JP3320855B2 - Exhaust gas purification method - Google Patents
Exhaust gas purification methodInfo
- Publication number
- JP3320855B2 JP3320855B2 JP23846193A JP23846193A JP3320855B2 JP 3320855 B2 JP3320855 B2 JP 3320855B2 JP 23846193 A JP23846193 A JP 23846193A JP 23846193 A JP23846193 A JP 23846193A JP 3320855 B2 JP3320855 B2 JP 3320855B2
- Authority
- JP
- Japan
- Prior art keywords
- exhaust gas
- purifying
- catalyst
- oxygen
- supported
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 238000000746 purification Methods 0.000 title claims description 22
- 238000000034 method Methods 0.000 title claims description 15
- 239000003054 catalyst Substances 0.000 claims description 56
- 239000007789 gas Substances 0.000 claims description 50
- 229910052751 metal Inorganic materials 0.000 claims description 24
- 239000002184 metal Substances 0.000 claims description 24
- 229910052783 alkali metal Inorganic materials 0.000 claims description 19
- 150000001340 alkali metals Chemical class 0.000 claims description 19
- 229910052761 rare earth metal Inorganic materials 0.000 claims description 19
- MWUXSHHQAYIFBG-UHFFFAOYSA-N nitrogen oxide Inorganic materials O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 claims description 18
- 150000002910 rare earth metals Chemical class 0.000 claims description 17
- 229930195733 hydrocarbon Natural products 0.000 claims description 16
- 150000002430 hydrocarbons Chemical class 0.000 claims description 16
- 229910052697 platinum Inorganic materials 0.000 claims description 14
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 claims description 12
- 229910052763 palladium Inorganic materials 0.000 claims description 10
- 229910052700 potassium Inorganic materials 0.000 claims description 8
- XTQHKBHJIVJGKJ-UHFFFAOYSA-N sulfur monoxide Chemical class S=O XTQHKBHJIVJGKJ-UHFFFAOYSA-N 0.000 claims description 8
- 229910052744 lithium Inorganic materials 0.000 claims description 7
- 150000002739 metals Chemical class 0.000 claims description 7
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 claims description 6
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 6
- 229910002091 carbon monoxide Inorganic materials 0.000 claims description 6
- 229910052760 oxygen Inorganic materials 0.000 claims description 6
- 239000001301 oxygen Substances 0.000 claims description 6
- 239000002131 composite material Substances 0.000 claims description 5
- 229910052746 lanthanum Inorganic materials 0.000 claims description 5
- 229910052815 sulfur oxide Inorganic materials 0.000 claims description 5
- 229910052777 Praseodymium Inorganic materials 0.000 claims description 4
- 229910052742 iron Inorganic materials 0.000 claims description 4
- 229910052748 manganese Inorganic materials 0.000 claims description 4
- 229910052759 nickel Inorganic materials 0.000 claims description 4
- 229910052779 Neodymium Inorganic materials 0.000 claims description 3
- 229910052772 Samarium Inorganic materials 0.000 claims description 3
- 229910052799 carbon Inorganic materials 0.000 claims description 2
- TXKMVPPZCYKFAC-UHFFFAOYSA-N disulfur monoxide Inorganic materials O=S=S TXKMVPPZCYKFAC-UHFFFAOYSA-N 0.000 claims 3
- 239000000126 substance Substances 0.000 claims 1
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Substances [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 13
- 239000000446 fuel Substances 0.000 description 10
- PNEYBMLMFCGWSK-UHFFFAOYSA-N Alumina Chemical compound [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 9
- 230000007423 decrease Effects 0.000 description 9
- KDLHZDBZIXYQEI-UHFFFAOYSA-N palladium Substances [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 description 9
- 239000007864 aqueous solution Substances 0.000 description 7
- 230000000694 effects Effects 0.000 description 7
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 7
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 4
- 230000000052 comparative effect Effects 0.000 description 4
- 238000011156 evaluation Methods 0.000 description 4
- 229920006395 saturated elastomer Polymers 0.000 description 4
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 description 3
- 229910001963 alkali metal nitrate Inorganic materials 0.000 description 3
- 239000011248 coating agent Substances 0.000 description 3
- 238000000576 coating method Methods 0.000 description 3
- 239000011591 potassium Substances 0.000 description 3
- 239000010948 rhodium Substances 0.000 description 3
- 239000002002 slurry Substances 0.000 description 3
- 229910052717 sulfur Inorganic materials 0.000 description 3
- 238000012360 testing method Methods 0.000 description 3
- 229910052723 transition metal Inorganic materials 0.000 description 3
- 150000003624 transition metals Chemical class 0.000 description 3
- 229910002651 NO3 Inorganic materials 0.000 description 2
- NHNBFGGVMKEFGY-UHFFFAOYSA-N Nitrate Chemical compound [O-][N+]([O-])=O NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 description 2
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 2
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 2
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 description 2
- 229910052784 alkaline earth metal Inorganic materials 0.000 description 2
- 150000001342 alkaline earth metals Chemical class 0.000 description 2
- IXSUHTFXKKBBJP-UHFFFAOYSA-L azanide;platinum(2+);dinitrite Chemical compound [NH2-].[NH2-].[Pt+2].[O-]N=O.[O-]N=O IXSUHTFXKKBBJP-UHFFFAOYSA-L 0.000 description 2
- 229910052792 caesium Inorganic materials 0.000 description 2
