JPH09215922A - Catalyst for purifying exhaust gas - Google Patents
Catalyst for purifying exhaust gasInfo
- Publication number
- JPH09215922A JPH09215922A JP8024000A JP2400096A JPH09215922A JP H09215922 A JPH09215922 A JP H09215922A JP 8024000 A JP8024000 A JP 8024000A JP 2400096 A JP2400096 A JP 2400096A JP H09215922 A JPH09215922 A JP H09215922A
- Authority
- JP
- Japan
- Prior art keywords
- parts
- exhaust gas
- catalyst
- supported
- purifying catalyst
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は排ガスを浄化する排
ガス浄化用触媒に関し、詳しくは触媒金属としてパラジ
ウムを担持したＰｄ系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 an exhaust gas purifying catalyst for purifying exhaust gas, and more particularly to a Pd-based catalyst carrying palladium as a catalytic metal.
【０００２】[0002]
【従来の技術】従来より、自動車の排ガス浄化用触媒と
して、ＣＯ及びＨＣの酸化とＮＯx の還元とを行って排
ガスを浄化する三元触媒が用いられている。このような
三元触媒としては、例えばコーディエライトなどからな
る耐熱性担体基材にγ−アルミナからなるコート層を形
成し、そのコート層に白金（Ｐｔ）、ロジウム（Ｒ
ｈ）、パラジウム（Ｐｄ）などの白金族元素から選ばれ
る触媒金属を担持させたものが広く知られている。2. Description of the Related Art Conventionally, a three-way catalyst for purifying exhaust gas by oxidizing CO and HC and reducing NO x has been used as an exhaust gas purifying catalyst for automobiles. As such a three-way catalyst, for example, a coat layer made of γ-alumina is formed on a heat-resistant carrier base made of cordierite or the like, and platinum (Pt), rhodium (R)
h) and those carrying a catalytic metal selected from platinum group elements such as palladium (Pd) are widely known.
【０００３】このうちＰｔ及びＰｄは主としてＣＯ及び
ＨＣの酸化浄化に寄与し、Ｒｈは主としてＮＯx の還元
浄化に寄与するとともに、Ｐｔ又はＰｄのシンタリング
を防止する作用があり耐熱性が向上することがわかって
いる。したがって三元触媒では、Ｐｔ又はＰｄとＲｈと
を併用することが望ましいことが知られている。また白
金族元素のなかでは、ＰｔやＲｈに比べてＰｄが安価で
あり、Ｐｄを用いれば排ガス浄化用触媒のコストを低減
することができる。ところがＰｄは、Ｒｈを共存させた
としても高温時のシンタリングによる劣化が大きく、Ｐ
ｄ−Ｒｈ系触媒は耐久性に劣るという不具合がある。Of these, Pt and Pd mainly contribute to the oxidative purification of CO and HC, and Rh mainly contributes to the reduction purification of NO x , and also has the function of preventing sintering of Pt or Pd, and the heat resistance is improved. I know that. Therefore, it is known that it is desirable to use Pt or Pd and Rh together in a three-way catalyst. Among the platinum group elements, Pd is cheaper than Pt and Rh, and the cost of the exhaust gas purifying catalyst can be reduced by using Pd. However, even if Rh coexists, Pd is greatly deteriorated due to sintering at high temperature.
The d-Rh-based catalyst has a problem that it is inferior in durability.
【０００４】そこで例えば特開平３−１０６４４６号公
報には、Ｐｄ−Ｒｈ系触媒にさらにバリウム（Ｂａ）と
セリウム（Ｃｅ）を共存させた排ガス浄化用触媒が開示
されている。この排ガス浄化用触媒では、Ｂａの作用に
よりＰｄが常に酸化状態となるため、金属Ｐｄ状態で生
じるシンタリングを防止することができる。したがって
Ｐｄを用いてＰｔ−Ｒｈ系触媒とほぼ同等の触媒性能を
確保することができ、しかも安価な排ガス浄化用触媒と
することができる。Therefore, for example, Japanese Patent Application Laid-Open No. 3-106446 discloses an exhaust gas purifying catalyst in which barium (Ba) and cerium (Ce) are further allowed to coexist in a Pd-Rh type catalyst. In this exhaust gas-purifying catalyst, since Pd is always in an oxidized state due to the action of Ba, it is possible to prevent sintering that occurs in the metallic Pd state. Therefore, by using Pd, it is possible to secure a catalytic performance that is almost equal to that of the Pt-Rh-based catalyst, and it is possible to provide an inexpensive exhaust gas purifying catalyst.
【０００５】一方、近年、地球環境保護の観点から、自
動車などの内燃機関から排出される排ガス中の二酸化炭
素（ＣＯ2 ）が問題とされ、その解決策として酸素過剰
雰囲気において希薄燃焼させるいわゆるリーンバーンが
有望視されている。このリーンバーンにおいては、燃費
が向上するために燃料の使用量が低減され、その結果燃
焼排ガスであるＣＯ2 の発生を抑制することができる。On the other hand, in recent years, carbon dioxide (CO 2 ) in exhaust gas emitted from internal combustion engines such as automobiles has become a problem from the viewpoint of protecting the global environment, and as a solution to this problem, so-called lean combustion in which oxygen is excessively burned is used. Burn is promising. In this lean burn, the amount of fuel used is reduced in order to improve fuel efficiency, and as a result, the generation of CO 2 as combustion exhaust gas can be suppressed.
【０００６】これに対し、従来の三元触媒は、空燃比が
理論空燃比（ストイキ）において排ガス中のＣＯ，Ｈ
Ｃ，ＮＯx を同時に酸化・還元し、浄化するものであっ
て、リーンバーン時の排ガスの酸素過剰雰囲気下におけ
るＮＯx の還元除去に対しては充分な浄化性能を示さな
い。このため、酸素過剰雰囲気下においても効率よくＮ
Ｏx を浄化しうる触媒及び浄化システムの開発が望まれ
ている。On the other hand, in the conventional three-way catalyst, when the air-fuel ratio is the stoichiometric air-fuel ratio (stoichiometric), CO, H in the exhaust gas
It purifies by oxidizing and reducing C and NO x at the same time, and does not show sufficient purification performance for reducing and removing NO x in an oxygen excess atmosphere of exhaust gas during lean burn. Therefore, even in an oxygen-excess atmosphere, N
There is a demand for the development of a catalyst and a purification system capable of purifying O x .
【０００７】そこで本願出願人は、先にアルカリ土類金
属とＰｔをアルミナなどの多孔質担体に担持した排ガス
浄化用触媒（特開平５−３１７６５２号公報）や、ラン
タンとＰｔを多孔質担体に担持した排ガス浄化用触媒
（特開平５−１６８８６０号公報）、あるいはアルカリ
金属とＰｔとをアルミナ担体に担持した排ガス浄化用触
媒（特開平６−３１１３９号公報）を提案している。こ
れらの排ガス浄化用触媒によれば、リーン側ではＮＯx
がアルカリ土類金属の酸化物やランタンの酸化物（ＮＯ
x 吸蔵元素）に吸蔵され、それがストイキ又はリッチ側
でＨＣやＣＯなどの還元性成分と反応するため、リーン
側においてもＮＯx の浄化性能に優れている。Therefore, the applicant of the present application has previously proposed an exhaust gas purifying catalyst in which an alkaline earth metal and Pt are supported on a porous carrier such as alumina (Japanese Patent Laid-Open No. 5-317652), or lanthanum and Pt on a porous carrier. An exhaust gas purifying catalyst that is carried (JP-A-5-168860) or an exhaust gas-purifying catalyst that carries an alkali metal and Pt on an alumina carrier (JP-A-6-31139) is proposed. According to these exhaust gas purifying catalysts, NO x
Are alkaline earth metal oxides or lanthanum oxides (NO
x storage element), which reacts with reducing components such as HC and CO on the stoichiometric or rich side, so that the lean side also has excellent NO x purification performance.
【０００８】[0008]
【発明が解決しようとする課題】上記した特開平３−１
０６４４６号公報に記載の排ガス浄化用触媒では、Ｐｄ
とＲｈ及びＢａを共存させている。したがってＰｄのシ
ンタリングが防止されるとともに、ＢａによるＮＯx 吸
蔵作用によりＮＯx 浄化率の向上も期待される。ところ
がこの排ガス浄化用触媒にあっては、Ｂａを含まないＰ
ｄ−Ｒｈ系触媒に比べてさほど性能の向上がみられず、
Ｂａをさらに添加した効果が十分に引き出せないという
不具合があった。DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
In the exhaust gas purifying catalyst described in JP-A-06446, Pd
And Rh and Ba coexist. Therefore, it is expected that sintering of Pd is prevented and that the NO x storage rate of Ba improves the NO x purification rate. However, in this exhaust gas-purifying catalyst, P containing no Ba
The performance is not so much improved as compared with the d-Rh catalyst,
There is a problem that the effect of further adding Ba cannot be fully brought out.
