JPS6271542A - Catalyst for cleaning up exhaust gas of engine - Google Patents
Catalyst for cleaning up exhaust gas of engineInfo
- Publication number
- JPS6271542A JPS6271542A JP60211639A JP21163985A JPS6271542A JP S6271542 A JPS6271542 A JP S6271542A JP 60211639 A JP60211639 A JP 60211639A JP 21163985 A JP21163985 A JP 21163985A JP S6271542 A JPS6271542 A JP S6271542A
- Authority
- JP
- Japan
- Prior art keywords
- catalyst
- exhaust gas
- agent
- content
- coating layer
- 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 98
- 238000004140 cleaning Methods 0.000 title abstract 2
- 239000007789 gas Substances 0.000 claims abstract description 73
- 239000003795 chemical substances by application Substances 0.000 claims abstract description 56
- 239000011247 coating layer Substances 0.000 claims abstract description 39
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims abstract description 22
- 239000010410 layer Substances 0.000 claims abstract description 22
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 claims abstract description 19
- 239000010948 rhodium Substances 0.000 claims abstract description 10
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 claims abstract description 9
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims abstract description 9
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 9
- 239000001301 oxygen Substances 0.000 claims abstract description 9
- 229910052697 platinum Inorganic materials 0.000 claims abstract description 9
- 229910052763 palladium Inorganic materials 0.000 claims abstract description 5
- 229910052703 rhodium Inorganic materials 0.000 claims abstract description 5
- MHOVAHRLVXNVSD-UHFFFAOYSA-N rhodium atom Chemical compound [Rh] MHOVAHRLVXNVSD-UHFFFAOYSA-N 0.000 claims abstract description 5
- 229910000480 nickel oxide Inorganic materials 0.000 claims abstract description 3
- GNRSAWUEBMWBQH-UHFFFAOYSA-N oxonickel Chemical compound [Ni]=O GNRSAWUEBMWBQH-UHFFFAOYSA-N 0.000 claims abstract description 3
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 claims description 4
- 229910000476 molybdenum oxide Inorganic materials 0.000 claims description 2
- PQQKPALAQIIWST-UHFFFAOYSA-N oxomolybdenum Chemical compound [Mo]=O PQQKPALAQIIWST-UHFFFAOYSA-N 0.000 claims description 2
- 229910052684 Cerium Inorganic materials 0.000 claims 1
- GWXLDORMOJMVQZ-UHFFFAOYSA-N cerium Chemical compound [Ce] GWXLDORMOJMVQZ-UHFFFAOYSA-N 0.000 claims 1
- 230000001590 oxidative effect Effects 0.000 claims 1
- 229910000420 cerium oxide Inorganic materials 0.000 abstract description 21
- BMMGVYCKOGBVEV-UHFFFAOYSA-N oxo(oxoceriooxy)cerium Chemical compound [Ce]=O.O=[Ce]=O BMMGVYCKOGBVEV-UHFFFAOYSA-N 0.000 abstract description 21
- 238000006243 chemical reaction Methods 0.000 abstract description 5
- 238000002485 combustion reaction Methods 0.000 abstract 1
- 230000003247 decreasing effect Effects 0.000 abstract 1
- 238000000746 purification Methods 0.000 description 31
- 239000002002 slurry Substances 0.000 description 17
- 230000000694 effects Effects 0.000 description 10
- 238000000034 method Methods 0.000 description 10
- 230000007423 decrease Effects 0.000 description 9
- 239000011248 coating agent Substances 0.000 description 8
- 238000000576 coating method Methods 0.000 description 8
- 239000007788 liquid Substances 0.000 description 8
- 230000015572 biosynthetic process Effects 0.000 description 7
- 238000011156 evaluation Methods 0.000 description 7
- 238000003786 synthesis reaction Methods 0.000 description 7
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 6
- 229910001593 boehmite Inorganic materials 0.000 description 6
- FAHBNUUHRFUEAI-UHFFFAOYSA-M hydroxidooxidoaluminium Chemical compound O[Al]=O FAHBNUUHRFUEAI-UHFFFAOYSA-M 0.000 description 6
- 229910017604 nitric acid Inorganic materials 0.000 description 6
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 6
- 230000000052 comparative effect Effects 0.000 description 5
- 239000010970 precious metal Substances 0.000 description 5
- 150000001875 compounds Chemical class 0.000 description 4
- 238000010586 diagram Methods 0.000 description 4
- 239000000203 mixture Substances 0.000 description 4
- 239000006255 coating slurry 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
- 238000010304 firing Methods 0.000 description 3
- 239000000446 fuel Substances 0.000 description 3
- 238000010438 heat treatment Methods 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- MWUXSHHQAYIFBG-UHFFFAOYSA-N nitrogen oxide Inorganic materials O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 description 3
- 229910000510 noble metal Inorganic materials 0.000 description 3
- 239000002253 acid Substances 0.000 description 2
- 239000007864 aqueous solution Substances 0.000 description 2
- 239000010953 base metal Substances 0.000 description 2
- 238000007664 blowing Methods 0.000 description 2
- 230000003197 catalytic effect Effects 0.000 description 2
- CETPSERCERDGAM-UHFFFAOYSA-N ceric oxide Chemical compound O=[Ce]=O CETPSERCERDGAM-UHFFFAOYSA-N 0.000 description 2
- 229910000422 cerium(IV) oxide Inorganic materials 0.000 description 2
- 230000006866 deterioration Effects 0.000 description 2
- 238000001035 drying Methods 0.000 description 2
- SONJTKJMTWTJCT-UHFFFAOYSA-K rhodium(iii) chloride Chemical compound [Cl-].[Cl-].[Cl-].[Rh+3] SONJTKJMTWTJCT-UHFFFAOYSA-K 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- 238000003756 stirring Methods 0.000 description 2
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical group [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 1
- 239000004480 active ingredient Substances 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 229910002091 carbon monoxide Inorganic materials 0.000 description 1
- 239000000969 carrier Substances 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 239000002270 dispersing agent Substances 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 150000002430 hydrocarbons Chemical class 0.000 description 1
- 239000012784 inorganic fiber Substances 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 210000003127 knee Anatomy 0.000 description 1
- 229940057995 liquid paraffin Drugs 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 231100000572 poisoning Toxicity 0.000 description 1
- 230000000607 poisoning effect Effects 0.000 description 1
- 239000002689 soil Substances 0.000 description 1
- 229910052717 sulfur Inorganic materials 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
- 229910052720 vanadium Inorganic materials 0.000 description 1
- 235000021419 vinegar Nutrition 0.000 description 1
- 239000000052 vinegar Substances 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Landscapes
- Exhaust Gas Treatment By Means Of Catalyst (AREA)
- Catalysts (AREA)
Abstract
Description
【発明の詳細な説明】
（産業上の利用分野）
未発８Ｂは 肉歇周朋篤 灼１３−白ｍｈ市ｈ１＾挑出
六れる排気ガス中の一酸化炭素（以下、ＣＯという）、
炭化水素（以下、Ｉ Ｃという）および酸化窒素（以下
、ＮＯＸという）を低減せしめるために用いられるエン
ジンの排気ガス浄化用触媒に関するものである。[Detailed description of the invention] (Industrial application field) Unexploded 8B is carbon monoxide (hereinafter referred to as CO) in the exhaust gas,
The present invention relates to a catalyst for purifying engine exhaust gas used to reduce hydrocarbons (hereinafter referred to as IC) and nitrogen oxides (hereinafter referred to as NOX).
