JPH05237384A - Catalyst for purifying exhaust gas - Google Patents
Catalyst for purifying exhaust gasInfo
- Publication number
- JPH05237384A JPH05237384A JP4042920A JP4292092A JPH05237384A JP H05237384 A JPH05237384 A JP H05237384A JP 4042920 A JP4042920 A JP 4042920A JP 4292092 A JP4292092 A JP 4292092A JP H05237384 A JPH05237384 A JP H05237384A
- Authority
- JP
- Japan
- Prior art keywords
- oxide
- catalyst
- palladium
- rhodium
- exhaust gas
- 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
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は自動車等の内燃機関から
の排気ガス中に含まれる有害成分である一酸化炭素（Ｃ
Ｏ）、炭化水素（ＨＣ）及び窒素酸化物（ＮＯｘ）を同
時に除去する排気ガス浄化用触媒に関するものである。BACKGROUND OF THE INVENTION The present invention relates to carbon monoxide (C) which is a harmful component contained in exhaust gas from an internal combustion engine such as an automobile.
O), hydrocarbons (HC) and nitrogen oxides (NOx) at the same time.
【０００２】[0002]
【従来の技術】内燃機関から排出される排気ガス中の有
害成分を除去する方法として、種々の排気ガス浄化用触
媒が提案されている。2. Description of the Related Art Various exhaust gas purifying catalysts have been proposed as a method for removing harmful components in exhaust gas discharged from an internal combustion engine.
【０００３】従来、パラジウム触媒は高い耐熱性を有し
ていることや、エンジン排気ガスの酸化雰囲気（いわゆ
るリーン；空気／燃料（Ａ／Ｆ）が空気側大）における
ＣＯ、ＨＣの高い浄化能を有することは一般に知られて
いる。しかし、エンジン排ガスが還元雰囲気（いわゆる
リッチ；（Ａ／Ｆ）が燃料側大）の場合、ＮＯｘ浄化能
が著しく低いことが挙げられ、パラジウムのみでは、三
元触媒として機能し難いことが知られている。そのため
に、一般的に高いＮＯｘ浄化能を有するロジウムを上記
パラジウムと組み合せて、ＣＯ、ＨＣ及びＮＯｘを同時
に浄化する三元触媒として用いられている。一方、その
性能は白金・ロジウム系触媒にくらべ低く、かつ耐久性
能にも問題があることが一般に知られている。しかしパ
ラジウムは、白金・ロジウム系に比べ、著しく低コスト
であるため、安価なパラジウムを使用した触媒系でのＣ
Ｏ，ＨＣ及びＮＯｘを同時に浄化できる触媒が望まれて
いる。Conventionally, a palladium catalyst has a high heat resistance and a high purification ability of CO and HC in an oxidizing atmosphere of an engine exhaust gas (so-called lean; air / fuel (A / F) is large on the air side). It is generally known to have However, when the engine exhaust gas is in a reducing atmosphere (so-called rich; (A / F) is large on the fuel side), the NOx purification capacity is extremely low, and it is known that palladium alone is difficult to function as a three-way catalyst. ing. Therefore, in general, rhodium, which has a high NOx purification ability, is used in combination with the above palladium as a three-way catalyst for simultaneously purifying CO, HC and NOx. On the other hand, it is generally known that its performance is lower than that of platinum / rhodium-based catalysts and that it also has a problem in durability performance. However, palladium is significantly lower in cost than platinum / rhodium-based catalysts, so C in a catalyst system using inexpensive palladium
A catalyst capable of simultaneously purifying O, HC and NOx is desired.
【０００４】[0004]
【発明が解決しようとする課題】本発明は、先に述べた
パラジウムの問題点である還元雰囲気におけるＮＯｘ浄
化能及び耐久性を改良することにより、高性能パラジウ
ム・ロジウム系触媒を開発し、さらに、白金・ロジウム
系触媒の白金の一部又は全部をパラジウムに替えること
による安価な触媒を提供することを目的とする。DISCLOSURE OF THE INVENTION The present invention has developed a high-performance palladium-rhodium-based catalyst by improving the NOx purifying ability and durability in a reducing atmosphere, which is a problem of palladium described above. An object of the present invention is to provide an inexpensive catalyst by replacing part or all of platinum in a platinum / rhodium-based catalyst with palladium.
【０００５】[0005]
【課題を解決するための手段】本発明者らは、この課題
を解決するために鋭意研究した結果、貴金属として、
（ａ）パラジウム及びロジウム、又は（ｂ）パラジウ
ム、ロジウム及び白金、並びにアルカリ土類金属酸化
物、ランタン酸化物、セリウム酸化物、ジルコニウム酸
化物及び耐火性無機酸化物よりなる系で、従来のパラジ
ウム・ロジウム系に比べ、著しい性能向上を示し、さら
に、白金・ロジウム系三元触媒に比べても同等以上の性
能を有することを見出し本発明を完成するに至ったので
ある。Means for Solving the Problems As a result of intensive studies to solve this problem, the present inventors
(A) Palladium and Rhodium, or (b) Palladium, Rhodium and Platinum, and a system comprising conventional alkaline earth metal oxides, lanthanum oxides, cerium oxides, zirconium oxides and refractory inorganic oxides. The present invention has been completed by discovering that the performance is remarkably improved as compared with the rhodium-based catalyst and that the platinum-rhodium-based three-way catalyst has the same or higher performance.
