JPH0549940A - Exhaust gas purifying device - Google Patents
Exhaust gas purifying deviceInfo
- Publication number
- JPH0549940A JPH0549940A JP3202752A JP20275291A JPH0549940A JP H0549940 A JPH0549940 A JP H0549940A JP 3202752 A JP3202752 A JP 3202752A JP 20275291 A JP20275291 A JP 20275291A JP H0549940 A JPH0549940 A JP H0549940A
- Authority
- JP
- Japan
- Prior art keywords
- exhaust gas
- catalyst
- oxide
- palladium
- outflow side
- 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.)
- Pending
Links
- 239000003054 catalyst Substances 0.000 claims abstract description 119
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 claims abstract description 62
- 229910052763 palladium Inorganic materials 0.000 claims abstract description 31
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 claims abstract description 30
- 229910000420 cerium oxide Inorganic materials 0.000 claims abstract description 20
- BMMGVYCKOGBVEV-UHFFFAOYSA-N oxo(oxoceriooxy)cerium Chemical compound [Ce]=O.O=[Ce]=O BMMGVYCKOGBVEV-UHFFFAOYSA-N 0.000 claims abstract description 19
- RVTZCBVAJQQJTK-UHFFFAOYSA-N oxygen(2-);zirconium(4+) Chemical compound [O-2].[O-2].[Zr+4] RVTZCBVAJQQJTK-UHFFFAOYSA-N 0.000 claims abstract description 16
- 229910052703 rhodium Inorganic materials 0.000 claims abstract description 16
- 239000010948 rhodium Substances 0.000 claims abstract description 16
- MHOVAHRLVXNVSD-UHFFFAOYSA-N rhodium atom Chemical compound [Rh] MHOVAHRLVXNVSD-UHFFFAOYSA-N 0.000 claims abstract description 16
- 229910001928 zirconium oxide Inorganic materials 0.000 claims abstract description 16
- 229910052697 platinum Inorganic materials 0.000 claims abstract description 15
- 229910000287 alkaline earth metal oxide Inorganic materials 0.000 claims abstract description 13
- 238000000746 purification Methods 0.000 claims description 35
- 229910052809 inorganic oxide Inorganic materials 0.000 claims description 15
- 239000006104 solid solution Substances 0.000 claims description 3
- 229910052784 alkaline earth metal Inorganic materials 0.000 claims description 2
- 150000001342 alkaline earth metals Chemical class 0.000 claims description 2
- DRVWBEJJZZTIGJ-UHFFFAOYSA-N cerium(3+);oxygen(2-) Chemical class [O-2].[O-2].[O-2].[Ce+3].[Ce+3] DRVWBEJJZZTIGJ-UHFFFAOYSA-N 0.000 claims 1
- 238000006243 chemical reaction Methods 0.000 claims 1
- 239000010970 precious metal Substances 0.000 claims 1
- 239000007789 gas Substances 0.000 abstract description 68
- MWUXSHHQAYIFBG-UHFFFAOYSA-N Nitric oxide Chemical compound O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 abstract description 32
- 229930195733 hydrocarbon Natural products 0.000 abstract description 21
- 150000002430 hydrocarbons Chemical class 0.000 abstract description 21
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 abstract description 15
- 229910002091 carbon monoxide Inorganic materials 0.000 abstract description 15
- 229910000510 noble metal Inorganic materials 0.000 abstract description 5
- 239000004215 Carbon black (E152) Substances 0.000 abstract 2
- 239000007864 aqueous solution Substances 0.000 description 11
- 239000000446 fuel Substances 0.000 description 11
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 8
- ITHZDDVSAWDQPZ-UHFFFAOYSA-L barium acetate Chemical compound [Ba+2].CC([O-])=O.CC([O-])=O ITHZDDVSAWDQPZ-UHFFFAOYSA-L 0.000 description 8
- GPNDARIEYHPYAY-UHFFFAOYSA-N palladium(ii) nitrate Chemical compound [Pd+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O GPNDARIEYHPYAY-UHFFFAOYSA-N 0.000 description 8
- 239000000203 mixture Substances 0.000 description 7
- 239000002002 slurry Substances 0.000 description 7
- 230000000052 comparative effect Effects 0.000 description 6
- 238000001035 drying Methods 0.000 description 6
- 230000000694 effects Effects 0.000 description 6
- 238000000034 method Methods 0.000 description 6
- 238000010304 firing Methods 0.000 description 5
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 4
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 4
- QVQLCTNNEUAWMS-UHFFFAOYSA-N barium oxide Chemical compound [Ba]=O QVQLCTNNEUAWMS-UHFFFAOYSA-N 0.000 description 4
- IATRAKWUXMZMIY-UHFFFAOYSA-N strontium oxide Chemical compound [O-2].[Sr+2] IATRAKWUXMZMIY-UHFFFAOYSA-N 0.000 description 4
- 150000003754 zirconium Chemical class 0.000 description 4
- 150000000703 Cerium Chemical class 0.000 description 3
- 230000003197 catalytic effect Effects 0.000 description 3
- 239000002131 composite material Substances 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
- 238000011068 loading method Methods 0.000 description 3
- 150000003839 salts Chemical class 0.000 description 3
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 2
- 229910052684 Cerium Inorganic materials 0.000 description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 2
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 description 2
- 239000000654 additive Substances 0.000 description 2
- BRPQOXSCLDDYGP-UHFFFAOYSA-N calcium oxide Chemical compound [O-2].[Ca+2] BRPQOXSCLDDYGP-UHFFFAOYSA-N 0.000 description 2
- ODINCKMPIJJUCX-UHFFFAOYSA-N calcium oxide Inorganic materials [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 description 2
- 239000000292 calcium oxide Substances 0.000 description 2
- GWXLDORMOJMVQZ-UHFFFAOYSA-N cerium Chemical compound [Ce] GWXLDORMOJMVQZ-UHFFFAOYSA-N 0.000 description 2
- 239000002737 fuel gas Substances 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 229910017604 nitric acid Inorganic materials 0.000 description 2
- 230000001590 oxidative effect Effects 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 239000000377 silicon dioxide Substances 0.000 description 2
- 238000001238 wet grinding Methods 0.000 description 2
- 229910052726 zirconium Inorganic materials 0.000 description 2
- FRWYFWZENXDZMU-UHFFFAOYSA-N 2-iodoquinoline Chemical compound C1=CC=CC2=NC(I)=CC=C21 FRWYFWZENXDZMU-UHFFFAOYSA-N 0.000 description 1
