JPH0523593A - Exhaust emission control system - Google Patents
Exhaust emission control systemInfo
- Publication number
- JPH0523593A JPH0523593A JP3180861A JP18086191A JPH0523593A JP H0523593 A JPH0523593 A JP H0523593A JP 3180861 A JP3180861 A JP 3180861A JP 18086191 A JP18086191 A JP 18086191A JP H0523593 A JPH0523593 A JP H0523593A
- Authority
- JP
- Japan
- Prior art keywords
- catalyst
- oxide
- exhaust gas
- palladium
- inflow 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 58
- 229910052763 palladium Inorganic materials 0.000 claims abstract description 29
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 claims abstract description 28
- 229910000420 cerium oxide Inorganic materials 0.000 claims abstract description 21
- BMMGVYCKOGBVEV-UHFFFAOYSA-N oxo(oxoceriooxy)cerium Chemical compound [Ce]=O.O=[Ce]=O BMMGVYCKOGBVEV-UHFFFAOYSA-N 0.000 claims abstract description 21
- RVTZCBVAJQQJTK-UHFFFAOYSA-N oxygen(2-);zirconium(4+) Chemical compound [O-2].[O-2].[Zr+4] RVTZCBVAJQQJTK-UHFFFAOYSA-N 0.000 claims abstract description 18
- 229910001928 zirconium oxide Inorganic materials 0.000 claims abstract description 18
- 229910052809 inorganic oxide Inorganic materials 0.000 claims abstract description 17
- 229910052697 platinum Inorganic materials 0.000 claims abstract description 14
- 229910052703 rhodium Inorganic materials 0.000 claims abstract description 13
- 239000010948 rhodium Substances 0.000 claims abstract description 13
- MHOVAHRLVXNVSD-UHFFFAOYSA-N rhodium atom Chemical compound [Rh] MHOVAHRLVXNVSD-UHFFFAOYSA-N 0.000 claims abstract description 13
- 229910000287 alkaline earth metal oxide Inorganic materials 0.000 claims description 14
- 229910000510 noble metal Inorganic materials 0.000 claims description 5
- 239000006104 solid solution Substances 0.000 claims description 3
- 238000000746 purification Methods 0.000 abstract description 26
- 239000011248 coating agent Substances 0.000 abstract 2
- 238000000576 coating method Methods 0.000 abstract 2
- 229910044991 metal oxide Inorganic materials 0.000 abstract 2
- 229910003445 palladium oxide Inorganic materials 0.000 abstract 1
- JQPTYAILLJKUCY-UHFFFAOYSA-N palladium(ii) oxide Chemical compound [O-2].[Pd+2] JQPTYAILLJKUCY-UHFFFAOYSA-N 0.000 abstract 1
- 239000007789 gas Substances 0.000 description 60
- MWUXSHHQAYIFBG-UHFFFAOYSA-N nitrogen oxide Inorganic materials O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 description 22
- 229930195733 hydrocarbon Natural products 0.000 description 19
- 150000002430 hydrocarbons Chemical class 0.000 description 19
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 11
- 229910002090 carbon oxide Inorganic materials 0.000 description 11
- 239000000446 fuel Substances 0.000 description 11
- 239000007864 aqueous solution Substances 0.000 description 9
- 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
- 238000000034 method Methods 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
- 230000000694 effects Effects 0.000 description 7
- 239000000203 mixture Substances 0.000 description 7
- 239000002002 slurry Substances 0.000 description 7
- 230000000052 comparative effect Effects 0.000 description 6
- 150000003754 zirconium Chemical class 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
- 238000001035 drying Methods 0.000 description 4
- 238000010304 firing Methods 0.000 description 4
- IATRAKWUXMZMIY-UHFFFAOYSA-N strontium oxide Chemical compound [O-2].[Sr+2] IATRAKWUXMZMIY-UHFFFAOYSA-N 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
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 2
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 2
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 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
- RCFVMJKOEJFGTM-UHFFFAOYSA-N cerium zirconium Chemical compound [Zr].[Ce] RCFVMJKOEJFGTM-UHFFFAOYSA-N 0.000 description 2
- 239000002737 fuel gas Substances 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- 229910017604 nitric acid Inorganic materials 0.000 description 2
- 230000001590 oxidative effect Effects 0.000 description 2
- 239000000377 silicon dioxide Substances 0.000 description 2
- 238000001238 wet grinding Methods 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
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 1
- 239000004215 Carbon black (E152) Substances 0.000 description 1
- 229910052684 Cerium Inorganic materials 0.000 description 1
- FNIMOEHEAJDMAG-UHFFFAOYSA-N [Rh+3].[Rh+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O Chemical compound [Rh+3].[Rh+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O FNIMOEHEAJDMAG-UHFFFAOYSA-N 0.000 description 1