【０００６】本発明におけるアルカリ土類金属酸化物の
添加効果は、パラジウムに直接作用することで、その電
荷状態を変化させることにより反応性を高め、リッチ雰
囲気でのＮＯｘ浄化能を飛躍的に向上させるものであ
る。The effect of adding the alkaline earth metal oxide in the present invention is to directly react with palladium to change its charge state to enhance the reactivity and dramatically improve the NOx purification ability in a rich atmosphere. It is what makes them.
【０００７】また、セリウム酸化物及びジルコニウム酸
化物を用いることにより、前記の効果はより向上するの
みならず、燃料ガス組成が化学量論比（燃料ガスを完全
燃焼させるのに必要な空気量）近傍でのＣＯ、ＨＣ及び
ＮＯｘ浄化能も向上することが示される。Further, by using cerium oxide and zirconium oxide, not only the above effect is further improved but also the fuel gas composition has a stoichiometric ratio (the amount of air required to completely burn the fuel gas). It is also shown that CO, HC and NOx purifying ability in the vicinity is also improved.
【０００８】さらに、ランタン酸化物を耐火性無機酸化
物、セリウム酸化物又はジルコニウム酸化物の少なくと
も一種に担持させることにより、前記の効果は飛躍的に
向上する。ランタン酸化物は一体構造体１リットル当た
り０．１〜５０ｇ被覆されていることが好ましく、０．
１ｇ未満であるときは、添加効果が少なく、５０ｇを越
える時は、添加量に見合う効果が少ない。Further, by supporting lanthanum oxide on at least one of refractory inorganic oxide, cerium oxide and zirconium oxide, the above-mentioned effects are dramatically improved. The lanthanum oxide is preferably coated in an amount of 0.1 to 50 g per liter of the monolithic structure.
When it is less than 1 g, the effect of addition is small, and when it exceeds 50 g, the effect commensurate with the amount added is small.
【０００９】本発明は内燃機関の排ガス中の一酸化炭
素、炭化水素及び窒素酸化物を同時に除去する触媒にお
いて、触媒活性物質が、貴金属として（ａ）パラジウム
及びロジウム、又は（ｂ）パラジウム、ロジウム及び白
金のいずれかを含み、さらにアルカリ土類金属酸化物、
ランタン酸化物、セリウム酸化物、ジルコニウム酸化物
及び耐火性無機酸化物を含有してなる触媒活性物質を一
体構造体に被覆してなることを特徴とする排気ガス浄化
用触媒である。The present invention is a catalyst for simultaneously removing carbon monoxide, hydrocarbons and nitrogen oxides in exhaust gas of an internal combustion engine, wherein the catalytically active substance is (a) palladium and rhodium or (b) palladium and rhodium as noble metals. And any one of platinum, further alkaline earth metal oxide,
An exhaust gas purifying catalyst, characterized in that an integrated structure is coated with a catalytically active substance containing a lanthanum oxide, a cerium oxide, a zirconium oxide and a refractory inorganic oxide.
【００１０】本発明に係る貴金属の使用量は触媒の使用
条件によって異なるが、貴金属が（ａ）パラジウム及び
ロジウムである場合、触媒活性物質当たり、パラジウム
が０．１〜１０重量％であり、ロジウムが０．０１〜
２．０重量％であることが好ましい。貴金属が（ｂ）パ
ラジウム、ロジウム及び白金である場合、触媒活性物質
当たり、パラジウムが０．１〜１０重量％であり、ロジ
ウムが０．０１〜２．０重量％、白金が０．１〜１０重
量％であることが好ましい。The amount of the noble metal used according to the present invention varies depending on the use conditions of the catalyst. When the noble metal is (a) palladium and rhodium, the amount of palladium is 0.1 to 10% by weight based on the catalytically active substance, and rhodium is used. Is 0.01-
It is preferably 2.0% by weight. When the noble metal is (b) palladium, rhodium and platinum, palladium is 0.1 to 10% by weight, rhodium is 0.01 to 2.0% by weight, and platinum is 0.1 to 10 with respect to the catalytically active substance. It is preferably in the weight%.
【００１１】各貴金属の担持される位置は特に限定され
ないが、セリウム酸化物、ジルコニウム酸化物、ランタ
ン酸化物又は、耐火性無機酸化物上に、単独又はこれら
の酸化物にまたがって担持されることが好ましい。The position on which each noble metal is supported is not particularly limited, but it should be supported on cerium oxide, zirconium oxide, lanthanum oxide or refractory inorganic oxide, either alone or straddling these oxides. Is preferred.
【００１２】次にアルカリ土類金属酸化物としては、ベ
リリウム酸化物、マグネシウム酸化物、カルシウム酸化
物、ストロンチウム酸化物及びバリウム酸化物が挙げら
れるが、特に、カルシウム酸化物、ストロンチウム酸化
物及びバリウム酸化物からなる群より選ばれた少なくと
も一種が好ましい。また、アルカリ土類金属酸化物源と
しては、酸化物、有機塩又は無機塩のいずれでもよく、
特に限定されるものではない。Next, examples of the alkaline earth metal oxides include beryllium oxide, magnesium oxide, calcium oxide, strontium oxide and barium oxide, and particularly calcium oxide, strontium oxide and barium oxide. At least one selected from the group consisting of things is preferable. The alkaline earth metal oxide source may be an oxide, an organic salt or an inorganic salt,
It is not particularly limited.