【０００９】本発明はこのような事情に鑑みてなされた
ものであり、ＰｄにＲｈとＢａを共存させた場合にそれ
ぞれの元素のもつ性能が十分に発現できる排ガス浄化用
触媒とすることを目的とする。The present invention has been made in view of such circumstances, and an object thereof is to provide an exhaust gas purifying catalyst capable of sufficiently exhibiting the performance of each element when Rh and Ba coexist in Pd. And
【００１０】[0010]
【課題を解決するための手段】上記課題を解決する本発
明の排ガス浄化用触媒の特徴は、多孔質担体にＰｄ、Ｒ
ｈ及びＢａを担持してなる排ガス浄化用触媒において、
ＲｈとＢａの少なくとも一部は互いに分離した状態で多
孔質担体に担持されていることにある。The characteristics of the exhaust gas-purifying catalyst of the present invention for solving the above-mentioned problems are that Pd and R are added to the porous carrier.
In the exhaust gas purifying catalyst supporting h and Ba,
At least a part of Rh and Ba is carried on the porous carrier in a state of being separated from each other.
【００１１】[0011]
【発明の実施の形態】本発明者らは、ＰｄにＲｈとＢａ
を接触して担持させた場合の触媒挙動を鋭意研究した結
果、Ｒｈの触媒作用がＢａの接触により妨げられている
ことを発見し、本発明を完成した。つまり、ＰｄとＢａ
を接触担持させた場合には、図３に示すように耐久後の
ＮＯ５０％低減温度はＢａの添加量が増大するにつれて
大きく低下し、ＮＯx 浄化性能が向上する。ところがＲ
ｈとＢａを接触担持させた場合には、図４に示すように
耐久後のＮＯ５０％低減温度はＢａの添加量が増大する
につれて上昇し、ＮＯx 浄化性能が低下することが明ら
かとなった。BEST MODE FOR CARRYING OUT THE INVENTION The present inventors have found that Pd contains Rh and Ba.
As a result of earnest research on the catalytic behavior of the catalyst which was supported by contacting with, it was discovered that the catalytic action of Rh was hindered by the contact of Ba, and the present invention was completed. That is, Pd and Ba
In the case of carrying NO in contact, the NO50% reduction temperature after endurance greatly decreases as the addition amount of Ba increases, as shown in FIG. 3, and the NO x purification performance improves. However, R
When h and Ba were carried in contact with each other, as shown in FIG. 4, it was revealed that the NO 50% reduction temperature after endurance increased as the addition amount of Ba increased and the NO x purification performance decreased. .
【００１２】このようなＰｄ触媒又はＲｈ触媒へのＢａ
添加による活性変化は、Ｐｄ又はＲｈ上への排ガス成分
の吸着被毒の影響が考えられる。そこで本発明者らは、
Ｐｄ触媒及びＲｈ触媒と、それらにＢａを添加した触媒
について、次式（１）式に示すＨＣ−Ｏ2 反応の反応次
数の変化を測定してみた。その結果を表１に示す。なお
ＨＣとしてはＣ3 Ｈ6 を用いた。また（１）式におい
て、Ｖは反応速度、ｋは定数、ｐはＨＣの濃度、ＰはＯ
2 の濃度をそれぞれ示す。Ba for such Pd catalyst or Rh catalyst
The change in activity due to addition may be due to adsorption poisoning of the exhaust gas component on Pd or Rh. Therefore, the present inventors
With respect to the Pd catalyst, the Rh catalyst, and the catalyst to which Ba was added to them, the change in the reaction order of the HC-O 2 reaction represented by the following formula (1) was measured. Table 1 shows the results. C 3 H 6 was used as HC. In the equation (1), V is the reaction rate, k is a constant, p is the concentration of HC, and P is O.
2 concentrations are shown respectively.
【００１３】 Ｖ＝ｋ［ｐ（ＨＣ）］m ×［Ｐ（Ｏ2 ）］n （１）V = k [p (HC)] m × [P (O 2 )] n (1)
【００１４】 反応次数（ｍ，ｎ）がマイナスになり、その値が大きい
ほど吸着被毒が大きいことを示すから、表１よりＰｄ触
媒ではＢａの添加によりＨＣによる吸着被毒が低減され
ていることがわかる。しかしＲｈ触媒では、Ｂａの添加
によりＯ2 による吸着被毒が増大し、このため活性が低
下していると考えられる。したがって、Ｐｄ−Ｒｈ系触
媒にＢａをさらに添加すると、Ｒｈの酸素被毒が促進さ
れＲｈの作用が十分に引き出されないために、特開平３
−１０６４４６号公報に記載の排ガス浄化用触媒ではＢ
ａをさらに添加した効果が十分に引き出せないと推察さ
れた。[0014] Since the reaction order (m, n) becomes negative and the larger the value, the larger the adsorption poisoning, it can be seen from Table 1 that the addition of Ba in the Pd catalyst reduces the adsorption poisoning by HC. . However, it is considered that the addition of Ba increases the adsorption poisoning by O 2 in the Rh catalyst, and thus the activity is lowered. Therefore, when Ba is further added to the Pd-Rh-based catalyst, oxygen poisoning of Rh is promoted and the action of Rh is not sufficiently extracted.
In the exhaust gas purifying catalyst described in JP-A-106446, B
It was speculated that the effect of further adding a could not be brought out sufficiently.
【００１５】そこで本発明では、ＲｈとＢａとを互いに
分離した状態で多孔質担体に担持することとした。これ
によりＢａによるＲｈの酸素被毒促進が阻止され、Ｒｈ
の機能阻害が阻止されるため、ＮＯx 浄化性能が向上し
耐熱性も向上する。一方Ｂａは、そのＮＯx 吸蔵・放出
作用によりＮＯx 浄化性能を一層向上させるとともに、
以下のようにＰｄの酸化状態（ＰｄＯ）を維持してＰｄ
のシンタリングを防止する。つまり、Ｂａは容易に過酸
化物（ＢａＯ2 ）を形成し、これが熱又はガス雰囲気に
よって容易に分解して酸化バリウム（ＢａＯ）となる。
このとき放出される酸素がＰｄと結合して酸化パラジウ
ム（ＰｄＯ）を形成する。Ｐｄのシンタリングは金属パ
ラジウムの状態で生じるから、酸化パラジウムとなるこ
とによりシンタリングが防止される。Therefore, in the present invention, Rh and Ba are loaded on the porous carrier in a state of being separated from each other. This prevents Ba from promoting oxygen poisoning of Rh,
Since the inhibition of the function of is prevented, the NO x purification performance is improved and the heat resistance is also improved. On the other hand, Ba further improves the NO x purification performance by its NO x storage and release action, and
The Pd oxidation state (PdO) is maintained as follows.
Prevent sintering. That is, Ba easily forms a peroxide (BaO 2 ), which is easily decomposed by heat or a gas atmosphere into barium oxide (BaO).
Oxygen released at this time combines with Pd to form palladium oxide (PdO). Since the sintering of Pd occurs in the state of metallic palladium, it becomes palladium oxide to prevent sintering.
【００１６】このようにＲｈとＢａを分離した状態で多
孔質担体に担持するには、多孔質担体にＲｈを担持した
Ｒｈ担持粉末と、多孔質担体にＢａを担持したＢａ担持
粉末をそれぞれ調製し、これらを混合することで行うこ
とができる。このときＰｄは、少なくとも一方の粉末に
共存担持しておけばよい。また上記２種類の粉末を混合
後にＰｄを担持することもできる。In order to support Rh and Ba in a state where Rh and Ba are separated as described above, Rh-supporting powder in which Rh is supported in the porous carrier and Ba-supporting powder in which Ba is supported on the porous carrier are prepared respectively. However, it can be performed by mixing these. At this time, Pd may be co-loaded on at least one of the powders. Further, Pd can be supported after mixing the above two kinds of powders.
【００１７】また、Ｒｈを担持した層とＢａを担持した
層とを積層することもできる。この場合上下の層にどち
らの層を配置してもよいが、Ｂａの硫黄被毒を防止する
ために、Ｒｈを担持した層を上層とすることが好まし
い。またＰｄは少なくとも一方の層に担持することがで
きるが、ＰｄとＲｈの固溶によるＲｈの特性消失を防ぐ
ために少なくともＢａを含む層に担持することが望まし
い。なお、上層の厚さが厚すぎると下層の有効利用が図
れないので、上層の厚さは７０μｍ以下とすることが望
ましく、下層と上層の厚さの比は２：１〜４：１とする
ことが望ましい。It is also possible to stack a layer supporting Rh and a layer supporting Ba. In this case, either of the upper and lower layers may be arranged, but in order to prevent sulfur poisoning of Ba, the layer supporting Rh is preferably the upper layer. Further, Pd can be supported on at least one layer, but it is desirable to support Pd on a layer containing at least Ba in order to prevent loss of Rh characteristics due to solid solution of Pd and Rh. Since the lower layer cannot be effectively used if the upper layer is too thick, it is desirable that the thickness of the upper layer is 70 μm or less, and the ratio of the thickness of the lower layer to that of the upper layer is 2: 1 to 4: 1. Is desirable.
【００１８】多孔質担体としては、アルミナ、シリカ、
ジルコニア、チタニア、シリカ−アルミナ、ゼオライト
など従来用いられているものを用いることができる。な
かでも耐久後にも高い比表面積を示すアルミナが特に望
ましい。この多孔質担体は、コージェライトなどの耐熱
性無機質担体基材やメタル担体基材に被覆してコート層
としてもよいし、多孔質担体自体から担体基材を形成す
ることもできる。As the porous carrier, alumina, silica,
Conventional materials such as zirconia, titania, silica-alumina, and zeolite can be used. Of these, alumina, which has a high specific surface area even after durability, is particularly desirable. This porous carrier may be coated on a heat-resistant inorganic carrier substrate such as cordierite or a metal carrier substrate as a coat layer, or the carrier substrate may be formed from the porous carrier itself.
