JPH11253803A - Exhaust gas cleaning catalyst, its production and its utilization - Google Patents
Exhaust gas cleaning catalyst, its production and its utilizationInfo
- Publication number
- JPH11253803A JPH11253803A JP10056530A JP5653098A JPH11253803A JP H11253803 A JPH11253803 A JP H11253803A JP 10056530 A JP10056530 A JP 10056530A JP 5653098 A JP5653098 A JP 5653098A JP H11253803 A JPH11253803 A JP H11253803A
- Authority
- JP
- Japan
- Prior art keywords
- exhaust gas
- catalyst
- gas purifying
- powder
- purifying catalyst
- 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.)
- Granted
Links
- 239000003054 catalyst Substances 0.000 title claims abstract description 123
- 238000004519 manufacturing process Methods 0.000 title claims description 7
- 238000004140 cleaning Methods 0.000 title abstract 6
- 239000000843 powder Substances 0.000 claims abstract description 56
- 239000002245 particle Substances 0.000 claims abstract description 32
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 claims abstract description 31
- 238000000034 method Methods 0.000 claims abstract description 28
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 claims abstract description 21
- 229910052763 palladium Inorganic materials 0.000 claims abstract description 17
- 229910000510 noble metal Inorganic materials 0.000 claims abstract description 14
- 239000010948 rhodium Substances 0.000 claims abstract description 14
- 229910052703 rhodium Inorganic materials 0.000 claims abstract description 12
- 239000000446 fuel Substances 0.000 claims abstract description 11
- 239000002002 slurry Substances 0.000 claims abstract description 11
- 229910052697 platinum Inorganic materials 0.000 claims abstract description 10
- MHOVAHRLVXNVSD-UHFFFAOYSA-N rhodium atom Chemical compound [Rh] MHOVAHRLVXNVSD-UHFFFAOYSA-N 0.000 claims abstract description 9
- 239000002131 composite material Substances 0.000 claims description 37
- 229910052783 alkali metal Inorganic materials 0.000 claims description 13
- 150000001340 alkali metals Chemical class 0.000 claims description 13
- 229910052784 alkaline earth metal Inorganic materials 0.000 claims description 12
- 150000001342 alkaline earth metals Chemical class 0.000 claims description 12
- 239000007789 gas Substances 0.000 abstract description 64
- 229910052746 lanthanum Inorganic materials 0.000 abstract description 10
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 abstract description 8
- 229910052700 potassium Inorganic materials 0.000 abstract description 7
- 238000010298 pulverizing process Methods 0.000 abstract description 7
- 229910052712 strontium Inorganic materials 0.000 abstract description 7
- 229910052684 Cerium Inorganic materials 0.000 abstract description 6
- 229910052792 caesium Inorganic materials 0.000 abstract description 6
- 229910052791 calcium Inorganic materials 0.000 abstract description 6
- 229910052749 magnesium Inorganic materials 0.000 abstract description 6
- 229910017052 cobalt Inorganic materials 0.000 abstract description 5
- 239000010941 cobalt Substances 0.000 abstract description 5
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 abstract description 5
- 150000001875 compounds Chemical class 0.000 abstract description 5
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 abstract description 4
- 229910052779 Neodymium Inorganic materials 0.000 abstract description 4
- 229910052772 Samarium Inorganic materials 0.000 abstract description 4
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 abstract description 4
- 229910052759 nickel Inorganic materials 0.000 abstract description 4
- 229910052760 oxygen Inorganic materials 0.000 abstract description 4
- 239000001301 oxygen Substances 0.000 abstract description 4
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 abstract description 3
- 230000001747 exhibiting effect Effects 0.000 abstract description 3
- 229910052748 manganese Inorganic materials 0.000 abstract description 3
- 239000011572 manganese Substances 0.000 abstract description 3
- 229910052796 boron Inorganic materials 0.000 abstract description 2
- 229910052742 iron Inorganic materials 0.000 abstract description 2
- MWUXSHHQAYIFBG-UHFFFAOYSA-N nitrogen oxide Inorganic materials O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 description 93
- 230000000694 effects Effects 0.000 description 19
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 17
- 238000000746 purification Methods 0.000 description 15
- 238000010521 absorption reaction Methods 0.000 description 12
- 229910052788 barium Inorganic materials 0.000 description 9
- DSAJWYNOEDNPEQ-UHFFFAOYSA-N barium atom Chemical compound [Ba] DSAJWYNOEDNPEQ-UHFFFAOYSA-N 0.000 description 9
- FZLIPJUXYLNCLC-UHFFFAOYSA-N lanthanum atom Chemical compound [La] FZLIPJUXYLNCLC-UHFFFAOYSA-N 0.000 description 8
- 239000000203 mixture Substances 0.000 description 8
- 238000006243 chemical reaction Methods 0.000 description 6
- KRKNYBCHXYNGOX-UHFFFAOYSA-N citric acid Chemical compound OC(=O)CC(O)(C(O)=O)CC(O)=O KRKNYBCHXYNGOX-UHFFFAOYSA-N 0.000 description 6
- 230000000052 comparative effect Effects 0.000 description 6
- 238000011156 evaluation Methods 0.000 description 6
- 239000007864 aqueous solution Substances 0.000 description 5
- 239000011575 calcium Substances 0.000 description 5
- 230000003197 catalytic effect Effects 0.000 description 5
- ZMIGMASIKSOYAM-UHFFFAOYSA-N cerium Chemical compound [Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce] ZMIGMASIKSOYAM-UHFFFAOYSA-N 0.000 description 5
- 239000011777 magnesium Substances 0.000 description 5
- 239000002994 raw material Substances 0.000 description 5
- CIOAGBVUUVVLOB-UHFFFAOYSA-N strontium atom Chemical compound [Sr] CIOAGBVUUVVLOB-UHFFFAOYSA-N 0.000 description 5
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 5
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 description 4
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 description 4
- 239000000470 constituent Substances 0.000 description 4
- 239000007788 liquid Substances 0.000 description 4
- 239000011591 potassium Substances 0.000 description 4
- -1 rare earth compound Chemical class 0.000 description 4
- QTBSBXVTEAMEQO-UHFFFAOYSA-M Acetate Chemical compound CC([O-])=O QTBSBXVTEAMEQO-UHFFFAOYSA-M 0.000 description 3
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 3
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 3
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 3
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 3
- 229910002651 NO3 Inorganic materials 0.000 description 3
- NHNBFGGVMKEFGY-UHFFFAOYSA-N Nitrate Chemical compound [O-][N+]([O-])=O NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 description 3
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 description 3
- 150000001341 alkaline earth metal compounds Chemical class 0.000 description 3
- TVFDJXOCXUVLDH-UHFFFAOYSA-N caesium atom Chemical compound [Cs] TVFDJXOCXUVLDH-UHFFFAOYSA-N 0.000 description 3
- 238000001354 calcination Methods 0.000 description 3
- 229910002091 carbon monoxide Inorganic materials 0.000 description 3
- 229910052878 cordierite Inorganic materials 0.000 description 3
- 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 3
- 238000005470 impregnation Methods 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- QEFYFXOXNSNQGX-UHFFFAOYSA-N neodymium atom Chemical compound [Nd] QEFYFXOXNSNQGX-UHFFFAOYSA-N 0.000 description 3
- 239000011148 porous material Substances 0.000 description 3
- 239000002244 precipitate Substances 0.000 description 3
- 229910052761 rare earth metal Inorganic materials 0.000 description 3
- KZUNJOHGWZRPMI-UHFFFAOYSA-N samarium atom Chemical compound [Sm] KZUNJOHGWZRPMI-UHFFFAOYSA-N 0.000 description 3
- 229910052708 sodium Inorganic materials 0.000 description 3
- 239000011734 sodium Substances 0.000 description 3
- 238000003746 solid phase reaction Methods 0.000 description 3
- 239000000243 solution Substances 0.000 description 3
- 229910052717 sulfur Inorganic materials 0.000 description 3
- 229910052723 transition metal Inorganic materials 0.000 description 3
- 229910052726 zirconium Inorganic materials 0.000 description 3
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 2