- 150000001242 acetic acid derivatives Chemical class 0.000 description 1
- 230000032683 aging Effects 0.000 description 1
- 229910052783 alkali metal Inorganic materials 0.000 description 1
- 150000001340 alkali metals Chemical class 0.000 description 1
- LTPBRCUWZOMYOC-UHFFFAOYSA-N beryllium oxide Inorganic materials O=[Be] LTPBRCUWZOMYOC-UHFFFAOYSA-N 0.000 description 1
- VSGNNIFQASZAOI-UHFFFAOYSA-L calcium acetate Chemical compound [Ca+2].CC([O-])=O.CC([O-])=O VSGNNIFQASZAOI-UHFFFAOYSA-L 0.000 description 1
- 239000001639 calcium acetate Substances 0.000 description 1
- 229960005147 calcium acetate Drugs 0.000 description 1
- 235000011092 calcium acetate Nutrition 0.000 description 1
- 238000006555 catalytic reaction Methods 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- RCFVMJKOEJFGTM-UHFFFAOYSA-N cerium zirconium Chemical compound [Zr].[Ce] RCFVMJKOEJFGTM-UHFFFAOYSA-N 0.000 description 1
- 150000001805 chlorine compounds Chemical class 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 229910017052 cobalt Inorganic materials 0.000 description 1
- 239000010941 cobalt Substances 0.000 description 1
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 238000005470 impregnation Methods 0.000 description 1
- 229910017053 inorganic salt Inorganic materials 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- UEGPKNKPLBYCNK-UHFFFAOYSA-L magnesium acetate Chemical group [Mg+2].CC([O-])=O.CC([O-])=O UEGPKNKPLBYCNK-UHFFFAOYSA-L 0.000 description 1
- 239000011654 magnesium acetate Substances 0.000 description 1
- 229940069446 magnesium acetate Drugs 0.000 description 1
- 235000011285 magnesium acetate Nutrition 0.000 description 1
- CPLXHLVBOLITMK-UHFFFAOYSA-N magnesium oxide Inorganic materials [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 1
- 239000000395 magnesium oxide Substances 0.000 description 1
- AXZKOIWUVFPNLO-UHFFFAOYSA-N magnesium;oxygen(2-) Chemical compound [O-2].[Mg+2] AXZKOIWUVFPNLO-UHFFFAOYSA-N 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 150000002823 nitrates Chemical class 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 239000002243 precursor Substances 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 229910052761 rare earth metal Inorganic materials 0.000 description 1
- 150000002910 rare earth metals Chemical class 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
- 239000000243 solution Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- RXSHXLOMRZJCLB-UHFFFAOYSA-L strontium;diacetate Chemical group [Sr+2].CC([O-])=O.CC([O-])=O RXSHXLOMRZJCLB-UHFFFAOYSA-L 0.000 description 1
- 150000003467 sulfuric acid derivatives Chemical class 0.000 description 1
Classifications
-
- Y02T10/22—
Landscapes
- Catalysts (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、自動車等の内燃機関か
らの排気ガス中に含まれる有害成分である一酸化炭素
（ＣＯ）、炭化水素（ＨＣ）及び窒素酸化物（ＮＯｘ）
を同時に除去する排気ガス浄化システムに関するもので
ある。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to carbon monoxide (CO), hydrocarbons (HC) and nitrogen oxides (NOx) which are harmful components contained in exhaust gas from internal combustion engines such as automobiles.
The present invention relates to an exhaust gas purification system that simultaneously removes.
【０００２】[0002]
【従来の技術】近年、低燃費化等により、排気ガス温度
の低下、現行よりさらに強化された排ガス規制、特にＨ
Ｃ規制が施行されつつある状況下で従来の三元触媒を用
いる排気ガス浄化システムでは性能面で十分とは言い難
い。2. Description of the Related Art In recent years, exhaust gas temperature has been lowered due to low fuel consumption, etc.
Under the situation where the C regulation is being enforced, it cannot be said that the performance of the conventional exhaust gas purification system using a three-way catalyst is sufficient.
【０００３】また、従来のパラジウム触媒を用いた排気
ガス浄化システムは、パラジウムが高い耐熱性を有して
いることやエンジン排気ガスの酸化雰囲気（いわゆるリ
ーン；空気／燃料（Ａ／Ｆ）が空気側大）におけるＣ
Ｏ，ＨＣの高い浄化能を有することが一般に知られてい
るにもかかわらず、エンジン排気ガスが還元雰囲気（い
わゆるリッチ；（Ａ／Ｆ）が燃料側大）の場合にＨＣ浄
化能は高いが、ＮＯｘ浄化能が極めて低いという問題点
を有しているために、パラジウム触媒を実際に使用する
に際しては、リーン側のみでの使用、例えば、いわゆる
酸化触媒として使用したり、又は高いＮＯｘ浄化能を有
するロジウムを上記パラジウムと組み合せて、ＣＯ，Ｈ
ＣおよびＮＯｘを同時に浄化する三元触媒として使用す
ることで排気ガス浄化システムとして用いられている。Further, the conventional exhaust gas purification system using a palladium catalyst has a high heat resistance of palladium, and an oxidizing atmosphere of engine exhaust gas (so-called lean; air / fuel (A / F) is air). C)
Although generally known to have a high purification capacity for O and HC, the HC purification capacity is high when the engine exhaust gas is in a reducing atmosphere (so-called rich; (A / F) is large on the fuel side). Since it has a problem that the NOx purification capacity is extremely low, when the palladium catalyst is actually used, it is used only on the lean side, for example, it is used as a so-called oxidation catalyst or has a high NOx purification capacity. Rhodium having the formula: CO, H
It is used as an exhaust gas purification system by using it as a three-way catalyst that simultaneously purifies C and NOx.
【０００４】しかし、上記のロジウムを使用する三元触
媒を用いた排気ガス浄化システムは、非常に高価である
ために、触媒成分中のロジウムの使用量の減少、または
使用しないことが望まれているが、高いＮＯｘ浄化能を
有するという特徴を有するために、一酸化炭素（Ｃ
Ｏ）、炭化水素（ＨＣ）及び窒素酸化物（ＮＯｘ）を同
時に除去する排気ガス浄化システムに用いる排気ガス浄
化用触媒の成分としては、必須成分として不可欠なシス
テムである。However, since the exhaust gas purification system using the above-mentioned three-way catalyst using rhodium is extremely expensive, it is desired to reduce the amount of rhodium used in the catalyst component or not use it. However, since it has a characteristic that it has a high NOx purification capacity, carbon monoxide (C
O), hydrocarbons (HC) and nitrogen oxides (NOx) are simultaneously removed as an essential component as a component of the exhaust gas purification catalyst used in the exhaust gas purification system.
【０００５】従って、ロジウムを使用しない、またはロ
ジウム使用量を減少させた実用に足るに十分な排気ガス
浄化システムは見出されていないのが現状である。Therefore, in the present situation, no exhaust gas purification system has been found which does not use rhodium or has a reduced amount of rhodium and is sufficient for practical use.