【００１９】本発明の排ガス浄化用触媒において、各触
媒成分の担持量は以下のとおりである。Ｐｄは、排ガス
浄化用触媒の容積１リットルに対して１〜２０ｇの範囲
で担持することが望ましい。１ｇより少ないと効果が得
られず、２０ｇを超えて担持しても効果が飽和するとと
もにコストの増大をきたす。特に望ましい範囲は５〜１
０ｇである。Ｒｈは、排ガス浄化用触媒の容積１リット
ルに対して０．０１〜１ｇの範囲で担持することが望ま
しい。０．０１ｇより少ないと添加した効果が得られ
ず、１ｇを超えて担持しても効果が飽和するとともにコ
ストの増大をきたす。特に望ましい範囲は０．１〜０．
５ｇである。またＢａは、排ガス浄化用触媒の容積１リ
ットルに対して０．０５〜０．４モルの範囲が望まし
い。０．０５モルより少ないと添加した効果が得られ
ず、０．４モルより多く担持すると効果が飽和するとと
もにコストの上昇をきたす。特に望ましい範囲は０．１
〜０．２モルである。In the exhaust gas-purifying catalyst of the present invention, the loading amount of each catalyst component is as follows. Pd is preferably loaded in the range of 1 to 20 g with respect to the volume of the exhaust gas purifying catalyst of 1 liter. If the amount is less than 1 g, the effect cannot be obtained, and if the amount exceeds 20 g, the effect is saturated and the cost is increased. Particularly desirable range is 5 to 1
0 g. Rh is preferably loaded in the range of 0.01 to 1 g with respect to the volume of the exhaust gas purifying catalyst of 1 liter. If the amount is less than 0.01 g, the effect of the addition is not obtained, and even if the amount exceeds 1 g, the effect is saturated and the cost is increased. A particularly desirable range is 0.1-0.
It is 5 g. Further, Ba is preferably in the range of 0.05 to 0.4 mol with respect to the volume of the exhaust gas purifying catalyst of 1 liter. If the amount is less than 0.05 mol, the effect of addition cannot be obtained, and if the amount is more than 0.4 mol, the effect is saturated and the cost is increased. A particularly desirable range is 0.1
０．２0.2 mol.
【００２０】なお、本発明の排ガス浄化用触媒には上記
触媒成分に加えて、公知の触媒金属や助触媒成分を担持
することもできる。例えばセリウム（Ｃｅ）を担持すれ
ば、Ｃｅの酸素吸蔵・放出能によりリッチ雰囲気の排ガ
スにおいてもＢａと酸素の反応が生じやすくなり、Ｐｄ
のシンタリングを一層防止することができる。Ｃｅの担
持量は、排ガス浄化用触媒の容積１リットルに対して
０．１〜０．５モルの範囲が最適である。また、Ｃｅを
ジルコニウムとの複合酸化物として担持することも好ま
しい。さらに、ランタン（Ｌａ）を担持することも好ま
しい。酸化ランタンはＮＯx 吸蔵能に特に優れるので、
ＮＯx 浄化性能が一層向上する。このＬａの担持量は、
排ガス浄化用触媒の容積１リットルに対して０．０５〜
０．４モルの範囲が最適である。The exhaust gas-purifying catalyst of the present invention may carry a known catalyst metal or co-catalyst component in addition to the above catalyst components. For example, when cerium (Ce) is supported, the reaction between Ba and oxygen is likely to occur even in exhaust gas in a rich atmosphere due to the oxygen storage / release capacity of Ce.
It is possible to prevent further sintering. The optimal amount of Ce carried is in the range of 0.1 to 0.5 mol per 1 liter of the exhaust gas purifying catalyst. It is also preferable to support Ce as a complex oxide with zirconium. Further, it is also preferable to support lanthanum (La). Since lanthanum oxide is particularly excellent in NO x storage capacity,
The NO x purification performance is further improved. The amount of La carried is
0.05 to 1 liter of exhaust gas purifying catalyst volume
The optimum range is 0.4 mol.
【００２１】[0021]
【実施例】以下、実施例及び比較例により本発明を具体
的に説明する。なお、以下にいう「部」は全て重量部を
意味する。 （実施例１） ＜Ｐｄ−Ｂａ／Ａｌ2 Ｏ3 の調製＞アルミナ粉末６０部
に、所定濃度の硝酸パラジウム水溶液の所定量と、酢酸
バリウム４０部と、純水１２０部を混合攪拌し、１００
℃にて１０時間乾燥した後、５００℃で１時間焼成して
Ｐｄ−Ｂａ担持アルミナ粉末を調製した。EXAMPLES The present invention will be specifically described below with reference to Examples and Comparative Examples. In addition, all "parts" mentioned below mean parts by weight. 60 parts of alumina powder <Preparation of Pd-Ba / Al 2 O 3 > ( Example 1), and a predetermined amount of an aqueous palladium nitrate solution having a predetermined concentration, and barium acetate 40 parts of pure water 120 parts were mixed and stirred, 100
After drying at 50 ° C. for 10 hours, it was calcined at 500 ° C. for 1 hour to prepare a Pd-Ba supported alumina powder.
【００２２】＜Ｒｈ／Ａｌ2 Ｏ3 の調製＞アルミナ粉末
１００部に、所定濃度の硝酸ロジウム水溶液の所定量
と、純水１２０部を混合攪拌し、１００℃にて１０時間
乾燥した後、５００℃で１時間焼成してＲｈ担持アルミ
ナ粉末を調製した。 ＜触媒の調製＞Ｐｄ−Ｂａ担持アルミナ粉末５０部と、
Ｒｈ担持アルミナ粉末５０部と、アルミナゾル（アルミ
ナ１０重量％）１０部と、純水１２０部を混合攪拌して
スラリーを調製した。そしてコージェライト製ハニカム
担体基材（容積１．７リットル）を水に浸漬し、余分な
水を吹き払った後このスラリーに浸漬した。取り出して
余分なスラリーを吹き払い、８０℃で２０分間乾燥後、
６００℃で１時間焼成して実施例１の排ガス浄化用触媒
を得た。<Preparation of Rh / Al 2 O 3 > Alumina powder 100 parts was mixed with a predetermined amount of a rhodium nitrate aqueous solution having a predetermined concentration and pure water 120 parts, and the mixture was stirred and dried at 100 ° C. for 10 hours. A Rh-supported alumina powder was prepared by firing at 1 ° C. for 1 hour. <Preparation of catalyst> 50 parts of Pd-Ba supported alumina powder,
50 parts of Rh-supported alumina powder, 10 parts of alumina sol (10% by weight of alumina), and 120 parts of pure water were mixed and stirred to prepare a slurry. Then, the honeycomb carrier base material made of cordierite (volume: 1.7 liter) was immersed in water, and after blowing off excess water, it was immersed in this slurry. Take it out, blow off the excess slurry, dry at 80 ° C for 20 minutes,
The catalyst for exhaust gas purification of Example 1 was obtained by firing at 600 ° C. for 1 hour.
【００２３】なお、この排ガス浄化用触媒には、ハニカ
ム担体基材１リットル当たりＰｄが１０ｇ、Ｒｈが０．
４ｇ、Ｂａが０．１モル担持されている。 （実施例２） ＜Ｐｄ−Ｒｈ／Ａｌ2 Ｏ3 の調製＞アルミナ粉末１００
部に、所定濃度の硝酸パラジウム水溶液の所定量と、所
定濃度の硝酸ロジウム水溶液の所定量と、純水１２０部
を混合攪拌し、１００℃にて１０時間乾燥した後、５０
０℃で１時間焼成してＰｄ−Ｒｈ担持アルミナ粉末を調
製した。In this exhaust gas purifying catalyst, Pd was 10 g and Rh was 0.
4 g and 0.1 mol of Ba are carried. (Example 2) <Preparation of Pd-Rh / Al 2 O 3 > alumina powder 100
Parts, a predetermined amount of a palladium nitrate aqueous solution having a predetermined concentration, a predetermined amount of a rhodium nitrate aqueous solution having a predetermined concentration, and 120 parts of pure water were mixed and stirred, and after drying at 100 ° C. for 10 hours, 50
Firing was performed at 0 ° C. for 1 hour to prepare a Pd—Rh-supported alumina powder.
【００２４】＜触媒の調製＞Ｐｄ−Ｂａ担持アルミナ粉
末５０部と、Ｐｄ−Ｒｈ担持アルミナ粉末５０部と、ア
ルミナゾル１０部と、純水１２０部を混合攪拌したスラ
リを用いたこと以外は実施例１と同様にして、実施例２
の排ガス浄化用触媒を得た。この排ガス浄化用触媒に
は、ハニカム担体基材１リットル当たりＰｄが１０ｇ、
Ｒｈが０．４ｇ、Ｂａが０．１モル担持されている。<Preparation of Catalyst> 50 parts of Pd-Ba-supporting alumina powder, 50 parts of Pd-Rh-supporting alumina powder, 10 parts of alumina sol, and 120 parts of pure water were mixed and stirred in the working examples. Example 2 as in Example 1
A catalyst for purification of exhaust gas was obtained. This exhaust gas-purifying catalyst contains 10 g of Pd per liter of the honeycomb carrier substrate,
0.4 g of Rh and 0.1 mol of Ba are supported.