- 150000001242 acetic acid derivatives Chemical class 0.000 description 1
- 230000032683 aging Effects 0.000 description 1
- 229910000272 alkali metal oxide Inorganic materials 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
- 229910002091 carbon monoxide Inorganic materials 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- GWXLDORMOJMVQZ-UHFFFAOYSA-N cerium Chemical compound [Ce] GWXLDORMOJMVQZ-UHFFFAOYSA-N 0.000 description 1
- 150000001805 chlorine compounds Chemical class 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
- 230000009970 fire resistant effect Effects 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 229910017053 inorganic salt 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
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910000480 nickel oxide 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
- GNRSAWUEBMWBQH-UHFFFAOYSA-N oxonickel Chemical compound [Ni]=O GNRSAWUEBMWBQH-UHFFFAOYSA-N 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 239000002243 precursor Substances 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 229910001404 rare earth metal oxide Inorganic materials 0.000 description 1
- 239000012266 salt solution Substances 0.000 description 1
- 150000003839 salts Chemical class 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—
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用触媒に関するものであ
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 purifying catalyst that removes at the same time.
【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では
性能面で十分とは言い難い。2. Description of the Related Art In recent years, due to lower fuel consumption, the temperature of exhaust gas has been lowered, and exhaust gas regulations have been strengthened more than ever, especially H
Under the situation where the C regulation is being enforced, it cannot be said that the performance of the conventional three-way catalyst is sufficient.
【０００３】従来パラジウム触媒は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は、一般に知られて
いた。一方問題点として、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、
ＨＣ浄化能は高いが、ＮＯx浄化能が極めて低いことが
挙げられる。そのため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、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用いら
れている。Conventional palladium catalysts have high heat resistance and C in the oxidizing atmosphere of engine exhaust gas (so-called lean; air / fuel (A / F) is on the air side).
It was generally known that O and HC have high purification ability. On the other hand, as a problem, when the engine exhaust gas is in a reducing atmosphere (so-called rich; (A / F) is large on the fuel side),
Although it has a high HC purification capacity, it has a very low NOx purification capacity. Therefore, it is used only on the lean side, for example, as a so-called oxidation catalyst, or by combining rhodium having a high NOx purification ability with the above palladium, CO, H
It is used as a three-way catalyst that simultaneously purifies C and NOx.
【０００４】しかし、ロジウムは、非常に高価であるた
めに、触媒成分中の使用量が減少、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（ＣＯ）、炭化水素
（ＨＣ）及び窒素酸化物（ＮＯx）を同時に除去する排
気ガス浄化用触媒の成分としては、必須成分として不可
欠である。However, since rhodium is very expensive, it is desirable that the amount of rhodium used in the catalyst component be reduced or not used. It is indispensable as an essential component of the exhaust gas purifying catalyst that simultaneously removes carbon oxide (CO), hydrocarbon (HC) and nitrogen oxide (NOx).
【０００５】[0005]
【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 exhaust gas purification system using a catalytic converter that has a high performance of purifying exhaust gas containing a large amount of HC and that is inexpensive.
【０００６】[0006]
【課題を解決するための手段】本発明者らは、この課題
を解決するために鋭意研究の結果、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をみいだした。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。Means for Solving the Problems As a result of intensive research to solve this problem, the present inventors have found that by adding an alkaline earth metal oxide to a palladium catalyst, it directly acts on palladium and its charge It has been found that the condition is modified and the NOx purification capacity in a rich atmosphere is improved. Further, by using cerium oxide and zirconium oxide, the above-mentioned effect is further improved, and CO and HC are generated even in the vicinity of the stoichiometric ratio of the fuel gas (the amount of air required to completely burn the fuel gas). And, the improvement of NOx purification capacity was found.