- 206010021143 Hypoxia Diseases 0.000 description 2
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 2
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 2
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 2
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 2
- 239000000654 additive Substances 0.000 description 2
- 150000001339 alkali metal compounds Chemical class 0.000 description 2
- AYJRCSIUFZENHW-UHFFFAOYSA-L barium carbonate Chemical compound [Ba+2].[O-]C([O-])=O AYJRCSIUFZENHW-UHFFFAOYSA-L 0.000 description 2
- 238000009826 distribution Methods 0.000 description 2
- 229910052735 hafnium Inorganic materials 0.000 description 2
- VBJZVLUMGGDVMO-UHFFFAOYSA-N hafnium atom Chemical compound [Hf] VBJZVLUMGGDVMO-UHFFFAOYSA-N 0.000 description 2
- 229930195733 hydrocarbon Natural products 0.000 description 2
- 150000002430 hydrocarbons Chemical class 0.000 description 2
- 239000012535 impurity Substances 0.000 description 2
- 238000005342 ion exchange Methods 0.000 description 2
- 229910052744 lithium Inorganic materials 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- 231100000572 poisoning Toxicity 0.000 description 2
- 230000000607 poisoning effect Effects 0.000 description 2
- 150000002910 rare earth metals Chemical class 0.000 description 2
- 150000003839 salts Chemical class 0.000 description 2
- 238000001179 sorption measurement Methods 0.000 description 2
- 239000011593 sulfur Substances 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 150000003624 transition metals Chemical class 0.000 description 2
- YPFNIPKMNMDDDB-UHFFFAOYSA-K 2-[2-[bis(carboxylatomethyl)amino]ethyl-(2-hydroxyethyl)amino]acetate;iron(3+) Chemical compound [Fe+3].OCCN(CC([O-])=O)CCN(CC([O-])=O)CC([O-])=O YPFNIPKMNMDDDB-UHFFFAOYSA-K 0.000 description 1
- 239000004215 Carbon black (E152) Substances 0.000 description 1
- KRKNYBCHXYNGOX-UHFFFAOYSA-K Citrate Chemical compound [O-]C(=O)CC(O)(CC([O-])=O)C([O-])=O KRKNYBCHXYNGOX-UHFFFAOYSA-K 0.000 description 1
- 229910017569 La2(CO3)3 Inorganic materials 0.000 description 1
- 238000002441 X-ray diffraction Methods 0.000 description 1
- 239000002250 absorbent Substances 0.000 description 1
- 230000002745 absorbent Effects 0.000 description 1
- 150000001242 acetic acid derivatives Chemical class 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 239000012670 alkaline solution Substances 0.000 description 1
- 150000003863 ammonium salts Chemical class 0.000 description 1
- 239000002585 base Substances 0.000 description 1
- 150000004649 carbonic acid derivatives Chemical class 0.000 description 1
- 239000000969 carrier Substances 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- CETPSERCERDGAM-UHFFFAOYSA-N ceric oxide Chemical compound O=[Ce]=O CETPSERCERDGAM-UHFFFAOYSA-N 0.000 description 1
- 229910000422 cerium(IV) oxide Inorganic materials 0.000 description 1
- 238000000975 co-precipitation Methods 0.000 description 1
- 229910021446 cobalt carbonate Inorganic materials 0.000 description 1
- ZOTKGJBKKKVBJZ-UHFFFAOYSA-L cobalt(2+);carbonate Chemical compound [Co+2].[O-]C([O-])=O ZOTKGJBKKKVBJZ-UHFFFAOYSA-L 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 230000002950 deficient Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 238000010304 firing Methods 0.000 description 1
- 150000004820 halides Chemical class 0.000 description 1
- 150000004679 hydroxides Chemical class 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- NZPIUJUFIFZSPW-UHFFFAOYSA-H lanthanum carbonate Chemical compound [La+3].[La+3].[O-]C([O-])=O.[O-]C([O-])=O.[O-]C([O-])=O NZPIUJUFIFZSPW-UHFFFAOYSA-H 0.000 description 1
- 229960001633 lanthanum carbonate Drugs 0.000 description 1
- UEGPKNKPLBYCNK-UHFFFAOYSA-L magnesium acetate Chemical compound [Mg+2].CC([O-])=O.CC([O-])=O UEGPKNKPLBYCNK-UHFFFAOYSA-L 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 150000002823 nitrates Chemical class 0.000 description 1
- 229910017604 nitric acid Inorganic materials 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- GPNDARIEYHPYAY-UHFFFAOYSA-N palladium(ii) nitrate Chemical compound [Pd+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O GPNDARIEYHPYAY-UHFFFAOYSA-N 0.000 description 1
- 239000003208 petroleum Substances 0.000 description 1
- 239000012071 phase Substances 0.000 description 1
- 239000010970 precious metal Substances 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 230000009257 reactivity Effects 0.000 description 1
- 239000011819 refractory material Substances 0.000 description 1
- 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 1
- 238000005245 sintering Methods 0.000 description 1
- 159000000000 sodium salts Chemical class 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 239000007858 starting material Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 238000010792 warming Methods 0.000 description 1
- 238000001238 wet grinding Methods 0.000 description 1
Landscapes
- Exhaust Gas Treatment By Means Of Catalyst (AREA)
- Catalysts (AREA)
- Exhaust Gas After Treatment (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、自動車、ボイラー
等の内燃機関から排出される排気ガス中の炭化水素（Ｈ
Ｃ）、一酸化炭素（ＣＯ）および窒素酸化物（ＮＯｘ）
を浄化する排気ガス浄化用触媒、その製造方法及びその
使用方法に関し、特に酸素過剰雰囲気下でのＮＯｘの浄
化性能に優れる排気ガス浄化用触媒、その製造方法及び
その使用方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to hydrocarbons (H) contained in exhaust gas discharged from an internal combustion engine such as an automobile and a boiler.
C), carbon monoxide (CO) and nitrogen oxides (NOx)
The present invention relates to an exhaust gas purifying catalyst for purifying NOx, a method for producing the same, and a method for using the same, and more particularly to an exhaust gas purifying catalyst excellent in NOx purifying performance in an oxygen-excess atmosphere, a method for producing the same, and a method for using the same.
【０００２】[0002]
【従来の技術】近年、石油資源の枯渇問題および地球温
暖化問題の関点から、低燃費自動車の実現が期待されて
おり、特にガソリン自動車に対しては希薄燃焼自動車の
開発が注目されている。希薄燃焼自動車においては、希
薄燃焼走行時の排気ガス雰囲気は、理論空燃状態（以
下、「ストイキ状態」と称す）に比べて酸素過剰雰囲気
（以下、「リーン雰囲気」と称す）となる。リーン雰囲
気において、従来の三元触媒を適応させた場合には、過
剰な酸素の影響からＮＯｘ浄化作用が不十分となるとい
う問題があった。このためリーン雰囲気下においてもＮ
Ｏｘを浄化できる触媒の開発が望まれていた。2. Description of the Related Art In recent years, in view of the problem of depletion of petroleum resources and the problem of global warming, the realization of fuel-efficient vehicles is expected. . In a lean-burn vehicle, the exhaust gas atmosphere during lean-burn operation is an oxygen-excess atmosphere (hereinafter, referred to as a "lean atmosphere") as compared to a stoichiometric air-fuel state (hereinafter, referred to as a "stoichiometric state"). When a conventional three-way catalyst is applied in a lean atmosphere, there has been a problem that the effect of excessive oxygen makes the NOx purification action insufficient. Therefore, even in a lean atmosphere, N
The development of a catalyst that can purify Ox has been desired.
【０００３】従来より、リーン雰囲気下におけるＮＯｘ
浄化性能を向上させる触媒は種々提案されており、例え
ば特開平５−１６８８６０号公報には、ランタンと白金
（Ｐｔ）とを多孔質担体に担持させてランタンをＮＯｘ
吸収材として用いる触媒が開示されている。これはリー
ン雰囲気下でＮＯｘを吸収し、ストイキ状態あるいは燃
料過剰（リッチ）雰囲気下でＮＯｘを放出浄化するもの
である。Conventionally, NOx in a lean atmosphere has been
Various catalysts for improving the purification performance have been proposed. For example, JP-A-5-168860 discloses that lanthanum and platinum (Pt) are supported on a porous carrier to convert lanthanum into NOx.
A catalyst for use as an absorbent is disclosed. This is to absorb NOx in a lean atmosphere and to release and purify NOx in a stoichiometric or fuel-rich (rich) atmosphere.
【０００４】しかしながら、上記従来のＮＯｘ吸収触媒
（例えばＰｔ−ランタン触媒）は、その特性上、リーン
雰囲気で定常走行を行うとＮＯｘ吸収量が飽和に達して
やがて吸収作用が消失するという問題があり、ＮＯｘ浄
化性能が不足し、耐久後の性能も十分でなく、幅広い運
転条件下でＮＯｘを浄化することができない。However, the conventional NOx absorption catalyst (for example, a Pt-lanthanum catalyst) has a problem in that, when the vehicle is steadily driven in a lean atmosphere, the amount of absorbed NOx reaches saturation and the absorption action eventually disappears. , NOx purification performance is insufficient, the performance after durability is not sufficient, and NOx cannot be purified under a wide range of operating conditions.
【０００５】[0005]
【発明が解決しようとする課題】従って、請求項１〜５
記載の発明の目的は、従来の触媒では十分な活性を示さ
なかったリーン雰囲気下におけるＮＯｘ浄化性能を向上
させることができ、かつ三元触媒としての機能を十分に
発現することができる排気ガス浄化用触媒を提供するに
ある。SUMMARY OF THE INVENTION Accordingly, claims 1 to 5 are provided.