【０００６】[0006]
【発明が解決しようとする課題】本発明は、排気ガス温
度が低下する状況下において、低温着火性を有し、さら
に排気ガス規制、特にＨＣ規制が高まるなかで、燃料リ
ッチな雰囲気において排出されるＨＣの多い排気ガスを
浄化する性能が高く、かつ安価な触媒コンバータによる
排気ガス浄化システムが求められている。DISCLOSURE OF THE INVENTION The present invention has a low temperature ignitability in a situation where the exhaust gas temperature is lowered, and is exhausted in a fuel-rich atmosphere while the exhaust gas regulation, particularly the HC regulation, is increased. There is a demand for an inexpensive exhaust gas purification system using a catalytic converter that has a high performance of purifying exhaust gas containing a large amount of HC.
【０００７】[0007]
【課題を解決するための手段】本発明者らは、この課題
を鋭意研究したところ、パラジウム触媒にアルカリ土類
金属酸化物を添加することによりパラジウムに直接作用
し、その電荷状態を修飾させ、リッチ雰囲気でのＮＯｘ
浄化能を向上させることがみいだされた。さらに、セリ
ウム酸化物及びジルコニウム酸化物を用いることによ
り、前記の効果はさらに向上し、かつ、燃料ガスが化学
量論比（燃料ガスを完全燃焼させるのに必要な空気量）
近傍でもＣＯ，ＨＣ及びＮＯｘ浄化能の向上が見いださ
れた。本発明者らは、この知見を基に、排気ガス流通下
で、種々の触媒を複数個組み合せ検討した結果、（Ａ）
排気ガス流入側の触媒と（Ｂ）排気ガス流出側の触媒と
からなり、（Ａ）排気ガス流入側の触媒が貴金属として
（ａ）ロジウム及び白金、または（ｂ）ロジウム、白金
及びパラジウム、並びに耐火性無機酸化物（ｃ）を含有
してなる触媒成分を一体構造体に被覆したものであり、
（Ｂ）排気ガス流出側の触媒がパラジウム、アルカリ土
類金属酸化物、セリウム酸化物、ジルコニウム酸化物及
び耐火性無機酸化物（ｄ）より構成される触媒成分を一
体構造体に被覆したものであることを特徴とする排気ガ
ス浄化システムにより、ＣＯ，ＨＣ及びＮＯｘ浄化能の
向上化を見い出し、本発明を完成するに到ったのであ
る。Means for Solving the Problems The inventors of the present invention have diligently studied this problem. As a result, by adding an alkaline earth metal oxide to a palladium catalyst, the palladium acts directly on the palladium to modify its charge state. NOx in a rich atmosphere
It was found to improve the purification capacity. Further, by using cerium oxide and zirconium oxide, the above-mentioned effect is further improved, and the fuel gas has a stoichiometric ratio (the amount of air required to completely burn the fuel gas).
Improvements in CO, HC and NOx purification capacities were also found in the vicinity. Based on this finding, the inventors of the present invention studied a combination of various catalysts under exhaust gas circulation, and as a result, (A)
It is composed of an exhaust gas inflow side catalyst and (B) exhaust gas outflow side catalyst, and (A) the exhaust gas inflow side catalyst is a noble metal (a) rhodium and platinum, or (b) rhodium, platinum and palladium, and A monolithic structure coated with a catalyst component containing a refractory inorganic oxide (c),
(B) The catalyst on the exhaust gas outflow side is formed by coating a catalyst component composed of palladium, an alkaline earth metal oxide, a cerium oxide, a zirconium oxide, and a refractory inorganic oxide (d) on an integral structure. The present invention has been completed by finding improvement in the CO, HC, and NOx purification ability by the exhaust gas purification system characterized by the above.
【０００８】本発明に係る（Ｂ）排気ガス流出側に設置
する触媒は、パラジウム、アルカリ土類金属酸化物、セ
リウム酸化物、ジルコニウム酸化物及び耐火性無機酸化
物（ｄ）より構成される触媒成分を一体構造体に被覆し
たものである。The catalyst (B) installed on the exhaust gas outflow side according to the present invention is a catalyst composed of palladium, alkaline earth metal oxide, cerium oxide, zirconium oxide and refractory inorganic oxide (d). It is a monolithic structure coated with components.
【０００９】パラジウムの使用量は触媒の使用条件によ
って異なるが、通常触媒１リットル当り、０．５〜３０
ｇ、好ましくは０．５〜２５ｇである。パラジウムの量
が０．５未満である場合は、浄化能が低く、また３０ｇ
を越える場合は添加量に見合う性能の向上はみられない
ものである。The amount of palladium used varies depending on the conditions under which the catalyst is used, but is usually 0.5 to 30 per liter of the catalyst.
g, preferably 0.5 to 25 g. If the amount of palladium is less than 0.5, the purification capacity is low, and 30g
When the amount exceeds the range, no improvement in performance commensurate with the amount added is seen.
【００１０】パラジウムの担持される位置は、その使用
量及び使用条件によりことなるが、ジルコニウム酸化
物、酸化セリウム又は耐火性無機酸化物（ｄ）に単独に
又はまたがって担持されてなる。The position on which palladium is supported varies depending on the amount and conditions of use, but it is supported on zirconium oxide, cerium oxide or the refractory inorganic oxide (d) alone or straddling it.
【００１１】アルカリ土類金属酸化物としては、ベリリ
ウム酸化物、マグネシウム酸化物、カルシウム酸化物、
ストロンチウム酸化物及びバリウム酸化物が挙げられる
が、特にカルシウム酸化物、ストロンチウム酸化物及び
バリウム酸化物からなる群より選ばれた少なくとも一種
が好ましい。アルカリ土類金属酸化物の使用量は触媒１
リットル当り０．１〜５０ｇ、好ましくは０．５〜４０
ｇである。０．１ｇ未満であるときは、添加効果が少な
く、５０ｇを越えるときは、添加に見合う効果が少な
い。The alkaline earth metal oxides include beryllium oxide, magnesium oxide, calcium oxide,
Examples thereof include strontium oxide and barium oxide, but at least one selected from the group consisting of calcium oxide, strontium oxide and barium oxide is particularly preferable. The amount of alkaline earth metal oxide used is catalyst 1
0.1 to 50 g per liter, preferably 0.5 to 40
It is g. If it is less than 0.1 g, the effect of addition is small, and if it exceeds 50 g, the effect commensurate with the addition is small.
【００１２】アルカリ土類金属酸化物は、セリウム酸化
物とジルコニウム酸化物、又は各酸化物の一方のみにセ
リウム・ジルコニウム複合酸化物又は耐火性無機酸化物
（ｄ）のいずれに担持されてもよい。さらに使用される
アルカリ土類金属酸化物は、酸化物自体を用いることも
できるし、その前駆体、例えば、有機塩、又は無機塩い
ずれでも用いることができ、特に限定されない。The alkaline earth metal oxide may be supported on either the cerium oxide and the zirconium oxide, or on either one of the oxides and the cerium-zirconium composite oxide or the refractory inorganic oxide (d). .. The alkaline earth metal oxide used may be either the oxide itself or a precursor thereof, such as an organic salt or an inorganic salt, and is not particularly limited.