（従来技術）
従来より、自動車排気ガス中のＣ０１ＨＣ，ＮＯｘを浄
化する触媒として、白金（ｐｔ）、ロジウム（Ｒｈ）、
パラジウム（Ｐｄ）等の一貴金属をアルミナ（Ａ（ｌｚ
ｏ＋）に担持したものが用いられている。又、これら貴
金属の触媒性能を向上させるために、酸素貯蔵能効果（
排気ガス中の酸素を取り込み、この酸素を触媒の浄化に
寄与させる効果）がある酸化セリウム（ＣｅＯｚ）を、
貴金属といっしょにアルミナコート層に含有させ、排気
ガスの浄化率を高めようとした触媒が製造されてきてい
る。(Prior art) Conventionally, platinum (PT), rhodium (Rh),
A noble metal such as palladium (Pd) is mixed with alumina (A(lz
o+) is used. In addition, in order to improve the catalytic performance of these precious metals, the oxygen storage capacity effect (
Cerium oxide (CeOz) has the effect of capturing oxygen from exhaust gas and contributing to the purification of the catalyst.
Catalysts have been manufactured in which precious metals are included in the alumina coat layer to increase the purification rate of exhaust gas.
しかし、貴金属および卑金属の触媒成分と、酸化セリウ
ム等の酸素貯蔵能付与剤（以下、Ｏ８Ｃ剤という）とを
アルミナコート層に共存させて担持する方法には、以下
に述べるような問題があった。However, the method of coexisting and supporting noble metal and base metal catalyst components and an oxygen storage capacity imparting agent (hereinafter referred to as O8C agent) such as cerium oxide on an alumina coating layer has the following problems. .
（ａ）Ｏ３Ｃ剤はアルミナコート層に均一に担持されて
いるため、必ずしもボア付近の排気ガスと接触しやすい
領域に担持されていない。つまり、Ｏ８Ｃ剤の多くは、
排気ガスの拡散しずらい部分に担持されており、浄化反
応に関与せず、高浄化率が得られない。(a) Since the O3C agent is uniformly supported on the alumina coat layer, it is not necessarily supported in the area near the bore where it is likely to come into contact with exhaust gas. In other words, many O8C agents are
It is carried in parts of the exhaust gas that are difficult to diffuse, and does not participate in the purification reaction, making it impossible to obtain a high purification rate.
（ｂ）ｏｓｃ剤と、触媒成分およびアルミナとの直接的
な接触が多くなるため、Ｏ８Ｃ剤の熱不安定性がこれら
に悪影響をおよぼす。(b) Thermal instability of the O8C agent adversely affects the OSC agent as there is more direct contact with the catalyst components and alumina.
（ｃ）ＯＳＣ剤が触媒成分といっしょに担持されている
ため、両者が化合物をつくり、触媒成分の分散性を低下
させ、排気ガス浄化性能が低下する。(c) Since the OSC agent is supported together with the catalyst component, both of them form a compound, reducing the dispersibility of the catalyst component and reducing the exhaust gas purification performance.
また、触媒担体に、Ｐｔ、Ｐｄなどを含有する触媒層を
設け、該触媒層の保護のためにアルミナまたはアルミナ
と酸化セリウム（アルミナに対して型車比で０．１〜０
．５％）の混合物からなる酸化物の被覆層を設けるよう
にしたものが提案されている（特開昭６０−５２３０号
公報参照）。この公知技術の場合、ＯＳＣ剤の濃度が低
濃度すぎるため、酸素貯蔵能効果を期待することができ
ない。In addition, a catalyst layer containing Pt, Pd, etc. is provided on the catalyst carrier, and in order to protect the catalyst layer, alumina or alumina and cerium oxide (0.1 to 0.0
．． 5%) has been proposed (see Japanese Patent Laid-Open No. 60-5230). In the case of this known technique, the concentration of the OSC agent is too low, so no effect on oxygen storage capacity can be expected.
そこで、高濃度のＯ８Ｃ剤を含有する被覆層を形成する
ことが考えられるが、一般にＯ８Ｃ剤の熱容量が大きい
ところから、被覆層に覆われた触媒層の暖気性が悪（な
り、エンジンの低温始動時におけ乞排気ガス浄化性能が
充分得られないという問題が生ずるおそれがある。Therefore, it is possible to form a coating layer containing a high concentration of O8C agent, but since the heat capacity of O8C agent is generally large, the warm-up properties of the catalyst layer covered with the coating layer are poor (and the low temperature of the engine There is a possibility that a problem may arise in that sufficient exhaust gas purification performance cannot be obtained at the time of startup.
（発明の目的）
本発明は、上記の問題点に鑑みてなされたもので、貴金
属あるいは卑金属からなる触媒成分を含む触媒層の上面
に設けた高濃度のＯ８Ｃ剤を含有する被覆層において、
反応寄与の高い排気ガス入り口側におけるＯ８Ｃ剤含有
量を排気ガス出口側より減少さ仕ることζごより、エン
ジン始動時におけるコールドスタート性能の向上を図る
ことを目的とするものである。(Object of the Invention) The present invention has been made in view of the above-mentioned problems, and includes a coating layer containing a high concentration of O8C agent provided on the upper surface of a catalyst layer containing a catalyst component made of a noble metal or a base metal.