- 229910052878 cordierite Inorganic materials 0.000 description 2
- JSKIRARMQDRGJZ-UHFFFAOYSA-N dimagnesium dioxido-bis[(1-oxido-3-oxo-2,4,6,8,9-pentaoxa-1,3-disila-5,7-dialuminabicyclo[3.3.1]nonan-7-yl)oxy]silane Chemical compound [Mg++].[Mg++].[O-][Si]([O-])(O[Al]1O[Al]2O[Si](=O)O[Si]([O-])(O1)O2)O[Al]1O[Al]2O[Si](=O)O[Si]([O-])(O1)O2 JSKIRARMQDRGJZ-UHFFFAOYSA-N 0.000 description 2
- 238000001035 drying Methods 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- GPNDARIEYHPYAY-UHFFFAOYSA-N palladium(ii) nitrate Chemical compound [Pd+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O GPNDARIEYHPYAY-UHFFFAOYSA-N 0.000 description 2
- 238000006722 reduction reaction Methods 0.000 description 2
- 229910052703 rhodium Inorganic materials 0.000 description 2
- 229910052701 rubidium Inorganic materials 0.000 description 2
- 239000000377 silicon dioxide Substances 0.000 description 2
- 229910052708 sodium Inorganic materials 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- 238000001179 sorption measurement Methods 0.000 description 2
- LSNNMFCWUKXFEE-UHFFFAOYSA-L sulfite Chemical compound [O-]S([O-])=O LSNNMFCWUKXFEE-UHFFFAOYSA-L 0.000 description 2
- 239000011593 sulfur Substances 0.000 description 2
- BNGXYYYYKUGPPF-UHFFFAOYSA-M (3-methylphenyl)methyl-triphenylphosphanium;chloride Chemical compound [Cl-].CC1=CC=CC(C[P+](C=2C=CC=CC=2)(C=2C=CC=CC=2)C=2C=CC=CC=2)=C1 BNGXYYYYKUGPPF-UHFFFAOYSA-M 0.000 description 1
- 229910021536 Zeolite Inorganic materials 0.000 description 1
- 229910052788 barium Inorganic materials 0.000 description 1
- IWOUKMZUPDVPGQ-UHFFFAOYSA-N barium nitrate Chemical compound [Ba+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O IWOUKMZUPDVPGQ-UHFFFAOYSA-N 0.000 description 1
- 238000007664 blowing Methods 0.000 description 1
- 238000001354 calcination Methods 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- HNPSIPDUKPIQMN-UHFFFAOYSA-N dioxosilane;oxo(oxoalumanyloxy)alumane Chemical compound O=[Si]=O.O=[Al]O[Al]=O HNPSIPDUKPIQMN-UHFFFAOYSA-N 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 229910052747 lanthanoid Inorganic materials 0.000 description 1
- 150000002602 lanthanoids Chemical class 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 229910000510 noble metal Inorganic materials 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 229910001404 rare earth metal oxide Inorganic materials 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- MHOVAHRLVXNVSD-UHFFFAOYSA-N rhodium atom Chemical compound [Rh] MHOVAHRLVXNVSD-UHFFFAOYSA-N 0.000 description 1
- 150000003467 sulfuric acid derivatives Chemical class 0.000 description 1
- 229910002001 transition metal nitrate Inorganic materials 0.000 description 1
- 239000010457 zeolite Substances 0.000 description 1
Landscapes
- Catalysts (AREA)
- Exhaust Gas Treatment By Means Of Catalyst (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本発明は排気ガスの浄化方法に関
し、詳しくは、排気ガス中に含まれる一酸化炭素（Ｃ
Ｏ）や炭化水素（ＨＣ）を酸化するのに必要な量より過
剰な酸素が含まれている排気ガス中の、窒素酸化物（Ｎ
Ｏｘ）を効率よく浄化する方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for purifying exhaust gas, and more particularly to a method for purifying carbon monoxide (C) contained in exhaust gas.
O) and nitrogen oxides (N) in exhaust gas containing oxygen in excess of that required to oxidize hydrocarbons (HC).
A method for efficiently purifying Ox).
【０００２】[0002]
【従来の技術】従来より、自動車の排気ガス浄化用触媒
として、ＣＯ及びＨＣの酸化とＮＯｘの還元とを同時に
行って排気ガスを浄化する三元触媒が用いられている。
このような触媒としては、例えばコージェライトなどの
耐熱性担体にγ−アルミナからなる担持層を形成し、そ
の担持層にＰｔ，Ｐｄ，Ｒｈなどの貴金属触媒を担持さ
せたものが広く知られている。2. Description of the Related Art Conventionally, a three-way catalyst for purifying exhaust gas by simultaneously oxidizing CO and HC and reducing NOx has been used as an exhaust gas purifying catalyst for automobiles.
As such a catalyst, for example, a catalyst in which a support layer made of γ-alumina is formed on a heat-resistant carrier such as cordierite and a noble metal catalyst such as Pt, Pd, and Rh is supported on the support layer is widely known. I have.
【０００３】ところで、このような排気ガス浄化用触媒
の浄化性能は、エンジンの空燃比（Ａ／Ｆ）によって大
きく異なる。すなわち、空燃比の大きい、つまり燃料濃
度が希薄なリーン側では排気ガス中の酸素量が多くな
り、ＣＯやＨＣを浄化する酸化反応が活発である反面Ｎ
Ｏｘを浄化する還元反応が不活発になる。逆に空燃比の
小さい、つまり燃料濃度が濃いリッチ側では排気ガス中
の酸素量が少なくなり、酸化反応は不活発となるが還元
反応は活発になる。[0003] The purifying performance of such an exhaust gas purifying catalyst greatly varies depending on the air-fuel ratio (A / F) of the engine. That is, on the lean side where the air-fuel ratio is large, that is, on the lean side where the fuel concentration is lean, the amount of oxygen in the exhaust gas increases, and the oxidation reaction for purifying CO and HC is active, but N
The reduction reaction for purifying Ox becomes inactive. Conversely, on the rich side where the air-fuel ratio is low, that is, on the rich side where the fuel concentration is high, the amount of oxygen in the exhaust gas decreases, and the oxidation reaction becomes inactive but the reduction reaction becomes active.
【０００４】一方、自動車の走行において、市街地走行
の場合には発進・停止が頻繁に行われ、空燃比はストイ
キ（理論空燃比）近傍からリッチ状態までの範囲内で頻
繁に変化する。このような走行における低燃費化の要請
に応えるには、なるべく酸素過剰の混合気を供給するリ
ーン側での運転が必要となる。したがってリーン側にお
いてもＮＯｘを十分に浄化できる触媒の開発が望まれて
いる。[0004] On the other hand, in the case of traveling in an urban area, the vehicle frequently starts and stops, and the air-fuel ratio frequently changes within a range from near stoichiometric (stoichiometric air-fuel ratio) to a rich state. In order to meet the demand for fuel economy in such traveling, it is necessary to operate on the lean side, which supplies an air-fuel mixture as much as possible. Therefore, development of a catalyst that can sufficiently purify NOx on the lean side is also desired.