【００２５】（実施例３） ＜Ｒｈ−Ｐｔ／Ａｌ2 Ｏ3 の調製＞アルミナ粉末１００
部に、所定濃度の硝酸ロジウム水溶液の所定量と、所定
濃度のジニトロジアンミン白金硝酸水溶液の所定量と、
純水１２０部を混合攪拌し、１００℃にて１０時間乾燥
した後、５００℃で１時間焼成してＲｈ−Ｐｔ担持アル
ミナ粉末を調製した。(Example 3) <Preparation of Rh-Pt / Al 2 O 3 > Alumina powder 100
Part, a predetermined amount of a predetermined concentration of rhodium nitrate aqueous solution, a predetermined concentration of a predetermined concentration of dinitrodiammine platinum nitric acid aqueous solution,
120 parts of pure water was mixed and stirred, dried at 100 ° C. for 10 hours, and then calcined at 500 ° C. for 1 hour to prepare an Rh—Pt-supported alumina powder.
【００２６】＜触媒の調製＞Ｐｄ−Ｂａ担持アルミナ粉
末５０部と、Ｒｈ−Ｐｔ担持アルミナ粉末５０部と、ア
ルミナゾル１０部と、純水１２０部を混合攪拌したスラ
リを用いたこと以外は実施例１と同様にして、実施例３
の排ガス浄化用触媒を得た。この排ガス浄化用触媒に
は、ハニカム担体基材１リットル当たりＰｄが１０ｇ、
Ｒｈが０．４ｇ、Ｐｔが１ｇ、Ｂａが０．１モル担持さ
れている。<Preparation of catalyst> Pd-Ba-supported alumina powder 50 parts, Rh-Pt-supported alumina powder 50 parts, alumina sol 10 parts, and pure water 120 parts were mixed and stirred in the working examples. Example 3 as in Example 1
A catalyst for purification of exhaust gas was obtained. This exhaust gas-purifying catalyst contains 10 g of Pd per liter of the honeycomb carrier substrate,
Rh is 0.4 g, Pt is 1 g, and Ba is 0.1 mol.
【００２７】（実施例４）Ｐｄ−Ｂａ担持アルミナ粉末
５０部と、Ｒｈ担持アルミナ粉末５０部と、ＣｅＯ2 −
ＺｒＯ2 複合酸化物粉末（モル比でＣｅ／Ｚｒ＝５：
１）５０部と、アルミナゾル１０部と、純水１２０部を
混合攪拌したスラリを用いたこと以外は実施例１と同様
にして、実施例４の排ガス浄化用触媒を得た。この排ガ
ス浄化用触媒には、ハニカム担体基材１リットル当たり
Ｐｄが１０ｇ、Ｒｈが０．４ｇ、ＣｅＯ2 −ＺｒＯ2 複
合酸化物が０．３モル、Ｂａが０．１モル担持されてい
る。[0027] (Example 4) and Pd-Ba-carrying alumina powder 50 parts, and Rh supported alumina powder, 50 parts of CeO 2 -
ZrO 2 composite oxide powder (molar ratio Ce / Zr = 5:
1) An exhaust gas purifying catalyst of Example 4 was obtained in the same manner as in Example 1 except that a slurry obtained by mixing 50 parts, 10 parts of alumina sol, and 120 parts of pure water was stirred. This exhaust gas-purifying catalyst carries 10 g of Pd, 0.4 g of Rh, 0.3 mol of CeO 2 —ZrO 2 composite oxide, and 0.1 mol of Ba per liter of the honeycomb carrier substrate.
【００２８】（実施例５）Ｐｄ−Ｂａ担持アルミナ粉末
５０部と、Ｒｈ担持アルミナ粉末５０部と、炭酸ランタ
ン２０部と、アルミナゾル１０部と、純水１２０部を混
合攪拌したスラリを用いたこと以外は実施例１と同様に
して、実施例５の排ガス浄化用触媒を得た。この排ガス
浄化用触媒には、ハニカム担体基材１リットル当たりＰ
ｄが１０ｇ、Ｒｈが０．４ｇ、Ｌａが０．１モル、Ｂａ
が０．１モル担持されている。(Example 5) A slurry prepared by mixing 50 parts of Pd-Ba-supporting alumina powder, 50 parts of Rh-supporting alumina powder, 20 parts of lanthanum carbonate, 10 parts of alumina sol, and 120 parts of pure water was used. An exhaust gas purifying catalyst of Example 5 was obtained in the same manner as in Example 1 except for the above. This exhaust gas purifying catalyst contains P per liter of honeycomb carrier substrate.
d is 10 g, Rh is 0.4 g, La is 0.1 mol, Ba
Is supported by 0.1 mol.
【００２９】（実施例６）図１に本実施例の排ガス浄化
用触媒の構成を示す。この排ガス浄化用触媒は、ハニカ
ム担体基材１と、担体基材１表面に形成されたコート層
２とからなり、コート層２にはＰｄ−Ｂａ担持アルミナ
粉末２０と、Ｒｈ担持アルミナ粉末２１と、ＣｅＯ2 −
ＺｒＯ2 複合酸化物粉末２２と、酸化ランタン粉末２３
とが含まれ、ＲｈとＢａとは分離担持されている。この
排ガス浄化用触媒は以下のようにして調製された。(Embodiment 6) FIG. 1 shows the structure of an exhaust gas purifying catalyst of this embodiment. This exhaust gas-purifying catalyst comprises a honeycomb carrier base material 1 and a coat layer 2 formed on the surface of the carrier base material 1, and the coat layer 2 contains Pd-Ba-supported alumina powder 20 and Rh-supported alumina powder 21. , CeO 2 −
ZrO 2 composite oxide powder 22 and lanthanum oxide powder 23
And Rh and Ba are separately carried. This exhaust gas-purifying catalyst was prepared as follows.
【００３０】Ｐｄ−Ｂａ担持アルミナ粉末５０部と、Ｒ
ｈ担持アルミナ粉末５０部と、ＣｅＯ2 −ＺｒＯ2 複合
酸化物粉末（モル比でＣｅ／Ｚｒ＝５：１）５０部と、
炭酸ランタン２０部と、アルミナゾル１０部と、純水１
２０部を混合攪拌したスラリを用いたこと以外は実施例
１と同様にして、実施例６の排ガス浄化用触媒を得た。
この排ガス浄化用触媒には、ハニカム担体基材１リット
ル当たりＰｄが１０ｇ、Ｒｈが０．４ｇ、ＣｅＯ2 −Ｚ
ｒＯ2 複合酸化物が０．３モル、Ｌａが０．１モル、Ｂ
ａが０．１モル担持されている。50 parts of alumina powder supporting Pd-Ba and R
50 parts of h-supported alumina powder, 50 parts of CeO 2 —ZrO 2 composite oxide powder (in molar ratio Ce / Zr = 5: 1),
20 parts lanthanum carbonate, 10 parts alumina sol, 1 pure water
An exhaust gas purifying catalyst of Example 6 was obtained in the same manner as in Example 1 except that 20 parts of the slurry was mixed and stirred.
This exhaust gas-purifying catalyst contains 10 g of Pd, 0.4 g of Rh, and CeO 2 -Z per liter of the honeycomb carrier substrate.
0.3 mol of rO 2 composite oxide, 0.1 mol of La, B
a is supported by 0.1 mol.
【００３１】（実施例７） ＜Ｐｄ−Ｐｔ−Ｂａ／Ａｌ2 Ｏ3 の調製＞アルミナ粉末
６０部に、所定濃度の硝酸パラジウム水溶液の所定量
と、所定濃度のジニトロジアンミン白金硝酸水溶液の所
定量と、酢酸バリウム４０部と、純水１２０部を混合攪
拌し、１００℃にて１０時間乾燥した後、５００℃で１
時間焼成してＰｄ−Ｐｔ−Ｂａ担持アルミナ粉末を調製
した。(Example 7) <Preparation of Pd-Pt-Ba / Al 2 O 3 > A predetermined amount of an aqueous solution of palladium nitrate having a predetermined concentration and a predetermined amount of an aqueous solution of dinitrodiammine platinum nitric acid having a predetermined concentration were added to 60 parts of alumina powder. 40 parts of barium acetate and 120 parts of pure water were mixed and stirred, dried at 100 ° C. for 10 hours, and then dried at 500 ° C. for 1 hour.
Firing was carried out for a period of time to prepare a Pd-Pt-Ba supported alumina powder.
【００３２】＜触媒の調製＞Ｐｄ−Ｐｔ−Ｂａ担持アル
ミナ粉末５０部と、Ｒｈ担持アルミナ粉末５０部と、ア
ルミナゾル１０部と、純水１２０部を混合攪拌したスラ
リを用いたこと以外は実施例１と同様にして、実施例７
の排ガス浄化用触媒を得た。この排ガス浄化用触媒に
は、ハニカム担体基材１リットル当たりＰｄが１０ｇ、
Ｒｈが０．４ｇ、Ｐｔが１ｇ、Ｂａが０．１モル担持さ
れている。<Preparation of catalyst> Pd-Pt-Ba-supported alumina powder 50 parts, Rh-supported alumina powder 50 parts, alumina sol 10 parts, and pure water 120 parts were mixed and stirred in the working examples. Example 7 as in Example 1.