The purpose is to improve the cold start performance when starting the engine by reducing the O8C agent content on the exhaust gas inlet side, which has a high reaction contribution, than on the exhaust gas outlet side.
（目的を達成するための手段）
本発明では、上記目的を達成するための手段として、触
媒担体に担持され、触媒成分を含有した触媒１の上面に
、高濃度のＯ８Ｃ剤を含む被覆層を設けるに当たって、
前記触媒担体の排気ガス入り口側の被覆層におけるＯ８
Ｃ剤の含有量が、排気ガス出口側の含有量の２０〜５０
％となるようにしている。(Means for achieving the object) In the present invention, as a means for achieving the above object, a coating layer containing a high concentration of O8C agent is provided on the upper surface of the catalyst 1 supported on a catalyst carrier and containing a catalyst component. In establishing the
O8 in the coating layer on the exhaust gas inlet side of the catalyst carrier
The content of C agent is 20 to 50 of the content on the exhaust gas outlet side.
%.
ここで、触媒成分としては、ＰＬ、Ｒｈ％Ｐｄなどの公
知成分およびそれらの二種以上の混合物が使用される。Here, as the catalyst component, known components such as PL, Rh%Pd, and mixtures of two or more thereof are used.
また、Ｏ８Ｃ剤の成分としては、酸化セリウム（ＣｅＯ
，）、酸化ニッケル（Ｎｉｐ）、酸化モリブデン（Ｍｏ
ｂ）、酸化鉄（Ｆｅ、ＯｚあるいはＦｅｄ）などの公知
成分およびそれらの二種以上の混合物が使用されるが、
Ｃｅｎｔが最も効果的である。In addition, as a component of the O8C agent, cerium oxide (CeO
), nickel oxide (Nip), molybdenum oxide (Mo
b), known components such as iron oxide (Fe, Oz or Fed) and mixtures of two or more thereof are used;
Cent is the most effective.
前記被覆層において、排気ガス入り口側におけるＯ８Ｃ
剤含有１を、排気ガス出口側における含有Ｍの２０〜５
０％とするには、排気ガス入り口側と排気ガス出口側と
で被覆層の厚さを変える方法あるいは排気ガス入り口側
と排気ガス出口側とでＯ８Ｃ剤の濃度を変える方法等が
採用される。In the coating layer, O8C on the exhaust gas inlet side
agent content 1 and content M on the exhaust gas outlet side 20 to 5
To make it 0%, a method is adopted such as changing the thickness of the coating layer on the exhaust gas inlet side and the exhaust gas outlet side, or changing the concentration of the O8C agent on the exhaust gas inlet side and the exhaust gas outlet side. .
前記被覆層の組成は、５０〜９５重量％のＯ８Ｃ剤とＩ
ＩＸ部の活性アルミナとオスのが望すｊ−？−そのコー
ティングは、Ｏ８Ｃ剤、活性アルミナ、水和アルミナ、
その他の分散剤からなる水性スラリーを用いて行う。な
お、被覆層の付着量は触媒担体に対して２〜３０重１％
とするのが望ましい。The composition of the coating layer is 50 to 95% by weight of O8C agent and I
Activated alumina of part IX and male desired j-? - The coating consists of O8C agent, activated alumina, hydrated alumina,
It is carried out using an aqueous slurry consisting of other dispersants. The amount of coating layer deposited is 2 to 30% by weight relative to the catalyst carrier.
It is desirable to do so.
かくして形成された排気ガス浄化用触媒の一例が第１図
および第２図に拡大して示されている。An example of the exhaust gas purifying catalyst thus formed is shown enlarged in FIGS. 1 and 2.
ここで、符号ｌは触媒担体、２は触媒層、３は被覆層、
３ａは排気ガス入り口側、３ｂは排気ガス出口側をそれ
ぞれ示している。該触媒担体ｌとしては、コージライト
等のセラミックスからなるハニカム構造体あるいは耐熱
金属及び耐熱無機繊維よりなる各種担体が使用される。Here, the code l is a catalyst carrier, 2 is a catalyst layer, 3 is a coating layer,
3a indicates the exhaust gas inlet side, and 3b indicates the exhaust gas outlet side. As the catalyst carrier 1, a honeycomb structure made of ceramics such as cordierite or various carriers made of heat-resistant metals and heat-resistant inorganic fibers are used.
（作 用）
上記のように、触媒成分の上層に高濃度Ｏ８Ｃ剤を含む
被覆層をコーチ１ングすることにより、Ｏ８Ｃ剤が触媒
成分に酸素貯蔵能を発生し易いように、近接して担持さ
れるばかりでなく、排気ガスと接触し易い表面コートの
ボア付近にＯ８Ｃ剤が効率よく担持される状態となり、
しかも、高濃度のＯ８Ｃ剤を含む被覆層に覆われている
ため、触媒層が被毒劣化および熱劣化を受けにくくなる
ところから、高浄化性能を示す。(Function) As mentioned above, by coating the upper layer of the catalyst component with a coating layer containing a high concentration O8C agent, the O8C agent is supported in close proximity to the catalyst component so that it can easily generate oxygen storage capacity. Not only that, but the O8C agent is efficiently supported near the bore of the surface coat that easily comes into contact with exhaust gas,
Furthermore, since the catalyst layer is covered with a coating layer containing a high concentration of O8C agent, the catalyst layer is less susceptible to poisoning deterioration and thermal deterioration, thus exhibiting high purification performance.
また、触媒層と被覆層とが分雌伏態で形成されているこ
とにより、触媒成分がＯ８Ｃ剤の熱不安定性の影響を受
けたり、化合物を生成したりすることもない。Further, since the catalyst layer and the coating layer are formed in a closed state, the catalyst component is not affected by the thermal instability of the O8C agent, and no compounds are generated.
さらに、被覆屑において、排気ガス入り口側にお１ノる
Ｏ８Ｃ剤含有量を排気ガス出口側のＯＳＣＳ合剤量の２
０〜５０％としたことにより、反応寄与の高い排気ガス
入り口側では、熱容量の大きなＯ８Ｃ剤が少なくなり、
エンジン始動時におけるコールドスタート性能が良好に
なる。Furthermore, in the coating waste, the O8C agent content on the exhaust gas inlet side is 2 times the amount of OSCS mixture on the exhaust gas outlet side.
