O3.
Preferably, the three-way catalyst for reducing THC emissions, wherein: the barium salt is one or two of barium sulfate and barium carbonate, and the coating amount is 1-50 g/L.
Preferably, the three-way catalyst for reducing THC emissions, wherein: the coating amount of the lower coating air inlet section and the coating amount of the air outlet section are both 60-200 g/L.
Preferably, the three-way catalyst for reducing THC emissions, wherein: the coating quantity of the upper coating is 50-150 g/L.
A method for preparing a three-way catalyst for reducing THC emissions, wherein: the preparation method comprises the following steps:
(1) Coating of the lower coating air inlet section: taking a honeycomb carrier, sequentially mixing a Pd noble metal solution, a Rh noble metal solution, a cerium-zirconium solid solution and deionized water, and preparing a coating slurry I after ball milling; coating the first coating slurry on an air inlet section of a carrier, and drying the coated catalyst at 100-200 ℃ for 5-20 min to obtain a first semi-finished product;
(2) Coating of the lower coating air outlet section: mixing Pd noble metal solution, barium salt, la 2O3-Al2O3 and deionized water, and preparing a coating slurry II after ball milling; coating the second coating slurry on an air outlet section, drying the coated catalyst at 100-200 ℃ for 5-20 min, then programming the temperature of the dried catalyst to 450-800 ℃ at a temperature rising rate of 0.5-25 ℃/min, and roasting for 1-8 h to obtain a second semi-finished product;
(3) And (3) coating an upper coating: mixing a Pt noble metal solution, la 2O3-Al2O3, a cerium-zirconium solid solution and deionized water, and preparing a coating slurry III after ball milling; coating the coating slurry III on a semi-finished product II from the air inlet end of the lower coating, drying for 5-20 min at the temperature of 100-200 ℃, then programming the temperature of the dried catalyst to 450-800 ℃ at the temperature rising rate of 0.5-25 ℃/min, and roasting for 1-8 h to obtain the catalyst finished product.
The invention has the advantages that:
The invention relates to a three-way catalyst for reducing THC emission and a preparation method thereof, the three-way catalyst comprises a carrier and a coating coated on the carrier, the coating comprises a lower coating arranged on the carrier and an upper coating arranged on the lower coating, the lower coating comprises an air inlet section and an air outlet section, the air inlet section comprises noble metals Pd and Rh, the noble metals Pd and Rh are loaded on a cerium-zirconium solid solution, the air outlet section is noble metals Pd, pd is loaded on barium salt and La 2O3-Al2O3, the upper coating comprises noble metals Pt, the noble metals Pt are loaded on La 2O3-Al2O3 and the cerium-zirconium solid solution, the processing capacity of THC is improved by optimizing the composition distribution of the coating, and the tail gas purification performance is enhanced.
Detailed Description
The invention will be further illustrated with reference to specific examples.
Example 1
A three-way catalyst for reducing THC emission comprises a honeycomb ceramic carrier with the specification of phi 118.4mm multiplied by 152.4mm, the pore density of 600cpsi, the pore wall thickness of 4.3mil and the volume of 1.678L; one end of the honeycomb carrier is an air inlet end and the other end is an air outlet end according to the air inlet direction, the air inlet section of the lower coating comprises noble metal Pd and noble metal Rh, the noble metal Pd and the noble metal Rh are loaded on a cerium-zirconium solid solution, the coating amount is 120g/L, the Pd content is 100g/ft 3, and the Rh content is 5g/ft 3; the gas outlet section of the lower coating comprises precious metal Pd, the Pd is loaded on barium sulfate and La 2O3-Al2O3, the coating amount is 120g/L, the Pd content is 60g/ft 3, and the barium sulfate coating amount is 5g/L; the upper coating layer comprises La 2O3-Al2O3 and cerium zirconium solid solution loaded with Pt, the coating amount is 100g/L, and the content of Pt is 5g/ft 3.