【００１３】アルカリ土類金属酸化物の使用量は触媒１
リットル当り０．１〜５０ｇ、好ましくは０．５〜４０
ｇである。アルカリ土類金属酸化物は、セリウム酸化
物、ジルコニウム酸化物若しくはそれらの複合物、固溶
体、ランタン酸化物又は耐火性無機酸化物のいずれに担
持されてもよく、この担持の調製方法は、特に限定され
ない。The amount of alkaline earth metal oxide used is the amount of catalyst 1
0.1 to 50 g per liter, preferably 0.5 to 40
It is g. The alkaline earth metal oxide may be supported on any of cerium oxide, zirconium oxide or a composite thereof, a solid solution, lanthanum oxide or a refractory inorganic oxide, and the method for preparing this support is not particularly limited. Not done.
【００１４】アルカリ土類金属酸化物とパラジウムの関
係は、それらの重量比（アルカリ土類金属酸化物／パラ
ジウム）で、１：１００〜１５０：１、好ましくは、
１：１００〜１００：１である。１：１００よりアルカ
リ土類金属酸化物の量が少なくなると、三元性能が悪く
なり、特に、ＮＯ浄化率が劣り、１５０：１よりアルカ
リ土類金属酸化物の量が多くなると添加効果は向上する
が、その他酸化物等の担持量、触媒の強度の関係によ
り、担持比率、担持量を制限される。The relationship between the alkaline earth metal oxide and the palladium is 1: 100 to 150: 1, preferably by weight ratio (alkaline earth metal oxide / palladium).
It is 1: 100 to 100: 1. When the amount of the alkaline earth metal oxide is less than 1: 100, the ternary performance is poor, and in particular, the NO purification rate is poor, and when the amount of the alkaline earth metal oxide is more than 150: 1, the addition effect is improved. However, the loading ratio and loading amount are limited by the relationship between the loading amount of oxides and the strength of the catalyst.
【００１５】セリウム酸化物としては、特に限定される
ものではないが、酸化物のまま、又は種々の水溶性の塩
等を焼成することによりセリウム酸化物として用いるこ
とができる。セリウム酸化物の使用量は、触媒１リット
ル当り１０〜１５０ｇが好ましく、１０ｇ未満である場
合は、浄化能が低く、また１５０ｇを超える場合は、そ
れ以上加えても大きな効果はみられない。The cerium oxide is not particularly limited, but it can be used as the cerium oxide as it is or by burning various water-soluble salts or the like. The amount of cerium oxide used is preferably 10 to 150 g per liter of the catalyst, and when it is less than 10 g, the purifying ability is low, and when it exceeds 150 g, even if it is added more than that, no great effect is observed.
【００１６】ジルコニウム酸化物としては、特に限定さ
れるものではないが、酸化物のまま、又は種々の水溶性
の塩等を焼成することによりジルコニウム酸化物として
もちいることができる。ジルコニウム酸化物の使用量
は、触媒１リットル当り０．１〜５０ｇが好ましく、
０．１未満である場合は、効果が少なく、５０ｇを超え
る場合は、浄化性能が低下する。The zirconium oxide is not particularly limited, but it can be used as the zirconium oxide as it is or by firing various water-soluble salts or the like. The amount of zirconium oxide used is preferably 0.1 to 50 g per liter of the catalyst,
If it is less than 0.1, the effect is small, and if it exceeds 50 g, the purification performance is deteriorated.
【００１７】セリウム酸化物とジルコニウム酸化物は、
少なくとも一部が複合物又は、固溶体として存在してな
ることが好ましい。さらに好ましくは、このセリウム酸
化物とジルコニウム酸化物の比（酸化物換算重量比）
が、１００：２〜１００：６０であり、より好ましく
は、１００：４〜１００：４０である。この比が、１０
０：２よりセリウム酸化物が多くなると、性能が低く、
１００：６０よりジルコニウム酸化物が多くなると、性
能が低くなる傾向となるものである。Cerium oxide and zirconium oxide are
It is preferable that at least a part thereof is present as a composite or a solid solution. More preferably, the ratio of this cerium oxide and zirconium oxide (weight ratio in terms of oxide)
Is 100: 2 to 100: 60, and more preferably 100: 4 to 100: 40. This ratio is 10
When the amount of cerium oxide is more than 0: 2, the performance is low,
If the amount of zirconium oxide is more than 100: 60, the performance tends to be low.
【００１８】セリウム酸化物とジルコニウム酸化物の複
合物又は、固溶体の調製方法を以下に示すが、これらの
酸化物の少なくとも一部が複合物又は、固溶体として存
在してなるものであれば、特に限定されることはない
が、上記の比の範囲内にあることが好ましい。A method for preparing a composite of cerium oxide and zirconium oxide or a solid solution is shown below. If at least a part of these oxides exists as a composite or a solid solution, it is particularly preferable. Although not limited, it is preferably within the range of the above ratio.