By setting it at 0% to 50%, there is less O8C agent with large heat capacity on the exhaust gas inlet side where reaction contribution is high.
Cold start performance when starting the engine is improved.
なお、排気ガス浄化用触媒において、排気ガス入り口側
のＯ８Ｃ剤含有量を減少させると、コールドスタート性
能は改善されるが、排気ガス出口側の含有量（通常のＯ
８Ｃ剤含有量、例えば、約４゜０ｍｇ／ｃＩ！＋’）の
２０％以下になると、触媒成分とＯ９Ｃ剤とが効果的に
担持される割合が極端に減少し、充分な酸素貯蔵能効果
が得られなくなる。また、排気ガス入り口側のＯ５Ｃ剤
含有量が排気ガス出口側の含有量の５０％以上になると
、コールドスタート性能の改善効果か表れなくなる。In addition, in the exhaust gas purifying catalyst, if the content of O8C agent on the exhaust gas inlet side is reduced, the cold start performance is improved, but the content on the exhaust gas outlet side (normal O8C agent content) is improved.
8C agent content, for example, about 4°0 mg/cI! +') below 20%, the ratio at which the catalyst component and O9C agent are effectively supported is extremely reduced, making it impossible to obtain a sufficient oxygen storage effect. Furthermore, when the content of the O5C agent on the exhaust gas inlet side becomes 50% or more of the content on the exhaust gas outlet side, the effect of improving cold start performance is no longer apparent.
以下、本発明の好適な実施例を説明する。Hereinafter, preferred embodiments of the present invention will be described.
実施例１
γ−アルミナ１６０ｇ、ベーマイト１６０ｇ、水５００
ｃｃ。Example 1 γ-alumina 160g, boehmite 160g, water 500g
cc.
濃硝酸４ｃｃをホモミキサーにより１０時間混合撹拌し
、アルミナウォッンユコート用スラリーを得た。4 cc of concentrated nitric acid was mixed and stirred using a homomixer for 10 hours to obtain a slurry for alumina wonyu coat.
このスラリーにハニカム触媒担体（コージライト製）を
浸漬して引き上げた後、余分のスラリーを高圧エアブロ
−で除去し、１２０℃で１時間乾燥後、６００℃で１時
間焼成した。A honeycomb catalyst carrier (made of cordierite) was immersed in this slurry and pulled up, the excess slurry was removed by high-pressure air blowing, dried at 120°C for 1 hour, and then calcined at 600°C for 1 hour.
このアルミナコートした触媒担体を所定の濃度の塩化白
金酸・塩化ロジウム混合水溶液に浸漬して引き上げた後
、１５０℃で１時間乾燥し、次いで６００℃で２時間焼
成した。焼成後の貴金属含有量１よ白金（ＰＬ）１．０
ｇ／（１，ロジウム（Ｒｈ）０．２ｇ／（ｌテアツタ。This alumina-coated catalyst carrier was immersed in a mixed aqueous solution of chloroplatinic acid and rhodium chloride at a predetermined concentration, pulled up, dried at 150°C for 1 hour, and then calcined at 600°C for 2 hours. Precious metal content after firing: 1 to platinum (PL) 1.0
g/(1, rhodium (Rh) 0.2 g/(l).
次いで、酸化セリウム４４０ｇ、ベーマイト１１０ｇ、
水５００ｃｃ、濃硝酸５ｃｃをホモミキサーにより混合
撹拌してＯ８Ｃ剤コー套用スラリー液を得た。このスラ
リー液中に、先のアルミナ及び貴金属を付着させた触媒
担体の半分を浸漬したのち、未浸漬側を下方にして１５
０℃で１時間乾燥した。さらに、前記Ｏ８Ｃ剤コート用
スラリー液に先の手順と同じ方法により、先に浸漬した
半分側を再度浸漬して引き上げ、未浸漬方向から余分の
スラリーを高圧エアブロ−で除去し、１５０℃で１時間
乾燥後、６５０℃で２時間焼成した。これによって、触
媒担体上に形成された触媒層（Ｐｔ、 Ｒｈを含む）の
上面に、８０重量％の酸化セリウムと２０重量％のγ−
アルミナとからなる被覆層が形成され且つ該被覆層の厚
さが、−刃側（触媒の排気ガス出口側）で３０μ、中間
部分で２０〜２２μ、他方側（触媒の排気ガス入り口側
）で７〜ｌＯμである触媒が得られた。Next, 440 g of cerium oxide, 110 g of boehmite,
500 cc of water and 5 cc of concentrated nitric acid were mixed and stirred using a homomixer to obtain a slurry liquid for O8C agent coating. After immersing half of the catalyst carrier to which alumina and precious metals were attached in this slurry liquid, place the unsoaked side downward for 15 minutes.
It was dried at 0°C for 1 hour. Furthermore, in the same manner as in the previous procedure, the previously immersed half side was immersed again in the O8C agent coating slurry liquid and pulled up. After drying for an hour, it was fired at 650°C for 2 hours. As a result, 80% by weight of cerium oxide and 20% by weight of γ-
A coating layer made of alumina is formed, and the thickness of the coating layer is 30μ on the -blade side (exhaust gas outlet side of the catalyst), 20 to 22μ on the middle part, and on the other side (exhaust gas inlet side of the catalyst). A catalyst of 7-10μ was obtained.
実施例２
γ−アルミナ１６０ｇ、ベーマイト１６０ｇ、水５００
ｃｃ。Example 2 γ-alumina 160g, boehmite 160g, water 500g
cc.
濃硝酸４ｃｃをホモミキサーによりｌＯ時間混合撹拌し
、アルミナウォッシュコート用スラリーを得た。4 cc of concentrated nitric acid was mixed and stirred for 10 hours using a homomixer to obtain a slurry for an alumina wash coat.
このスラリーにハニカム触媒担体（コージライト製）を
浸漬して引き上げた後、余分のスラリーを宣匡丁マイー
ー１体土＋ １Ｑｎ’／’切１物問酢旭づ鼻６００
℃で１時間焼成した。After immersing a honeycomb catalyst carrier (made of cordierite) in this slurry and pulling it up, the excess slurry was mixed with 1 piece of soil + 1 piece of vinegar Asahi Zuhana 600
It was baked at ℃ for 1 hour.