A preparation method of a three-way catalyst for reducing THC emission comprises the following steps:
(1) Coating of the lower coating air inlet section: 1000g of cerium-zirconium solid solution (30 mass percent CeO 2,60mass％ZrO2,5mass％La2O3 and 5 bass percent Y 2O3), 30.51g of Pd-containing palladium nitrate solution, 1.53g of Rh-containing rhodium nitrate solution and 1500g of deionized water are mixed and ball-milled to obtain slurry, and then the coating slurry is coated with one quarter of the catalyst length from the air inlet end of the honeycomb ceramic carrier according to the coating amount of 120g/L, and is quickly dried, wherein the drying temperature is 180 ℃ and the drying time is 8min;
(2) Coating of the lower coating air outlet section: mixing 44.42g of barium sulfate, 1000gLa 2O3-Al2O3 (containing 98mass percent of Al 2O3), 18.82g of Pd-containing palladium nitrate solution and 1500g of deionized water, performing ball milling to obtain slurry, coating three-quarters of catalyst length from the air outlet end of the honeycomb ceramic carrier with a coating amount of 120g/L, performing quick drying, wherein the drying temperature is 180 ℃, the drying time is 8min, then performing programmed heating to 500 ℃ at a heating rate of 10 ℃/min, and roasting for 1h to obtain a semi-finished catalyst;
(3) And (3) coating an upper coating: mixing 500g La 2O3-Al2O3 (containing 98mass percent Al 2O3), 500g cerium-zirconium solid solution (containing 40mass percent CeO 2,50mass％ZrO2,5mass％La2O3 and 5mass percent Pr 6O11), 1.77g Pt-containing platinum nitrate solution and 1500g deionized water, ball milling to obtain slurry, coating the slurry on the semi-finished catalyst product prepared in the step (2) from the air inlet end with the coating amount of 100g/L, coating three-quarters of the length of the catalyst, drying at 180 ℃ for 8min, programming to be at 500 ℃ at the heating rate of 20 ℃/min after drying, and roasting for 2h to obtain the finished catalyst product.
Example 2
A three-way catalyst for reducing THC emission comprises a honeycomb ceramic carrier with the specification of phi 118.4mm multiplied by 152.4mm, the pore density of 600cpsi, the pore wall thickness of 4.3mil and the volume of 1.678L; one end of the honeycomb carrier in the gas inlet and outlet direction is an air inlet end, and the other end is an air outlet end; the air inlet section of the lower coating comprises cerium-zirconium solid solution loaded with Pd and Rh, the coating amount is 140g/L, the Pd content is 80g/ft 3, and the Rh content is 2g/ft 3; the gas outlet section of the lower coating comprises barium carbonate and La 2O3-Al2O3 loaded with Pd, the coating amount is 120g/L, the Pd content is 50g/ft 3, and the barium carbonate coating amount is 10g/L; the upper coating layer comprises La 2O3-Al2O3 and cerium zirconium solid solution loaded with Pt, the coating amount is 80g/L, and the content of Pt is 5g/ft 3.
A preparation method of a three-way catalyst for reducing THC emission comprises the following steps:
(1) Coating of the lower coating air inlet section: 1000g of cerium-zirconium solid solution (containing 50mass percent CeO 2,40mass％ZrO2,5mass％La2O3 and 5mass percent Nd 2O3), 24.41g of Pd-containing palladium nitrate solution, 0.61g of Rh-containing rhodium nitrate solution and 1500g of deionized water are mixed and ball-milled to obtain slurry, and then the coating slurry is coated with one half of the catalyst length from the air inlet end of the honeycomb ceramic carrier according to the coating amount of 140g/L, and is quickly dried, wherein the drying temperature is 180 ℃ and the drying time is 8min;
(2) Coating of the lower coating air outlet section: mixing 92.62g of barium carbonate, 1000gLa 2O3-Al2O3 g of solution containing 96mass percent of Al 2O3, 16.35g of Pd of palladium nitrate and 1500g of deionized water, performing ball milling to obtain slurry, coating one half of the catalyst length from the air outlet end of the honeycomb ceramic carrier with a coating amount of 120g/L, performing quick drying, wherein the drying temperature is 180 ℃, the drying time is 8min, and then performing programmed heating to 500 ℃ at a heating rate of 10 ℃/min for 1h to obtain a semi-finished catalyst;
(3) And (3) coating an upper coating: mixing 500g La 2O3-Al2O3 (containing 96mass percent Al 2O3), 500g cerium-zirconium solid solution (containing 50mass percent CeO 2,40mass％ZrO2,5mass％La2O3 and 5mass percent Y 2O3), 2.21g Pt-containing platinum nitrate solution and 1500g ionized water, ball milling to obtain slurry, coating the slurry on the semi-finished catalyst product prepared in the step (2) from an air inlet end with a coating amount of 80g/L, coating the whole catalyst length, drying at 180 ℃ for 8min, programming to be at 500 ℃ at a heating rate of 20 ℃/min after drying, and roasting for 2h to obtain the finished catalyst product.