【０００５】そこで本願出願人は、Ｂａに代表されるア
ルカリ土類金属とＰｔを担持した触媒（特願平4-130904
号）、Ｌａに代表される希土類酸化物とＰｔを担持した
触媒（特願平3-344781号）あるいはカリウムとＰｔを担
持した触媒（特願平4-184892号）を開示している。これ
らの触媒によれば、ＮＯｘはリーン側での運転時にアル
カリ土類金属などに吸着し、それがストイキ又はリッチ
側での運転となった時にＨＣなどの還元性ガスと反応し
て浄化されるため、リーン側においてもＮＯｘの浄化性
能に優れている。Therefore, the applicant of the present application has proposed a catalyst supporting an alkaline earth metal represented by Ba and Pt (Japanese Patent Application No. 4-130904).
), A catalyst supporting rare earth oxides represented by La and Pt (Japanese Patent Application No. 3-344781) or a catalyst supporting potassium and Pt (Japanese Patent Application No. 4-184892). According to these catalysts, NOx is adsorbed on alkaline earth metals or the like during operation on the lean side, and is purified by reacting with a reducing gas such as HC when operating on the stoichiometric or rich side. Therefore, the NOx purification performance is also excellent on the lean side.
【０００６】このようになる理由は、例えば特願平4-13
0904号に開示された触媒では、Ｂａが単独酸化物として
担体に担持され、それがＮＯｘと反応して硝酸バリウム
（Ｂａ（ＮＯ3 ）2 ）を生成することでＮＯｘを吸着す
るためと考えられている。The reason for this is described in, for example, Japanese Patent Application
In the catalyst disclosed in No. 0904, Ba is supported on the carrier as a single oxide, which reacts with NOx to generate barium nitrate (Ba (NO 3 ) 2 ), thereby adsorbing NOx. ing.
【０００７】[0007]
【発明が解決しようとする課題】ところが排気ガス中に
は、燃料中に含まれる硫黄（Ｓ）が燃焼して生成したＳ
Ｏ2 が含まれ、それが酸素過剰雰囲気中で触媒金属によ
りさらに酸化されてＳＯ 3 となる。そしてそれがやはり
排気ガス中に含まれる水蒸気により容易に硫酸となり、
これらの硫酸イオンや亜硫酸イオンが希土類金属、アル
カリ土類金属あるいはカリウムと反応してＮＯｘ吸着能
をもたない亜硫酸塩や硫酸塩を生成するため、ＮＯｘ浄
化性能の高温耐久性が充分でないという不具合があっ
た。However, in the exhaust gas,
Represents sulfur generated by combustion of sulfur (S) contained in fuel.
OTwoContained in the catalyst metal in an oxygen-rich atmosphere.
Further oxidized to SO ThreeBecomes And that is still
It becomes sulfuric acid easily due to the water vapor contained in the exhaust gas,
These sulfate ions and sulfite ions are rare earth metals,
NOx adsorption capacity by reacting with potassium earth metal or potassium
NOx purification to generate sulfites and sulfates
There is a problem that the high temperature durability of
Was.
【０００８】本発明はこのような事情に鑑みてなされた
ものであり、ＮＯｘの浄化性能の高温耐久性を向上させ
ることを目的とする。The present invention has been made in view of such circumstances, and has as its object to improve the high-temperature durability of NOx purification performance.
【０００９】[0009]
【課題を解決するための手段】上記課題を解決する本発
明の排気ガス浄化方法は、希薄燃焼エンジンから排出さ
れた酸素過剰雰囲気下における硫黄酸化物を含んだ排気
ガス中の一酸化炭素、炭化水素及び窒素酸化物を同時に
浄化して排ガスを浄化する方法であって、酸素過剰の排
気ガスと接触する排気ガス浄化用触媒に担持された金属
に特色を有する。Exhaust gas purification method of the present invention to solve the above object, according to an aspect of the exhaust of the lean burn engine
A method for purifying exhaust gas by simultaneously purifying carbon monoxide, hydrocarbons and nitrogen oxides in an exhaust gas containing sulfur oxides in an oxygen-excess atmosphere, wherein the exhaust gas contacts an oxygen-excess exhaust gas. The metal carried on the gas purification catalyst has a characteristic.
【００１０】先ず、本発明に用いられる排気ガス浄化用
触媒には、Ｐｔ（白金）及びＰｄ（パラジウム）の少な
くとも一種が担持されている。これに加えてロジウム
（Ｒｈ）を担持させることも好ましい。この触媒金属の
担持量は、単独であれば0.1 〜10g/リットル、併用であ
れば合計で0.1 〜10g/リットルとするのが好ましい。特
に望ましい範囲は0.5 〜３．０ｇ／リットルである。First, the exhaust gas purifying catalyst used in the present invention carries at least one of Pt (platinum) and Pd (palladium). In addition, it is also preferable to support rhodium (Rh). The amount of the supported catalyst metal is preferably 0.1 to 10 g / l when used alone, and 0.1 to 10 g / l when used together. A particularly desirable range is from 0.5 to 3.0 g / l.
【００１１】本発明の第１発明に用いられる排気ガス浄
化用触媒には、上記触媒金属に加えてＬａ，Ｐｒ，Ｎｄ
及びＳｍの中から選ばれる少なくとも２種の金属が担持
されていることを特徴としている。この希土類金属の担
持量は、２種類の合計で０．０５〜２．０mol/リットル
が適当である。これより少ないとＮＯｘの浄化性能の高
温耐久性が低下し、多過ぎても効果が飽和するとともに
担体の表面積が低下するため好ましくない。The exhaust gas purifying catalyst used in the first invention of the present invention includes La, Pr, Nd in addition to the above-mentioned catalyst metal.