このアルミナコートした触媒担体を所定の濃度の塩化白
金酸・塩化ロジウム混合水溶液に浸漬して引き上げた後
、１５０℃で１時間乾燥し、次いで６００℃で２時間焼
成した。焼成後の貴金属含有量は白金（Ｐ ｔ）１．Ｏ
ｇ／ （１、ロジウム（Ｒｈ）０．２ｇ／ １１であっ
た。This alumina-coated catalyst carrier was immersed in a mixed aqueous solution of chloroplatinic acid and rhodium chloride at a predetermined concentration, pulled up, dried at 150°C for 1 hour, and then calcined at 600°C for 2 hours. The precious metal content after firing is platinum (Pt) 1. O
g/(1), rhodium (Rh) 0.2 g/11.
次いで、酸化セリウム４４０ｇ、ベーマイト１１０ｇ、
水５００ｃｃ、 ａ硝酸５ｃｃをホモミキサーにより、
見合撹拌してＯ８Ｃ剤コート用スラリー液を得た。そし
て、前記の如くアルミナコートした触媒担体の半分を流
動パラフィン溶液に浸漬してｌ／２パラフィン付着触媒
担体となし、これを館記Ｏ８Ｃ剤コート用スラリー液中
に浸漬して引き上げたのち、余分なスラリー液を高圧エ
アブロ−により除去し、ＨＯ℃で１時間乾燥後、６００
℃で１時間焼成した。Next, 440 g of cerium oxide, 110 g of boehmite,
Add 500cc of water and 5cc of nitric acid using a homomixer.
A slurry liquid for O8C agent coating was obtained by stirring at intervals. Then, half of the alumina-coated catalyst carrier as described above was immersed in a liquid paraffin solution to obtain a 1/2 paraffin-attached catalyst carrier, which was then immersed in a slurry solution for coating with a Tateki O8C agent and pulled out. The slurry liquid was removed by high-pressure air blowing, and after drying at HO℃ for 1 hour,
It was baked at ℃ for 1 hour.
さらに、酸化セリウム１２５ｇ、ベーマイト４２５ｇ、
水５００ｃｃ、 ａ硝酸５ｃｃをホモミキサーにより混
合撹拌して前記Ｏ８Ｃ剤コート用スラリー液より低濃度
のＯ８Ｃ剤を含有するＯ６Ｃ剤コート用スラリー液を得
た。このスラリー液中に前記触媒担体の被覆層未付着部
分を浸漬し、前記と同様の焼成を行った。In addition, 125g of cerium oxide, 425g of boehmite,
500 cc of water and 5 cc of nitric acid were mixed and stirred using a homomixer to obtain an O6C agent coating slurry containing a lower concentration of O8C agent than the O8C agent coating slurry. The portion of the catalyst carrier to which the coating layer was not attached was immersed in this slurry liquid, and the same firing as described above was performed.
これにより、触媒の一方の半分（排気ガス入り口側）に
おけろ被覆層には低濃度（１，１ｍｇ／ａｍ”）の酸化
セリウムが含有され、触媒の他方の半分（排気ガス出口
側）における被覆層には高濃度（４，０ｍｇ７ｃｍ”）
の酸化セリウムが含有されてなる触媒が得られた。As a result, the filter coating layer on one half of the catalyst (exhaust gas inlet side) contains a low concentration (1.1 mg/am") of cerium oxide, and the other half of the catalyst (exhaust gas outlet side) contains cerium oxide at a low concentration (1.1 mg/am"). High concentration (4.0mg7cm”) in the coating layer
A catalyst containing cerium oxide was obtained.
上記実施例で得られた排気ガス浄化用触媒の浄化性能を
、下記の比較例と比較してウオームアツプ性能評価テス
トを行ったところ、第３図ないし第６図に示す結果が得
られた。A warm-up performance evaluation test was conducted to compare the purification performance of the exhaust gas purification catalyst obtained in the above example with the following comparative example, and the results shown in FIGS. 3 to 6 were obtained.
比較例
前記各実施例と同様の方法により、触媒成分（Ｐｔ１．
０ｇ７１１Ｊｔｈｏ、２ｇ／（１）を触媒担体上のアル
ミナコートに担持させたのち、酸化セリウム４４０ｇ、
ベーマイトｆｌｏｇ、水５００ｃｃ、 ａ硝酸５ｃｃを
混合撹拌して得られたＯ８Ｃ剤コート用スラリー液中に
前記触媒担体全体を浸漬して引き上げ、余分なスラリー
液を高圧エアブロ−で除去し、その後°前記実施例と同
様に焼成して、全体に約３０μの厚さの被覆層を有する
触媒を得た。Comparative Example Catalyst components (Pt1.
After supporting 0g711Jtho, 2g/(1) on the alumina coat on the catalyst carrier, 440g of cerium oxide,
The entire catalyst carrier was immersed in a slurry for O8C agent coating obtained by mixing and stirring boehmite log, 500 cc of water, and 5 cc of nitric acid, and then pulled up.Excess slurry was removed with a high-pressure air blower, and then the The catalyst was calcined in the same manner as in the example to obtain a catalyst having a coating layer with a total thickness of about 30 μm.
前記ウオームアツプ性能評価テストは、第７図図示の如
き方法で行なわれた。即ち、第７図（イ）。The warm-up performance evaluation test was conducted as shown in FIG. That is, Fig. 7 (a).
図示の如く、テスト開始前には、テスト触媒５を５０℃
に保ち、合成ガスは電気炉６にて８００℃定温となるよ
うにし、且つ該合成ガスをバイパス通路７側にバイパス
させてテスト触媒５に触れさせないようにし、その後、
第７図（ロ）図示の如く、バイパス通路７を閉じて８０
０℃の合成ガスをテスト触媒５側に流し、合成ガスが流
れ始めてからの浄化性能を時間とともに測定するのであ
る。なお、テスト触媒は、大気中にて１０００℃で熱ニ
ーソングを行なったのちに使用された。テスト条件は、
触媒容１：２４ｃｃ、空間速度ＳＪ□４００ＱＱ／ｆｉ
ｒであった。As shown in the figure, before starting the test, test catalyst 5 was heated to 50°C.