Example 3
A three-way catalyst for reducing THC emission comprises a honeycomb ceramic carrier with the specification of phi 118.4mm multiplied by 152.4mm, the pore density of 600cpsi, the pore wall thickness of 4.3mil and the volume of 1.678L; one end of the honeycomb carrier is an air inlet end and the other end is an air outlet end according to the air inlet and outlet direction, the air inlet section of the lower coating comprises cerium-zirconium solid solution loaded with Pd and Rh, the coating amount is 140g/L, the Pd content is 120g/ft 3, and the Rh content is 4g/ft 3; the gas outlet section of the lower coating comprises barium sulfate and La 2O3-Al2O3 loaded with Pd, the coating amount is 120g/L, the Pd content is 70g/ft 3, and the barium sulfate coating amount is 15g/L; the upper coating layer comprises La 2O3-Al2O3 and cerium zirconium solid solution loaded with Pt, the coating amount is 120g/L, and the content of Pt is 5g/ft 3.
A preparation method of a three-way catalyst for reducing THC emission comprises the following steps:
(1) Coating of the lower coating air inlet section: 1000g of cerium-zirconium solid solution (60 mass percent CeO 2,30mass％ZrO2,5mass％La2O3 and 5 bass percent Nd 2O3), 36.61g of Pd-containing palladium nitrate solution, 1.22g of Rh-containing rhodium nitrate solution and 1500g of deionized water are mixed and ball-milled to obtain slurry, and then the coating slurry is coated with one half of the catalyst length from the air inlet end of the honeycomb ceramic carrier according to the coating amount of 140g/L, and is quickly dried, wherein the drying temperature is 180 ℃ and the drying time is 8min;
(2) Coating of the lower coating air outlet section: 146.83g of barium sulfate, 1000gLa 2O3-Al2O3 (containing 96mass percent of Al 2O3), 24.20g of Pd-containing palladium nitrate solution and 1500g of deionized water are mixed and ball-milled to obtain slurry, a half of the catalyst length is coated from the air outlet end of the honeycomb ceramic carrier in a coating amount of 120g/L, the catalyst is quickly dried, the drying temperature is 180 ℃, the drying time is 8min, then the dried catalyst is programmed to be heated to 500 ℃ at a heating rate of 10 ℃/min, and the catalyst is roasted for 1h to obtain a semi-finished catalyst;
(3) And (3) coating an upper coating: mixing 500g La 2O3-Al2O3 (containing 96mass percent Al 2O3), 500g cerium-zirconium solid solution (containing 60mass percent CeO 2,30mass％ZrO2,5mass％La2O3 and 5mass percent Nd 2O3), 1.47gPt platinum nitrate solution and 1500g deionized water, ball milling to obtain slurry, coating the slurry on the semi-finished catalyst product prepared in the step (2) from an air inlet end with a coating amount of 120g/L, coating the whole catalyst length, coating and drying at 180 ℃ for 8min, programming to be at 500 ℃ at a heating rate of 20 ℃/min after drying, and roasting for 2h to obtain the finished catalyst.