【０００７】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（ｃ）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り、
（Ｂ）排気ガス流出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（ｄ）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ＮＯ
ｘの浄化能の向上、特にＨＣの浄化能の著しい向上が見
出され本発明を完成するに到ったのである。以下に、更
に詳しく本発明に係る排気ガス浄化システム及びそれを
構成する触媒について説明する。On the basis of this finding, the inventors of the present invention studied a combination of various catalysts under exhaust gas circulation, and as a result,
(A) Exhaust gas inflow side catalyst and (B) Exhaust gas outflow side catalyst, wherein (A) exhaust gas inflow side catalyst is palladium, alkaline earth metal oxide, cerium oxide, zirconium oxide and A monolithic structure coated with a catalyst component composed of a refractory inorganic oxide (c),
(B) A catalyst component on the exhaust gas outflow side contains a catalyst component containing (a) rhodium and platinum as noble metals, or (b) rhodium, platinum and palladium, and a refractory inorganic oxide (d) in an integral structure. With the exhaust gas purification system characterized by being coated, CO, HC and NO
The improvement of the purification ability of x, particularly the purification ability of HC was found, and the present invention was completed. Hereinafter, the exhaust gas purification system according to the present invention and the catalyst constituting the same will be described in more detail.
【０００８】本発明に係る（Ａ）排気ガス流入側に設置
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 (A) installed on the exhaust gas inflow side according to the present invention integrally comprises a catalyst component composed of palladium, alkaline earth metal oxide, cerium oxide, zirconium oxide and refractory inorganic oxide. The structure is coated.
【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
If it 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、セリウム酸化物又は耐火性無機酸化物に単独に又は
またがって担持されてなる。The position on which palladium is carried depends on the amount and conditions of use, but it is carried on zirconium oxide, cerium oxide, or refractory inorganic oxide alone or straddling.
【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０．５〜２０
ｇである。０．１ｇ未満であるときは、添加効果が少な
く、５０ｇを超えるときは、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 20
It is g. When it is less than 0.1 g, the effect of addition is small, and when 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
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. The alkaline earth metal oxide used may be either the oxide itself or a precursor thereof, for example, 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 the alkaline earth metal oxide is less than 1/100, the ternary performance is deteriorated, and in particular, the NO purification rate is poor, and when the amount of the alkaline earth metal oxide is more than 150/1, the addition effect is improved. However, the loading ratio and loading amount are limited depending on the relationship between the loading amount of oxides and the like 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 single mixture. 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よりセリウム酸化物が多くな
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
セリウム酸化物とジルコニウム酸化物の固溶体の調製方
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 the cerium oxide and the zirconium oxide will be described below, but the preparation method is not particularly limited as long as it has the above composition ratio.
【００１７】市販のセリウム酸化物に水可溶性のジルコ
ニウム塩を担持する方法、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、水可溶性のセ
リウム塩、ジルコニウム塩を混合後、耐火性無機酸化物
（ｃ）に担持する方法あるいは、一体構造体に耐火性無
機酸化物（ｃ）を塗布後、セリウム塩、ジルコニウム塩
溶液を浸漬する方法等が挙げられる。また用いるセリウ
ム、ジルコニウム各塩は特に限定されず、市販の硝酸
塩、酢酸塩、硫酸塩あるいは塩化物等が用いられる。A method of supporting a water-soluble zirconium salt on a commercially available cerium oxide, a method of mixing and drying the water-soluble cerium salt and the zirconium salt, and a method of firing the mixture, a method of mixing the water-soluble cerium salt and the zirconium salt, and fire resistance. Examples thereof include a method of supporting the inorganic oxide (c) or a method of immersing a cerium salt or zirconium salt solution after applying the refractory inorganic oxide (c) to the integral structure. The cerium and zirconium salts 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（ｃ）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
排気ガス流入側の完成触媒とする。Examples of the refractory inorganic oxide (c) 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 inflow side.
【００１９】使用される耐火性無機酸化物（ｃ）の量
は、好ましくは触媒１リットル当たり、５０ｇ〜３００
ｇ、さらに好ましくは、５０ｇ〜２５０ｇである。The amount of refractory inorganic oxide (c) used is preferably from 50 g to 300 per liter of catalyst.
g, and more preferably 50 to 250 g.
【００２０】本発明に係る（Ｂ）排気ガス流出側の触媒
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（ｄ）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 (B) exhaust gas outflow side catalyst according to the present invention contains (a) rhodium and platinum, or (b) rhodium, platinum and palladium, and a refractory inorganic oxide (d) as a noble metal. Is a monolithic structure coated with the following 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、好ましくは触媒１リット
ル当たり０．１ｇ〜１０．０ｇ、さらに好ましくは０．
３ｇ〜５．０ｇである。０．１ｇ未満である場合は、浄
化能が低く、１０．０ｇを越える場合は、添加量に見合
う効果が少ないものである。The noble metal used is (a) rhodium and platinum, or (b) rhodium, platinum and palladium, and the amount of these is preferably 0.1 g to 10.0 g, and more preferably 1 g per liter of the catalyst. Is 0.