The synthesis gas was maintained at a constant temperature of 800° C. in the electric furnace 6, and the synthesis gas was bypassed to the bypass passage 7 side so as not to come into contact with the test catalyst 5, and then,
FIG. 7(B) As shown, the bypass passage 7 is closed and 80
Synthesis gas at 0°C is flowed to the test catalyst 5 side, and the purification performance is measured over time after the syngas starts flowing. Note that the test catalyst was used after performing a thermal knee song at 1000° C. in the atmosphere. The test conditions are
Catalyst volume 1: 24cc, space velocity SJ□400QQ/fi
It was r.
上記評価テストの結果によると、本発明の実施例による
排気ガス浄化用触媒は、比較例のものに比べて合成ガス
を流し始めて５〜６分間までの浄化性能が良好であるこ
とがわかる。これは、被覆層の入り口側において、熱容
量の大きな酸化セリウム含有量が少なくなっているため
、暖気効率がよくなり、浄化反応が良好になるためであ
る。According to the results of the above evaluation test, it can be seen that the exhaust gas purifying catalyst according to the example of the present invention has better purification performance for 5 to 6 minutes after starting to flow the synthesis gas compared to the catalyst of the comparative example. This is because the content of cerium oxide, which has a large heat capacity, is reduced on the inlet side of the coating layer, which improves the heating efficiency and improves the purification reaction.
なお、合成ガスを流し始めてから６分を過ぎると、充分
暖気されるため、実施例、比較例とも同一温度になり、
浄化性能に差はなくなる。In addition, after 6 minutes have passed since the syngas started flowing, the temperature is the same in both the example and the comparative example because the air is sufficiently warmed up.
There will be no difference in purification performance.
また、前記実施例１の方法により、触媒入り口側（即ち
、排気ガス入り口側）の被覆層における酸化セリウム含
有量が出口側（即ち、排気ガス出口側）の含有量に対し
て１５．２０．４０．５０．６０％である触媒（試料Ｎ
ｏｔ、２．３．４．５）を作成した。被覆層コート用ス
ラリー液は実施例１と同一のものを使用したため、これ
ら触媒の出口側における触媒担体単位面積当たりのＣｅ
ｎｔ担持量は４ｍｇ／ｃｍ’、平均厚さは３０μであり
、各試料とも同じであった。Furthermore, by the method of Example 1, the cerium oxide content in the coating layer on the catalyst inlet side (i.e., exhaust gas inlet side) was 15.20% higher than that on the outlet side (i.e., exhaust gas outlet side). 40.50.60% catalyst (sample N
ot, 2.3.4.5) was created. Since the slurry liquid for coating the coating layer was the same as in Example 1, the Ce per unit area of the catalyst carrier on the outlet side of these catalysts was
The amount of nt supported was 4 mg/cm', and the average thickness was 30 μ, which were the same for each sample.
上記各試料を１０００℃で２４時間加熱させた後、ウオ
ームアツプ測定および４００℃での排気ガス浄化性能を
調べたところ、表−１に示す結果が得られた。After heating each of the above samples at 1000°C for 24 hours, warm-up measurements and exhaust gas purification performance at 400°C were investigated, and the results shown in Table 1 were obtained.
表−１
ここで、ウオームアツプ性能とは、第７図図示の測定装
置を用いて、８００℃の合成ガスを流し始めて１分後の
ＣＯ浄化率のことであり、４００℃排気ガスの浄化率は
、空燃比Ａ／Ｆ＝１４．７の組成である合成ガスで空間
速度Ｓ、Ｖ＝ ６００００／ｌｌｒでのＣＯ浄化率であ
る。Table 1 Here, warm-up performance refers to the CO purification rate one minute after starting to flow 800°C synthesis gas using the measuring device shown in Figure 7, and the purification rate of 400°C exhaust gas. is the CO purification rate at space velocity S and V = 60000/llr using synthetic gas with an air-fuel ratio A/F = 14.7.
これによれば、入り口側被覆層におけるＣｅＯ２含有量
が出口側における含有量の２０〜５０％において良好な
浄化性能を示すことかわかる。According to this, it can be seen that good purification performance is exhibited when the CeO2 content in the inlet side coating layer is 20 to 50% of the content in the outlet side.
さらに、面記実施例２の方法により、触媒入り口側（即
ち、排気ガス入り口側）の被覆層における酸化セリウム
含有量が出口側（即ち、排気ガス出口側）の含有１に対
して１５．２０．４０．５０．６０％である触媒（試料
Ｎｏｔ、２．３．４．５）を作成した。彼覆層コート用
スラリー液は実施例１と同一のものを使用したため、こ
れら触媒の出口側における触媒担体単位面積当たりのＣ
ｅＯ，担持量は４ｍｇ／ｃｍ’、平均厚さは３０μであ
り、各試料とも同じであった。Furthermore, by the method of Example 2, the cerium oxide content in the coating layer on the catalyst inlet side (i.e., exhaust gas inlet side) was 15.20% of the content of 1 on the outlet side (i.e., exhaust gas outlet side). A catalyst (sample Not, 2.3.4.5) was made that was .40.50.60%. Since the same slurry liquid for coating layer was used as in Example 1, the C per unit area of the catalyst carrier on the outlet side of these catalysts was
eO, the supported amount was 4 mg/cm', and the average thickness was 30 μ, which were the same for each sample.
上記各試料を１０００℃で２４時間加熱させた後、ウオ
ームアツプ測定および４００°Ｃでの排気ガス浄化性能
を調べたところ、表−２に示す結果が得られた。After heating each of the above samples at 1000°C for 24 hours, warm-up measurements and exhaust gas purification performance at 400°C were investigated, and the results shown in Table 2 were obtained.
表−２
ここで、ウオームアツプ性能とは、第７図図示の測定装
置を用いて、８００℃の合成ガスを流し始めて１分後の
ＣＯ浄化率のことであり、４００℃排気ガスの浄化率は
、空燃比Ａ／Ｐ＝１４．７の組成である合成ガスで空間
速度ＳＪ＝ ６００００／ＨｒでのＣＯ浄化率である。Table 2 Here, warm-up performance refers to the CO purification rate one minute after starting to flow 800°C synthesis gas using the measuring device shown in Figure 7, and the purification rate of 400°C exhaust gas. is the CO purification rate at space velocity SJ = 60000/Hr using synthesis gas with an air-fuel ratio A/P = 14.7.
これによれば、入り口側被覆層におけるＣｅＯ。According to this, CeO in the entrance side coating layer.