【００１９】（１）水に溶解性のあるセリウム塩とジル
コニウム塩の水溶液を乾燥、焼成する方法、（２）セリ
ウム酸化物とジルコニウム酸化物とを固相反応させる方
法、（３）セリウム酸化物に水溶性ジルコニウム塩の水
溶液を浸し乾燥、焼成する方法、（４）耐火性無機酸化
物に水に溶解性のあるセリウム塩とジルコニウム塩の水
溶液を含浸後、乾燥、焼成する方法、又は（５）一体構
造体に耐火性無機酸化物を被覆した後に水に溶解性のあ
るセリウム塩とジルコニウム塩の水溶液を乾燥、焼成す
る方法等、触媒の調製に応じて種々の方法を適宜用いる
ことができる。(1) A method of drying and calcining an aqueous solution of cerium salt and zirconium salt which are soluble in water, (2) a method of solid-phase reaction of cerium oxide and zirconium oxide, (3) cerium oxide (4) A method of soaking an aqueous solution of a water-soluble zirconium salt in an aqueous solution and drying and firing, and (4) a method of impregnating a water-soluble aqueous solution of a cerium salt and a zirconium salt into a refractory inorganic oxide, followed by drying and firing. ) Various methods can be appropriately used depending on the preparation of the catalyst, such as a method of coating the monolithic structure with a refractory inorganic oxide and then drying and calcining an aqueous solution of water-soluble cerium salt and zirconium salt. ..
【００２０】ランタン酸化物としては、特に限定される
ものではないが、酸化物、又は種々の水溶性塩等を耐火
性無機酸化物、セリウム酸化物、ジルコニウム酸化物に
単独に、又はこれらの酸化物にまたがって担持されるも
のである。The lanthanum oxide is not particularly limited, but oxides, various water-soluble salts and the like may be used alone as refractory inorganic oxides, cerium oxides, zirconium oxides, or oxidation thereof. It is carried across objects.
【００２１】ランタン酸化物の使用量は、一体構造体１
リットル当たり０．１から５０ｇが好ましく、０．１ｇ
未満である場合は効果が少なく、５０ｇを越える場合
は、それ以上加えてもそれに見合う効果はみられない。The amount of lanthanum oxide used is 1
0.1 to 50 g per liter is preferred, 0.1 g
If the amount is less than 50 g, the effect is small, and if the amount exceeds 50 g, even if more than 50 g is added, the corresponding effect is not observed.
【００２２】耐火性無機酸化物としては、活性アルミ
ナ、シリカ、ジルコニア等の高表面積を有するものが挙
げられるが、特に活性アルミナが好ましい。Examples of the refractory inorganic oxide include those having a high surface area such as activated alumina, silica and zirconia, and activated alumina is particularly preferable.
【００２３】触媒を調製する方法としては、（１）上記
した触媒組成物を、ボールミル等を用いて水性スラリー
とし、一体構造体に被覆したのち、乾燥、必要により焼
成して完成触媒とする方法、（２）耐火性酸化物を予め
一体構造体に被覆し、次いで、水に溶解性のあるセリウ
ム塩、ジルコニウム塩の水溶液に該一体構造体を浸漬し
たのち、乾燥、焼成後、次いで同様の手順でランタン塩
を担持する方法等があるが、作業手順の便により適宜変
更し使用される。As a method for preparing a catalyst, (1) a method in which the above-mentioned catalyst composition is made into an aqueous slurry by using a ball mill or the like, coated on an integral structure, dried and, if necessary, calcined to obtain a finished catalyst. (2) The monolithic structure is coated in advance with a refractory oxide, and then the monolithic structure is immersed in an aqueous solution of a cerium salt or zirconium salt that is soluble in water, dried, fired, and then the same. There is a method of supporting lanthanum salt in the procedure, etc., but it is appropriately changed and used depending on the convenience of the work procedure.
【００２４】一体構造体１リットルに対する触媒組成物
は、５０〜４００ｇ好ましくは、１００〜３５０ｇであ
る。５０ｇ未満である場合は、浄化性能が低く、４００
ｇを超える場合は、一体成形体に触媒組成物を被覆した
場合、触媒組成物の被覆量が多くなり、触媒の背圧が上
昇し好ましくないものである。The catalyst composition per liter of the monolithic structure is 50 to 400 g, preferably 100 to 350 g. If the amount is less than 50 g, the purification performance is low and 400
When it exceeds g, when the catalyst composition is coated on the integrally molded body, the coating amount of the catalyst composition increases, and the back pressure of the catalyst increases, which is not preferable.
【００２５】[0025]
【実施例】以下に実施例により具体的に説明するが、本
発明の趣旨に反しない限り、これらの実施例に限定され
るものでない。EXAMPLES The present invention will be specifically described below with reference to examples, but the invention is not limited to these examples unless it goes against the gist of the present invention.
【００２６】（実施例１）市販のセリウム酸化物（比表
面積１４９m2／ｇ）にオキシ硝酸ジルコニル水溶液を、
それぞれＣｅＯ2／ＺｒＯ2が１００／１０（ＣｅＯ2＋
ＺｒＯ2が１００ｇ）となる比で混合し、乾燥後５００
℃×１時間にて焼成した粉体１００ｇ（ＣｅＯ2・Ｚｒ
Ｏ2）を得た。次にパラジウムを１．６６７ｇ含有する
硝酸パラジウム水溶液とロジウムを０．３３３ｇ含有す
る硝酸ロジウム水溶液及びランタン酸化物として、２０
ｇとなる酢酸ランタン水溶液を混合した溶液に、活性ア
ルミナ（γ−Ａｌ2Ｏ3、比表面積１５５m2／ｇ）１８０
ｇを含浸し乾燥後、５００℃×１時間にて焼成して粉体
２００ｇを得た。Example 1 Commercially available cerium oxide (specific surface area 149 m 2 / g) was treated with an aqueous zirconyl oxynitrate solution.