A catalyst for purification of exhaust gas was obtained. This exhaust gas-purifying catalyst contains 10 g of Pd per liter of the honeycomb carrier substrate,
Rh is 0.4 g, Pt is 1 g, and Ba is 0.1 mol.
【００３３】（実施例８） ＜Ｒｈ／ＺｒＯ2 の調製＞ジルコニア粉末１００部に、
所定濃度の硝酸ロジウム水溶液の所定量と、純水１２０
部を混合攪拌し、１００℃にて１０時間乾燥した後、５
００℃で１時間焼成してＲｈ担持ジルコニア粉末を調製
した。Example 8 <Preparation of Rh / ZrO 2 > To 100 parts of zirconia powder,
A predetermined amount of a rhodium nitrate aqueous solution having a predetermined concentration and pure water 120
Parts were mixed and stirred, dried at 100 ° C. for 10 hours, and then 5
A Rh-supported zirconia powder was prepared by firing at 00 ° C. for 1 hour.
【００３４】＜触媒の調製＞Ｐｄ−Ｂａ担持アルミナ粉
末５０部と、Ｒｈ担持ジルコニア粉末５０部と、アルミ
ナゾル１０部と、純水１２０部を混合攪拌したスラリを
用いたこと以外は実施例１と同様にして、実施例８の排
ガス浄化用触媒を得た。この排ガス浄化用触媒には、ハ
ニカム担体基材１リットル当たりＰｄが１０ｇ、Ｒｈが
０．４ｇ、Ｂａが０．１モル担持されている。<Preparation of catalyst> Example 1 except that 50 parts of Pd-Ba supported alumina powder, 50 parts of Rh supported zirconia powder, 10 parts of alumina sol and 120 parts of pure water were mixed and stirred. Similarly, an exhaust gas purifying catalyst of Example 8 was obtained. This exhaust gas purifying catalyst carries 10 g of Pd, 0.4 g of Rh, and 0.1 mol of Ba per liter of the honeycomb carrier substrate.
【００３５】（実施例９） ＜Ｒｈ／ＺｒＯ2 −Ａｌ2 Ｏ3 の調製＞アルミナ粉末１
００部を硝酸ジルコニウム水溶液に浸漬し、アンモニア
水を滴下してアルミナ上にジルコニアを共沈させた。こ
のジルコニア共沈アルミナ粉末１００部に、所定濃度の
硝酸ロジウム水溶液の所定量と、純水１２０部を混合攪
拌し、１００℃にて１０時間乾燥した後、５００℃で１
時間焼成してＲｈ担持ジルコニア共沈アルミナ粉末を調
製した。(Example 9) <Preparation of Rh / ZrO 2 -Al 2 O 3 > Alumina powder 1
00 parts was immersed in an aqueous zirconium nitrate solution, ammonia water was added dropwise to coprecipitate zirconia on alumina. To 100 parts of this zirconia coprecipitated alumina powder, a predetermined amount of an aqueous rhodium nitrate solution having a predetermined concentration and 120 parts of pure water were mixed and stirred, dried at 100 ° C. for 10 hours, and then dried at 500 ° C.
It was calcined for an hour to prepare a Rh-supported zirconia coprecipitated alumina powder.
【００３６】＜触媒の調製＞Ｐｄ−Ｂａ担持アルミナ粉
末５０部と、Ｒｈ担持ジルコニア共沈アルミナ粉末５０
部と、アルミナゾル１０部と、純水１２０部を混合攪拌
したスラリを用いたこと以外は実施例１と同様にして、
実施例９の排ガス浄化用触媒を得た。この排ガス浄化用
触媒には、ハニカム担体基材１リットル当たりＰｄが１
０ｇ、Ｒｈが０．４ｇ、Ｂａが０．１モル担持されてい
る。<Preparation of catalyst> 50 parts of Pd-Ba-supporting alumina powder and Rh-supporting zirconia coprecipitated alumina powder 50
Parts, 10 parts of alumina sol, and 120 parts of pure water were mixed and stirred in the same manner as in Example 1 except that a slurry was used.
An exhaust gas-purifying catalyst of Example 9 was obtained. In this exhaust gas purifying catalyst, Pd is 1 per liter of the honeycomb carrier substrate.
0 g, 0.4 g of Rh and 0.1 mol of Ba are supported.
【００３７】（実施例１０）図２に本実施例の排ガス浄
化用触媒の構成を示す。この排ガス浄化用触媒は、ハニ
カム担体基材１と、担体基材１表面に形成されたコート
層３とからなり、コート層３は下層３０と上層３１の二
層構造となっている。そして下層３０にはＰｄ−Ｂａ担
持アルミナ粉末が含まれ、上層３１にはＲｈ担持アルミ
ナ粉末が含まれている。したがってＲｈとＢａとは分離
担持されている。この排ガス浄化用触媒は以下のように
して調製された。(Embodiment 10) FIG. 2 shows the structure of the exhaust gas purifying catalyst of this embodiment. This exhaust gas-purifying catalyst comprises a honeycomb carrier base material 1 and a coat layer 3 formed on the surface of the carrier base material 1, and the coat layer 3 has a two-layer structure of a lower layer 30 and an upper layer 31. The lower layer 30 contains Pd-Ba-supporting alumina powder, and the upper layer 31 contains Rh-supporting alumina powder. Therefore, Rh and Ba are separately carried. This exhaust gas-purifying catalyst was prepared as follows.
【００３８】Ｐｄ−Ｂａ担持アルミナ粉末５０部と、ア
ルミナゾル５部と、純水６０部を混合攪拌してスラリー
を調製した。そしてコージェライト製ハニカム担体１
（容積１．７リットル）を水に浸漬し、余分な水を吹き
払った後このスラリーに浸漬した。取り出して余分なス
ラリーを吹き払い、８０℃で２０分間乾燥後６００℃で
１時間焼成し、下層３０を形成した。50 parts of Pd-Ba-supported alumina powder, 5 parts of alumina sol, and 60 parts of pure water were mixed and stirred to prepare a slurry. And a cordierite honeycomb carrier 1
(Volume 1.7 liter) was immersed in water, and after blowing off excess water, it was immersed in this slurry. It was taken out, the excess slurry was blown off, dried at 80 ° C. for 20 minutes, and then baked at 600 ° C. for 1 hour to form the lower layer 30.
【００３９】次にＲｈ担持アルミナ粉末５０部と、アル
ミナゾル５部と、純水６０部を混合攪拌してスラリーを
調製した。そして下層３０をもつハニカム担体基材１を
水に浸漬し、余分な水を吹き払った後このスラリーに浸
漬した。取り出して余分なスラリーを吹き払い、８０℃
で２０分間乾燥後６００℃で１時間焼成し、下層３０表
面に上層３１を形成して実施例１０の排ガス浄化用触媒
を得た。下層３０の厚さは１００μｍ、上層３１の厚さ
は５０μｍであって、厚さの比は下層：上層＝２：１で
ある。この排ガス浄化用触媒には、ハニカム担体基材１
リットル当たりＰｄが１０ｇ、Ｒｈが０．４ｇ、Ｂａが
０．１モル担持されている。Next, 50 parts of Rh-supported alumina powder, 5 parts of alumina sol, and 60 parts of pure water were mixed and stirred to prepare a slurry. Then, the honeycomb carrier base material 1 having the lower layer 30 was immersed in water, and after blowing off excess water, it was immersed in this slurry. Remove and blow off excess slurry to 80 ℃
After drying for 20 minutes at 600 ° C. for 1 hour, an upper layer 31 was formed on the surface of the lower layer 30 to obtain an exhaust gas purifying catalyst of Example 10. The lower layer 30 has a thickness of 100 μm, the upper layer 31 has a thickness of 50 μm, and the thickness ratio is lower layer: upper layer = 2: 1. The exhaust gas-purifying catalyst includes a honeycomb carrier substrate 1
Pd is 10 g, Rh is 0.4 g, and Ba is 0.1 mol per liter.
【００４０】（実施例１１）Ｐｄ−Ｒｈ担持アルミナ粉
末５０部と、アルミナゾル５部と、純水６０部を混合攪
拌してスラリーを調製した。そして実施例１０で形成さ
れた下層をもつハニカム担体基材を水に浸漬し、余分な
水を吹き払った後このスラリーに浸漬した。取り出して
余分なスラリーを吹き払い、８０℃で２０分間乾燥後６
００℃で１時間焼成し、下層表面に上層を形成して実施
例１１の排ガス浄化用触媒を得た。上層の厚さは５０μ
ｍであり、厚さの比は下層：上層＝２：１である。この
排ガス浄化用触媒には、ハニカム担体基材１リットル当
たりＰｄが１０ｇ、Ｒｈが０．４ｇ、Ｂａが０．１モル
担持されている。(Example 11) 50 parts of Pd-Rh-supported alumina powder, 5 parts of alumina sol, and 60 parts of pure water were mixed and stirred to prepare a slurry. Then, the honeycomb carrier base material having the lower layer formed in Example 10 was immersed in water, and after blowing off excess water, it was immersed in this slurry. Remove and blow off excess slurry, dry at 80 ° C for 20 minutes 6
The catalyst for flue gas purification of Example 11 was obtained by firing at 00 ° C. for 1 hour to form an upper layer on the lower layer surface. The thickness of the upper layer is 50μ
m, and the thickness ratio is lower layer: upper layer = 2: 1. This exhaust gas purifying catalyst carries 10 g of Pd, 0.4 g of Rh, and 0.1 mol of Ba per liter of the honeycomb carrier substrate.