Comparative example 1
A three-way catalyst for reducing THC emission comprises a honeycomb ceramic carrier with the specification of phi 118.4mm multiplied by 152.4mm, the pore density of 600cpsi, the pore wall thickness of 4.3mil and the volume of 1.678L; one end of the honeycomb carrier is an air inlet end and the other end is an air outlet end according to the air inlet and outlet direction, the air inlet section of the lower coating comprises cerium-zirconium solid solution loaded with Pd and Rh, the coating amount is 120g/L, the Pd content is 100g/ft 3, and the Rh content is 5g/ft 3; the gas outlet section of the lower coating comprises La 2O3-Al2O3 loaded with Pd, the coating amount is 120g/L, and the Pd content is 60g/ft 3; the upper coating layer comprises La 2O3-Al2O3 and cerium zirconium solid solution loaded with Pt, the coating amount is 100g/L, and the content of Pt is 5g/ft 3.
A preparation method of a three-way catalyst for reducing THC emission comprises the following steps:
(1) Coating of the lower coating air inlet section: 1000g of cerium-zirconium solid solution (30 mass percent CeO 2,60mass％ZrO2,5mass％La2O3 and 5 bass percent Y 2O3), 30.51g of Pd-containing palladium nitrate solution, 1.53g of Rh-containing rhodium nitrate solution and 1500g of deionized water are mixed and ball-milled to obtain slurry, and then the coating slurry is coated with one quarter of the catalyst length from the air inlet end of the honeycomb ceramic carrier according to the coating amount of 120g/L, and is quickly dried, wherein the drying temperature is 180 ℃ and the drying time is 8min;
(2) Coating of the lower coating air outlet section: mixing 1000gLa 2O3-Al2O3 (containing 98mass percent Al 2O3), palladium nitrate solution containing 18.82g Pd and 1500g deionized water, performing ball milling to obtain slurry, coating three-quarters of catalyst length from the air outlet end of the honeycomb ceramic carrier with the coating amount of 120g/L, performing quick drying at 180 ℃ for 8min, then performing programmed heating of the dried catalyst to 500 ℃ at the heating rate of 10 ℃/min, and roasting for 1h to obtain a semi-finished catalyst;
(3) And (3) coating an upper coating: mixing 500g La 2O3-Al2O3 (containing 98mass percent Al 2O3), 500g cerium-zirconium solid solution (containing 40mass percent CeO 2,50mass％ZrO2,5mass％La2O3 and 5mass percent Pr 6O11), 1.77g Pt-containing platinum nitrate solution and 1500g deionized water, ball milling to obtain slurry, coating the slurry on the semi-finished catalyst product prepared in the step (2) from the air inlet end with the coating amount of 100g/L, coating three-quarters of the length of the catalyst, drying at 180 ℃ for 8min, programming to be at 500 ℃ at the heating rate of 20 ℃/min after drying, and roasting for 2h to obtain the finished catalyst product.
Comparative example 2
A three-way catalyst for reducing THC emission comprises a honeycomb ceramic carrier with the specification of phi 118.4mm multiplied by 152.4mm, the pore density of 600cpsi, the pore wall thickness of 4.3mil and the volume of 1.678L; one end of the honeycomb carrier in the gas inlet and outlet direction is an air inlet end, and the other end is an air outlet end; the air inlet section of the lower coating comprises cerium-zirconium solid solution loaded with Pd and Pt, the coating amount is 140g/L, the Pd content is 80g/ft 3, and the Pt content is 5g/ft 3; the gas outlet section of the lower coating comprises barium carbonate and La 2O3-Al2O3 loaded with Pd, the coating amount is 120g/L, the Pd content is 50g/ft 3, and the barium carbonate coating amount is 10g/L; the upper coating layer comprises La 2O3-Al2O3 and cerium zirconium solid solution loaded with Rh, the coating amount is 80g/L, and the Rh content is 2g/ft 3.