含有量が出口側における含有量の２０〜５０％において
良好な浄化性能を示すことがわかる。It can be seen that good purification performance is exhibited when the content is 20 to 50% of the content on the outlet side.
上記の事実を勘案すると、触媒入り口側の被覆層におけ
る酸化セリウムの濃度を変えても、被覆層の厚みを変え
ても、低温時における性能改善効果があることがわかる
。このことは、触媒担体単位面積当たりの酸化セリウム
含有量を入り口側において減少させることにより、性能
改善がなされることを表している。また、入り口側の酸
化セリウム含有量は、出口側の２０〜５０％とするのが
好主しいことがわかる。Taking the above facts into consideration, it can be seen that changing the concentration of cerium oxide in the coating layer on the catalyst inlet side or changing the thickness of the coating layer has the effect of improving performance at low temperatures. This indicates that performance is improved by reducing the cerium oxide content per unit area of the catalyst support on the inlet side. Further, it can be seen that the cerium oxide content on the inlet side is preferably 20 to 50% of that on the outlet side.
本実施例においては、酸化セリウムの被覆層中における
含有量を８０重量％とじているが、酸化セリウム含有量
は、５０〜９５重量％の範囲とすることができる。In this example, the content of cerium oxide in the coating layer is limited to 80% by weight, but the content of cerium oxide can range from 50 to 95% by weight.
一般に、被覆層中のＯ８Ｃ剤含有量が減少するに従って
触媒性能は次第に低下し、５０％以下では急激に低下す
る。その理由は、Ｏ８Ｃ剤の濃度が低下すると、活性成
分との相互作用が得られなくなるからである。ちなみに
、Ｏ８Ｃ剤としてＣｅ０、を用いた被覆層中におけるＣ
ａ０ｔの含有量（重量％）に対する４００℃におけるＣ
Ｏの浄化率（％）の変化を測定した結果が第８図に示さ
れている。本結果は、活性測定条件を、空燃比Ａ／Ｆ＝
１４．７±０．９、空間速度Ｓ、■・６０００Ｇ／Ｈｒ
とし、台上エンジンにおいて排気ガス温度８５０℃で３
０（ｌｌｌｒ運転した耐久テスト後の触媒を用いて評価
したものである。これによれば、Ｃｅ Ｏｔが５０％以
下になるとＣＯ浄化率が大幅に低下している。Generally, as the O8C agent content in the coating layer decreases, the catalyst performance gradually decreases, and below 50%, the catalyst performance decreases rapidly. The reason is that as the concentration of the O8C agent decreases, interaction with the active ingredient is no longer obtainable. By the way, C in the coating layer using Ce0 as the O8C agent
C at 400°C for the content (wt%) of a0t
The results of measuring changes in the O purification rate (%) are shown in FIG. This result shows that the activity measurement conditions are changed to air-fuel ratio A/F=
14.7±0.9, space velocity S, ■・6000G/Hr
3 at an exhaust gas temperature of 850℃ in a bench engine.
This is an evaluation using a catalyst after a durability test in which it was operated for 0 (lllr).According to this, when CeOt becomes 50% or less, the CO purification rate decreases significantly.
一方、Ｏ８Ｃ剤の含有量が高くなると、触媒活性は向上
するが、Ｏ８Ｃ剤自体の結合力が弱いために、物理的強
度（耐剥離性）が減少し、耐久性が低減する。ちなみに
、Ｏ８Ｃ剤としてＣｅｎｔを用いた被覆層中におけるＣ
ｅｎｔの含有量（重量％）を変化させて、剥離テストを
行ったところ、表−３に示す結果が得られた。ここで、
剥離量＝（テスト前のコート付着量−テスト後のコート
付着量）／（テスト前のコート付着量）、また、テスト
方法としては、直径１インチ、高さ１インチの円筒テで
冷却という手順をミロ繰り返した後、充分乾燥し、剥離
量を測定する方法が採用された。On the other hand, when the content of the O8C agent increases, the catalytic activity improves, but since the binding force of the O8C agent itself is weak, the physical strength (peeling resistance) decreases and the durability decreases. By the way, C in the coating layer using Cent as the O8C agent
When a peel test was conducted while changing the content (wt%) of ENT, the results shown in Table 3 were obtained. here,
Amount of peeling = (Amount of coat applied before test - Amount of coat applied after test) / (Amount of coat applied before test) Also, the test method involves cooling with a cylindrical tube with a diameter of 1 inch and a height of 1 inch. The method used was to repeat this process several times, dry thoroughly, and then measure the amount of peeling.
表−３
上記剥離テストの結果から、被覆層中のＣｅＯ２含有１
は、９５％以下とするのか好ましいことがわかる。Table 3 From the results of the above peel test, CeO2 content 1 in the coating layer
It can be seen that it is preferable to set it to 95% or less.
前記被覆層の触媒担体に対する付着割合が２重量％以下
では触媒層の表面を効果的に被覆オろことができなくな
るため、触媒性能が急激ｌこ低下し、３０重量％を越え
ろと、物理的強度か低下し、剥離しやすくなるとともに
、活性成分と排気ガスとの接触が阻害されるため、急激
に触媒性能が低下する。このことを勘案すると、被覆層
の付着割合を２〜３０重量％とするのが望ましい。If the adhesion ratio of the coating layer to the catalyst carrier is less than 2% by weight, the surface of the catalyst layer cannot be effectively coated, resulting in a rapid decline in catalyst performance. The strength of the catalyst decreases, it becomes easy to peel off, and contact between the active component and the exhaust gas is inhibited, resulting in a sudden drop in catalyst performance. Taking this into consideration, it is desirable that the adhesion ratio of the coating layer be 2 to 30% by weight.
（発明の効果）
収車の如く 、本発明によれば、活性触媒成分（Ｐｔ、
Ｒｈ、等）を含有する触媒層と、ＯＳＣ剤（ＣｅＯ７
、ＮｉＯ等）を含有する被覆層とを分離して形成してい
るので、活性触媒成分とＯＳＣ剤とが化合物を形成する
ことかなくなり、従来の活性触媒成分とＯＳＣ剤とを混
在させたものに比べて、排気ガス浄化性能が向上すると
いう優れた効果がある。(Effect of the invention) According to the present invention, active catalyst components (Pt,
Rh, etc.) and an OSC agent (CeO7).
Since the active catalyst component and the OSC agent do not form a compound, the active catalyst component and the OSC agent do not form a compound. It has an excellent effect of improving exhaust gas purification performance.