The object of the invention described is to improve the NOx purification performance in a lean atmosphere, which has not exhibited sufficient activity with a conventional catalyst, and to achieve exhaust gas purification capable of fully exhibiting a function as a three-way catalyst. To provide a catalyst for use.
【０００６】請求項６記載の発明の目的は、本発明の排
気ガス浄化用触媒を経済的に、かつ効率的に製造するこ
とができ、特にその平均粒径を精密に調整することがで
きる排気ガス浄化用触媒の製造方法を提供するにある。An object of the present invention is to provide an exhaust gas purifying catalyst of the present invention which can be produced economically and efficiently, and in particular, an exhaust gas whose average particle diameter can be precisely adjusted. An object of the present invention is to provide a method for producing a gas purification catalyst.
【０００７】また、請求項７及び８記載の発明の目的
は、本発明の排気ガス浄化用触媒のそのＮＯｘ浄化作用
が特に有効に発現できる排気ガス浄化用触媒の使用方法
を提供するにある。It is another object of the present invention to provide a method of using an exhaust gas purifying catalyst in which the NOx purifying action of the exhaust gas purifying catalyst of the present invention can be exhibited particularly effectively.
【０００８】[0008]
【課題を解決するための手段】請求項１記載の排気ガス
浄化用触媒は、白金、パラジウム及びロジウムから成る
群より選ばれた少なくとも一種の貴金属を多孔質体に担
持した粉末と、次の一般式According to a first aspect of the present invention, there is provided an exhaust gas purifying catalyst comprising: a powder having a porous body carrying at least one noble metal selected from the group consisting of platinum, palladium and rhodium; formula
【数２】 で表される複合酸化物粉末とを含有し、前記白金、パラ
ジウム及びロジウムから成る群より選ばれた少なくとも
１種を多孔質体に担持した粉末及び複合酸化物粉末の平
均粒径が共に４μｍ以下であることを特徴とする。(Equation 2) And a composite oxide powder containing at least one selected from the group consisting of platinum, palladium and rhodium supported on a porous body, and the composite oxide powder both having an average particle size of 4 μm or less. It is characterized by being.
【０００９】請求項２記載の排気ガス浄化用触媒は、請
求項１記載の排気ガス浄化用触媒において、貴金属をパ
ラジウム及びロジウムとすることを特徴とする。An exhaust gas purifying catalyst according to a second aspect of the present invention is the exhaust gas purifying catalyst according to the first aspect, wherein the noble metals are palladium and rhodium.
【００１０】請求項３記載の排気ガス浄化用触媒は、請
求項１記載の排気ガス浄化用触媒において、貴金属をパ
ラジウムとすることを特徴とする。An exhaust gas purifying catalyst according to a third aspect of the present invention is the exhaust gas purifying catalyst according to the first aspect, wherein the noble metal is palladium.
【００１１】請求項４記載の排気ガス浄化用触媒は、請
求項１〜３いずれかの項記載の排気ガス浄化用触媒にお
いて、平均粒径を２〜４μｍとすることを特徴とする。According to a fourth aspect of the present invention, there is provided an exhaust gas purifying catalyst according to any one of the first to third aspects, wherein the average particle diameter is 2 to 4 μm.
【００１２】請求項５記載の排気ガス浄化用触媒は、請
求項１〜４いずれかの項記載の排気ガス浄化用触媒にお
いて、更に、アルカリ金属及び／又はアルカリ土類金属
を含むことを特徴とする。According to a fifth aspect of the present invention, there is provided the exhaust gas purifying catalyst according to any one of the first to fourth aspects, further comprising an alkali metal and / or an alkaline earth metal. I do.
【００１３】請求項６記載の排気ガス浄化用触媒の製造
方法は、請求項１〜５いずれかの項記載の排気ガス浄化
用触媒を製造するにあたり貴金属担持多孔質体と複合酸
化物とを含む水性スラリーを湿式粉砕して、粉末の平均
粒径を４μｍ以下とする工程を含むことを特徴とする。According to a sixth aspect of the present invention, there is provided a method for producing an exhaust gas purifying catalyst comprising a noble metal-supporting porous body and a composite oxide in producing the exhaust gas purifying catalyst according to any one of the first to fifth aspects. The method is characterized by including a step of wet-grinding the aqueous slurry to reduce the average particle diameter of the powder to 4 μm or less.
【００１４】請求項７記載の排気ガス浄化用触媒の使用
方法は、上記本発明の排気ガス浄化用触媒のより有効な
ＮＯｘ吸収、放出サイクルを発現させるために、請求項
１〜５いずれかの項記載の排気ガス浄化用触媒を、空然
比が１０〜１５の範囲を繰り返すリーンバーンエンジン
車に使用することを特徴とする。According to a seventh aspect of the present invention, there is provided a method for using an exhaust gas purifying catalyst according to any one of the first to fifth aspects, in order to develop a more effective NOx absorption / release cycle of the exhaust gas purifying catalyst of the present invention. The exhaust gas purifying catalyst described in the above item is used for a lean burn engine vehicle in which the air ratio repeatedly ranges from 10 to 15.
【００１５】請求項８記載の排気ガス浄化用触媒の使用
方法は、上記本発明の排気ガス浄化用触媒のより有効な
ＮＯｘ吸収、放出サイクルを発現させるために、請求項
１〜５いずれかの項記載の排気ガス浄化用触媒を、空燃
比が１０〜１４．８と、１５〜５０の範囲とを繰り返す
リーンバーンエンジン車に使用することを特徴とする。The method for using an exhaust gas purifying catalyst according to the present invention is characterized in that the exhaust gas purifying catalyst of the present invention exhibits a more effective NOx absorption / release cycle. The exhaust gas purifying catalyst described in the item is used for a lean burn engine vehicle in which an air-fuel ratio repeatedly ranges from 10 to 14.8 and from 15 to 50.
【００１６】[0016]
【発明の実施の形態】本発明の排気ガス浄化用触媒中に
は、まず白金、パラジウム及びロジウムから成る群より
選ばれた少なくとも１種の貴金属を多孔質体に担持した
粉末が含まれる。かかる貴金属としては、白金、パラジ
ウム及びロジウムから成る群より選ばれる少なくとも１
種が用いられ、例えばＰｔとＲｈ、ＰｄとＲｈ、Ｐｄの
み等の種々の組み合わせが可能であるが、特にＰｄとＲ
ｈ、Ｐｄのみの貴金属を用いると、数２の式で表わされ
る複合酸化物との相互作用が更に高まりＮＯｘ吸収作用
がより向上するため好ましい。BEST MODE FOR CARRYING OUT THE INVENTION The exhaust gas purifying catalyst of the present invention includes a powder in which at least one noble metal selected from the group consisting of platinum, palladium and rhodium is supported on a porous body. As such a noble metal, at least one selected from the group consisting of platinum, palladium and rhodium
Species are used, and various combinations such as Pt and Rh, Pd and Rh, and Pd alone are possible.
It is preferable to use a noble metal consisting only of h and Pd, because the interaction with the composite oxide represented by the formula (2) is further increased, and the NOx absorption action is further improved.
【００１７】前記貴金属の含有量は、ＮＯｘ吸収能と三
元触媒性能が十分に得られれば特に限定されないが、
０．１ｇより少ないと十分な三元性能が得られず、１０
ｇより多く使用しても有意な特性向上はみられない点か
ら、本発明の排気ガス浄化用触媒１Ｌあたり０．１〜１
０ｇが好ましい。The content of the noble metal is not particularly limited as long as the NOx absorption capacity and the three-way catalyst performance are sufficiently obtained.
If the amount is less than 0.1 g, sufficient ternary performance cannot be obtained, and
g of the exhaust gas purifying catalyst of the present invention.
0 g is preferred.
【００１８】本発明の触媒はストイキ時の三元触媒とし
ての機能も必要であるため、Ｐｔ，Ｐｄ及びＲｈから成
る群より選ばれた少なくとも一種は、少なくとも一部が
多孔質体に担持されることが好ましく、特にアルミナに
担持されることが好ましい。ここで用いるアルミナは耐
熱性の高いものが好ましく、なかでも比表面積が５０〜
３００ｍ2 ／ｇの活性アルミナが好ましい。またアルミ
ナの耐熱性を向上させるために、従来から三元触媒で適
用されているように、セリウム、ランタン等の希土類化
合物やジルコニウムなどの添加物をさらに加えてもよ
い。Since the catalyst of the present invention also needs to function as a three-way catalyst during stoichiometry, at least one selected from the group consisting of Pt, Pd and Rh is at least partially supported on a porous material. It is particularly preferable that it is supported on alumina. The alumina used here is preferably one having high heat resistance.
300 m 2 / g of activated alumina is preferred. In order to improve the heat resistance of alumina, a rare earth compound such as cerium or lanthanum or an additive such as zirconium may be further added as conventionally used in a three-way catalyst.