A preparation method of a three-way catalyst for reducing THC emission comprises the following steps:
(1) Coating of the lower coating air inlet section: 1000g of cerium-zirconium solid solution (containing 50mass percent CeO 2,40mass％ZrO2,5mass％La2O3 and 5mass percent Nd 2O3), 24.41g of Pd-containing palladium nitrate solution, 1.53g of Pt-containing platinum nitrate solution and 1500g of deionized water are mixed and ball-milled to obtain slurry, and then the coating slurry is coated with one half of the catalyst length from the air inlet end of the honeycomb ceramic carrier according to the coating amount of 140g/L, and is quickly dried, wherein the drying temperature is 180 ℃ and the drying time is 8min;
(2) Coating of the lower coating air outlet section: mixing 92.62g of barium carbonate, 1000gLa 2O3-Al2O3 g of solution containing 96mass percent of Al 2O3, 16.35g of Pd of palladium nitrate and 1500g of deionized water, performing ball milling to obtain slurry, coating one half of the catalyst length from the air outlet end of the honeycomb ceramic carrier with a coating amount of 120g/L, performing quick drying, wherein the drying temperature is 180 ℃, the drying time is 8min, and then performing programmed heating to 500 ℃ at a heating rate of 10 ℃/min for 1h to obtain a semi-finished catalyst;
(3) And (3) coating an upper coating: mixing 500g La 2O3-Al2O3 (containing 96mass percent Al 2O3), 500g cerium-zirconium solid solution (containing 50mass percent CeO 2,40mass％ZrO2,5mass％La2O3 and 5mass percent Y 2O3), rhodium nitrate solution containing 0.88g Rh and 1500g deionized water, ball milling to obtain slurry, coating the slurry on the semi-finished catalyst product prepared in the step (2) from an air inlet end with a coating amount of 80g/L, coating the whole catalyst length, drying at 180 ℃ for 8min, heating to 500 ℃ at a heating rate of 20 ℃/min after drying, and roasting for 2h to obtain the finished catalyst product.
A method for testing a three-way catalyst for reducing THC emissions, comprising the steps of:
the catalyst samples obtained in examples 1 to 3 and comparative examples 1 to 2 were aged for 20 hours in a high temperature tube furnace at 1050 ℃ under the same conditions, and then packaged into a purifier, and a whole vehicle emission test was performed according to a WLTC type i test, the engine displacement of the test vehicle was 1.6L, and the emission test results are shown in table 1.
TABLE 1 comparison of catalytic Properties of the catalysts obtained in examples 1-3 and comparative examples 1-2
| THC(mg/km) | CO(mg/km) | NOX(mg/km) | |
| Example 1 | 23.5 | 200.6 | 30.2 |
| Example 2 | 20.3 | 190.5 | 31.8 |
| Example 3 | 23.4 | 207.8 | 32.2 |
| Comparative example 1 | 35.5 | 226.9 | 33.7 |
| Comparative example 2 | 39.3 | 210.8 | 34.1 |
Note that: THC in table 1 represents an abbreviation for the total amount of hydrocarbons contained in the gas.
As shown in Table 1, the results of catalyst performance evaluation show that the three-way catalysts prepared in examples 1-3 of the present invention have excellent exhaust gas purifying ability under various transient conditions, and exhibit better catalytic performance for THC, compared with comparative examples 1-2.
The invention relates to a three-way catalyst for reducing THC emission, which comprises a carrier and a coating coated on the carrier, wherein the coating comprises a lower coating arranged on the carrier and an upper coating arranged on the lower coating, the lower coating comprises an air inlet section and an air outlet section, the air inlet section comprises noble metals Pd and Rh, the noble metals Pd and Rh are loaded on a cerium-zirconium solid solution, the air outlet section is noble metal Pd, and Pd is loaded on barium salt and La 2O3-Al2O3; the upper coating comprises noble metal Pt which is loaded on the La 2O3-Al2O3 and cerium-zirconium solid solution, and the invention improves the processing capacity of THC and enhances the tail gas purification performance by optimizing the coating composition distribution.