【００４１】（実施例１２）Ｐｄ−Ｂａ担持アルミナ粉
末５０部と、アルミナゾル５部と、純水６０部を混合攪
拌してスラリーを調製した。そしてコージェライト製ハ
ニカム担体基材（容積１．７リットル）を水に浸漬し、
余分な水を吹き払った後このスラリーに浸漬した。取り
出して余分なスラリーを吹き払い、８０℃で２０分間乾
燥後６００℃で１時間焼成し、下層を形成した。(Example 12) 50 parts of alumina powder supporting Pd-Ba, 5 parts of alumina sol, and 60 parts of pure water were mixed and stirred to prepare a slurry. Then, the honeycomb carrier base material made of cordierite (volume: 1.7 liter) is immersed in water,
It was immersed in this slurry after blowing off excess water. It was taken out, the excess slurry was blown off, dried at 80 ° C. for 20 minutes, and then baked at 600 ° C. for 1 hour to form a lower layer.
【００４２】次にＲｈ−Ｐｔ担持アルミナ粉末５０部
と、アルミナゾル５部と、純水６０部を混合攪拌してス
ラリーを調製した。そして下層をもつハニカム担体基材
を水に浸漬し、余分な水を吹き払った後このスラリーに
浸漬した。取り出して余分なスラリーを吹き払い、８０
℃で２０分間乾燥後６００℃で１時間焼成し、下層表面
に上層を形成して実施例１２の排ガス浄化用触媒を得
た。下層の厚さは１００μｍ、上層の厚さは５０μｍで
あって、厚さの比は下層：上層＝２：１である。この排
ガス浄化用触媒には、ハニカム担体基材１リットル当た
りＰｄが１０ｇ、Ｒｈが０．４ｇ、Ｐｔが１ｇ、Ｂａが
０．１モル担持されている。Next, 50 parts of Rh-Pt-supported alumina powder, 5 parts of alumina sol, and 60 parts of pure water were mixed and stirred to prepare a slurry. Then, the honeycomb carrier base material having the lower layer was immersed in water, and after blowing off excess water, it was immersed in this slurry. Remove and blow away excess slurry, 80
After drying at 20 ° C. for 20 minutes and baking at 600 ° C. for 1 hour, an upper layer was formed on the lower layer surface to obtain an exhaust gas purifying catalyst of Example 12. The lower layer has a thickness of 100 μm, the upper layer has a thickness of 50 μm, and the thickness ratio is lower layer: upper layer = 2: 1. This exhaust gas purifying catalyst carries 10 g of Pd, 0.4 g of Rh, 1 g of Pt, and 0.1 mol of Ba per liter of the honeycomb carrier substrate.
【００４３】（実施例１３）上層の厚さを７５μｍと
し、下層の厚さを同じ７５μｍとして、厚さの比を下
層：上層＝１：１としたこと以外は実施例１０と同様に
して、実施例１３の排ガス浄化用触媒を調製した。この
排ガス浄化用触媒にも、ハニカム担体基材１リットル当
たりＰｄが１０ｇ、Ｒｈが０．４ｇ、Ｐｔが１ｇ、Ｂａ
が０．１モル担持されている。Example 13 The same procedure as in Example 10 was repeated except that the upper layer had a thickness of 75 μm, the lower layer had the same thickness of 75 μm, and the thickness ratio was lower layer: upper layer = 1: 1. The exhaust gas-purifying catalyst of Example 13 was prepared. Also in this exhaust gas-purifying catalyst, Pd is 10 g, Rh is 0.4 g, Pt is 1 g, and Ba per liter of the honeycomb carrier substrate.
Is supported by 0.1 mol.
【００４４】（比較例１） ＜Ｐｄ／Ａｌ2 Ｏ3 の調製＞アルミナ粉末１００部に、
所定濃度の硝酸パラジウム水溶液の所定量と、純水１２
０部を混合攪拌し、１００℃にて１０時間乾燥した後、
５００℃で１時間焼成してＰｄ担持アルミナ粉末を調製
した。Comparative Example 1 <Preparation of Pd / Al 2 O 3 > To 100 parts of alumina powder,
A predetermined amount of palladium nitrate aqueous solution with a predetermined concentration and pure water 12
After mixing and stirring 0 parts and drying at 100 ° C. for 10 hours,
Pd-supported alumina powder was prepared by firing at 500 ° C. for 1 hour.
【００４５】＜触媒の調製＞Ｐｄ担持アルミナ粉末１０
０部と、アルミナゾル１０部と、純水１２０部を混合攪
拌したスラリを用いたこと以外は実施例１と同様にし
て、比較例１の排ガス浄化用触媒を得た。この排ガス浄
化用触媒には、ハニカム担体基材１リットル当たりＰｄ
が１０ｇ担持されている。<Preparation of catalyst> Pd-supported alumina powder 10
An exhaust gas purifying catalyst of Comparative Example 1 was obtained in the same manner as in Example 1, except that 0 parts, 10 parts of alumina sol, and 120 parts of pure water were mixed and stirred. This exhaust gas-purifying catalyst contains Pd per liter of the honeycomb carrier substrate.
Is carried by 10 g.
【００４６】（比較例２） ＜触媒の調製＞Ｐｄ−Ｂａ担持アルミナ粉末１００部
と、アルミナゾル１０部と、純水１２０部を混合攪拌し
たスラリを用いたこと以外は実施例１と同様にして、比
較例２の排ガス浄化用触媒を得た。この排ガス浄化用触
媒には、ハニカム担体基材１リットル当たりＰｄが１０
ｇ、Ｂａが０．１モル担持されている。Comparative Example 2 <Preparation of Catalyst> The same procedure as in Example 1 was carried out except that a slurry prepared by mixing 100 parts of Pd-Ba-supported alumina powder, 10 parts of alumina sol and 120 parts of pure water was stirred. An exhaust gas purifying catalyst of Comparative Example 2 was obtained. In this exhaust gas-purifying catalyst, Pd was 10 per liter of the honeycomb carrier substrate.
0.1 mol of g and Ba are supported.
【００４７】（比較例３） ＜触媒の調製＞Ｐｄ−Ｒｈ担持アルミナ粉末１００部
と、アルミナゾル１０部と、純水１２０部を混合攪拌し
たスラリを用いたこと以外は実施例１と同様にして、比
較例３の排ガス浄化用触媒を得た。この排ガス浄化用触
媒には、ハニカム担体基材１リットル当たりＰｄが１０
ｇ、Ｒｈが０．４ｇ担持されている。Comparative Example 3 <Preparation of Catalyst> The same procedure as in Example 1 was repeated except that 100 parts of Pd-Rh-supported alumina powder, 10 parts of alumina sol and 120 parts of pure water were mixed and stirred. An exhaust gas purifying catalyst of Comparative Example 3 was obtained. In this exhaust gas-purifying catalyst, Pd was 10 per liter of the honeycomb carrier substrate.
0.4 g of g and Rh are carried.
【００４８】（比較例４） ＜Ｐｄ−Ｒｈ−Ｂａ／Ａｌ2 Ｏ3 の調製＞アルミナ粉末
１００部に、所定濃度の硝酸パラジウム水溶液の所定量
と、所定濃度の硝酸ロジウム水溶液の所定量と、酢酸バ
リウム２０部と、純水１２０部を混合攪拌し、１００℃
にて１０時間乾燥した後、５００℃で１時間焼成してＰ
ｄ−Ｒｈ−Ｂａ担持アルミナ粉末を調製した。(Comparative Example 4) <Preparation of Pd-Rh-Ba / Al 2 O 3 > 100 parts of alumina powder were charged with a predetermined amount of a palladium nitrate aqueous solution having a predetermined concentration and a predetermined amount of a rhodium nitrate aqueous solution having a predetermined concentration. 20 parts of barium acetate and 120 parts of pure water are mixed and stirred at 100 ° C.
After drying at 10 ° C for 10 hours, baking at 500 ° C for 1 hour
A d-Rh-Ba-supported alumina powder was prepared.
【００４９】＜触媒の調製＞Ｐｄ−Ｒｈ−Ｂａ担持アル
ミナ粉末１００部と、アルミナゾル１０部と、純水１２
０部を混合攪拌したスラリを用いたこと以外は実施例１
と同様にして、比較例４の排ガス浄化用触媒を得た。こ
の排ガス浄化用触媒には、ハニカム担体基材１リットル
当たりＰｄが１０ｇ、Ｒｈが０．４ｇ、Ｂａが０．１モ
ル担持されている。<Preparation of catalyst> Pd-Rh-Ba-supported alumina powder 100 parts, alumina sol 10 parts, and pure water 12
Example 1 except that a slurry obtained by mixing and stirring 0 parts was used.
An exhaust gas purifying catalyst of Comparative Example 4 was obtained in the same manner as in. This exhaust gas purifying catalyst carries 10 g of Pd, 0.4 g of Rh, and 0.1 mol of Ba per liter of the honeycomb carrier substrate.