【００１９】更に本発明で用いる触媒は、ストイキ時の
三元触媒としての機能も必要であるため、従来から三元
触媒で用いられている添加物を更に加えても良く、例え
ば酸素ストレージ機能を有するセリアや、貴金属へのＨ
Ｃ吸着被毒を緩和するバリウムや、Ｒｈの耐熱性向上に
寄与するジルコニア等である。Further, since the catalyst used in the present invention also needs to function as a three-way catalyst at the time of stoichiometry, additives conventionally used in three-way catalysts may be further added. H to ceria and precious metals
Barium, which alleviates C adsorption poisoning, and zirconia, which contributes to improving the heat resistance of Rh.
【００２０】また、本発明の排気ガス浄化用触媒中に含
まれる複合酸化物は、次の一般式The composite oxide contained in the exhaust gas purifying catalyst of the present invention has the following general formula:
【数３】 で表される。(Equation 3) It is represented by
【００２１】前記複合酸化物には、希土類金属と、アル
カリ金属及び／又はアルカリ土類金属と、少なくとも１
種の遷移金属とが含まれる。The composite oxide contains at least one of a rare earth metal, an alkali metal and / or an alkaline earth metal.
Species of transition metals.
【００２２】希土類金属としては、ランタン、セリウ
ム、ネオジム及びサマリウムが、アルカリ金属としては
カリウム、ナトリウム及びセシウムが、アルカリ土類金
属としてはマグネシウム、カルシウム、ストロンチウム
及びバリウムが、また遷移金属としては、鉄、コバル
ト、ニッケル及びマンガンが好適に使用できる。The rare earth metals are lanthanum, cerium, neodymium and samarium, the alkali metals are potassium, sodium and cesium, the alkaline earth metals are magnesium, calcium, strontium and barium, and the transition metals are iron , Cobalt, nickel and manganese can be suitably used.
【００２３】このような上記ペロブスカイト型酸化物の
ような複合酸化物は、酸素欠損を生じ、この生成した酸
素欠損を介してＮＯｘの吸着が容易になり、リーン雰囲
気においてＮＯｘを吸収するという特性を利用すること
により、ＮＯｘの浄化性能を向上させることが可能とな
っている。A composite oxide such as the above-described perovskite-type oxide has characteristics of causing oxygen deficiency, easily adsorbing NOx via the generated oxygen deficiency, and absorbing NOx in a lean atmosphere. Utilization makes it possible to improve NOx purification performance.
【００２４】また、一般にペロブスカイト型酸化物は触
媒組成物中のアルミナ系酸化物と固相反応を起こして活
性が失活する場合があり、これを抑制するために、アル
ミナ系酸化物にランタン等をプリコートする方法や、ジ
ルコニアのようにペロブスカイトとの反応性が小さい材
料を用いる方法がある。In general, the perovskite-type oxide may cause a solid phase reaction with the alumina-based oxide in the catalyst composition to deactivate the activity. In order to suppress this, lanthanum or the like is added to the alumina-based oxide. And a method using a material having low reactivity with perovskite such as zirconia.
【００２５】これに対して本発明のようにペロブスカイ
ト型酸化物のＡサイトを量論比から僅かに欠損させるこ
とにより、ペロブスカイト型酸化物と接する他の酸化物
（アルミナ等）との間での固相反応を抑制し、熱的安定
性を向上させ、熱耐久後の浄化性能を高く維持できるこ
とが可能となった。On the other hand, by slightly losing the A site of the perovskite-type oxide from the stoichiometric ratio as in the present invention, the A-site between the perovskite-type oxide and another oxide (alumina or the like) in contact therewith can be removed. It has become possible to suppress the solid-phase reaction, improve the thermal stability, and maintain high purification performance after heat endurance.
【００２６】Ａサイトの置換量は、０＜α＜１であり特
に限定されないが、ＮＯｘ吸収能力を十分に得るために
は、特に、０．２≦α＜１であることが好ましい。The substitution amount of the A site is 0 <α <1 and is not particularly limited. However, in order to obtain a sufficient NOx absorption capacity, it is particularly preferable that 0.2 ≦ α <1.
【００２７】βの値は、１以上だと単相のペロブスカイ
ト構造を構成しなくなるので０＜α＜１であることが好
ましい。δの値は各原子の価数を満足する酸素量であ
り、およそ０＜δ＜４程度である。If the value of β is 1 or more, a single-phase perovskite structure is not formed, so that 0 <α <1 is preferable. The value of δ is the amount of oxygen that satisfies the valence of each atom, and is approximately 0 <δ <4.
【００２８】本発明で用いられる複合酸化物、特に部分
置換ペロブスカイト酸化物は、その部分置換量とともに
リーン雰囲気下でＮＯｘを吸収する性能を発現させる
が、その吸収機構は、気相中のＮＯｘが複合酸化物上で
ＮＯ2 に酸化され、複合酸化物表面のＭｇ，Ｃａ，Ｓ
ｒ，Ｂａ，Ｎａ，Ｋ及びＣｓから成る群より選ばれた少
なくとも１種の元素の近傍に硝酸基あるいはそれに近い
状態で吸収されるものと考えられる。従ってリーン雰囲
気下でＮＯｘを有効に吸収するための複合酸化物の組成
は、硝酸塩を容易に製造し得るＭｇ，Ｃａ，Ｓｒ，Ｂ
ａ，Ｎａ，Ｋ及びＣｓから成る群より選ばれた少なくと
も１種の元素を含有し、更に、ＮＯｘをＮＯ2に酸化す
ることができる遷移金属元素を含有することが重要であ
る。The composite oxide used in the present invention, particularly the partially substituted perovskite oxide, exhibits the ability to absorb NOx in a lean atmosphere together with the partially substituted amount thereof. Oxidized to NO 2 on the composite oxide, and Mg, Ca, S on the surface of the composite oxide
It is considered that nitric acid is absorbed in the vicinity of at least one element selected from the group consisting of r, Ba, Na, K and Cs in the state of a nitric acid group or a state close thereto. Therefore, the composition of the composite oxide for effectively absorbing NOx under a lean atmosphere is made of Mg, Ca, Sr, B which can easily produce nitrate.
a, containing at least one element selected from the group consisting of Na, K and Cs, further, it is important to contain a transition metal element capable of oxidizing NOx to NO 2.
【００２９】該複合酸化物の各構成元素は、触媒に含ま
れるこれらの全てが複合化している場合に、その上記し
た作用は最大限に発揮されるが、少なくとも一部が複合
体を形成しうる場合でも十分に上記作用を得ることがで
きる。Each of the constituent elements of the composite oxide exerts the above-mentioned effects to the maximum when all of these contained in the catalyst are complexed, but at least a part of the complex oxide forms a complex. Even if it is possible, the above effect can be sufficiently obtained.
【００３０】該複合酸化物の各構成元素は、熱耐久後で
も別々の酸化物として分離することなく複合酸化物とし
て存在することができ、これは例えばＸ線回折測定によ
り確認することができる。Each constituent element of the composite oxide can exist as a composite oxide without being separated as a separate oxide even after thermal endurance, and this can be confirmed by, for example, X-ray diffraction measurement.
【００３１】該複合酸化物中の各構成元素には、その上
記作用を妨げる量でなければ微量の不純物を含んでも構
わず、例えばバリウム中に含まれるストロンチウムや、
ランタン中に含まれるセリウム、ネオジム、サマリウム
やジルコニウム中に含まれるハフニウムやイオウ等であ
る。Each constituent element in the composite oxide may contain a trace amount of impurities as long as it does not interfere with the above-mentioned action. For example, strontium contained in barium,
Cerium, neodymium, samarium contained in lanthanum and hafnium and sulfur contained in zirconium.
【００３２】前記複合酸化物は、その作用が得られる量
が触媒中に含有されれば特に含有量は限定されず、本発
明の排気ガス浄化用触媒１Ｌあたり２０〜１００ｇ含有
されることが好ましい。The content of the composite oxide is not particularly limited as long as the amount capable of obtaining the effect is contained in the catalyst. The content is preferably 20 to 100 g per liter of the exhaust gas purifying catalyst of the present invention. .
【００３３】本発明の排気ガス浄化用触媒は、前記貴金
属と、複合酸化物とを共存させることにより、各々単独
では得られないＮＯｘ浄化作用を得ることが可能となっ
ている。即ち、排気ガス雰囲気がリーンとなった場合に
は、本発明の排気ガス浄化用触媒中の複合酸化物による
ＮＯｘ吸収作用により、高いＮＯｘ浄化性能が得られ
る。該複合酸化物のＮＯｘ吸収し、また排気ガス雰囲気
がリーンからストイキに変化すると該複合酸化物からＮ
Ｏｘが放出され、高いＮＯｘ浄化性能が得られる。該複
合酸化物を構成する各成分の単独物を単に混合しただけ
では得られない優れたＮＯｘ浄化性能を得るものであ
る。In the exhaust gas purifying catalyst of the present invention, the coexistence of the noble metal and the composite oxide makes it possible to obtain an NOx purifying action which cannot be obtained by itself. That is, when the exhaust gas atmosphere becomes lean, high NOx purification performance can be obtained by the NOx absorbing action of the composite oxide in the exhaust gas purification catalyst of the present invention. When the composite oxide absorbs NOx and the exhaust gas atmosphere changes from lean to stoichiometric,
Ox is released, and high NOx purification performance is obtained. It is intended to obtain excellent NOx purification performance which cannot be obtained by simply mixing individual components of the composite oxide.