CeO 2 / ZrO 2 is 100/10 (CeO 2 +
ZrO 2 is mixed at a ratio of 100 g), dried and then 500
100 g of powder calcined at ℃ × 1 hour (CeO 2 · Zr
O 2 ) was obtained. Then, as a palladium nitrate aqueous solution containing 1.667 g of palladium, a rhodium nitrate aqueous solution containing 0.333 g of rhodium and a lanthanum oxide, 20
180 g of activated alumina (γ-Al 2 O 3 , specific surface area 155 m 2 / g) was added to a solution obtained by mixing an aqueous solution of lanthanum acetate to be g.
After impregnating with g and drying, 200 g of powder was obtained by firing at 500 ° C. for 1 hour.
【００２７】上記の得られた粉体と酢酸バリウム１６．
７ｇをボールミルで湿式粉砕することにより水性スラリ
ーを調製した。断面積１インチ平方当り４００個のセル
を有するコージェライト製モノリス担体（内径３３mm×
長さ７６mmＬ）を上記スラリーに浸漬し取り出した後セ
ル内の過剰スラリーを圧縮空気で吹き飛ばした後、乾燥
し必要により焼成し完成触媒を得た。The powder obtained above and barium acetate 16.
An aqueous slurry was prepared by wet grinding 7 g with a ball mill. Cordierite monolith carrier with 400 cells per square inch cross section (inner diameter 33 mm x
A length of 76 mmL) was dipped in the above slurry, taken out, and the excess slurry in the cell was blown off with compressed air, followed by drying and firing if necessary to obtain a finished catalyst.
【００２８】（実施例２）実施例１で用いたセリウム酸
化物にオキシ硝酸ジルコニル水溶液をＣｅＯ2／ＺｒＯ2
の比で１０／１（ＣｅＯ2とＺｒＯ2の合計が１００
ｇ）、及びランタン酸化物として２０ｇ含有する酢酸ラ
ンタン水溶液を混合し、乾燥後、５００℃で１時間乾燥
して粉体１２０ｇを得た。次に、パラジウムを１．６６
７ｇ含有する硝酸パラジウム水溶液とロジウムを０．３
３３ｇ含有する硝酸ロジウム水溶液を混合した溶液に実
施例１で用いたものと同じ活性アルミナ１８０ｇを含浸
し乾燥後、５００℃×１時間にて焼成して粉体１８０ｇ
を得た。上記の得られた粉体と酢酸バリウム１６．７ｇ
をボールミルにて湿式粉砕し、スラリーを得、実施例１
と同様にして完成触媒を得た。Example 2 The cerium oxide used in Example 1 was mixed with an aqueous solution of zirconyl oxynitrate to CeO 2 / ZrO 2.
Ratio of 10/1 (the total of CeO 2 and ZrO 2 is 100
g) and lanthanum acetate aqueous solution containing 20 g of lanthanum oxide were mixed, dried and then dried at 500 ° C. for 1 hour to obtain 120 g of powder. Then 1.66 of palladium
Palladium nitrate aqueous solution containing 7 g and rhodium 0.3
180 g of the same activated alumina as used in Example 1 was impregnated into a solution containing 33 g of an aqueous rhodium nitrate solution, dried, and then fired at 500 ° C. for 1 hour to give 180 g of powder.
Got 16.7 g of the above-obtained powder and barium acetate
Was pulverized with a ball mill to obtain a slurry.
A completed catalyst was obtained in the same manner as in.
【００２９】（実施例３）実施例１で得られるＣｅＯ2
・ＺｒＯ2の粉体１００ｇ及び実施例２で得られるパラ
ジウム、ロジウム担持アルミナ１８０ｇを混合した粉体
に、ランタン酸化物として２０ｇ含有する酢酸ランタン
水溶液を加え乾燥後５００℃×１時間焼成して得た粉体
３００ｇ及び酢酸バリウム１６．７ｇをボールミルにて
湿式粉砕し、スラリーを得、実施例１と同様にして完成
触媒を得た。Example 3 CeO 2 obtained in Example 1
Obtained by adding 100 g of ZrO 2 powder and 180 g of palladium- and rhodium-supported alumina obtained in Example 2 to a powder of lanthanum acetate aqueous solution containing 20 g of lanthanum oxide, and drying and firing at 500 ° C. for 1 hour. 300 g of the powder and 16.7 g of barium acetate were wet pulverized with a ball mill to obtain a slurry, and a completed catalyst was obtained in the same manner as in Example 1.
【００３０】（実施例４）実施例１で得られるＣｅＯ2
・ＺｒＯ2粉体１００ｇ、及び実施例２で得られるパラ
ジウム、ロジウム担持アルミナ１８０ｇとランタン酸化
物として２０ｇ含有する酢酸ランタン、及び酢酸バリウ
ム１６．７ｇをボールミルにて湿式粉砕しスラリーを
得、実施例１と同様にして完成触媒を得た。Example 4 CeO 2 obtained in Example 1
100 g of ZrO 2 powder, palladium obtained in Example 2, 180 g of rhodium-supported alumina, 20 g of lanthanum acetate as lanthanum oxide, and 16.7 g of barium acetate were wet-milled with a ball mill to obtain a slurry. A completed catalyst was obtained in the same manner as in 1.