Finally, it should be noted that the above-mentioned embodiments are only for illustrating the technical solution of the present invention, and not for limiting the same, and although the present invention has been described in detail with reference to examples, it should be understood by those skilled in the art that modifications and equivalents may be made to the technical solution of the present invention without departing from the spirit and scope of the technical solution of the present invention, and all such modifications and equivalents are intended to be encompassed in the scope of the claims of the present invention.
Claims (8)
1. A three-way catalyst for reducing THC emissions, characterized in that: the catalyst comprises a carrier and a coating coated on the carrier, wherein the coating comprises a lower coating arranged on the carrier and an upper coating arranged on the lower coating, the lower coating comprises an air inlet section and an air outlet section, the air inlet section comprises noble metal Pd and noble metal Rh, the noble metal Pd and the noble metal Rh are loaded on a cerium-zirconium solid solution, the air outlet section is noble metal Pd, and the noble metal Pd is loaded on barium salt and La 2O3-Al2O3; the upper coating comprises noble metal Pt, wherein the noble metal Pt is supported on La 2O3-Al2O3 and cerium-zirconium solid solution; the loading capacity of the precious metal Pd in the gas inlet section of the lower coating is 5-350 g/ft 3, the loading capacity of the precious metal Rh is 0.1-50 g/ft 3, and the loading capacity of the precious metal Pd in the gas outlet section is 5-350 g/ft 3; the loading amount of the upper coating noble metal Pt is 0.1-100 g/ft 3.
2. A three-way catalyst for reducing THC emissions according to claim 1, wherein: the cerium-zirconium solid solution comprises ZrO 2 and CeO 2, wherein the content of CeO 2 is 30-wt-80 wt%.
3. A three-way catalyst for reducing THC emissions according to claim 2, wherein: the cerium-zirconium solid solution also comprises one or more of La 2O3、Y2O3、Pr6O11、Nd2O3, and the content of the cerium-zirconium solid solution is 1-wt% -15% by weight.
4. A three-way catalyst for reducing THC emissions according to claim 1, wherein: the La 2O3-Al2O3 comprises the following components: 1 wt-10 wt% of La 2O3 and 90 wt-99 wt% of Al 2O3.
5. A three-way catalyst for reducing THC emissions according to claim 1, wherein: the barium salt is one or two of barium sulfate and barium carbonate, and the coating amount is 1-50 g/L.
6. A three-way catalyst for reducing THC emissions according to claim 1, wherein: the coating amount of the lower coating air inlet section and the coating amount of the lower coating air outlet section are both 60-200 g/L.
7. A three-way catalyst for reducing THC emissions according to claim 1, wherein: the coating quantity of the upper coating is 50-150 g/L.
8. The method for preparing a three-way catalyst for reducing THC emissions according to any one of claims 1 to 7, wherein: the preparation method comprises the following steps:
(1) Coating of the lower coating air inlet section: taking a honeycomb carrier, sequentially mixing a Pd noble metal solution, a Rh noble metal solution, a cerium-zirconium solid solution and deionized water, and preparing a coating slurry I after ball milling; coating the first coating slurry on an air inlet section of a carrier, and drying the coated catalyst at 100-200 ℃ for 5-20 min to obtain a first semi-finished product;
(2) Coating of the lower coating air outlet section: mixing Pd noble metal solution, barium salt, la 2O3-Al2O3 and deionized water, and preparing a coating slurry II after ball milling; coating the second coating slurry on an air outlet section, drying the coated catalyst at the temperature of 100-200 ℃ for 5-20 min, then programming the temperature of the dried catalyst to 450-800 ℃ at the temperature rising rate of 0.5-25 ℃/min, and roasting for 1-8 h to obtain a second semi-finished product;
(3) And (3) coating an upper coating: mixing a Pt noble metal solution, la 2O3-Al2O3, a cerium-zirconium solid solution and deionized water, and preparing a coating slurry III after ball milling; and (3) coating the coating slurry III on a semi-finished product II from the air inlet end of the lower coating, drying for 5-20 min at the temperature of 100-200 ℃, then programming the temperature of the dried catalyst to 450-800 ℃ at the temperature rising rate of 0.5-25 ℃/min, and roasting for 1-8 h to obtain a catalyst finished product.