【００１３】アルカリ土類金属酸化物とパラジウムの関
係は、それらの重量比（アルカリ土類金属酸化物／パラ
ジウム）で、１／１００〜１５０／１、好ましくは、１
／１００〜１００／１である。１／１００よりアルカリ
土類金属酸化物の量が少なくなると、三元性能が悪くな
り、特に、ＮＯ浄化率が劣り、１５０／１よりアルカリ
土類金属酸化物の量が多くなると添加効果は向上する
が、その他酸化物等の担持量、触媒の強度の関係によ
り、担持比率、担持量を制限される。The relationship between the alkaline earth metal oxide and palladium is 1/100 to 150/1, preferably 1 in terms of their weight ratio (alkaline earth metal oxide / palladium).
/ 100 to 100/1. When the amount of alkaline earth metal oxide is less than 1/100, the ternary performance is poor, and particularly, the NO purification rate is poor, and when the amount of alkaline earth metal oxide is more than 150/1, the addition effect is improved. However, the loading ratio and loading amount are limited by the relationship between the loading amount of oxides and the strength of the catalyst.
【００１４】セリウム酸化物とジルコニウム酸化物は、
各単独の混合物として用いても効果はある。さらに好ま
しくは、セリウム酸化物とジルコニウム酸化物は少なく
とも一部が複合酸化物、または固溶体として存在してい
る場合である。Cerium oxide and zirconium oxide are
It is also effective when used as a mixture of each. More preferably, at least a part of the cerium oxide and the zirconium oxide is present as a composite oxide or a solid solution.
【００１５】その組成比がセリウム酸化物／ジルコニウ
ム酸化物で、１００／２〜１００／６０（酸化物換算重
量比）、好ましくは１００／４〜１００／４０である。
その組成比が、１００／２より酸化セリウムが多くなる
と浄化性能が低く、１００／６０よりジルコニウム酸化
物が多くなると浄化性能の低くなる傾向となるものであ
る。The composition ratio of cerium oxide / zirconium oxide is 100/2 to 100/60 (weight ratio in terms of oxide), preferably 100/4 to 100/40.
When the composition ratio of cerium oxide is more than 100/2, the purification performance is low, and when the zirconium oxide is more than 100/60, the purification performance tends to be low.
【００１６】セリウム・ジルコニウム複合酸化物、及び
酸化セリウムと酸化ジルコニウムの固溶体の調製方法を
次に示すが、上記の組成比であれば調製方法は特に限定
されない。The method for preparing the cerium / zirconium composite oxide and the solid solution of cerium oxide and zirconium oxide will be described below, but the preparation method is not particularly limited as long as it has the above composition ratio.
【００１７】例えば、（１）市販の酸化セリウムに水可
溶性のジルコニウム塩を担持する方法、（２）水可溶性
のセリウム塩、ジルコニウム塩を混合乾燥後、焼成する
方法、（３）水可溶性のセリウム塩、ジルコニウム塩の
混合水溶液を耐火性無機酸化物（ｄ）に含浸、乾燥、焼
成し、担持する方法、又は（４）一体構造体に耐火性無
機酸化物（ｄ）を塗布後、セリウム塩、ジルコニウム塩
の混合水溶液を浸漬する方法等が挙げられる。又用いる
セリウム、ジルコニウムの各塩は特に限定されるもので
はなく、市販の硝酸塩、酢酸塩、硫酸塩、又は塩化物等
が用いられる。For example, (1) a method of supporting a water-soluble zirconium salt on commercially available cerium oxide, (2) a method of mixing and drying the water-soluble cerium salt and the zirconium salt, and (3) a water-soluble cerium salt. A method of impregnating a refractory inorganic oxide (d) with a mixed aqueous solution of a salt and a zirconium salt, drying, firing and supporting, or (4) applying the refractory inorganic oxide (d) to an integral structure, and then cerium salt And a method of immersing a mixed aqueous solution of zirconium salt. The salts of cerium and zirconium used are not particularly limited, and commercially available nitrates, acetates, sulfates, chlorides and the like can be used.
【００１８】耐火性無機酸化物（ｄ）としては、活性ア
ルミナ、シリカ、チタニア等の高表面積を有するものが
挙げられるが特に活性アルミナが好ましい。上記した各
触媒成分はボールミル等を用いて水性スラリーとし、一
体構造体に塗布し、その後乾燥し、必要により焼成して
排気ガス流出側の完成触媒とする。Examples of the refractory inorganic oxide (d) include those having a high surface area such as activated alumina, silica, and titania, and activated alumina is particularly preferable. Each of the above catalyst components is made into an aqueous slurry by using a ball mill or the like, applied to an integral structure, then dried and, if necessary, fired to obtain a finished catalyst on the exhaust gas outflow side.
【００１９】使用される耐火性無機酸化物（ｄ）の量は
触媒１リットル当たり、５０ｇ〜３００ｇ、好ましく
は、５０ｇ〜２５０ｇである。The amount of refractory inorganic oxide (d) used is 50 g to 300 g, preferably 50 g to 250 g, per liter of catalyst.
【００２０】本発明に係る（Ａ）排気ガス流入側の触媒
は、貴金属として（ａ）ロジウム及び白金、または
（ｂ）ロジウム、白金及びパラジウム、並びに耐火性無
機酸化物（ｃ）を含有してなる触媒成分を一体構造体に
被覆したものである。The exhaust gas inflow side catalyst (A) according to the present invention contains (a) rhodium and platinum as noble metals, or (b) rhodium, platinum and palladium, and a refractory inorganic oxide (c). Is a monolithic structure coated with the catalyst component.
【００２１】用いられる貴金属としては、（ａ）ロジウ
ム及び白金、または（ｂ）ロジウム、白金及びパラジウ
ムであり、これらの使用量は触媒１リットル当たり０．
１ｇ〜１０ｇ、好ましくは０．３ｇ〜５ｇである。０．
１ｇ未満である場合は、浄化能が低く、１０ｇを越える
場合は、添加量に見合う効果が少ない。The noble metal used is (a) rhodium and platinum, or (b) rhodium, platinum and palladium, and the amount of these used is 0.
It is 1 g to 10 g, preferably 0.3 g to 5 g. 0.
If it is less than 1 g, the purifying ability is low, and if it exceeds 10 g, the effect corresponding to the added amount is small.