It is 3 g to 5.0 g. If it is less than 0.1 g, the purifying ability is low, and if it exceeds 10.0 g, the effect commensurate with the added amount is small.
【００２２】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、セリウム酸化物、ジルコニ
ウム酸化物、アルカリ金属酸化物、アルカリ土類金属酸
化物、希土類金属酸化物、酸化鉄、酸化コバルト、酸化
ニッケル等が使用される。これらの酸化物のうち好まし
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。Examples of the refractory inorganic oxide (d) include activated alumina, silica, titania, cerium oxide, zirconium oxide, alkali metal oxide, alkaline earth metal oxide, rare earth metal oxide, iron oxide, and oxide. Cobalt, nickel oxide, etc. are used. Of these oxides, activated alumina, cerium oxide, and zirconium oxide are preferable.
【００２３】使用される耐火性無機酸化物（ｄ）の量
は、好ましくは触媒１リットル当たり５０ｇ〜３５０
ｇ、さらに好ましくは、５０ｇ〜３００ｇである。The amount of refractory inorganic oxide (d) used is preferably from 50 g to 350 per liter of catalyst.
g, and more preferably 50 g to 300 g.
【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 for (A) the exhaust gas inflow side catalyst and (B) the exhaust gas outflow side catalyst is
Generally, 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, and the material is fire resistant. Any of these may be used, and for example, an integrated 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、好ましくは１００：１〜
１：１００、さらに好ましくは、５０：１〜１：５０で
ある。１００：１より（Ａ）排気ガス流入側の触媒の体
積が大きい場合、または１：１００より（Ａ）排気ガス
流入側の触媒の体積が小さい場合のいずれであっても組
合せの効果が少ないものである。The volume ratio of (A) the exhaust gas inflow side catalyst to (B) the exhaust gas outflow side catalyst is preferably 100: 1 to 1: 1.
1: 100, more preferably 50: 1 to 1:50. If the volume of the catalyst on the exhaust gas inflow side (A) is larger than 100: 1, or if the volume of the catalyst on the (A) exhaust gas inflow side is smaller than 1: 100, the effect of the combination is small. Is.
【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、触媒の搭載位置によ
り適宜、各々分離して設置することもできる。The catalyst on the exhaust gas inflow side (A) and the catalyst on the exhaust gas outflow side (B) can be installed in the same catalytic converter, and are appropriately separated according to the exhaust pipe and the mounting position of the catalyst. It can also be installed.
【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
割し使用ることもできる。It is not necessary that each of (A) the exhaust gas inflow side catalyst and (B) the exhaust gas outflow side catalyst be one, and the shape of the exhaust pipe, the place where the catalyst is installed, and the exhaust gas back pressure increase. (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 present 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：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／ＺｒＯ2の比で１０／１（ＣｅＯ2とＺｒＯ2
の合計が１００ｇ）となるように混合し、乾燥後、５０
０℃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０．５ｌ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: commercially available cerium oxide (CeO 2 ,
An aqueous zirconyl oxynitrate solution having a specific surface area of 149 m 2 / g was used as a CeO 2 / ZrO 2 ratio of 10/1 (CeO 2 and ZrO 2).
So that the total amount is 100 g), and after drying, 50
200 g of powder obtained by firing at 0 ° C. for 1 hour and 400 g of activated alumina (γ · Al 2 O 3 , specific surface area of 155 m 2 / g), 33.4 g of barium acetate, and 12 g of palladium were added to the aqueous solution of palladium nitrate, An aqueous slurry was prepared by wet milling with a ball mill. 0.5 l of a cordierite monolithic carrier having 400 cells per 1 inch square in cross section was immersed in this slurry, taken out, and the 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：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・Ａ
ｌ2Ｏ3、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（ＣｅＯ2：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。Exhaust gas outflow side catalyst: Nitric acid aqueous solution of dinitrodiamine platinum containing 3.33 g of platinum and rhodium
Rhodium nitrate containing 667 g was activated alumina (γ ・ A
l 2 O 3 and a specific surface area of 155 m 2 / g) 400 g were impregnated, dried and calcined at 400 ° C. for 2 hours, and a commercially available cerium oxide (CeO 2 : specific surface area 149 m 2 / g) 200 g was ball-milled. An aqueous slurry was prepared by wet milling with. This slurry has a cross-sectional area of 400 per square inch
Cordierite monolithic carrier with 0.5 cells 0.5
After immersing and taking out 1 liter, the excess slurry in the cell was blown off with compressed air, followed by drying and firing to obtain a finished catalyst.