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Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20070050131A (en) * | 2005-11-10 | 2007-05-15 | 현대자동차주식회사 | The double layered three way catalyst with zone coating and method for manufacturing the same |
| CN105916580A (en) * | 2013-12-16 | 2016-08-31 | 巴斯夫公司 | Manganese-containing diesel oxidation catalyst |
| CN108778491A (en) * | 2016-03-22 | 2018-11-09 | 株式会社科特拉 | Exhaust gas purification catalyst |
| CN109153014A (en) * | 2016-05-24 | 2019-01-04 | 株式会社科特拉 | Exhaust gas purification catalyst |
| CN109985624A (en) * | 2019-04-29 | 2019-07-09 | 无锡威孚环保催化剂有限公司 | Catalysts for Motorcycles coated three times and preparation method thereof |
| CN110586088A (en) * | 2019-10-12 | 2019-12-20 | 无锡威孚环保催化剂有限公司 | Preparation method of segmented national six natural gas equivalence ratio catalyst |
| CN113750996A (en) * | 2021-09-29 | 2021-12-07 | 无锡威孚环保催化剂有限公司 | Catalyst for enhancing internal combustion engine tail gas purification and preparation method thereof |
| CN115555032A (en) * | 2022-09-23 | 2023-01-03 | 无锡威孚环保催化剂有限公司 | High-performance tail gas purifying catalyst for inhibiting sulfur poisoning and preparation method thereof |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP3034166B1 (en) * | 2013-12-13 | 2020-10-07 | Cataler Corporation | Exhaust gas purification catalyst |
| US20190240643A1 (en) * | 2016-07-28 | 2019-08-08 | Basf Corporation | Catalyst comprising bimetallic platinum group metal nanoparticles |
| JP7288331B2 (en) * | 2019-03-29 | 2023-06-07 | 株式会社キャタラー | Exhaust gas purification catalyst device |
-
2022
- 2022-11-03 CN CN202211369473.XA patent/CN115920884B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20070050131A (en) * | 2005-11-10 | 2007-05-15 | 현대자동차주식회사 | The double layered three way catalyst with zone coating and method for manufacturing the same |
| CN105916580A (en) * | 2013-12-16 | 2016-08-31 | 巴斯夫公司 | Manganese-containing diesel oxidation catalyst |
| CN108778491A (en) * | 2016-03-22 | 2018-11-09 | 株式会社科特拉 | Exhaust gas purification catalyst |
| CN109153014A (en) * | 2016-05-24 | 2019-01-04 | 株式会社科特拉 | Exhaust gas purification catalyst |
| CN109985624A (en) * | 2019-04-29 | 2019-07-09 | 无锡威孚环保催化剂有限公司 | Catalysts for Motorcycles coated three times and preparation method thereof |
| CN110586088A (en) * | 2019-10-12 | 2019-12-20 | 无锡威孚环保催化剂有限公司 | Preparation method of segmented national six natural gas equivalence ratio catalyst |
| CN113750996A (en) * | 2021-09-29 | 2021-12-07 | 无锡威孚环保催化剂有限公司 | Catalyst for enhancing internal combustion engine tail gas purification and preparation method thereof |
| CN115555032A (en) * | 2022-09-23 | 2023-01-03 | 无锡威孚环保催化剂有限公司 | High-performance tail gas purifying catalyst for inhibiting sulfur poisoning and preparation method thereof |
Non-Patent Citations (2)
| Title |
|---|
| "Catalytic converter design for minimisation of cold-start emissions";Tronci, S et al.;《CHEMICAL ENGINEERING COMMUNICATIONS》;19990101;第173卷;53-77 * |
| "涂层材料及涂覆方式对DPF催化剂的性能影响";王刚等;《金属功能材料》;20230228;第30卷(第1期);66-72 * |
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