And at least two metals selected from Sm and Sm are supported. The amount of the rare earth metal to be carried is suitably 0.05 to 2.0 mol / liter in total of the two types. If the amount is less than this, the high-temperature durability of the NOx purification performance decreases, and if the amount is too large, the effect is saturated and the surface area of the carrier decreases, which is not preferable.
【００１２】[0012]
【００１３】本発明の第２発明に用いられる排気ガス浄
化用触媒には、上記触媒金属に加えてＫ及びＬｉが担持
されている。Ｋ及びＬｉの担持量は、２種類の合計で
０．０５〜２．０mol/リットルが適当である。これより
少ないとＮＯｘの浄化性能の高温耐久性が低下し、多過
ぎても効果が飽和するとともに担体の表面積が低下する
ため好ましくない。The exhaust gas purifying catalyst used in the second invention of the present invention carries K and Li in addition to the above-mentioned catalyst metal. The amount of K and Li carried is suitably 0.05 to 2.0 mol / liter in total of the two types. If the amount is less than this, the high-temperature durability of the NOx purification performance decreases, and if the amount is too large, the effect is saturated and the surface area of the carrier decreases, which is not preferable.
【００１４】本発明の第３発明に用いられる排気ガス浄
化用触媒には、上記触媒金属に加えてアルカリ金属の中
から選ばれる少なくとも１種の金属と、希土類金属の中
から選ばれる少なくとも１種の金属が担持されている。
アルカリ金属としてはＫ，Ｌｉ，Ｎａ，Ｒｂ，Ｃｓなど
が用いられる。また希土類金属としてはＬａ，Ｐｒ，Ｎ
ｄ，Ｓｍなどのランタノイドが特に好ましい。アルカリ
金属の担持量は０．０５〜１．０mol/リットルが適当で
あり、希土類金属の担持量は０．０５〜１．０mol/リッ
トルが適当であって、両者の合計量は０．１〜２．０mo
l/リットルの範囲が好ましい。これより少ないとＮＯｘ
の浄化性能の高温耐久性が低下し、多過ぎても効果が飽
和するとともに担体の表面積が低下するため好ましくな
い。The exhaust gas purifying catalyst used in the third invention of the present invention includes at least one metal selected from alkali metals and at least one metal selected from rare earth metals in addition to the above catalyst metals. Is carried.
As the alkali metal, K, Li, Na, Rb, Cs or the like is used. La, Pr, N are rare earth metals.
Lanthanoids such as d and Sm are particularly preferred. The supporting amount of the alkali metal is suitably 0.05 to 1.0 mol / l, the supporting amount of the rare earth metal is suitably 0.05 to 1.0 mol / l, and the total amount of both is 0.1 to 1.0 mol / l. 2.0mo
A range of l / liter is preferred. If less than this, NOx
The high-temperature durability of the purification performance decreases, and if the amount is too large, the effect is saturated and the surface area of the carrier decreases, which is not preferable.
【００１５】本発明の第４発明に用いられる排気ガス浄
化用触媒には、上記触媒金属に加えてアルカリ金属の中
から選ばれる少なくとも１種の金属と、Ｆｅ，Ｎｉ，Ｃ
ｏ，Ｍｎの遷移金属の中から選ばれる少なくとも１種の
金属が担持されている。アルカリ金属としてはＫ，Ｌ
ｉ，Ｎａ，Ｒｂ，Ｃｓなどが用いられる。アルカリ金属
の担持量は０．０５〜１．０mol/リットルが適当であ
り、遷移金属の担持量は０．０５〜１．０mol/リットル
が適当であって、両者の合計量は０．１〜２．０mol/リ
ットルの範囲が好ましい。これより少ないとＮＯx の浄
化性能の高温耐久性が低下し、多過ぎても効果が飽和す
るとともに担体の表面積が低下するため好ましくない。[0015] The exhaust gas purifying catalyst used in the fourth invention of the present invention includes at least one metal selected from alkali metals in addition to the above-mentioned catalyst metals, Fe, Ni, C
At least one metal selected from transition metals of o and Mn is supported. K, L as alkali metal
i, Na, Rb, Cs and the like are used. The supporting amount of the alkali metal is suitably 0.05 to 1.0 mol / liter, and the supporting amount of the transition metal is suitably 0.05 to 1.0 mol / liter, and the total amount of both is 0.1 to 1.0 mol / l. A range of 2.0 mol / liter is preferred. If the amount is less than this, the high-temperature durability of the NO x purification performance decreases, and if the amount is too large, the effect is saturated and the surface area of the carrier decreases, which is not preferable.
【００１６】なお、多孔質体としては、アルミナ、ゼオ
ライト、ジルコニア、シリカアルミナ、シリカなどが例
示される。これらの多孔質体自体から担体を形成しても
よいし、コージェライト、耐熱金属などから形成された
ハニカム体にコートして用いてもよい。The porous material is exemplified by alumina, zeolite, zirconia, silica alumina, silica and the like. The carrier may be formed from the porous body itself, or may be used by coating a honeycomb body formed of cordierite, a heat-resistant metal, or the like.
【００１７】[0017]
【作用】第１発明では、担体にＬａ，Ｐｒ，Ｎｄ及びＳ
ｍの中から選ばれる少なくとも２種の希土類金属が複合
担持されている。この少なくとも２種の希土類金属は、
排気ガス中に含まれるＳＯ2 を触媒中に複合硫酸塩とし
て取り込む。According to the first invention, La, Pr, Nd and S are added to the carrier.
and at least two kinds of rare earth metals selected from m . The at least two rare earth metals are
SO 2 contained in the exhaust gas is taken into the catalyst as complex sulfate.