【００３４】また本発明の触媒は熱耐久後においても高
いＮＯｘ吸収作用を有し、これは該複合酸化物がＡサイ
ト割合の少ないペロブスカイト型構造をとっており、他
成分（例えばアルミナ）との固相反応が回避されたため
である。Further, the catalyst of the present invention has a high NOx absorbing effect even after heat endurance. This is because the composite oxide has a perovskite structure having a small proportion of A sites, and has a high NOx absorption effect with other components (for example, alumina). This is because the solid-phase reaction was avoided.
【００３５】本発明に用いる貴金属担持多孔質体と複合
酸化物は、その平均粒径（メジアン径）が４μｍ以下で
なければならない。粒径をこのような範囲とすること
で、リーン時のＮＯｘ吸収能力を向上させることができ
る。The noble metal-supporting porous material and the composite oxide used in the present invention must have an average particle size (median size) of 4 μm or less. By setting the particle size in such a range, the NOx absorbing ability at the time of lean can be improved.
【００３６】即ち、貴金属担持多孔質体及び複合酸化物
を含む触媒は、ガス流れ速度を遅くすると優れたＮＯｘ
吸収作用を発揮でき、このような効果は、上記範囲の平
均粒径とすることで達成され、その結果高いＮＯｘ吸収
活性を得ることができるのである。That is, the catalyst containing the noble metal-supported porous body and the composite oxide can provide excellent NOx when the gas flow rate is reduced.
An absorption effect can be exhibited, and such an effect can be achieved by setting the average particle diameter in the above range, and as a result, a high NOx absorption activity can be obtained.
【００３７】更に、かかる平均粒径とすることによっ
て、好ましくは本発明の排気ガス触媒中に担持されるア
ルカリ金属及び／又はアルカリ土類金属を高分散化し、
ＮＯｘ吸収作用を高めることもできる。Furthermore, by setting the average particle diameter to such a value, preferably, the alkali metal and / or alkaline earth metal supported in the exhaust gas catalyst of the present invention is highly dispersed,
The NOx absorbing action can be enhanced.
【００３８】特に、前記効果を更に向上させるために
は、平均粒径は２〜４μｍであることが好ましい。本明
細書における平均粒径は、レーザー回折型粒度分布計に
より測定されたものである。In particular, in order to further improve the above effects, it is preferable that the average particle size is 2 to 4 μm. The average particle size in the present specification is measured by a laser diffraction type particle size distribution meter.
【００３９】好ましくは、本発明の排気ガス浄化用触媒
の低温活性及び還元（酸素不足）雰囲気下における触媒
活性をより高めるため、更にアルカリ金属及び／又はア
ルカリ土類金属を本発明の排気ガス浄化用触媒に含有す
る。Preferably, in order to further enhance the low-temperature activity of the catalyst for purifying exhaust gas of the present invention and the catalytic activity in a reducing (oxygen-deficient) atmosphere, an alkali metal and / or an alkaline earth metal is further purified by the present invention. Contained in the catalyst for use.
【００４０】使用されるアルカリ金属及び／又はアルカ
リ土類金属には、リチウム、カリウム、セリウム、マグ
ネシウム、カルシウム、ストロンチウム及びバリウムが
含まれる。その含有量は触媒１Ｌ中１〜４０ｇである。
１ｇ未満では、炭化水素種の吸着被毒やパラジウムのシ
ンタリングを抑制することができず、４０ｇを越えても
有為な増量効果が得られず逆に性能を悪化させる。The alkali metals and / or alkaline earth metals used include lithium, potassium, cerium, magnesium, calcium, strontium and barium. Its content is 1 to 40 g per liter of catalyst.
If it is less than 1 g, adsorption poisoning of hydrocarbon species and sintering of palladium cannot be suppressed, and even if it exceeds 40 g, a significant effect of increasing the amount cannot be obtained, and conversely, the performance is deteriorated.
【００４１】本発明に用いる複合酸化物は、複合酸化物
の各構成元素の硝酸塩、酢酸塩、炭酸塩、クエン酸、塩
酸塩等を、所望する複合酸化物の組成比に混合し、仮焼
成した後粉砕して、熱処理焼成する固相反応や、複合酸
化物の各構成元素の硝酸塩、酢酸塩、炭酸塩、塩酸塩、
クエン酸塩等を、所望する複合酸化物の組成比に混合
し、水に溶解した後、必要に応じてＮＨ4 ＯＨやＮＨ3
ＣＯ3 等のアルカリ溶液を滴下して沈殿物を生成し、ろ
過した後沈殿物を乾燥させて焼成する共沈法により調製
することができるが、これらの方法に限定されるもので
はなく、前記以外の方法でも複合酸化物が形成されるも
のであればよい。The composite oxide used in the present invention is prepared by mixing nitrate, acetate, carbonate, citric acid, hydrochloride and the like of each constituent element of the composite oxide in a desired composition ratio of the composite oxide, and calcining the mixture. And then pulverized and heat treated and calcined, and the nitrate, acetate, carbonate, hydrochloride,
Citrate and the like are mixed in a desired composite oxide composition ratio and dissolved in water, and then, if necessary, NH 4 OH or NH 3
A precipitate is formed by dropping an alkaline solution such as CO 3 and the like, and the precipitate can be prepared by a coprecipitation method in which the precipitate is dried, filtered, dried and calcined, but is not limited to these methods. Any other method may be used as long as the composite oxide is formed.
【００４２】かかる方法により、複合酸化物を構成する
各成分の少なくとも一部を複合化することができる。According to such a method, at least a part of each component constituting the composite oxide can be composited.
【００４３】本発明で用いる複合酸化物の触媒調製用原
料には、前記したように、その上記作用を妨げる量でな
ければ微量の不純物を含んでも構わず、例えばバリウム
中に含まれるストロンチウムや、ランタン中に含まれる
セリウム、ネオジム、サマリウムや、ジルコニウム中に
含まれるハフニウムやイオウ等である。As described above, the raw material for preparing the catalyst of the composite oxide used in the present invention may contain a trace amount of impurities as long as the amount does not interfere with the above-mentioned effects. For example, strontium contained in barium, Cerium, neodymium, and samarium contained in lanthanum, and hafnium and sulfur contained in zirconium.
【００４４】本発明に用いる貴金属担持多孔質体の貴金
属原料化合物としては、無機酸塩、炭酸塩、アンモニウ
ム塩、有機酸塩、ハロゲン化物、酸化物、ナトリウム
塩、アンミン錯化合物等を組み合わせて使用することが
できるが、特に水溶性の塩を使用することが触媒性能を
向上させる観点から好ましい。貴金属の多孔質体への担
持法としては特殊な方法に限定されず、成分の著しい偏
在を伴わない限り、公知の蒸発乾固法、沈殿法、含浸
法、イオン交換法等の種々の方法を用いることができ
る。特にアルミナへの担持には、分散性を高める点から
含浸法が好ましい。As the noble metal raw material compound of the noble metal-supporting porous material used in the present invention, inorganic acid salts, carbonates, ammonium salts, organic acid salts, halides, oxides, sodium salts, ammine complex compounds and the like are used in combination. However, it is particularly preferable to use a water-soluble salt from the viewpoint of improving the catalyst performance. The method of supporting the noble metal on the porous body is not limited to a special method, and various methods such as a known evaporating and drying method, a precipitation method, an impregnation method, and an ion exchange method can be used as long as there is no significant uneven distribution of components. Can be used. In particular, the impregnation method is preferable for supporting on alumina, from the viewpoint of increasing dispersibility.
【００４５】イオン交換法、含浸法による場合、金属原
料は溶液で用いることが多いため、その溶液に酸あるい
は塩基を添加して、ｐＨを調節することもできる。ｐＨ
を調節することにより、更に、高分散担持できる可能性
もある。In the case of the ion exchange method or the impregnation method, since the metal raw material is often used in a solution, the pH can be adjusted by adding an acid or a base to the solution. pH
By adjusting the value, it is possible that the particles can be further highly dispersed and supported.
【００４６】本発明の触媒は、一体構造型担体に担持し
て用いるのが好ましく、貴金属担持多孔質体と複合酸化
物とを粉砕してスラリーとし、触媒担体にコートして、
４００〜９００℃の温度で焼成することにより、本発明
の排気ガス浄化用触媒を得ることができる。The catalyst of the present invention is preferably used by being supported on a monolithic carrier. The noble metal-supported porous body and the composite oxide are pulverized to form a slurry, which is coated on the catalyst carrier.