【００３１】（実施例５）実施例１において、ランタン
酸化物２０ｇを１ｇに変えた以外は実施例１と同様にし
て完成触媒を得た。Example 5 A completed catalyst was obtained in the same manner as in Example 1 except that 20 g of lanthanum oxide was changed to 1 g.
【００３２】（実施例６）実施例１において、ランタン
酸化物２０ｇを９０ｇに変えた以外は実施例１と同様に
して完成触媒を得た。Example 6 A completed catalyst was obtained in the same manner as in Example 1 except that 20 g of lanthanum oxide was changed to 90 g.
【００３３】（実施例７）実施例１において、酢酸バリ
ウム１６．７ｇを１３３．６ｇに変えた以外は実施例１
と同様にして完成触媒を得た。Example 7 Example 1 was repeated except that 16.7 g of barium acetate was changed to 133.6 g.
A completed catalyst was obtained in the same manner as in.
【００３４】（実施例８）実施例１において、酢酸バリ
ウム１６．７ｇを０．８３ｇに変えた以外は実施例１と
同様にして完成触媒を得た。(Example 8) A completed catalyst was obtained in the same manner as in Example 1 except that 16.7 g of barium acetate was changed to 0.83 g.
【００３５】（実施例９）実施例１において、酢酸バリ
ウムを酢酸カルシウム２８．２ｇに変えた以外は実施例
１と同様にして完成触媒を得た。(Example 9) A completed catalyst was obtained in the same manner as in Example 1 except that barium acetate was changed to 28.2 g of calcium acetate.
【００３６】（実施例１０）実施例１において、酢酸バ
リウムを酢酸ストロンチウム１９．８ｇに変えた以外
は、実施例１と同様にして完成触媒を得た。(Example 10) A completed catalyst was obtained in the same manner as in Example 1 except that barium acetate was changed to strontium acetate 19.8 g.
【００３７】（実施例１１）実施例１において、ＣｅＯ
2／ＺｒＯ2の比を１０／１（ＣｅＯ2とＺｒＯ2の合計が
３０ｇ）に変えた以外は、実施例１と同様にして完成触
媒を得た。(Embodiment 11) In Embodiment 1, CeO
A completed catalyst was obtained in the same manner as in Example 1 except that the ratio of 2 / ZrO 2 was changed to 10/1 (the total of CeO 2 and ZrO 2 was 30 g).
【００３８】（実施例１２）実施例１において、ＣｅＯ
2／ＺｒＯ2の比を１０／１（ＣｅＯ2とＺｒＯ2の合計が
２００ｇ）に変えた以外は、実施例１と同様にして完成
触媒を得た。(Embodiment 12) In Embodiment 1, CeO
A completed catalyst was obtained in the same manner as in Example 1 except that the ratio of 2 / ZrO 2 was changed to 10/1 (the total of CeO 2 and ZrO 2 was 200 g).
【００３９】（実施例１３）実施例１において、ＣｅＯ
2／ＺｒＯ2の比を１０／１（ＣｅＯ2とＺｒＯ2の合計が
２８０ｇ）に変えた以外は、実施例１と同様にして完成
触媒を得た。(Example 13) In Example 1, CeO
A completed catalyst was obtained in the same manner as in Example 1 except that the ratio of 2 / ZrO 2 was changed to 10/1 (the total of CeO 2 and ZrO 2 was 280 g).
【００４０】（実施例１４）実施例１において、ＣｅＯ
2／ＺｒＯ2の比を１０／３（ＣｅＯ2とＺｒＯ2の合計が
１００ｇ）に変えた以外は、実施例１と同様にして完成
触媒を得た。Example 14 In Example 1, CeO was used.
A completed catalyst was obtained in the same manner as in Example 1 except that the ratio of 2 / ZrO 2 was changed to 10/3 (the total amount of CeO 2 and ZrO 2 was 100 g).
【００４１】（実施例１５）実施例１において、ＣｅＯ
2／ＺｒＯ2の比を２５／１（ＣｅＯ2とＺｒＯ2の合計が
１００ｇ）に変えた以外は、実施例１と同様にして完成
触媒を得た。Example 15 In Example 1, CeO was used.
A completed catalyst was obtained in the same manner as in Example 1 except that the ratio of 2 / ZrO 2 was changed to 25/1 (total of CeO 2 and ZrO 2 was 100 g).
【００４２】（実施例１６）実施例１において、酢酸バ
リウムを酢酸マグネシウム３５．３ｇに変えた以外は、
実施例１と同様にして完成触媒を得た。(Example 16) In Example 16, except that barium acetate was changed to 35.3 g of magnesium acetate,
A completed catalyst was obtained in the same manner as in Example 1.
【００４３】（実施例１７）実施例２において、パラジ
ウム・ロジウム含有粉体をパラジウムを０．８３３ｇ含
有する硝酸パラジウム水溶液と白金を０．８３３ｇ含有
するジニトロジアミン白金水溶液及びロジウムを０．３
３３ｇ含有する硝酸ロジウム水溶液を混合した溶液に活
性アルミナ（γ・Ａｌ2Ｏ3、比表面積１５５m2／ｇ）１
８０ｇを含浸担持した粉体に変えた以外は実施例１と同
様にして完成触媒を得た。(Example 17) In Example 2, the palladium / rhodium-containing powder was added to an aqueous palladium nitrate solution containing 0.833 g of palladium, an aqueous dinitrodiamine platinum solution containing 0.833 g of platinum, and 0.3 g of rhodium.