【００２２】耐火性無機酸化物（ｃ）としては、活性ア
ルミナ、シリカ、チタニア、セリウム酸化物、ジルコニ
ウム酸化物、アルカリ金属、アルカリ土類金属、希土類
金属、鉄、コバルト、ニッケル等の添加物を金属、金属
酸化物等の形態で加えることができる。これらの添加物
のうち好ましくは、活性アルミナ、セリウム酸化物、ジ
ルコニウム酸化物である。As the refractory inorganic oxide (c), additives such as activated alumina, silica, titania, cerium oxide, zirconium oxide, alkali metal, alkaline earth metal, rare earth metal, iron, cobalt and nickel are used. It can be added in the form of metal, metal oxide or the like. Of these additives, activated alumina, cerium oxide and zirconium oxide are preferable.
【００２３】使用される耐火性無機酸化物（ｃ）の量
は、触媒１リットル当たり５０ｇ〜３５０ｇ、好ましく
は、５０ｇ〜３００ｇである。The amount of refractory inorganic oxide (c) used is 50 g to 350 g, preferably 50 g to 300 g, per liter of catalyst.
【００２４】（Ａ）排気ガス流入側の触媒及び（Ｂ）排
気ガス流出側の触媒に使用される一体構造体としては、
通常、排気ガス浄化用触媒に使用される一体構造体であ
ればいずれのものでも良く、例えばハニカム型、コルゲ
ート型等の一体構造体が用いられ、その材質は、耐火性
を有するものであればいずれのものであってもよく、例
えばコージェライト等の耐火性を有するセラミックス
製、フェライト系ステンレス等金属製の一体構造体が用
いられる。The integrated structure used in (A) the exhaust gas inflow side catalyst and (B) the exhaust gas outflow side catalyst is
In general, any one-piece structure may be used as long as it is used for an exhaust gas purification catalyst, for example, a honeycomb-type, corrugated-type one-piece structure is used, the material is fireproof Any of these may be used, and for example, an integral structure made of fireproof ceramics such as cordierite or metal such as ferritic stainless steel is used.
【００２５】（Ａ）排気ガス流入側の触媒と（Ｂ）排気
ガス流出側の触媒の体積比は１００：１〜１：１００、
好ましくは５０：１〜１：５０である。１００：１未満
である場合及び１：１００を越える場合は、組み合せに
よる性能向上は示されない。The volume ratio of (A) the exhaust gas inflow side catalyst to (B) the exhaust gas outflow side catalyst is 100: 1 to 1: 100,
It is preferably 50: 1 to 1:50. When it is less than 100: 1 and when it exceeds 1: 100, the performance improvement due to the combination is not shown.
【００２６】（Ａ）排気ガス流入側の触媒と（Ｂ）排気
ガス流出側の触媒は、同一の触媒コンバーター内に設置
することができるし、また排気管の形状、触媒の形状等
により適宜、各々分離して設置することもできる。The (A) exhaust gas inflow side catalyst and the (B) exhaust gas outflow side catalyst can be installed in the same catalytic converter, and depending on the shape of the exhaust pipe, the shape of the catalyst, etc. Each can be installed separately.
【００２７】（Ａ）排気ガス流入側の触媒、（Ｂ）排気
ガス流出側の触媒とも各々１個である必要はなく、排気
管の形状、触媒の設置する場所、排気ガスの背圧の上昇
等に支障がないかぎり、（Ａ）排気ガス流入側の触媒、
（Ｂ）排気ガス流出側の触媒とも各々複数個の触媒に分
割し使用することもできる。It is not necessary to have one catalyst for each of (A) exhaust gas inflow side catalyst and (B) exhaust gas outflow side catalyst. (A) Exhaust gas inflow side catalyst,
(B) The catalyst on the exhaust gas outflow side may be divided into a plurality of catalysts for use.
【００２８】以下、実施例にて具体的に説明するが、本
発明の趣旨に反しない限りこれらの実施例に限定される
ことはない。The present invention will be specifically described below with reference to Examples, but the invention is not limited to these Examples unless it goes against the gist of the present invention.
【００２９】[0029]
（実施例１） 排気ガス流入側触媒：白金３．３３ｇ含有するジニトロ
ジアミン白金の硝酸水溶液とロジウム０．６６７ｇ含有
する硝酸ロジウムを活性アルミナ（γ・Ａｌ2Ｏ3、比表
面積１５５ｍ2／ｇ）４００ｇに含浸し、乾燥後４００
℃で２時間焼成して得た粉体と市販の酸化セリウム（Ｃ
ｅＯ2：比表面積１４９ｍ2／ｇ）２００ｇをボールミル
で湿式粉砕することにより水性スラリーを調製した。こ
のスラリーに断面積１インチ平方当り４００個のセルを
有するコージェライト製モノリス担体０．５リットルを
浸漬し取り出した後、セル内の過剰スラリーを圧縮空気
で吹き飛ばした後乾燥、焼成し、完成触媒を得た。Example 1 Exhaust gas inflow side catalyst: Nitric acid aqueous solution of dinitrodiamine platinum containing 3.33 g of platinum and rhodium nitrate containing 0.667 g of rhodium on activated alumina (γ · Al 2 O 3 , specific surface area of 155 m 2 / g) 400g after impregnation and drying
Powder obtained by firing at ℃ for 2 hours and commercially available cerium oxide (C
An aqueous slurry was prepared by wet-milling 200 g of eO 2 : specific surface area 149 m 2 / g) with a ball mill. 0.5 liter of a cordierite monolithic carrier having 400 cells per 1 inch square in cross section was immersed in this slurry and taken out. Then, excess slurry in the cells was blown off with compressed air, followed by drying and firing to obtain a finished catalyst. Got
【００３０】排気ガス流出側触媒：市販の酸化セリウム
（ＣｅＯ2、比表面積１４９ｍ2／ｇ）にオキシ硝酸ジル
コニル水溶液をＣｅＯ2／ＺｒＯ3の比で１０／１（Ｃｅ
Ｏ2とＺｒＯ3の合計が１００ｇ）となるように混合し、
乾燥後、５００℃で１時間焼成して得た粉体２００ｇと
活性アルミナ（γ・Ａｌ2Ｏ3、比表面積１５５ｍ2／
ｇ）４００ｇ、酢酸バリウム３３．４ｇ、及びパラジウ
ム１２ｇ含有する硝酸パラジウム水溶液を加え、ボール
ミルで湿式粉砕することにより水性スラリーを調製し
た。このスラリーに断面積１インチ平方当り４００個の
セルを有するコージェライト製モノリス担体０．５リッ
トルを浸漬し、取り出した後、セル内の過剰スラリーを
圧縮空気で吹き飛ばした後乾燥、焼成し、完成触媒を得
た。Exhaust gas outflow side catalyst: Commercial cerium oxide (CeO 2 , specific surface area 149 m 2 / g) and an aqueous zirconyl oxynitrate solution at a ratio of CeO 2 / ZrO 3 of 10/1 (Ce.