By firing at a temperature of 400 to 900 ° C., the exhaust gas purifying catalyst of the present invention can be obtained.
【００４７】貴金属担持多孔質体と複合酸化物を粉砕す
るにあたっての粉砕方法は特に限定されず、好ましくは
貴金属担持多孔質体と複合酸化物とを含む水性スラリー
を湿式粉砕して、平均粒径が４μｍ以下となるように調
整する方法を用いることができる。The pulverization method for pulverizing the noble metal-supported porous body and the composite oxide is not particularly limited. Preferably, an aqueous slurry containing the noble metal-supported porous body and the composite oxide is wet-pulverized to obtain an average particle diameter. May be adjusted so that the particle size is 4 μm or less.
【００４８】粉砕に使用することのできる装置は特に限
定されず、市販のボール式振動ミルを用いることがで
き、ボール径、粉砕時間、振幅、振動周波数を調整して
所望の粒径を得る。The apparatus that can be used for the pulverization is not particularly limited, and a commercially available ball-type vibrating mill can be used, and a desired particle size is obtained by adjusting the ball diameter, the pulverizing time, the amplitude, and the vibration frequency.
【００４９】触媒担体としては、公知の触媒担体の中か
ら適宜選択して使用することができ、例えば耐火性材料
からなるモノリス構造を有するハニカム担体やメタル担
体等が挙げられる。The catalyst carrier can be appropriately selected from known catalyst carriers and used, for example, a honeycomb carrier or a metal carrier having a monolith structure made of a refractory material.
【００５０】この触媒担体の形状は、特に制限されない
が、通常はハニカム形状で使用することが好ましく、こ
のハニカム材料としては、一般に例えばセラミックス等
のコージェライト質のものが多く用いられるが、フェラ
イト系ステンレス等の金属材料からなるハニカムを用い
ることも可能であり、更には触媒粉末そのものをハニカ
ム形状に成形しても良い。触媒の形状をハニカム状とす
ることにより、触媒と排気ガスの触媒面積が大きくな
り、圧力損失も抑えられるため自動車用等として用いる
場合に極めて有利である。Although the shape of the catalyst carrier is not particularly limited, it is usually preferable to use a honeycomb shape. As the honeycomb material, for example, cordierite materials such as ceramics are generally used. It is also possible to use a honeycomb made of a metal material such as stainless steel, and further, the catalyst powder itself may be formed into a honeycomb shape. By making the shape of the catalyst into a honeycomb shape, the area of the catalyst and the exhaust gas becomes large, and the pressure loss can be suppressed.
【００５１】更に好ましくは、得られた前記排気ガス浄
化用触媒に、アルカリ金属及び／又はアルカリ土類金属
を含浸担持させる。使用できるアルカリ金属及びアルカ
リ土類金属としては、リチウム、ナトリウム、カリウ
ム、セシウム、マグネシウム、カルシウム、ストロンチ
ウム及びバリウムからなる群より選ばれる一種以上の元
素である。More preferably, the obtained exhaust gas purifying catalyst is impregnated and supported with an alkali metal and / or an alkaline earth metal. The usable alkali metal and alkaline earth metal are at least one element selected from the group consisting of lithium, sodium, potassium, cesium, magnesium, calcium, strontium and barium.
【００５２】使用できるアルカリ金属及びアルカリ土類
金属の化合物は、酸化物、酢酸塩、水酸化物、硝酸塩、
炭酸塩等の水溶性のものである。これによりパラジウム
の近傍に塩基性元素であるアルカリ金属及び／又はアル
カリ土類金属を分散性良く担持することが可能となる。
この際、アルカリ金属及びアルカリ土類金属の原料化合
物を同時に、あるいは別個に含有させてもよい。The alkali metal and alkaline earth metal compounds that can be used include oxides, acetates, hydroxides, nitrates,
It is water-soluble such as carbonate. This makes it possible to carry the alkali metal and / or alkaline earth metal as a basic element in the vicinity of palladium with good dispersibility.
At this time, the starting compounds of the alkali metal and the alkaline earth metal may be contained simultaneously or separately.
【００５３】即ち、アルカリ金属化合物及び／又はアル
カリ土類金属化合物からなる粉末の水溶液を、ウォッシ
ュコート成分を担持した上記触媒に含浸し、乾燥し、次
いで、空気中及び／又は空気流通下で２００℃〜６００
℃焼成するものである。これは、アルカリ金属及びアル
カリ土類金属の原料化合物を一度低温で熱処理し酸化物
形態でコート層中に含有させると、後に高温に曝されて
も複合酸化物を形成し難くなるからである。かかる焼成
温度が、２００℃未満だとアルカリ金属化合物及びアル
カリ土類金属化合物が充分に酸化物形態となることがで
きず、逆に６００℃を越えると原料塩が急激に分解して
しまい、担体がひび割れてしまうことがあるので好まし
くない。That is, an aqueous solution of a powder comprising an alkali metal compound and / or an alkaline earth metal compound is impregnated with the above-mentioned catalyst supporting a washcoat component, dried, and then dried in air and / or under a stream of air. ° C to 600
It is baked at ℃. This is because, once the alkali metal and alkaline earth metal raw material compounds are heat-treated at a low temperature and contained in the coat layer in the form of an oxide, it becomes difficult to form a composite oxide even when exposed to a high temperature later. If the calcination temperature is lower than 200 ° C., the alkali metal compound and the alkaline earth metal compound cannot be sufficiently converted into an oxide form. If the calcination temperature exceeds 600 ° C., the raw material salt is rapidly decomposed, and However, it is not preferable because it may crack.
【００５４】上記本発明の排気ガス浄化用触媒は、その
使用条件を特に限定されないが、好ましくは空燃比が１
０〜５０、更に好ましくは空燃比が１０〜１４．８と１
５〜５０の範囲とを繰り返すリーンバーンエンジン車に
使用することができる。このような使用方法とすること
により、ＮＯｘ吸収・放出のサイクルが極めて有効に成
立し、特に効率の良いＮＯｘ浄化が可能となる。即ち、
空燃比が１０〜５０の範囲内の空燃比の大きな領域（リ
ーン領域）でＮＯｘを吸収し、空燃比の小さな領域（リ
ッチおよび／またはストイキ）でＮＯｘを浄化すること
により、高いＮＯｘ浄化性能を得ることができるのであ
り、さらに好適な範囲は、空燃比の小さな領域が１０か
ら１４．８、空燃比の大きな領域が１５〜５０である。The use conditions of the exhaust gas purifying catalyst of the present invention are not particularly limited.
0 to 50, more preferably an air-fuel ratio of 10 to 14.8 and 1
It can be used for lean burn engine vehicles that repeat the range of 5 to 50. With such a method of use, the cycle of NOx absorption / release is extremely effectively established, and particularly efficient NOx purification becomes possible. That is,
High NOx purification performance is achieved by absorbing NOx in a large air-fuel ratio region (lean region) within an air-fuel ratio range of 10 to 50 and purifying NOx in a small air-fuel ratio region (rich and / or stoichiometric). More preferable ranges are 10 to 14.8 for a region having a small air-fuel ratio and 15 to 50 for a region having a large air-fuel ratio.
【００５５】[0055]
【実施例】以下、本発明を次の実施例及び比較例により
説明する。実施例１ 硝酸パラジウム水溶液を活性アルミナ粉末に含浸し、乾
燥後４００℃で１時間焼成して、Ｐｄ担持アルミナ粉末
（粉末Ａ）を得た。この粉末ＡのＰｄ濃度は５．０重量
％であった。The present invention will be described below with reference to the following examples and comparative examples. Example 1 Activated alumina powder was impregnated with an aqueous solution of palladium nitrate, dried and calcined at 400 ° C. for 1 hour to obtain Pd-supported alumina powder (powder A). The Pd concentration of this powder A was 5.0% by weight.
【００５６】硝酸ロジウム水溶液を活性アルミナ粉末に
含浸し、乾燥後４００℃で１時間焼成して、Ｒｈ担持ア
ルミナ粉末（粉末Ｂ）を得た。この粉末ＢのＲｈ濃度は
３．０重量％であった。The activated alumina powder was impregnated with an aqueous rhodium nitrate solution, dried and calcined at 400 ° C. for 1 hour to obtain a Rh-supported alumina powder (powder B). The Rh concentration of this powder B was 3.0% by weight.
【００５７】炭酸ランタンと炭酸バリウムと炭酸コバル
トとの混合物にクエン酸を加え、乾燥後７００℃で焼成
し、粉末Ｃを得た。この粉末Ｃは金属原子比でランタン
／バリウム／コバルト＝２／７／１０であった。Citric acid was added to a mixture of lanthanum carbonate, barium carbonate and cobalt carbonate, dried and calcined at 700 ° C. to obtain powder C. This powder C had a metal atomic ratio of lanthanum / barium / cobalt = 2/7/10.