【００１８】第２発明では、担体にＫ及びＬｉが複合担
持されている。これにより排気ガス中に含まれるＳＯ2
は触媒中に複合硫酸塩として取り込まれる。第３発明で
は、担体にアルカリ金属の少なくとも１種と希土類金属
の少なくとも１種が複合担持されている。これらの金属
は、排気ガス中に含まれるＳＯ2 を触媒中に複合硫酸塩
として取り込む。In the second invention , K and Li are compositely supported on the carrier. As a result, the SO 2 contained in the exhaust gas
Is incorporated as a complex sulfate in the catalyst. In the third invention , at least one kind of an alkali metal and at least one kind of a rare earth metal are compositely supported on a carrier. These metals, captures the SO 2 contained in the exhaust gas as a complex sulfate in the catalyst.
【００１９】第４発明では、担体にアルカリ金属の少な
くとも１種とＦｅ，Ｎｉ，Ｃｏ，Ｍｎの少なくとも１種
が複合担持されている。これらの金属は、排気ガス中に
含まれるＳＯ2 を触媒中に複合硫酸塩として取り込む。
このようにして生成した複合硫酸塩は、単独の金属によ
って生成する硫酸塩に比べてストイキ〜リッチ雰囲気で
低温度で分解しやすいため、希土類金属又はアルカリ金
属のＮＯｘ吸蔵効果を再度発現させることができる。In the fourth invention , at least one kind of alkali metal and at least one kind of Fe, Ni, Co, Mn are compositely supported on the carrier. These metals, captures the SO 2 contained in the exhaust gas as a complex sulfate in the catalyst.
Since the composite sulfate thus generated is easily decomposed at a low temperature in a stoichiometric to rich atmosphere as compared with a sulfate generated by a single metal, the NOx occlusion effect of a rare earth metal or an alkali metal can be exhibited again. it can.
【００２０】そして、リーン雰囲気時に排気ガス浄化用
触媒に吸着（吸蔵）されたＮＯｘは、ストイキ〜リッチ
雰囲気時に排気ガス中のＣＯ，ＨＣなどと反応してＮ2
に還元浄化され、このときＣＯ，ＨＣなども酸化浄化さ
れる。このような機構により、ＮＯｘ吸着能が長時間維
持され、高活性が維持されるものと考えられる。さら
に、２種以上の金属を複合担持することにより、希土類
金属やアルカリ金属の粒子径が細かくなり、かつ硫酸塩
としての結晶成長がないので、耐久後でもＰｔやＰｄと
ともに高分散状態を維持できることも高活性を維持でき
る理由の一つと推察される。The NOx adsorbed (occluded) by the exhaust gas purifying catalyst in the lean atmosphere reacts with CO, HC and the like in the exhaust gas in the stoichiometric to rich atmosphere to form N 2.
And CO and HC are also oxidized and purified. It is considered that the NOx adsorption ability is maintained for a long time by such a mechanism, and high activity is maintained. Furthermore, by carrying two or more metals in combination, the particle diameter of the rare earth metal or alkali metal becomes small and there is no crystal growth as sulfate, so that a high dispersion state can be maintained together with Pt and Pd even after durability. Is considered to be one of the reasons for maintaining high activity.
【００２１】[0021]
【実施例】以下、実施例により具体的に説明する。な
お、以下の例において「部」は特にことわらない限り
「重量部」を示す。 （第１実施例） ＜触媒の調製＞アルミナ粉末１００部と、アルミナゾル
（アルミナ含有率１０ｗｔ％）７０部と、４０ｗｔ％硝
酸アルミニウム水溶液１５部及び水３０部を混合し、コ
ーティング用スラリーを調製した。The present invention will be specifically described below with reference to examples. In the following examples, “parts” means “parts by weight” unless otherwise specified. (First Example) <Preparation of Catalyst> 100 parts of alumina powder, 70 parts of alumina sol (alumina content: 10 wt%), 15 parts of 40 wt% aluminum nitrate aqueous solution and 30 parts of water were mixed to prepare a slurry for coating. .
【００２２】そのスラリーにコージェライト質ハニカム
担体を浸漬後余分なスラリーを吹き払い、乾燥後６００
℃で１時間焼成してアルミナコート層を形成した。コー
ト量はハニカム担体の体積１リットル当たり１２０ｇで
ある。このアルミナコート層をもつハニカム担体をジニ
トロジアンミン白金水溶液又は硝酸パラジウム水溶液に
浸漬し、余分な水滴を吹き払った後２５０℃で乾燥して
Ｐｔ又はＰｄを担持させた。Ｐｔ又はＰｄの担持量は表
１に示すとおりである。After the cordierite-type honeycomb carrier is immersed in the slurry, excess slurry is blown off and dried, and then dried.
Calcination was carried out at 1 ° C. for 1 hour to form an alumina coat layer. The coating amount is 120 g per liter of the volume of the honeycomb carrier. The honeycomb carrier having the alumina coat layer was immersed in an aqueous solution of dinitrodiammine platinum or an aqueous solution of palladium nitrate, and after blowing off excess water droplets, dried at 250 ° C. to carry Pt or Pd. The supported amount of Pt or Pd is as shown in Table 1.
【００２３】次に、表１に示す担持量となるように調製
された所定濃度の希土類元素硝酸塩の混合水溶液に上記
Ｐｔ又はＰｄ担持ハニカム担体を浸漬し、余分な水滴を
吹き払って乾燥後６００℃で１時間焼成して、Ｎｏ．１
〜９の触媒を調製した。 （比較例１） さらに比較触媒として、表１に示すように１種類の希土
類金属のみを担持させたこと以外は上記と同様にしてＮ
ｏ．１０〜１７の触媒を調製した。 ＜浄化性能の評価＞ 希薄燃焼エンジン（１．６リットル）搭載車両の排気通
路に上記それぞれの触媒を設置し、市街地走行モード
（１０・１５モード）で走行してＣＯ，ＨＣ及びＮＯｘ
の浄化率を測定した。Next, the Pt or Pd-supported honeycomb carrier is immersed in a mixed aqueous solution of a rare earth element nitrate having a predetermined concentration prepared so as to have a supported amount shown in Table 1, and excess water droplets are blown off and dried. C. for 1 hour. 1
~ 9 catalysts were prepared. (Comparative Example 1) Further, as shown in Table 1, as a comparative catalyst, only one kind of rare earth metal was supported.
o. 10-17 catalysts were prepared. <Evaluation of Purification Performance> Each of the above catalysts was installed in an exhaust passage of a vehicle equipped with a lean burn engine (1.6 liter), and the CO, HC, and NOx were driven in a city driving mode (10/15 mode).