Mix so that the total of O 2 and ZrO 3 is 100 g),
After drying, 200 g of powder obtained by firing at 500 ° C. for 1 hour and activated alumina (γ · Al 2 O 3 , specific surface area of 155 m 2 /
g) 400 g, barium acetate 33.4 g, and a palladium nitrate aqueous solution containing 12 g of palladium were added, and an aqueous slurry was prepared by wet milling with a ball mill. 0.5 liters of cordierite monolithic carrier having 400 cells per 1 inch square in cross section is immersed in this slurry, taken out, and the excess slurry in the cells is blown off with compressed air, followed by drying and firing to complete. A catalyst was obtained.
【００３１】（実施例２）実施例１において、排ガス流
出側触媒の酢酸バリウム３３．４ｇを２６７．２ｇに変
えた以外は実施例１と同様にして完成触媒を得た。(Example 2) A finished catalyst was obtained in the same manner as in Example 1 except that 33.4 g of barium acetate as the exhaust gas outflow side catalyst was changed to 267.2 g.
【００３２】（実施例３）実施例１において、排ガス流
出側触媒の酢酸バリウム３３．４ｇを１．６６ｇに変え
た以外は実施例１と同様にして完成触媒を得た。(Example 3) A completed catalyst was obtained in the same manner as in Example 1 except that 33.4 g of barium acetate as the exhaust gas outlet side catalyst was changed to 1.66 g.
【００３３】（実施例４）実施例１において、排ガス流
出側触媒の酢酸バリウムを酢酸カルシウム５６．４ｇに
変えた以外は実施例１と同様にして完成触媒を得た。(Example 4) A completed catalyst was obtained in the same manner as in Example 1 except that 56.4 g of calcium acetate was used instead of barium acetate in the exhaust gas outflow side catalyst.
【００３４】（実施例５）実施例１において、排ガス流
出側触媒の酢酸バリウムを酢酸ストロンチウム３９．６
ｇに変えた以外は、実施例１と同様にして完成触媒を得
た。(Embodiment 5) In Embodiment 1, barium acetate as the catalyst on the exhaust gas outflow side was replaced with strontium acetate 39.6.
A finished catalyst was obtained in the same manner as in Example 1 except that g was changed.
【００３５】（実施例６）実施例１において、排ガス流
出側触媒のＣｅＯ2／ＺｒＯ2の比を１０／１（ＣｅＯ2
とＺｒＯ2の合計が６０ｇ）、かつ活性アルミナ５４０
ｇ以外は、実施例１と同様にして完成触媒を得た。Example 6 In Example 1, the ratio of CeO 2 / ZrO 2 of the exhaust gas outflow side catalyst was set to 10/1 (CeO 2
And ZrO 2 total 60 g), and activated alumina 540
A completed catalyst was obtained in the same manner as in Example 1 except for g.
【００３６】（実施例７）実施例１において、排ガス流
出側触媒のＣｅＯ2／ＺｒＯ2の比を１０／１（ＣｅＯ2
とＺｒＯ2の合計が３２０ｇ）、かつ活性アルミナ２８
０ｇに変えた以外は実施例１と同様にして完成触媒を得
た。Example 7 In Example 1, the ratio of CeO 2 / ZrO 2 of the exhaust gas outflow side catalyst was set to 10/1 (CeO 2
And the total of ZrO 2 are 320 g), and activated alumina 28
A finished catalyst was obtained in the same manner as in Example 1 except that the amount was changed to 0 g.
【００３７】（実施例８）実施例１において、排ガス流
出側触媒のＣｅＯ2／ＺｒＯ2の比を１０／３（ＣｅＯ2
とＺｒＯ2の合計が２００ｇ）に変えた以外は実施例１
と同様にして完成触媒を得た。Example 8 In Example 1, the ratio of CeO 2 / ZrO 2 of the exhaust gas outflow side catalyst was set to 10/3 (CeO 2
Example 1 except that the total amount of ZrO 2 and ZrO 2 was changed to 200 g).
A completed catalyst was obtained in the same manner as in.
【００３８】（実施例９）実施例１において、排ガス流
出側触媒のＣｅＯ2／ＺｒＯ2の比を２５／１（ＣｅＯ2
とＺｒＯ2の合計が１００ｇ）に変えた以外は実施例１
と同様にして完成触媒を得た。(Example 9) In Example 1, the ratio of CeO 2 / ZrO 2 of the exhaust gas outflow side catalyst was set to 25/1 (CeO 2
Example 1 except that the total of ZrO 2 and ZrO 2 was changed to 100 g).
A completed catalyst was obtained in the same manner as in.
【００３９】（実施例１０）実施例１において、排ガス
流出側触媒の酢酸バリウムを酢酸マグネシウム７０．６
ｇに変えた以外は、実施例１と同様にして完成触媒を得
た。(Example 10) In Example 1, barium acetate of the exhaust gas outflow side catalyst was replaced with magnesium acetate 70.6
A finished catalyst was obtained in the same manner as in Example 1 except that g was changed.
【００４０】（実施例１１）実施例１において、排ガス
流出側触媒のパラジウム１２ｇを含有する硝酸パラジウ
ム水溶液をパラジウム４ｇ含有する硝酸パラジウム水溶
液に変更する以外は実施例１と同様にして完成触媒を得
た。(Example 11) A completed catalyst was obtained in the same manner as in Example 1 except that the palladium nitrate aqueous solution containing 12 g of palladium of the exhaust gas outflow side catalyst was changed to the palladium nitrate aqueous solution containing 4 g of palladium. It was
【００４１】（実施例１２）実施例１において、排ガス
流出側触媒のパラジウム１２ｇを含有する硝酸パラジウ
ム水溶液をパラジウム３２ｇ含有する硝酸パラジウム水
溶液に変更する以外は実施例１と同様にして完成触媒を
得た。(Example 12) A finished catalyst was obtained in the same manner as in Example 1 except that the palladium nitrate aqueous solution containing 12 g of palladium of the exhaust gas outflow side catalyst was changed to the palladium nitrate aqueous solution containing 32 g of palladium. It was
【００４２】（実施例１３）実施例１において、排ガス
流出側触媒のパラジウム１２ｇを含有する硝酸パラジウ
ム水溶液をパラジウム８０ｇ含有する硝酸パラジウム水
溶液に変更する以外は実施例１と同様にして完成触媒を
得た。(Example 13) A finished catalyst was obtained in the same manner as in Example 1 except that the palladium nitrate aqueous solution containing 12 g of palladium of the exhaust gas outflow side catalyst was changed to the palladium nitrate aqueous solution containing 80 g of palladium. It was
【００４３】（実施例１４）実施例１において、排ガス
流入側触媒の白金３．３３ｇを、白金１．６７ｇ含有す
るジニトロジアミン白金の硝酸水溶液およびパラジウム
１．６７ｇ含有する硝酸パラジウムに変えた以外は実施
例１と同様にして完成触媒を得た。(Example 14) In Example 1, except that 3.33 g of platinum of the exhaust gas inflow side catalyst was changed to nitric acid aqueous solution of dinitrodiamine platinum containing 1.67 g of platinum and palladium nitrate containing 1.67 g of palladium. A completed catalyst was obtained in the same manner as in Example 1.