【００５８】上記粉末Ａを３４７ｇ、上記粉末Ｂを５８
ｇ、上記粉末Ｃを３６０ｇ、活性アルミナ粉末を３００
ｇ、水９００ｇを磁性ボールミルに投入し、１時間混合
粉砕してスラリー液を得た。このスラリー液をコーディ
エライト質モノリス担体（１．３Ｌ，４００セル）に付
着させ、空気流にてセル内の余剰のスラリーを取り除い
て１３０℃で乾燥した後、４００℃で１時間焼成し、コ
ート層重量２００ｇ／Ｌ−担体の排気ガス浄化用触媒を
得た。この触媒中の粉末の平均粒径は３．５μｍであっ
た。347 g of the powder A and 58 of the powder B were used.
g, the powder C was 360 g, and the activated alumina powder was 300
g of water and 900 g of water were charged into a magnetic ball mill and mixed and pulverized for 1 hour to obtain a slurry liquid. This slurry liquid was adhered to a cordierite-based monolithic carrier (1.3 L, 400 cells), excess slurry in the cells was removed by an air stream, dried at 130 ° C., and calcined at 400 ° C. for 1 hour. An exhaust gas purifying catalyst having a coat layer weight of 200 g / L-carrier was obtained. The average particle size of the powder in the catalyst was 3.5 μm.
【００５９】実施例２ 粉末Ｂのバリウムをカリウムとした以外は実施例１と同
様の方法で、排気ガス浄化用触媒を得た。この触媒中の
粉末の平均粒径は３．５μｍであった。 Example 2 An exhaust gas purifying catalyst was obtained in the same manner as in Example 1 except that barium in powder B was changed to potassium. The average particle size of the powder in the catalyst was 3.5 μm.
【００６０】実施例３ 粉末Ｂのバリウムをセシウムに代えた以外は実施例１と
同様の方法で、排気ガス浄化用触媒を得た。この触媒中
の粉末の平均粒径は３．５μｍであった。 Example 3 An exhaust gas purifying catalyst was obtained in the same manner as in Example 1, except that barium in Powder B was changed to Cesium. The average particle size of the powder in the catalyst was 3.5 μm.
【００６１】実施例４ 粉末Ｂのコバルトを鉄に代えた以外は実施例１と同様の
方法で、排気ガス浄化用触媒を得た。この触媒中の粉末
の平均粒径は３．５μｍであった。 Example 4 An exhaust gas purifying catalyst was obtained in the same manner as in Example 1 except that cobalt in Powder B was changed to Iron. The average particle size of the powder in the catalyst was 3.5 μm.
【００６２】実施例５ 粉末Ｂのコバルトをニッケルに代えた以外は実施例１と
同様の方法で、排気ガス浄化用触媒を得た。この触媒中
の粉末の平均粒径は３．５μｍであった。 Example 5 An exhaust gas purifying catalyst was obtained in the same manner as in Example 1 except that nickel in the powder B was replaced with nickel. The average particle size of the powder in the catalyst was 3.5 μm.
【００６３】実施例６ 粉末Ｂのコバルトをマンガンに代えた以外は実施例１と
同様の方法で、排気ガス浄化用触媒を得た。この触媒中
の粉末の平均粒径は３．５μｍであった。 Example 6 An exhaust gas purifying catalyst was obtained in the same manner as in Example 1 except that manganese was used instead of cobalt in Powder B. The average particle size of the powder in the catalyst was 3.5 μm.
【００６４】実施例７ 実施例１で得られた触媒に酢酸Ｂａ水溶液を含浸した後
４００℃で１時間焼成し、Ｂａを酸化物換算で３０ｇ／
Ｌ担持させて、排気ガス浄化用触媒を得た。この触媒中
の粉末の平均粒径は３．５μｍであった。 Example 7 The catalyst obtained in Example 1 was impregnated with an aqueous solution of Ba acetate and then calcined at 400 ° C. for 1 hour.
L was carried to obtain an exhaust gas purifying catalyst. The average particle size of the powder in the catalyst was 3.5 μm.
【００６５】実施例８ 実施例１で得られた触媒に酢酸Ｍｇ水溶液を含浸した後
４００℃で１時間焼成し、Ｍｇを酸化物換算で３０ｇ／
Ｌ担持させて、排気ガス浄化用触媒を得た。この触媒中
の粉末の平均粒径は３．５μｍであった。 Example 8 The catalyst obtained in Example 1 was impregnated with an aqueous solution of Mg acetate, and then calcined at 400 ° C. for 1 hour.
L was carried to obtain an exhaust gas purifying catalyst. The average particle size of the powder in the catalyst was 3.5 μm.
【００６６】実施例９ 粉末Ａを５０９ｇ、粉末Ｃを３６０ｇ、活性アルミナ粉
末を３２ｇ、水９００ｇの割合で混合した以外は、実施
例１と同様にして排気ガス浄化用触媒を得た。この触媒
中の粉末の平均粒径は３．５μｍであった。 Example 9 An exhaust gas purifying catalyst was obtained in the same manner as in Example 1 except that 509 g of powder A, 360 g of powder C, 32 g of activated alumina powder and 900 g of water were mixed. The average particle size of the powder in the catalyst was 3.5 μm.
【００６７】実施例１０ ジニトロジアンミンＰｔ水溶液を活性アルミナ粉末に含
浸し、乾燥空気中４００℃で１時間焼成して、Ｐｔ担持
粉末（粉末Ｄ）を得た。この粉末ＤのＰｔ濃度は３．０
重量％であった。 Example 10 An activated alumina powder was impregnated with an aqueous solution of dinitrodiammine Pt and calcined at 400 ° C. for 1 hour in dry air to obtain a Pt-supported powder (powder D). This powder D has a Pt concentration of 3.0.
% By weight.
【００６８】上記粉末Ｄを２８９ｇ、実施例１で得られ
た粉末Ｂを２９ｇと粉末Ｃを３６０ｇ、活性アルミナ粉
末を２２２ｇ、水９００ｇを磁性ボールミルに投入し、
１時間混合粉砕してスラリー液を得た。このスラリー液
をコーディライト質モノリス担体（１．３Ｌ、４００セ
ル）に付着させ、空気流にてセル内の余剰のスラリーを
取り除いて１３０℃で乾燥した後、４００℃で１時間焼
成し、コート層重量２００ｇ／Ｌ−担体の排気ガス浄化
用触媒を得た。この触媒中の粉末の平均粒径は３．５μ
ｍであった。289 g of the powder D, 29 g of the powder B obtained in Example 1, 360 g of the powder C, 222 g of the activated alumina powder, and 900 g of water were charged into a magnetic ball mill.
The mixture was pulverized for 1 hour to obtain a slurry liquid. This slurry liquid was adhered to a cordierite type monolithic carrier (1.3 L, 400 cells), excess slurry in the cells was removed by air flow, dried at 130 ° C., baked at 400 ° C. for 1 hour, and coated. An exhaust gas purifying catalyst having a layer weight of 200 g / L-carrier was obtained. The average particle size of the powder in this catalyst is 3.5μ.
m.
【００６９】比較例１ 粉砕時間を３０分に代えた以外は実施例１と同様の方法
で、排気ガス浄化用触媒を得た。この触媒中の粉末の平
均粒径は、４．５μｍであった。 Comparative Example 1 An exhaust gas purifying catalyst was obtained in the same manner as in Example 1 except that the pulverizing time was changed to 30 minutes. The average particle size of the powder in this catalyst was 4.5 μm.
【００７０】比較例２ 粉砕時間を２０分に代えた以外は実施例１と同様の方法
で、排気ガス浄化用触媒を得た。この触媒中の粉末の平
均粒径は、５．５μｍであった。 Comparative Example 2 An exhaust gas purifying catalyst was obtained in the same manner as in Example 1 except that the pulverizing time was changed to 20 minutes. The average particle size of the powder in this catalyst was 5.5 μm.
【００７１】前記実施例１〜１０及び比較例１〜２で得
られた排気ガス浄化用触媒の触媒組成及び粉末のその平
均粒径を表１に示す。Table 1 shows the catalyst compositions of the exhaust gas purifying catalysts obtained in Examples 1 to 10 and Comparative Examples 1 and 2 and the average particle size of the powder.
【００７２】[0072]
【表１】 [Table 1]
【００７３】試験例 前記実施例１〜１０及び比較例１〜２で得られた排気ガ
ス浄化用触媒について、以下の条件で初期及び耐久後の
触媒活性評価を行った。活性評価には、自動車の排気ガ
スを模したモデルガスを用いる自動評価装置を用いた。 Test Examples The exhaust gas purifying catalysts obtained in Examples 1 to 10 and Comparative Examples 1 and 2 were evaluated for initial and endurance catalytic activities under the following conditions. For the activity evaluation, an automatic evaluation device using a model gas simulating the exhaust gas of an automobile was used.