Activated alumina (γ · Al 2 O 3 , specific surface area 155 m 2 / g) was added to a solution containing 33 g of rhodium nitrate aqueous solution.
A finished catalyst was obtained in the same manner as in Example 1, except that 80 g of the powder was impregnated and supported.
【００４４】（比較例１）実施例１において、酢酸バリ
ウムを除いた以外は実施例１と同様にして完成触媒を得
た。Comparative Example 1 A completed catalyst was obtained in the same manner as in Example 1 except that barium acetate was omitted.
【００４５】（比較例２）実施例１において、オキシ硝
酸ジルコニルを除いた以外は、実施例１と同様にして完
成触媒を得た。Comparative Example 2 A finished catalyst was obtained in the same manner as in Example 1 except that zirconyl oxynitrate was omitted.
【００４６】（比較例３）実施例１において、オキシ硝
酸ジルコニル及び酢酸バリウムを除いた以外は実施例１
と同様にして完成触媒を得た。(Comparative Example 3) Example 1 is the same as Example 1 except that zirconyl oxynitrate and barium acetate are removed.
A completed catalyst was obtained in the same manner as in.
【００４７】（比較例４）実施例１において、ランタン
酸化物を除いた以外は、実施例１と同様にして完成触媒
を得た。(Comparative Example 4) A finished catalyst was obtained in the same manner as in Example 1 except that the lanthanum oxide was removed.
【００４８】（比較例５）白金を１．６６７ｇ含有する
ジニトロジアミン白金水溶液及びロジウムを０．３３３
ｇ含有する硝酸ロジウム水溶液を混合した溶液に活性ア
ルミナ（γ・Ａｌ2Ｏ3、比表面積１５５m2／ｇ）２００
ｇを含浸担持した粉体と市販のセリウム酸化物（比表面
積１４９m2／ｇ）１００ｇをボールミルにて湿式粉砕し
て水性スラリーを得、実施例１と同様にして完成触媒を
得た。Comparative Example 5 A dinitrodiamine platinum aqueous solution containing 1.667 g of platinum and 0.333 of rhodium.
Activated alumina (γ · Al 2 O 3 , specific surface area 155 m 2 / g) 200 was added to a solution containing a rhodium nitrate aqueous solution containing g.
A powder impregnated with g and 100 g of a commercially available cerium oxide (specific surface area 149 m 2 / g) were wet pulverized with a ball mill to obtain an aqueous slurry, and a completed catalyst was obtained in the same manner as in Example 1.
【００４９】（比較例６）比較例５において、白金を
１．６６７ｇ含有するジニトロジアミン白金水溶液をパ
ラジウム１．６６７ｇ含有する硝酸パラジウム水溶液に
変えた以外は比較例５と同様にして完成触媒を得た。Comparative Example 6 A completed catalyst was obtained in the same manner as in Comparative Example 5 except that the aqueous dinitrodiamine platinum solution containing 1.667 g of platinum was replaced with the aqueous palladium nitrate solution containing 1.667 g of palladium. It was
【００５０】このようにして得られた実施例と比較例の
触媒の１リットル当りの各触媒成分の担持量を表１に示
した。Table 1 shows the supported amounts of the respective catalyst components per liter of the catalysts of Examples and Comparative Examples thus obtained.
【００５１】（実施例１８）次に、実施例１から実施例
１７までの触媒と、比較例１から６の触媒のエンジン耐
久走行後の触媒活性を調べた。(Example 18) Next, the catalyst activities of the catalysts of Examples 1 to 17 and the catalysts of Comparative Examples 1 to 6 were examined after the running of the engine for a long time.
【００５２】市販の電子制御方式のエンジン（８気筒４
４００cc）を使用し、各触媒を充填したマルチコンバー
タをエンジンの排気系に連設して耐久テストを行なっ
た。エンジンは、定常運転６０秒、減速６秒（減速時に
燃料がカットされて、触媒は、高温酸化雰囲気の厳しい
条件にさらされる。）というモード運転で運転し触媒入
口ガス温度が定常運転時９００℃となる条件で５０時間
触媒をエージングした。Commercially available electronically controlled engine (8 cylinders 4
400cc) was used, and a multi-converter filled with each catalyst was connected to the exhaust system of the engine for a durability test. The engine operates in a mode operation of 60 seconds of steady operation and 6 seconds of deceleration (fuel is cut during deceleration, and the catalyst is exposed to severe conditions of high temperature oxidizing atmosphere), and the gas temperature at the catalyst inlet is 900 ° C during steady operation. The catalyst was aged for 50 hours under the following conditions.