Was measured.
【００２４】次に同じ型式のエンジンの排気系にその触
媒を装着し、エンジンベンチにて触媒入りガス温度６５
０℃で１００時間運転する耐久試験を行い、その後上記
と同じ条件でＣＯ，ＨＣ及びＮＯｘの浄化率を測定し耐
久後の浄化率とした。それぞれの結果を表１に示す。Next, the catalyst is mounted on the exhaust system of the same type of engine, and the temperature of the gas containing the catalyst is set at 65 ° C on the engine bench.
A durability test was performed at 0 ° C. for 100 hours, and then the purification rates of CO, HC, and NOx were measured under the same conditions as above, and the result was used as the purification rate after durability. Table 1 shows the results.
【００２５】[0025]
【表１】 [Table 1]
【００２６】＜評価＞ 表１より、希土類金属を２種類担持した触媒を用いるこ
とにより、単一の希土類金属を担持した触媒の場合に比
べて、耐久後のＮＯｘの浄化率が向上していることがわ
かる。 （実施例２・参考例１） 実施例１と同様のアルミナコート層をもつハニカム担体
をジニトロジアンミン白金水溶液又は硝酸パラジウム水
溶液に浸漬し、余分な水滴を吹き払った後２５０℃で乾
燥してＰｔ又はＰｄを担持させた。Ｐｔ又はＰｄの担持
量は表２に示すとおりである。<Evaluation> From Table 1, it was found that a catalyst supporting two kinds of rare earth metals was used.
Thus, it can be seen that the NOx purification rate after the durability is improved as compared with the case of a catalyst supporting a single rare earth metal. ( Example 2 and Reference Example 1 ) A honeycomb carrier having the same alumina coat layer as in Example 1 was immersed in an aqueous dinitrodiammineplatinum solution or an aqueous palladium nitrate solution. Alternatively, Pd was carried. The supported amount of Pt or Pd is as shown in Table 2.
【００２７】次に、表２に示す担持量となるように調製
された所定濃度のアルカリ金属硝酸塩の混合水溶液に上
記Ｐｔ又はＰｄ担持ハニカム担体を浸漬し、余分な水滴
を吹き払って乾燥後６００℃で１時間焼成して、Ｎｏ．
１８〜２９の触媒を調製した。 （実施例３） また、表３に示す担持量となるように調製された所定濃
度のアルカリ金属硝酸塩と希土類元素硝酸塩の混合水溶
液に上記Ｐｔ担持ハニカム担体を浸漬し、余分な水滴を
吹き払って乾燥後６００℃で１時間焼成して、Ｎｏ．３
９〜５２の触媒を調製した。 （実施例４） さらに、表４に示す担持量となるように調製された所定
濃度のアルカリ金属硝酸塩と遷移金属硝酸塩の混合水溶
液に上記Ｐｔ担持ハニカム担体を浸漬し、余分な水滴を
吹き払って乾燥後６００℃で１時間焼成して、Ｎｏ．５
３〜６４の触媒を調製した。 （比較例２） そして比較触媒として、表２に示すように１種類のアル
カリ金属のみを担持させたこと以外は上記と同様にして
Ｎｏ．３０〜３８の触媒を調製した。 ＜浄化性能の評価＞ 希薄燃焼エンジン（１．６リットル）搭載車両の排気通
路に上記それぞれの触媒を設置し、市街地走行モード
（１０・１５モード）で走行してＣＯ，ＨＣ及びＮＯｘ
の浄化率を測定した。Next, the above-mentioned Pt or Pd-supported honeycomb carrier was immersed in a mixed aqueous solution of alkali metal nitrate having a predetermined concentration prepared so as to have the supported amount shown in Table 2, and excess water droplets were blown off and dried. C. for 1 hour.
18-29 catalysts were prepared. ( Example 3 ) Further, the Pt-supported honeycomb carrier was immersed in a mixed aqueous solution of an alkali metal nitrate and a rare earth element nitrate having a predetermined concentration prepared so as to have a supported amount shown in Table 3, and excess water droplets were blown off. After drying, baking at 600 ° C. for 1 hour. 3
9-52 catalysts were prepared. ( Example 4 ) Further, the above-mentioned Pt-supported honeycomb carrier was immersed in a mixed aqueous solution of alkali metal nitrate and transition metal nitrate at a predetermined concentration prepared so as to have a supported amount shown in Table 4 , and excess water droplets were blown off. After drying, baking at 600 ° C. for 1 hour. 5
3 to 64 catalysts were prepared. (Comparative Example 2) As a comparative catalyst, as shown in Table 2, except that only one kind of alkali metal was supported, No. 30-38 catalysts were prepared. <Evaluation of Purification Performance> Each of the above catalysts was installed in the exhaust passage of a vehicle equipped with a lean burn engine (1.6 liter), and the CO, HC, and NOx were driven in a city driving mode (10/15 mode).
Was measured.
【００２８】次に同じ型式のエンジンの排気系にその触
媒を装着し、エンジンベンチにて触媒入りガス温度６５
０℃で１００時間運転する耐久試験を行い、その後上記
と同じ条件でＣＯ，ＨＣ及びＮＯｘの浄化率を測定し耐
久後の浄化率とした。それぞれの結果を表２〜表４に示
す。Next, the catalyst is mounted on the exhaust system of the same type of engine, and the temperature of the gas containing the catalyst is set at 65 ° C on the engine bench.
A durability test was performed at 0 ° C. for 100 hours, and then the purification rates of CO, HC, and NOx were measured under the same conditions as above, and the result was used as the purification rate after durability. Tables 2 to 4 show the results.