【００４４】（比較例１）実施例１において、排ガス流
出側触媒を流入側触媒と同じものに変えた以外は実施例
１と同様にした。(Comparative Example 1) The same procedure as in Example 1 was carried out except that the exhaust gas outflow side catalyst was changed to the same as the inflow side catalyst.
【００４５】（比較例２）実施例１において、排ガス流
出側触媒の酢酸バリウムを除いた以外は実施例１と同様
にして完成触媒を得た。(Comparative Example 2) A finished catalyst was obtained in the same manner as in Example 1 except that barium acetate as the exhaust gas outflow side catalyst was removed.
【００４６】（比較例３）実施例１の排ガス流出側触媒
においてオキシ硝酸ジルコニルを除いた以外は実施例１
と同様にして完成触媒を得た。Comparative Example 3 Example 1 except that zirconyl oxynitrate was removed from the exhaust gas outflow side catalyst of Example 1.
A completed catalyst was obtained in the same manner as in.
【００４７】（比較例４）実施例１の排ガス流出側触媒
において、オキシ硝酸ジルコニルを除き、かつ酢酸バリ
ウムを除いた以外は実施例１と同様にして完成触媒を得
た。Comparative Example 4 A finished catalyst was obtained in the same manner as in Example 1 except that zirconyl oxynitrate and barium acetate were removed from the exhaust gas outflow side catalyst of Example 1.
【００４８】このようにして得られた実施例と比較例の
触媒１リットル当りの各触媒成分の担持量を表１に示し
た。Table 1 shows the supported amounts of the respective catalyst components per liter of the catalysts of Examples and Comparative Examples thus obtained.
【００４９】（実施例１５）次に、実施例１から実施例
１４までの触媒と、比較例１から４の触媒のエンジン耐
久走行後の触媒活性を調べた。(Example 15) Next, the catalyst activities of the catalysts of Examples 1 to 14 and the catalysts of Comparative Examples 1 to 4 were examined after running the engine for a long time.
【００５０】市販の電子制御方式のエンジン（８気筒４
４００ｃｃ）を使用し、各触媒をエンジンの排気系に連
設して耐久テストを行なった。エンジンは、定常運転６
０秒、減速６秒（減速時に燃料がカットされて、触媒
は、高温酸化雰囲気の厳しい条件にさらされる。）とい
うモード運転で運転し触媒入口ガス温度が定常運転時８
５０℃となる条件で５０時間触媒をエージングした。A commercially available electronically controlled engine (8 cylinders 4
Using 400 cc), each catalyst was connected to the exhaust system of the engine and a durability test was conducted. Engine is in steady operation 6
0 seconds, deceleration 6 seconds (fuel is cut during deceleration, the catalyst is exposed to severe conditions of high temperature oxidizing atmosphere), and the catalyst inlet gas temperature is steady operation 8
The catalyst was aged for 50 hours under the condition of 50 ° C.
【００５１】エージング後の触媒性能の評価は、市販の
電子制御方式のエンジン（４気筒１８００ｃｃ）を使用
し、各触媒を、エンジンの排気系に連設して行なった。
触媒の三元性能は触媒入口ガス温度４００℃、空間速度
９０，０００ｈｒ~1の条件で評価した。この際、外部発
振器より１Ｈｚサイン波型シグナルをエンジンのコント
ロールユニットに導入して、空燃比（Ａ／Ｆ）を±１．
０Ａ／Ｆ、１Ｈｚで振動させながら平均空燃比を連続的
に変化させ、この時の触媒入口及び出口ガス組成を同時
に分析して、平均空燃比がＡ／Ｆが１５．１から１４．
１までＣＯ，ＨＣ及びＮＯの浄化能を求めた。The evaluation of the catalyst performance after aging was carried out by using a commercially available electronically controlled engine (four-cylinder 1800 cc) and connecting each catalyst to the exhaust system of the engine.
The three-way performance of the catalyst was evaluated under the conditions of a catalyst inlet gas temperature of 400 ° C. and a space velocity of 90,000 hr- 1 . At this time, a 1 Hz sine wave type signal was introduced from an external oscillator into the engine control unit to set the air-fuel ratio (A / F) to ± 1.
The average air-fuel ratio is continuously changed while oscillating at 0 A / F and 1 Hz, and the catalyst inlet and outlet gas compositions at this time are simultaneously analyzed, and the average air-fuel ratio A / F is 15.1 to 14.
Up to 1, the purifying ability of CO, HC and NO was obtained.
【００５２】上記のようにして求めたＣＯ，ＨＣ及びＮ
Ｏの浄化率対入口空燃比をグラフにプロットして、三元
特性曲線を作成し、ＣＯ，ＮＯ浄化率曲線の交点（クロ
スオーバーポイントと呼ぶ）の浄化率と、その交点のＡ
／Ｆ値におけるＨＣ浄化率さらに、Ａ／Ｆが１４．２
（エンジン排気ガスがリッチ）でのＣＯ，ＨＣおよびＮ
Ｏの浄化率を表２に示した。CO, HC and N obtained as described above
The purification rate of O versus the inlet air-fuel ratio is plotted in a graph to create a ternary characteristic curve, and the purification rate at the intersection (called a crossover point) of the CO and NO purification rates and the intersection A
HC purification rate at / F value Further, A / F is 14.2
CO, HC and N in (rich engine exhaust gas)
The purification rate of O is shown in Table 2.
【００５３】表２より、本発明に開示される触媒は、貴
金属として、ロジウムを含まずパラジウムのみで、Ｃ
Ｏ，ＨＣおよびＮＯｘの三成分を同時に除去できること
がわかる。From Table 2, the catalyst disclosed in the present invention contains no palladium as the noble metal, only palladium and no C
It can be seen that the three components of O, HC and NOx can be removed simultaneously.
【００５４】また、触媒の低温での浄化性能は、空燃比
を±０．５Ａ／Ｆ（１Ｈｚ）の条件で振動させながら、
平均空燃比をＡ／Ｆに１４．６に固定してエンジンを運
転し、エンジン排気系の触媒コンバータの前に熱交換器
を取り付けて、触媒入口ガス温度を２００℃〜５００℃
まで連続的に変化させ、触媒入口及び出口ガス組成を分
析して、ＣＯ，ＨＣ及びＮＯの浄化率を求めることによ
り評価した。上記の様にして求めた、ＣＯ，ＨＣ及びＮ
Ｏの浄化率５０％での温度（ライトオフ温度）を測定し
て表２に示した。Further, the purification performance of the catalyst at low temperature is as follows while vibrating the air-fuel ratio under the condition of ± 0.5 A / F (1 Hz).