【００５０】（比較例５） ＜Ｒｈ−Ｂａ／Ａｌ2 Ｏ3 の調製＞アルミナ粉末１００
部に、所定濃度の硝酸ロジウム水溶液の所定量と、酢酸
バリウム２０部と、純水１２０部を混合攪拌し、１００
℃にて１０時間乾燥した後、５００℃で１時間焼成して
Ｒｈ−Ｂａ担持アルミナ粉末を調製した。Comparative Example 5 <Preparation of Rh—Ba / Al 2 O 3 > Alumina powder 100
A predetermined amount of an aqueous solution of rhodium nitrate having a predetermined concentration, 20 parts of barium acetate, and 120 parts of pure water are mixed and stirred in 100 parts.
After drying at 0 ° C. for 10 hours, it was baked at 500 ° C. for 1 hour to prepare an Rh-Ba-supported alumina powder.
【００５１】＜触媒の調製＞Ｐｄ担持アルミナ粉末５０
部と、Ｒｈ−Ｂａ担持アルミナ粉末５０部と、アルミナ
ゾル１０部と、純水１２０部を混合攪拌したスラリを用
いたこと以外は実施例１と同様にして、比較例５の排ガ
ス浄化用触媒を得た。この排ガス浄化用触媒には、ハニ
カム担体基材１リットル当たりＰｄが１０ｇ、Ｒｈが
０．４ｇ、Ｂａが０．１モル担持されている。<Preparation of catalyst> Pd-supported alumina powder 50
Parts, 50 parts of Rh-Ba supported alumina powder, 10 parts of alumina sol, and 120 parts of pure water were mixed and stirred in the same manner as in Example 1 to prepare an exhaust gas purifying catalyst of Comparative Example 5. Obtained. This exhaust gas purifying catalyst carries 10 g of Pd, 0.4 g of Rh, and 0.1 mol of Ba per liter of the honeycomb carrier substrate.
【００５２】（評価）上記のそれぞれの排ガス浄化用触
媒を触媒コンバータに収納して２リットルエンジンの排
気系に装着し、空燃比（Ａ／Ｆ）を１４．６（ストイ
キ）を中心にして、振幅：約１Ａ／Ｆ、周期：約０．５
Ｈｚの条件で大きく変動させ、触媒床温１００℃で５０
時間運転する実排ガス耐久試験を行った。その後Ａ／Ｆ
＝１４．６のストイキ条件にて、触媒床温を２４０℃か
ら４４０℃まで昇温し、その時のＨＣ、ＣＯ及びＮＯx
の５０％浄化温度を測定した。それぞれの排ガス浄化用
触媒の結果を表２に示す。(Evaluation) Each of the above exhaust gas-purifying catalysts was housed in a catalytic converter and mounted in the exhaust system of a 2-liter engine, and the air-fuel ratio (A / F) was set to 14.6 (Stoichi), Amplitude: about 1 A / F, cycle: about 0.5
At a catalyst bed temperature of 100 ° C. and 50
An actual exhaust gas endurance test of operating for hours was performed. Then A / F
Under stoichiometric conditions of = 14.6, the catalyst bed temperature is raised from 240 ° C to 440 ° C, and HC, CO and NO x at that time are increased.
The 50% purification temperature was measured. Table 2 shows the results of the respective exhaust gas purifying catalysts.
【００５３】[0053]
【表２】 [Table 2]
【００５４】比較例１と比較例２及び比較例３の比較よ
り、ＰｄとＢａ又はＲｈを共存させることにより耐久後
の触媒性能が向上していることがわかる。しかし比較例
４のようにＲｈとＢａの両方をＰｄと共存させても比較
例３とほとんど同等の触媒性能を示し、Ｂａの添加効果
が現れていないことがわかる。また比較例５では、Ｒｈ
とＢａの接触する確率が高いため比較例４より触媒性能
が低下している。From the comparison between Comparative Example 1, Comparative Example 2 and Comparative Example 3, it can be seen that the coexistence of Pd and Ba or Rh improves the catalytic performance after endurance. However, as in Comparative Example 4, even when both Rh and Ba coexisted with Pd, the catalytic performance was almost the same as in Comparative Example 3, and it can be seen that the effect of adding Ba is not exhibited. In Comparative Example 5, Rh
The catalytic performance is lower than in Comparative Example 4 because the probability of contact between Ba and Ba is high.
【００５５】しかし実施例１は比較例に比べて格段に高
い触媒性能を示し、これはＲｈとＢａとを分離担持した
効果であることが明らかである。そして、実施例２及び
実施例３のように、Ｒｈ担持アルミナにＰｄ又はＰｔを
共存させることにより、実施例１に比べて触媒性能が若
干向上している。また実施例４〜６のように、ＣｅＯ2
−ＺｒＯ2 複合酸化物や酸化ランタンをさらに共存させ
ることにより、触媒性能が若干向上することもわかる。
また実施例７のようにＰｄ−Ｂａ担持アルミナにＰｔを
さらに共存させても触媒性能が若干向上し、実施例８や
実施例９のようにＲｈをジルコニア又はジルコニア共沈
アルミナに担持しても触媒性能が若干向上することがわ
かる。However, Example 1 shows a markedly higher catalytic performance than the Comparative Example, and it is clear that this is the effect of separating and supporting Rh and Ba. Then, as in Examples 2 and 3, the coexistence of Pd or Pt in the Rh-supported alumina slightly improved the catalytic performance as compared with Example 1. Also, as in Examples 4 to 6, CeO 2
It can also be seen that the catalytic performance is slightly improved by further coexisting the --ZrO 2 composite oxide and lanthanum oxide.
Further, even if Pt is further coexisted on Pd-Ba-supported alumina as in Example 7, the catalytic performance is slightly improved, and even if Rh is supported on zirconia or zirconia co-precipitated alumina as in Examples 8 and 9. It can be seen that the catalyst performance is slightly improved.
【００５６】さらに、比較例４と実施例１０の比較よ
り、ＲｈとＢａとをコート層の下層と上層とに分離担持
することで触媒性能が格段に向上していることが明らか
である。そして実施例１１及び実施例１２のように、Ｒ
ｈにＰｄ又はＰｔを共存させることで触媒性能が若干向
上することがわかる。しかし実施例１３では逆に触媒性
能が低下している。これは、上層の厚さが厚いために下
層の触媒成分の有効利用が困難となったためと考えられ
る。Further, it is clear from the comparison between Comparative Example 4 and Example 10 that catalytic performance is remarkably improved by separately carrying Rh and Ba in the lower layer and the upper layer of the coating layer. Then, as in Examples 11 and 12, R
It can be seen that the coexistence of Pd or Pt in h slightly improves the catalyst performance. However, in Example 13, conversely, the catalytic performance is lowered. It is considered that this is because the thick upper layer made it difficult to effectively use the catalyst component of the lower layer.
【００５７】[0057]
【発明の効果】すなわち本発明の排ガス浄化用触媒によ
れば、Ｐｄ、Ｒｈ及びＢａの各触媒成分の作用を最大に
引き出すことができ、耐久後にも高い触媒性能を確保す
ることができる。According to the catalyst for purifying exhaust gas of the present invention, the action of each catalyst component of Pd, Rh and Ba can be maximized, and high catalyst performance can be ensured even after durability.
【図１】本発明の実施例６の排ガス浄化用触媒の構成を
示す模式的断面図である。FIG. 1 is a schematic cross-sectional view showing the structure of an exhaust gas purifying catalyst of Example 6 of the present invention.
【図２】本発明の実施例１０の排ガス浄化用触媒の構成
を示す模式的断面図である。FIG. 2 is a schematic cross-sectional view showing the structure of an exhaust gas purification catalyst of Example 10 of the present invention.
【図３】Ｐｄ触媒のＢａ添加量とＮＯ５０％浄化温度と
の関係を示すグラフであるFIG. 3 is a graph showing the relationship between the amount of Ba added to the Pd catalyst and the NO50% purification temperature.
【図４】Ｒｈ触媒のＢａ添加量とＮＯ５０％浄化温度と
の関係を示すグラフである。FIG. 4 is a graph showing the relationship between the amount of Ba added to the Rh catalyst and the NO50% purification temperature.