【００２９】[0029]
【表２】 [Table 2]
【００３０】[0030]
【表３】 [Table 3]
【表４】 [Table 4]
【００３１】＜評価＞ 表２〜表４より、アルカリ金属を２種類担持した触媒、
アルカリ金属と希土類金属の両方を担持した触媒、ある
いはアルカリ金属と遷移金属の両方を担持した触媒を用
いることにより、単一のアルカリ金属を担持した触媒の
場合に比べて、耐久後のＮＯｘの浄化率が向上している
ことがわかる。<Evaluation> As shown in Tables 2 to 4 , a catalyst supporting two kinds of alkali metals was obtained.
By using a catalyst that supports both alkali metals and rare earth metals, or a catalyst that supports both alkali metals and transition metals, the purification of NOx after endurance compared to a catalyst that supports a single alkali metal It can be seen that the rate has improved.
【００３２】[0032]
【発明の効果】すなわち本発明の排気ガス浄化方法によ
れば、用いられる触媒は耐久試験後にも良好なＮＯｘ浄
化性能を示し、酸素過剰のリーン側で安定して効率よく
ＮＯｘを浄化することができる。According to the exhaust gas purifying method of the present invention, the catalyst used exhibits good NOx purifying performance even after the durability test, and can stably and efficiently purify NOx on the lean side with excess oxygen. it can.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 三好 直人 愛知県豊田市トヨタ町１番地 トヨタ自 動車株式会社内 (72)発明者 松本 伸一 愛知県豊田市トヨタ町１番地 トヨタ自 動車株式会社内 (72)発明者 林 高弘 愛知県豊田市トヨタ町１番地 トヨタ自 動車株式会社内 (72)発明者 谷沢 恒幸 愛知県豊田市トヨタ町１番地 トヨタ自 動車株式会社内 (72)発明者 井口 哲 愛知県豊田市トヨタ町１番地 トヨタ自 動車株式会社内 (72)発明者 田中 俊明 愛知県豊田市トヨタ町１番地 トヨタ自 動車株式会社内 (72)発明者 竹島 伸一 愛知県豊田市トヨタ町１番地 トヨタ自 動車株式会社内 (72)発明者 山崎 清 愛知県愛知郡長久手町大字長湫字横道41 番地の１ 株式会社豊田中央研究所内 (72)発明者 斎木 基久 愛知県愛知郡長久手町大字長湫字横道41 番地の１ 株式会社豊田中央研究所内 (72)発明者 鈴木 正 愛知県愛知郡長久手町大字長湫字横道41 番地の１ 株式会社豊田中央研究所内 (72)発明者 笠原 光一 静岡県小笠郡大東町千浜7800番地 キャ タラー工業株式会社内 (72)発明者 立石 修士 静岡県小笠郡大東町千浜7800番地 キャ タラー工業株式会社内 審査官 繁田 えい子 (56)参考文献 特開 平５−317722（ＪＰ，Ａ) 特開 平６−182213（ＪＰ，Ａ) 特開 昭63−162043（ＪＰ，Ａ) 特開 平４−219149（ＪＰ，Ａ) 特開 平４−367724（ＪＰ，Ａ) 特開 昭59−142849（ＪＰ，Ａ) 特開 平７−8755（ＪＰ，Ａ) 特表 平４−501084（ＪＰ，Ａ) 米国特許4497783（ＵＳ，Ａ) (58)調査した分野(Int.Cl.7，ＤＢ名) B01D 53/86 B01J 21/00 - 37/36 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Naoto Miyoshi 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (72) Inventor Shinichi Matsumoto 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation ( 72) Inventor Takahiro Hayashi 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation (72) Inventor Tsuneyuki Tanizawa 1 Toyota Town Toyota City, Aichi Prefecture Toyota Motor Corporation (72) Inventor Tetsu Iguchi Aichi Prefecture 1 Toyota Town, Toyota City Toyota Motor Corporation (72) Inventor Toshiaki Tanaka 1 Toyota Town Toyota City, Aichi Prefecture Toyota Motor Corporation (72) Inventor Shinichi Takeshima 1 Toyota Town Toyota City, Aichi Prefecture Toyota Motor (72) Inventor Kiyoshi Yamazaki, 41, 41, Yokomichi, Chukuji, Nagakute-cho, Aichi-gun, Aichi Prefecture (72) Inventor: Motohisa Saiki 41, Yokomichi, Nagakute-cho, Aichi-gun, Aichi-gun, Aichi Pref. 41 No. 1, Yokomichi Inside Toyota Central Research Laboratory Co., Ltd. (72) Inventor Koichi Kasahara 7800 Chitohama, Oto-cho, Ogasa-gun, Shizuoka Pref. Address: Eiko Shigeta, Examiner in Cataler Industry Co., Ltd. (56) References JP-A-5-317722 (JP, A) JP-A-6-182213 (JP, A) JP-A-63-162043 (JP, A) Japanese Unexamined Patent Publication No. Hei 4-219149 (JP, A) Japanese Unexamined Patent Publication No. Hei 4-367724 (JP, A) Japanese Unexamined Patent Publication No. Sho 59-142849 (JP, A) Japanese Unexamined Patent Publication No. Hei 7-8755 (JP, A) JP, A) U.S. Pat. No. 4,449,773 (US, A) (58) Fields investigated (Int. Cl. 7 , DB name) B01D 53/86 B01J 21/00-37/36
Claims (4)
剰雰囲気下における硫黄酸化物を含んだ排気ガス中の一
酸化炭素、炭化水素及び窒素酸化物を同時に浄化して排
気ガスを浄化する方法であって、Ｌａ，Ｐｒ，Ｎｄ及びＳｍの 中から選ばれる少なくとも
２種の金属と、Ｐｔ及びＰｄの少なくとも一種と、を多
孔質体からなる担体に担持してなる排気ガス浄化用触媒
と該硫黄酸化物を含んだ酸素過剰の排気ガスを接触さ
せ、少なくとも２種の希土類金属を含む複合硫酸塩を生
じさせることを特徴とする排気ガス浄化方法。1. A method for purifying exhaust gas by simultaneously purifying carbon monoxide, hydrocarbons and nitrogen oxides in exhaust gas containing sulfur oxides in an oxygen-excess atmosphere discharged from a lean burn engine. An exhaust gas purification catalyst comprising at least two metals selected from La, Pr, Nd and Sm and at least one of Pt and Pd supported on a porous carrier; A method for purifying exhaust gas, which comprises contacting an oxygen-excess exhaust gas containing substances to generate a composite sulfate containing at least two kinds of rare earth metals.