The engine is operated with the average air-fuel ratio fixed to A / F of 14.6, a heat exchanger is installed in front of the catalytic converter of the engine exhaust system, and the catalyst inlet gas temperature is 200 ° C to 500 ° C.
Was continuously changed, the catalyst inlet and outlet gas compositions were analyzed, and the purification rates of CO, HC and NO were obtained and evaluated. CO, HC and N determined as above
The temperature (light-off temperature) at a purification rate of O of 50% was measured and is shown in Table 2.
【００５５】本発明に開示された触媒は良好な三元性
能、特にＨＣ能の向上が示される。さらに低温でＨＣ，
ＣＯ及びＮＯの三成分を同時除去できることがわかる。The catalysts disclosed in this invention show good ternary performance, especially improved HC capacity. HC at lower temperatures,
It can be seen that the three components of CO and NO can be removed simultaneously.
【００５６】[0056]
【表１】 [Table 1]
【００５７】[0057]
【表２】 [Table 2]
───────────────────────────────────────────────────── フロントページの続き (72)発明者 大幡 知久 兵庫県姫路市網干区興浜字西沖992番地の １ 株式会社日本触媒触媒研究所内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tomohisa Ohata 1 992 Nishioki Okihama, Aboshi-ku, Himeji City, Hyogo Prefecture, Japan Catalysis Research Institute, Inc.
Claims (4)
気ガス流出側の触媒とからなり、（Ａ）排気ガス流入側
の触媒が貴金属として（ａ）ロジウム及び白金、または
（ｂ）ロジウム、白金及びパラジウム、 並びに耐火性無機酸化物（ｃ）を含有してなる触媒成分
を一体構造体に被覆したものであり、（Ｂ）排気ガス流
出側の触媒がパラジウム、アルカリ土類金属酸化物、セ
リウム酸化物、ジルコニウム酸化物及び耐火性無機酸化
物（ｄ）より構成される触媒成分を一体構造体に被覆し
たものであることを特徴とする排気ガス浄化システム。1. A catalyst comprising (A) an exhaust gas inflow side catalyst and (B) an exhaust gas outflow side catalyst, wherein (A) the exhaust gas inflow side catalyst is a precious metal (a) rhodium and platinum, or (b) ) Rhodium, platinum and palladium, and a catalyst component containing a refractory inorganic oxide (c) are coated on a monolithic structure, and (B) the exhaust gas outflow side catalyst is palladium or an alkaline earth metal. An exhaust gas purification system characterized in that an integral structure is coated with a catalyst component composed of oxide, cerium oxide, zirconium oxide and refractory inorganic oxide (d).
体１リットル当りに対してパラジウムが０．９〜３０
ｇ、アルカリ土類金属酸化物が０．１〜５０ｇ、セリウ
ム酸化物が１０〜１００ｇ、ジルコニウム酸化物が０．
１〜３０ｇ及び耐火性無機酸化物（ｄ）が１０〜３００
ｇを被覆したものである請求項１記載の排気ガス浄化シ
ステム。2. (B) The catalyst on the exhaust gas outflow side contains palladium in an amount of 0.9 to 30 per liter of the integrated structure.
g, 0.1 to 50 g of alkaline earth metal oxides, 10 to 100 g of cerium oxides, and 0.
1 to 30 g and the refractory inorganic oxide (d) is 10 to 300
The exhaust gas purification system according to claim 1, which is coated with g.
るセリウム酸化物とジルコニウム酸化物は少なくとも一
部が複合物又は固溶体として存在してなる請求項１記載
の排気ガス浄化システム。3. The exhaust gas purification system according to claim 1, wherein at least a part of (B) the cerium oxide and the zirconium oxide contained in the catalyst on the exhaust gas outflow side is present as a complex or a solid solution.
比（酸化物換算重量比）が１００：２〜１００：６０で
ある請求項１又は３記載の排気ガス浄化システム。4. The exhaust gas purification system according to claim 1, wherein the ratio of the cerium oxide and the zirconium oxide (oxide conversion weight ratio) is 100: 2 to 100: 60.
Priority Applications (8)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3202752A JPH0549940A (en) | 1991-08-13 | 1991-08-13 | Exhaust gas purifying device |
| CA002064977A CA2064977C (en) | 1991-04-05 | 1992-04-02 | Catalyst for purifying exhaust gas |
| DE69218017T DE69218017T2 (en) | 1991-04-05 | 1992-04-03 | Catalytic converter for cleaning exhaust gases |
| EP92302928A EP0507590B1 (en) | 1991-04-05 | 1992-04-03 | Catalyst for purifying exhaust gas |
| AT92302928T ATE149870T1 (en) | 1991-04-05 | 1992-04-03 | CATALYST FOR PURIFYING EXHAUST GASES |
| US07/862,967 US5260249A (en) | 1991-04-05 | 1992-04-03 | Catalyst for purifying automotive exhaust gas |
| KR1019920005664A KR960006924B1 (en) | 1991-04-05 | 1992-04-04 | Catalyst for purifying exhaust gas |
| BR929201213A BR9201213A (en) | 1991-04-05 | 1992-04-06 | EXHAUST GAS PURIFYING CATALYST AND EXHAUST GAS PURIFYING SYSTEM |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3202752A JPH0549940A (en) | 1991-08-13 | 1991-08-13 | Exhaust gas purifying device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0549940A true JPH0549940A (en) | 1993-03-02 |
Family
ID=16462581
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3202752A Pending JPH0549940A (en) | 1991-04-05 | 1991-08-13 | Exhaust gas purifying device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0549940A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005161311A (en) * | 1993-06-25 | 2005-06-23 | Engelhard Corp | Layered catalyst composite |
| JP2006181476A (en) * | 2004-12-27 | 2006-07-13 | Cataler Corp | Catalyst for purifying exhaust gas |
| US8127537B2 (en) | 2006-02-28 | 2012-03-06 | Johnson Matthey Public Limited Company | Exhaust system for a spark-ignited internal combustion engine |
| US8205437B2 (en) | 2007-08-31 | 2012-06-26 | Johnson Matthey Public Limited Company | On board diagnostic system |
-
1991
- 1991-08-13 JP JP3202752A patent/JPH0549940A/en active Pending
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005161311A (en) * | 1993-06-25 | 2005-06-23 | Engelhard Corp | Layered catalyst composite |
| JP2006181476A (en) * | 2004-12-27 | 2006-07-13 | Cataler Corp | Catalyst for purifying exhaust gas |
| US7846863B2 (en) | 2004-12-27 | 2010-12-07 | Cataler Corporation | Exhaust gas purifying catalyst |
| US8127537B2 (en) | 2006-02-28 | 2012-03-06 | Johnson Matthey Public Limited Company | Exhaust system for a spark-ignited internal combustion engine |
| US8205437B2 (en) | 2007-08-31 | 2012-06-26 | Johnson Matthey Public Limited Company | On board diagnostic system |
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