【００３１】（実施例２）実施例１において、排ガス流
入側触媒の酢酸バリウム３３．４ｇを１００．２ｇ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 catalyst on the exhaust gas inflow side was changed to 100.2 g.
【００３２】（実施例３）実施例１において、排ガス流
入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 finished catalyst was obtained in the same manner as in Example 1 except that 33.4 g of barium acetate as the exhaust gas inflow 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
入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 of the exhaust gas inflow side catalyst.
【００３４】（実施例５）実施例１において、排ガス流
入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 of the exhaust gas inflow side catalyst is 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
入側触媒の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 inflow 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
入側触媒の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 inflow side catalyst was set to 10/1 (CeO 2
And ZrO 2 total 320 g), and activated alumina 28
A completed 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
入側触媒の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 inflow 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
入側触媒の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 inflow 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
流入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 inflow 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
流入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 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 inflow 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
流入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 completed catalyst was obtained in the same manner as in Example 1 except that the palladium nitrate aqueous solution containing 12 g of palladium as the exhaust gas inflow 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
流入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 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 inflow 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
流出側触媒の白金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 Except that 3.33 g of platinum of the exhaust gas outflow 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 in Example 1. 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
入側触媒を流出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 inflow side catalyst was changed to the same as the outflow side catalyst.
【００４５】（比較例２）実施例１において、排ガス流
入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 inflow side catalyst was removed.
【００４６】（比較例３）実施例１の排ガス流入側触媒
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 was repeated except that zirconyl oxynitrate was omitted from the exhaust gas inflow 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の排ガス流入側触媒
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 inflow 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 the running of the engine.
【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６０
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８５０
℃となる条件で５０時間触媒をエージングした。Commercially available electronically controlled engine (8 cylinders 4
400cc) was used, and each catalyst was connected to the exhaust system of the engine and a durability test was conducted. Engine is in steady operation 60
Second, deceleration 6 seconds (fuel is cut during deceleration, catalyst is
Exposed to the severe conditions of high temperature oxidizing atmosphere. ) Mode operation and the catalyst inlet gas temperature is 850 during steady operation
The catalyst was aged for 50 hours under the condition of the temperature.
【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±１．０
Ａ／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 catalyst performance after aging was evaluated 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 the external oscillator into the engine control unit to adjust the air-fuel ratio (A / F) to ± 1.0.
While oscillating at A / F and 1 Hz, the average air-fuel ratio is continuously changed, 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 14.1.
Up to the purifying ability of CO, HC and NO.
【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 of the CO and NO purification rates curves (called a crossover point) 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 at 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 CO, HC, and NO purification rates were determined 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低温で、ＨＣ，
ＣＯ及びＮＯの三成分を同時除去できる。さらに、良好
な三元性能、特にＨＣ浄化能の向上が示される。The catalysts disclosed in the present invention are
The three components of CO and NO can be removed simultaneously. Furthermore, a good ternary performance, in particular an improvement in the HC purification capacity, is shown.
【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 ─────────────────────────────────────────────────── ─── Continued front page (72) Inventor Tomohisa Ohata Hyogo prefecture Himeji city 1 Inside Japan Catalyst Research Institute
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
（ｃ）より構成される触媒成分を一体構造体に被覆した
ものであり、（Ｂ）排気ガス流出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（ｄ）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
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 palladium, an alkaline earth metal oxide, or a cerium oxide. , A zirconium oxide and a refractory inorganic oxide (c) are coated on a monolithic structure, and (B) the exhaust gas outflow side catalyst has noble metals (a) rhodium and platinum, or (B) An exhaust gas purifying system characterized in that an integral structure is coated with a catalyst component containing rhodium, platinum and palladium, and a refractory inorganic oxide (d).
造体１リットル当りに対して、パラジウムが０．５〜３
０ｇ、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が１０〜３００ｇ
を被覆したものである請求項１の触媒。2. (A) The catalyst on the exhaust gas inflow side contains 0.5 to 3 palladium per liter of the integrated structure.
0 g, 0.1 to 50 g of alkaline earth metal oxide, 10 to 100 g of cerium oxide, 0.1 to 30 g of zirconium oxide, and 10 to 300 g of refractory inorganic oxide.
The catalyst according to claim 1, which is coated with.