剰雰囲気下における硫黄酸化物を含んだ排気ガス中の一
酸化炭素、炭化水素及び窒素酸化物を同時に浄化して排
気ガスを浄化する方法であって、 Ｋ及びＬｉと、Ｐｔ及びＰｄの少なくとも一種と、を多
孔質体からなる担体に担持してなる排気ガス浄化用触媒
と該硫黄酸化物を含んだ酸素過剰の排気ガスを接触さ
せ、Ｋ及びＬｉを含む複合硫酸塩を生じさせることを特
徴とする排気ガス浄化方法。2. A method for purifying exhaust gas by simultaneously purifying carbon monoxide, hydrocarbons and nitrogen oxides in exhaust gas containing sulfur oxides in an oxygen-excess atmosphere discharged from a lean burn engine. Contacting an exhaust gas-purifying catalyst comprising K and Li and at least one of Pt and Pd supported on a porous carrier with an oxygen-excess exhaust gas containing the sulfur oxide; An exhaust gas purification method comprising producing a composite sulfate containing Li and Li.
剰雰囲気下における硫黄酸化物を含んだ排気ガス中の一
酸化炭素、炭化水素及び窒素酸化物を同時に浄化して排
気ガスを浄化する方法であって、 アルカリ金属の中から選ばれる少なくとも１種の金属
と、希土類金属の中から選ばれる少なくとも１種の金属
と、Ｐｔ及びＰｄの少なくとも一種と、を多孔質体から
なる担体に担持してなる排気ガス浄化用触媒と該硫黄酸
化物を含んだ酸素過剰の排気ガスを接触させ、アルカリ
金属の少なくとも１種と希土類金属の少なくとも一種と
を含む複合硫酸塩を生じさせることを特徴とする排気ガ
ス浄化方法。3. A method for purifying exhaust gas by simultaneously purifying carbon monoxide, hydrocarbons and nitrogen oxides in an exhaust gas containing sulfur oxides in an oxygen-excess atmosphere discharged from a lean burn engine. And at least one metal selected from alkali metals, at least one metal selected from rare earth metals, and at least one of Pt and Pd supported on a porous carrier. An exhaust gas comprising contacting an exhaust gas purifying catalyst with an exhaust gas containing an excessive amount of oxygen containing the sulfur oxide to form a composite sulfate containing at least one kind of alkali metal and at least one kind of rare earth metal. Purification method.
剰雰囲気下における硫黄酸化物を含んだ排気ガス中の一
酸化炭素、炭化水素及び窒素酸化物を同時に浄化して排
気ガスを浄化する方法であって、 アルカリ金属の中から選ばれる少なくとも１種の金属
と、Ｆｅ，Ｎｉ，Ｃｏ，Ｍｎの中から選ばれる少なくと
も１種の金属と、Ｐｔ及びＰｄの少なくとも一種と、を
多孔質体からなる担体に担持してなる排気ガス浄化用触
媒と該硫黄酸化物を含んだ酸素過剰の排気ガスを接触さ
せ、アルカリ金属の少なくとも１種とＦｅ，Ｎｉ，Ｃ
ｏ，Ｍｎの中から選ばれる少なくとも１種の金属とを含
む複合硫酸塩を生じさせることを特徴とする排気ガス浄
化方法。4. A method for purifying exhaust gas by simultaneously purifying carbon monoxide, hydrocarbons and nitrogen oxides in an exhaust gas containing sulfur oxides in an oxygen-excess atmosphere discharged from a lean burn engine. A carrier comprising at least one metal selected from alkali metals, at least one metal selected from Fe, Ni, Co, and Mn, and at least one of Pt and Pd, comprising a porous body The exhaust gas purifying catalyst supported on the catalyst is brought into contact with an oxygen-excess exhaust gas containing the sulfur oxide, and at least one of alkali metals and Fe, Ni, C
An exhaust gas purification method comprising producing a composite sulfate containing at least one metal selected from o and Mn.
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23846193A JP3320855B2 (en) | 1993-01-11 | 1993-09-24 | Exhaust gas purification method |
| EP94100256A EP0613714B1 (en) | 1993-01-11 | 1994-01-10 | Process for purifying exhaust gases |
| DE69427602T DE69427602T2 (en) | 1993-01-11 | 1994-01-10 | Exhaust gas purification process |
| US08/544,260 US5911960A (en) | 1993-01-11 | 1995-10-17 | Process for purifying exhaust gases |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5-2491 | 1993-01-11 | ||
| JP249193 | 1993-01-11 | ||
| JP23846193A JP3320855B2 (en) | 1993-01-11 | 1993-09-24 | Exhaust gas purification method |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2002131412A Division JP3723151B2 (en) | 1993-01-11 | 2002-05-07 | Exhaust gas purification method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH06262040A JPH06262040A (en) | 1994-09-20 |
| JP3320855B2 true JP3320855B2 (en) | 2002-09-03 |
Family
ID=26335870
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP23846193A Expired - Lifetime JP3320855B2 (en) | 1993-01-11 | 1993-09-24 | Exhaust gas purification method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3320855B2 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA2212135A1 (en) * | 1995-02-02 | 1996-08-08 | Andrew Hourd | Catalyst |
| KR100408502B1 (en) * | 1996-07-23 | 2004-02-14 | 삼성전기주식회사 | Catalyst for purifying exhaust gas of vehicle |
| JP3952617B2 (en) | 1998-12-11 | 2007-08-01 | 株式会社日立製作所 | Exhaust gas purification device, exhaust gas purification method and exhaust gas purification catalyst for internal combustion engine |
-
1993
- 1993-09-24 JP JP23846193A patent/JP3320855B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH06262040A (en) | 1994-09-20 |
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