【００７４】耐久条件 エンジン４４００ｃｃの排気系に触媒を装着し、触媒入
口温度６００℃で、５０時間運転して耐久を行った。 Endurance conditions A catalyst was attached to the exhaust system of a 4400 cc engine, and operation was performed at a catalyst inlet temperature of 600 ° C. for 50 hours to endurance.
【００７５】評価条件 触媒活性評価は、排気量２０００ｃｃのエンジンの排気
系に各触媒を装着し、Ａ／Ｆ＝１４．６（ストイキ状
態）で６０秒間、その後Ａ／Ｆ＝２２（リーン雰囲気）
で２０秒間、その後Ａ／Ｆ＝５０（リーン雰囲気）で２
０秒間の運転を１サイクル行ない、各々平均転化率を測
定し、このＡ／Ｆ＝１４．６（ストイキ状態）の場合の
平均転化率とＡ／Ｆ＝２２（リーン雰囲気）の場合の平
均転化率とＡ／Ｆ＝５０（リーン雰囲気）の場合の平均
転化率とを平均してトータル転化率とした。この評価を
初期及び耐久後に各々行ない、触媒活性評価値を以下の
式により決定した。但し触媒入口温度を３５０℃とし
た。 Evaluation Conditions The catalyst activity was evaluated by mounting each catalyst on the exhaust system of an engine with a displacement of 2,000 cc, A / F = 14.6 (stoichiometric state) for 60 seconds, and then A / F = 22 (lean atmosphere).
For 20 seconds, then 2 at A / F = 50 (lean atmosphere)
One cycle of operation for 0 seconds was performed, and the average conversion was measured. The average conversion when A / F = 14.6 (stoichiometric state) and the average conversion when A / F = 22 (lean atmosphere). And the average conversion in the case of A / F = 50 (lean atmosphere) was averaged to obtain the total conversion. This evaluation was performed at the initial stage and after the endurance test, and the catalytic activity evaluation value was determined by the following equation. However, the catalyst inlet temperature was 350 ° C.
【００７６】[0076]
【数４】 (Equation 4)
【００７７】トータル転化率として得られた触媒活性評
価結果を表２に示す。比較例に比べて実施例は、触媒活
性が高く、後述する本発明の効果を確認することができ
た。Table 2 shows the catalytic activity evaluation results obtained as the total conversion. The catalytic activity of the example was higher than that of the comparative example, and the effect of the present invention described later could be confirmed.
【００７８】[0078]
【表２】 [Table 2]
【００７９】[0079]
【発明の効果】請求項１〜５記載の排気ガス浄化用触媒
は、従来の触媒では十分な活性を示さなかったリーン雰
囲気下におけるＮＯｘ浄化性能を向上させ、かつ三元触
媒としての機能を十分に発現することができ、更に熱耐
久後においても優れたＮＯｘ浄化性能を示すことができ
る。The exhaust gas purifying catalyst according to any one of claims 1 to 5 improves NOx purifying performance in a lean atmosphere, which has not exhibited sufficient activity with a conventional catalyst, and has a sufficient function as a three-way catalyst. And can exhibit excellent NOx purification performance even after heat endurance.
【００８０】請求項６記載の排気ガス浄化用触媒の製造
方法は、上記本発明の排気ガス浄化用触媒を経済的かつ
効率良く製造することができる。The method for producing an exhaust gas purifying catalyst according to claim 6 can economically and efficiently produce the exhaust gas purifying catalyst of the present invention.
【００８１】請求項７及び８記載の排気ガス浄化用触媒
の使用方法は、上記本発明の排気ガス浄化用触媒の有効
なＮＯｘ吸収、放出サイクルを特に効率良く発現させる
ことができる。According to the method of using the exhaust gas purifying catalyst according to the seventh and eighth aspects, the effective NOx absorption and release cycle of the exhaust gas purifying catalyst of the present invention can be exhibited particularly efficiently.
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.6 識別記号 ＦＩ Ｂ０１Ｊ 35/02 Ｂ０１Ｄ 53/36 Ｃ 37/00 １０４Ａ ──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. 6 Identification code FI B01J 35/02 B01D 53/36 C 37/00 104A
Claims (8)
群より選ばれた少なくとも一種の貴金属を多孔質体に担
持した粉末と、次の一般式 【数１】 で表される複合酸化物粉末とを含有し、前記白金、パラ
ジウム及びロジウムから成る群より選ばれた少なくとも
１種を多孔質体に担持した粉末及び複合酸化物粉末の平
均粒径が共に４μｍ以下であることを特徴とする排気ガ
ス浄化用触媒。1. A powder in which at least one noble metal selected from the group consisting of platinum, palladium and rhodium is supported on a porous body, and a powder represented by the following general formula: And a composite oxide powder containing at least one selected from the group consisting of platinum, palladium and rhodium supported on a porous body, and the composite oxide powder both having an average particle size of 4 μm or less. An exhaust gas purifying catalyst characterized by the following.
ことを特徴とする請求項１記載の排気ガス浄化用触媒。2. The exhaust gas purifying catalyst according to claim 1, wherein the noble metals are palladium and rhodium.
する請求項１記載の排気ガス浄化用触媒。3. The exhaust gas purifying catalyst according to claim 1, wherein the noble metal is palladium.
とする請求項１〜３いずれかの項記載の排気ガス浄化用
触媒。4. The exhaust gas purifying catalyst according to claim 1, wherein the average particle diameter is 2 to 4 μm.
土類金属を含むことを特徴とする請求項１〜４いずれか
の項記載の排気ガス浄化用触媒。5. The exhaust gas purifying catalyst according to claim 1, further comprising an alkali metal and / or an alkaline earth metal.
む水性スラリーを湿式粉砕して、粉末の平均粒径を４μ
ｍ以下とする工程を含むことを特徴とする請求項１〜５
いずれかの項記載の排気ガス浄化用触媒の製造方法。6. An aqueous slurry containing a noble metal-supported porous body and a composite oxide is wet-pulverized to have an average particle diameter of 4 μm.
m or less.
A method for producing an exhaust gas purifying catalyst according to any one of the preceding claims.
ス浄化用触媒を、空然比が１０〜１５の範囲を繰り返す
リーンバーンエンジン車に使用することを特徴とする排
気ガス浄化用触媒の使用方法。7. An exhaust gas purifying catalyst according to any one of claims 1 to 5, wherein the catalyst is used in a lean burn engine vehicle in which the air ratio repeatedly ranges from 10 to 15. How to use the catalyst.
ス浄化用触媒を、空然比が１０〜１４．８と、１５〜５
０の範囲とを繰り返すリーンバーンエンジン車に使用す
ることを特徴とする排気ガス浄化用触媒の使用方法。8. The exhaust gas purifying catalyst according to claim 1, wherein the air-fuel ratio is 10-14.8 and 15-5.
A method for using an exhaust gas purifying catalyst, which is used for a lean burn engine vehicle that repeats a range of 0.
Priority Applications (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP05653098A JP3885339B2 (en) | 1998-03-09 | 1998-03-09 | Exhaust gas purification catalyst, method for producing the same, and method for using the same |
| KR1019990007403A KR100326747B1 (en) | 1998-03-09 | 1999-03-06 | Device for Purifying Oxygen Rich Exhaust Gas |
| DE69931417T DE69931417T2 (en) | 1998-03-09 | 1999-03-08 | Apparatus for purifying oxygen-rich exhaust gas |
| US09/263,836 US6395675B1 (en) | 1998-03-09 | 1999-03-08 | Catalyst system for purifying oxygen rich exhaust gas |
| EP99104579A EP0941757B1 (en) | 1998-03-09 | 1999-03-08 | Device for purifying oxygen rich exhaust gas |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP05653098A JP3885339B2 (en) | 1998-03-09 | 1998-03-09 | Exhaust gas purification catalyst, method for producing the same, and method for using the same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH11253803A true JPH11253803A (en) | 1999-09-21 |
| JP3885339B2 JP3885339B2 (en) | 2007-02-21 |
Family
ID=13029661
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP05653098A Expired - Fee Related JP3885339B2 (en) | 1998-03-09 | 1998-03-09 | Exhaust gas purification catalyst, method for producing the same, and method for using the same |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3885339B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114032557A (en) * | 2021-11-08 | 2022-02-11 | 郑州大学 | Solid electrolyte battery for removing nitrogen oxides and preparation method thereof |
-
1998
- 1998-03-09 JP JP05653098A patent/JP3885339B2/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114032557A (en) * | 2021-11-08 | 2022-02-11 | 郑州大学 | Solid electrolyte battery for removing nitrogen oxides and preparation method thereof |
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| Publication number | Publication date |
|---|---|
| JP3885339B2 (en) | 2007-02-21 |
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