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の触
媒。3. The catalyst according to claim 1, wherein at least a part of (A) the cerium oxide and the zirconium oxide contained in the catalyst on the exhaust gas inflow side is present as a complex or 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記載の触媒。4. The catalyst according to claim 1, wherein the ratio of the cerium oxide to the zirconium oxide (weight ratio in terms of oxide) is 100: 2 to 100: 60.
Priority Applications (8)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3180861A JPH0523593A (en) | 1991-07-22 | 1991-07-22 | Exhaust emission control system |
| CA002064977A CA2064977C (en) | 1991-04-05 | 1992-04-02 | Catalyst for purifying exhaust gas |
| US07/862,967 US5260249A (en) | 1991-04-05 | 1992-04-03 | Catalyst for purifying automotive exhaust gas |
| AT92302928T ATE149870T1 (en) | 1991-04-05 | 1992-04-03 | CATALYST FOR PURIFYING EXHAUST GASES |
| EP92302928A EP0507590B1 (en) | 1991-04-05 | 1992-04-03 | Catalyst for purifying exhaust gas |
| DE69218017T DE69218017T2 (en) | 1991-04-05 | 1992-04-03 | Catalytic converter for cleaning exhaust gases |
| 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 |
|---|---|---|---|
| JP3180861A JPH0523593A (en) | 1991-07-22 | 1991-07-22 | Exhaust emission control system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0523593A true JPH0523593A (en) | 1993-02-02 |
Family
ID=16090639
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3180861A Pending JPH0523593A (en) | 1991-04-05 | 1991-07-22 | Exhaust emission control system |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0523593A (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005161311A (en) * | 1993-06-25 | 2005-06-23 | Engelhard Corp | Layered catalyst composite |
| JP2006026635A (en) * | 1993-04-28 | 2006-02-02 | Nippon Shokubai Co Ltd | Method of removing nitrogen oxides contained in exhaust gas |
| EP1674148A2 (en) | 2004-12-27 | 2006-06-28 | Cataler Corporation | Exhaust gas purifying catalyst |
| JP2010184238A (en) * | 1993-04-28 | 2010-08-26 | Nippon Shokubai Co Ltd | Method of removing nitrogen oxides in exhaust gas |
| US8071502B2 (en) | 2005-05-24 | 2011-12-06 | Cataler Corporation | Exhaust gas purifying catalyst |
| JP2013256954A (en) * | 2002-09-13 | 2013-12-26 | Johnson Matthey Plc | Compression ignition engine and exhaust system therefor |
| CN110152697A (en) * | 2019-06-25 | 2019-08-23 | 无锡威孚环保催化剂有限公司 | The preparation method of single coating gasoline car three-way catalyst |
-
1991
- 1991-07-22 JP JP3180861A patent/JPH0523593A/en active Pending
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006026635A (en) * | 1993-04-28 | 2006-02-02 | Nippon Shokubai Co Ltd | Method of removing nitrogen oxides contained in exhaust gas |
| JP2010184238A (en) * | 1993-04-28 | 2010-08-26 | Nippon Shokubai Co Ltd | Method of removing nitrogen oxides in exhaust gas |
| JP2012236193A (en) * | 1993-04-28 | 2012-12-06 | Nippon Shokubai Co Ltd | Method of removing nitrogen oxides in exhaust gas |
| JP2005161311A (en) * | 1993-06-25 | 2005-06-23 | Engelhard Corp | Layered catalyst composite |
| JP2013256954A (en) * | 2002-09-13 | 2013-12-26 | Johnson Matthey Plc | Compression ignition engine and exhaust system therefor |
| EP1674148A2 (en) | 2004-12-27 | 2006-06-28 | Cataler Corporation | Exhaust gas purifying catalyst |
| JP2006181476A (en) * | 2004-12-27 | 2006-07-13 | Cataler Corp | Catalyst for purifying exhaust gas |
| EP1674148A3 (en) * | 2004-12-27 | 2009-03-04 | Cataler Corporation | Exhaust gas purifying catalyst |
| US7846863B2 (en) | 2004-12-27 | 2010-12-07 | Cataler Corporation | Exhaust gas purifying catalyst |
| US8071502B2 (en) | 2005-05-24 | 2011-12-06 | Cataler Corporation | Exhaust gas purifying catalyst |
| CN110152697A (en) * | 2019-06-25 | 2019-08-23 | 无锡威孚环保催化剂有限公司 | The preparation method of single coating gasoline car three-way catalyst |
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