また、触媒担体において、排気ガス入り口側におけろ熱
容量の大きいＣｅＯ，等のＯＳＣ剤の含有ｍが出口側の
２０〜５０％となるように少なくしているので、排気ガ
ス温度の低いコールドスタート時に、低温での浄化性能
向上を図ることができるという効果もある。In addition, in the catalyst carrier, the content of OSC agents such as CeO, which has a large heat capacity, on the exhaust gas inlet side is reduced to 20 to 50% of that on the outlet side, resulting in a cold start with a low exhaust gas temperature. Sometimes, it also has the effect of improving purification performance at low temperatures.
さらに、触媒層上面がＯＳＣ剤を含む被覆層で被覆され
るところから、触媒層が還元雰囲気になり易くなり、排
気ガス中のＮＯｘの浄化性能が一段と向上するという利
点もある。Furthermore, since the upper surface of the catalyst layer is coated with a coating layer containing an OSC agent, the catalyst layer is easily placed in a reducing atmosphere, and there is an advantage that the NOx purification performance in exhaust gas is further improved.
第１図は、本発明にかかる排気ガス浄化用触媒の一例を
示す拡大図、第２図は、第１図の排気ガス浄化用触媒の
要部拡大図、第３図、第４図、第５図および第６図は、
本発明の実施例１．２と比較例とのウオームアツプ性能
評価テストの結果を示す特性図、第７図（イ）、（ロ）
は、前記ウオームアツプ性能評価テストの方法を示す略
図、第８図は、被覆層中におけるＣｅＯ！含有量（重量
％）に対する排気ガス中のＣＯ浄化率（％）の変化を示
す特性図である。
ｌ・・・・・触媒担体
２・・・・・触媒層
３・・・・・被覆層
３ａ・・・・ 排気ガス入り口側
３ｂ・・・・ 排気ガス出口側
／・・・・・触媒担体
２・・・・・触Ｉｓ層
３・・・・・被８２層
上・・・・・排気ガス入り口側
３ｂ・・・・・排気ガス出口側
排気ガス＝＝〉
第３図
時間（分）
第６図
詣
（、？）
第７図
トFIG. 1 is an enlarged view showing an example of the exhaust gas purification catalyst according to the present invention, FIG. 2 is an enlarged view of main parts of the exhaust gas purification catalyst of FIG. 1, and FIGS. Figures 5 and 6 are
Characteristic diagrams showing the results of the warm-up performance evaluation test of Example 1.2 of the present invention and the comparative example, FIGS. 7 (a) and (b)
is a schematic diagram showing the method of the warm-up performance evaluation test, and FIG. 8 is a schematic diagram showing the method of the warm-up performance evaluation test. FIG. 2 is a characteristic diagram showing changes in CO purification rate (%) in exhaust gas with respect to content (% by weight). l... Catalyst carrier 2... Catalyst layer 3... Covering layer 3a... Exhaust gas inlet side 3b... Exhaust gas outlet side/... Catalyst carrier 2...Touch Is layer 3...Top layer 82...Exhaust gas inlet side 3b...Exhaust gas outlet side Exhaust gas ==> Figure 3 Time (minutes) Figure 6 Pilgrimage (,?) Figure 7 To
Claims (1)
ウムよりなる群から選ばれた少なくとも一種類の触媒成
分を含有する触媒層と、該触媒層上に設けられ、酸素貯
蔵能付与剤として作用する酸化セリウム、酸化ニッケル
、酸化モリブデンおよび酸化鉄よりなる群から選ばれた
少なくとも一種類の酸化物を高濃度で含有するアルミナ
の被覆層とを備え、前記触媒担体の排気ガス入り口側の
被覆層における酸素貯蔵能付与剤の含有量が、排気ガス
出口側の含有量の約２０〜５０％とされていることを特
徴とするエンジンの排気ガス浄化用触媒。1. A catalyst layer supported on a catalyst carrier and containing at least one catalyst component selected from the group consisting of platinum, palladium, and rhodium, and an oxidizing layer provided on the catalyst layer and acting as an oxygen storage ability imparting agent. an alumina coating layer containing a high concentration of at least one oxide selected from the group consisting of cerium, nickel oxide, molybdenum oxide, and iron oxide; A catalyst for purifying exhaust gas of an engine, characterized in that the content of the storage capacity imparting agent is about 20 to 50% of the content on the exhaust gas outlet side.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60211639A JPH0622674B2 (en) | 1985-09-24 | 1985-09-24 | Engine exhaust gas purification catalyst |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60211639A JPH0622674B2 (en) | 1985-09-24 | 1985-09-24 | Engine exhaust gas purification catalyst |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6271542A true JPS6271542A (en) | 1987-04-02 |
| JPH0622674B2 JPH0622674B2 (en) | 1994-03-30 |
Family
ID=16609105
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP60211639A Expired - Lifetime JPH0622674B2 (en) | 1985-09-24 | 1985-09-24 | Engine exhaust gas purification catalyst |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0622674B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20020056498A (en) * | 2000-12-29 | 2002-07-10 | 이계안 | Oxidation catalyst for diesel engine |
| JP2006006995A (en) * | 2004-06-22 | 2006-01-12 | Mitsubishi Motors Corp | Hc adsorption catalyst and exhaust gas purifier using the same |
| CN104525196A (en) * | 2014-12-11 | 2015-04-22 | 天津大学 | Platinum-gallium catalyst loaded on double-oxide composite carrier as well as preparation method and application of platinum-gallium catalyst |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006205002A (en) * | 2005-01-26 | 2006-08-10 | Toyota Motor Corp | Catalyst for cleaning exhaust gas |
-
1985
- 1985-09-24 JP JP60211639A patent/JPH0622674B2/en not_active Expired - Lifetime
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20020056498A (en) * | 2000-12-29 | 2002-07-10 | 이계안 | Oxidation catalyst for diesel engine |
| JP2006006995A (en) * | 2004-06-22 | 2006-01-12 | Mitsubishi Motors Corp | Hc adsorption catalyst and exhaust gas purifier using the same |
| CN104525196A (en) * | 2014-12-11 | 2015-04-22 | 天津大学 | Platinum-gallium catalyst loaded on double-oxide composite carrier as well as preparation method and application of platinum-gallium catalyst |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0622674B2 (en) | 1994-03-30 |
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