１：担体基材 ２：コート層 ２０：Ｐｄ−Ｂａ担
持アルミナ粉末 ２１：Ｒｈ担持アルミナ粉末 ２２：ＣｅＯ2 −
ＺｒＯ2 複合酸化物粉末 ２３：酸化ランタン粉末 ３０：下層 ３
１：上層1: support substrate 2: coating layer 20: Pd-Ba-carrying alumina powder 21: Rh-carried alumina powder 22: CeO 2 -
ZrO 2 composite oxide powder 23: lanthanum oxide powder 30: lower layer 3
1: Upper layer
───────────────────────────────────────────────────── フロントページの続き (72)発明者 三好 直人 愛知県豊田市トヨタ町１番地 トヨタ自動 車株式会社内 (72)発明者 新庄 博文 愛知県愛知郡長久手町大字長湫字横道41番 地の１ 株式会社豊田中央研究所内 (72)発明者 曽布川 英夫 愛知県愛知郡長久手町大字長湫字横道41番 地の１ 株式会社豊田中央研究所内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Naoto Miyoshi 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation (72) Inventor Hirobumi Shinjo 1 of 41, Yokoshiro, Nagakute Town, Aichi District, Aichi Prefecture Toyota Central Research Institute Co., Ltd. (72) Inventor Hideo Sofagawa 1 41st Yokomichi, Nagakute-cho, Aichi-gun, Aichi-gun
Claims (1)
バリウムを担持してなる排ガス浄化用触媒において、 ロジウムとバリウムの少なくとも一部は互いに分離した
状態で該多孔質担体に担持されていることを特徴とする
排ガス浄化用触媒。1. A catalyst for exhaust gas purification, comprising palladium, rhodium and barium supported on a porous carrier, wherein at least a part of rhodium and barium are supported on the porous carrier in a state of being separated from each other. Exhaust gas purification catalyst.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8024000A JPH09215922A (en) | 1996-02-09 | 1996-02-09 | Catalyst for purifying exhaust gas |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8024000A JPH09215922A (en) | 1996-02-09 | 1996-02-09 | Catalyst for purifying exhaust gas |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2002126090A Division JP3798727B2 (en) | 2002-04-26 | 2002-04-26 | Exhaust gas purification catalyst |
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| Publication Number | Publication Date |
|---|---|
| JPH09215922A true JPH09215922A (en) | 1997-08-19 |
Family
ID=12126310
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP8024000A Pending JPH09215922A (en) | 1996-02-09 | 1996-02-09 | Catalyst for purifying exhaust gas |
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Cited By (18)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000051704A (en) * | 1998-08-13 | 2000-02-22 | Jisedai Haigas Shokubai Kenkyusho:Kk | Catalyst for purifying exhaust gas and its use method |
| JP2001104786A (en) * | 1999-10-08 | 2001-04-17 | Daihatsu Motor Co Ltd | Catalyst for purifying exhaust gas |
| JP2003080081A (en) * | 2001-09-12 | 2003-03-18 | Cataler Corp | Catalyst for cleaning exhaust gas |
| JP2004275842A (en) * | 2003-03-13 | 2004-10-07 | Cataler Corp | Waste gas purification catalyst |
| WO2005023421A1 (en) * | 2003-09-08 | 2005-03-17 | Valtion Teknillinen Tutkimuskeskus | Catalyst and method for contact decomposition of nitrogen oxide |
| WO2006040842A1 (en) * | 2004-10-15 | 2006-04-20 | Johnson Matthey Japan Incorporated | Catalyst for treating exhaust gas and device for treating exhaust gas using the same |
| JP2008069708A (en) * | 2006-09-14 | 2008-03-27 | Toyota Motor Corp | Exhaust gas state estimation device |
| JP2010046656A (en) * | 2008-07-22 | 2010-03-04 | Toyota Central R&D Labs Inc | Catalyst for purifying exhaust gas and exhaust gas purification method using the catalyst |
| WO2010103870A1 (en) * | 2009-03-09 | 2010-09-16 | 第一稀元素化学工業株式会社 | Exhaust gas purifying catalyst, exhaust gas purifying apparatus using same, and method for purifying exhaust gas |
| WO2013065421A1 (en) | 2011-10-31 | 2013-05-10 | エヌ・イー ケムキャット株式会社 | Exhaust gas purifying catalyst |
| WO2013111457A1 (en) | 2012-01-23 | 2013-08-01 | エヌ・イーケムキャット株式会社 | Alumina material containing barium sulfate and exhaust gas purifying catalyst using same |
| WO2013136821A1 (en) | 2012-03-14 | 2013-09-19 | エヌ・イーケムキャット株式会社 | Catalyst composition for exhaust gas cleaning and catalyst for automobile exhaust gas cleaning |
| WO2014002667A1 (en) | 2012-06-28 | 2014-01-03 | エヌ・イーケムキャット株式会社 | Catalyst composition for exhaust gas purification and exhaust gas purifying catalyst for automobiles |
| US8999252B2 (en) | 2006-04-03 | 2015-04-07 | Johnson Matthey Japan Incorporated | Exhaust gas catalyst and exhaust gas processing apparatus using same |
| JP2016123958A (en) * | 2015-01-07 | 2016-07-11 | 株式会社キャタラー | Catalyst for exhaust gas purification and system for exhaust gas purification |
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| WO2017150350A1 (en) * | 2016-03-01 | 2017-09-08 | 株式会社キャタラー | Exhaust gas purification catalyst |
| WO2017179679A1 (en) * | 2016-04-13 | 2017-10-19 | トヨタ自動車株式会社 | Exhaust gas cleaning catalyst, exhaust gas cleaning method, and exhaust gas cleaning system |
-
1996
- 1996-02-09 JP JP8024000A patent/JPH09215922A/en active Pending
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000051704A (en) * | 1998-08-13 | 2000-02-22 | Jisedai Haigas Shokubai Kenkyusho:Kk | Catalyst for purifying exhaust gas and its use method |
| JP2001104786A (en) * | 1999-10-08 | 2001-04-17 | Daihatsu Motor Co Ltd | Catalyst for purifying exhaust gas |
| JP2003080081A (en) * | 2001-09-12 | 2003-03-18 | Cataler Corp | Catalyst for cleaning exhaust gas |
| JP2004275842A (en) * | 2003-03-13 | 2004-10-07 | Cataler Corp | Waste gas purification catalyst |
| WO2005023421A1 (en) * | 2003-09-08 | 2005-03-17 | Valtion Teknillinen Tutkimuskeskus | Catalyst and method for contact decomposition of nitrogen oxide |
| US7422731B2 (en) | 2003-09-08 | 2008-09-09 | Honda Motor Co., Ltd. | Catalyst and method for contact decomposition of nitrogen oxides |
| US8153549B2 (en) | 2004-10-15 | 2012-04-10 | Johnson Matthey Public Limited Company | Catalyst for treating exhaust gas and device for treating exhaust gas using the same |
| WO2006040842A1 (en) * | 2004-10-15 | 2006-04-20 | Johnson Matthey Japan Incorporated | Catalyst for treating exhaust gas and device for treating exhaust gas using the same |
| US8999252B2 (en) | 2006-04-03 | 2015-04-07 | Johnson Matthey Japan Incorporated | Exhaust gas catalyst and exhaust gas processing apparatus using same |
| JP2008069708A (en) * | 2006-09-14 | 2008-03-27 | Toyota Motor Corp | Exhaust gas state estimation device |
| JP2010046656A (en) * | 2008-07-22 | 2010-03-04 | Toyota Central R&D Labs Inc | Catalyst for purifying exhaust gas and exhaust gas purification method using the catalyst |
| WO2010103870A1 (en) * | 2009-03-09 | 2010-09-16 | 第一稀元素化学工業株式会社 | Exhaust gas purifying catalyst, exhaust gas purifying apparatus using same, and method for purifying exhaust gas |
| JPWO2010103870A1 (en) * | 2009-03-09 | 2012-09-13 | 第一稀元素化学工業株式会社 | Exhaust gas purification catalyst, exhaust gas purification device using the same, and exhaust gas purification method |
| WO2013065421A1 (en) | 2011-10-31 | 2013-05-10 | エヌ・イー ケムキャット株式会社 | Exhaust gas purifying catalyst |
| US9061266B2 (en) | 2011-10-31 | 2015-06-23 | N.E. Chemcat Corporation | Exhaust gas purifying catalyst |
| WO2013111457A1 (en) | 2012-01-23 | 2013-08-01 | エヌ・イーケムキャット株式会社 | Alumina material containing barium sulfate and exhaust gas purifying catalyst using same |
| WO2013136821A1 (en) | 2012-03-14 | 2013-09-19 | エヌ・イーケムキャット株式会社 | Catalyst composition for exhaust gas cleaning and catalyst for automobile exhaust gas cleaning |
| US9339793B2 (en) | 2012-03-14 | 2016-05-17 | N.E. Chemcat Corporation | Catalyst composition for exhaust gas cleaning and catalyst for automobile exhaust gas cleaning |
| WO2014002667A1 (en) | 2012-06-28 | 2014-01-03 | エヌ・イーケムキャット株式会社 | Catalyst composition for exhaust gas purification and exhaust gas purifying catalyst for automobiles |
| US9339794B2 (en) | 2012-06-28 | 2016-05-17 | N.E. Chemcat Corporation | Catalyst composition for exhaust gas purification and exhaust gas purifying catalyst for automobiles |
| JP2016123958A (en) * | 2015-01-07 | 2016-07-11 | 株式会社キャタラー | Catalyst for exhaust gas purification and system for exhaust gas purification |
| DE102016120289A1 (en) | 2015-10-27 | 2017-04-27 | Cataler Corporation | exhaust gas purification device |
| US10118156B2 (en) | 2015-10-27 | 2018-11-06 | Cataler Corporation | Exhaust gas purification device |
| WO2017150350A1 (en) * | 2016-03-01 | 2017-09-08 | 株式会社キャタラー | Exhaust gas purification catalyst |
| JPWO2017150350A1 (en) * | 2016-03-01 | 2018-10-18 | 株式会社キャタラー | Exhaust gas purification catalyst |
| WO2017179679A1 (en) * | 2016-04-13 | 2017-10-19 | トヨタ自動車株式会社 | Exhaust gas cleaning catalyst, exhaust gas cleaning method, and exhaust gas cleaning system |
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