【００５３】エージング後の触媒性能の評価は、市販の
電子制御方式のエンジン（４気筒１８００cc）を使用
し、各触媒を充填したマルチコンバータを、エンジンの
排気系に連設して行なった。触媒の三元性能は触媒入口
ガス温度４００℃、空間速度９０，０００ｈr~1の条件
で評価した。この際、外部発振器より１Ｈｚサイン波型
シグナルをエンジンのコントロールユニットに導入し
て、空燃比（Ａ／Ｆ）を±１．０Ａ／Ｆ、１Ｈｚで振動
させながら平均空燃比を連続的に変化させ、この時の触
媒入口及び出口ガス組成を同時に分析して、平均空燃比
がＡ／Ｆが１５．１から１４．１までＣＯ，ＨＣ及びＮ
Ｏの浄化率を求めた。The catalyst performance after aging was evaluated by using a commercially available electronically controlled engine (four-cylinder 1800 cc) and connecting a multi-converter filled with each catalyst to the exhaust system of the engine. The three-way performance of the catalyst was evaluated under the conditions of a catalyst inlet gas temperature of 400 ° C. and a space velocity of 90,000 hr- 1 . At this time, a 1 Hz sine wave type signal was introduced into the engine control unit from an external oscillator to continuously change the average air-fuel ratio while oscillating the air-fuel ratio (A / F) at ± 1.0 A / F and 1 Hz. At the same time, the catalyst inlet and outlet gas compositions were analyzed at the same time, and the average air-fuel ratio from A / F 15.1 to 14.1 CO, HC and N
The purification rate of O was determined.
【００５４】上記のようにして求めたＣＯ，ＨＣ及びＮ
Ｏの浄化率対入口空燃比をグラフにプロットして、三元
特性曲線を作成し、ＣＯ，ＮＯ浄化率曲線の交点（クロ
スオーバーポイントと呼ぶ）の浄化率と、その交点のＡ
／Ｆ値におけるＨＣ浄化率さらに、Ａ／Ｆが１４．２
（エンジン排気ガスがリッチ）でのＮＯの浄化能を表２
に示した。CO, HC and N determined as described above
The purification rate of O versus the inlet air-fuel ratio is plotted in a graph to create a ternary characteristic curve, and the purification rate at the intersection (called a crossover point) of the CO and NO purification rates and the intersection A
HC purification rate at / F value Further, A / F is 14.2
Table 2 shows the NO purifying ability when the engine exhaust gas is rich.
It was shown to.
【００５５】表２より、本発明に開示させる触媒は、Ｃ
Ｏ，ＨＣおよびＮＯｘの三成分を同時に高性能に除去で
きることがわかる。From Table 2, the catalyst disclosed in the present invention is C
It can be seen that the three components of O, HC and NOx can be simultaneously removed with high performance.
【００５６】また、触媒の低温での浄化性能は、空燃比
を±０．５Ａ／Ｆ（１Ｈｚ）の条件で振動させながら、
平均空燃比をＡ／Ｆに１４．６に固定してエンジンを運
転し、エンジン排気系の触媒コンバータの前に熱交換器
を取り付けて、触媒入口ガス温度を２００℃〜５００℃
まで連続的に変化させ、触媒入口及び出口ガス組成を分
析して、ＣＯ，ＨＣ及びＮＯの浄化率を求めることによ
り評価した。上記の様にして求めた、ＣＯ，ＨＣ及びＮ
Ｏの浄化率５０％での温度（ライトオフ温度）を測定し
て表２に示した。Further, the purification performance of the catalyst at low temperature is as follows while vibrating the air-fuel ratio at ± 0.5 A / F (1 Hz).
The engine is operated with the average air-fuel ratio fixed to A / F of 14.6, a heat exchanger is installed in front of the catalytic converter of the engine exhaust system, and the catalyst inlet gas temperature is 200 ° C to 500 ° C.
Was continuously changed, the catalyst inlet and outlet gas compositions were analyzed, and the purification rates of CO, HC and NO were obtained and evaluated. CO, HC and N determined as above
The temperature (light-off temperature) at a purification rate of O of 50% was measured and is shown in Table 2.
【００５７】本発明に開示された触媒は著しく低温で、
ＨＣ，ＣＯ及びＮＯの三成分を同時除去でき、Ｐｄの問
題点を克服した高性能Ｐｄ／Ｒｈ触媒であることがわか
る。The catalysts disclosed in the present invention are
It can be seen that it is a high-performance Pd / Rh catalyst capable of simultaneously removing three components of HC, CO and NO and overcoming the problem of Pd.
【００５８】[0058]
【表１】 [Table 1]
【００５９】[0059]
【表２】 [Table 2]
───────────────────────────────────────────────────── フロントページの続き (72)発明者 大幡 知久 兵庫県姫路市網干区興浜字西沖992番地の １ 株式会社日本触媒触媒研究所内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tomohisa Ohata 1 992 Nishikioki, Kamahama, Aboshi-ku, Himeji-shi, Hyogo 1
Claims (4)
化水素及び窒素酸化物を同時に除去する触媒において、 貴金属として、（ａ）パラジウム及びロジウム、又は
（ｂ）パラジウム、ロジウム及び白金、 並びにアルカリ土類金属酸化物、ランタン酸化物、セリ
ウム酸化物、ジルコニウム酸化物及び耐火性無機酸化物
を含有する触媒活性成分を一体構造体に被覆してなるこ
とを特徴とする排気ガス浄化用触媒。1. A catalyst for simultaneously removing carbon monoxide, hydrocarbons and nitrogen oxides in exhaust gas of an internal combustion engine, wherein (a) palladium and rhodium, or (b) palladium, rhodium and platinum, and An exhaust gas purifying catalyst, characterized in that an integral structure is coated with a catalytically active component containing an alkaline earth metal oxide, a lanthanum oxide, a cerium oxide, a zirconium oxide and a refractory inorganic oxide.
は、少なくとも一部が複合物又は固溶体として存在して
なる請求項１記載の触媒。2. The catalyst according to claim 1, wherein at least a part of the cerium oxide and the zirconium oxide is present as a composite or solid solution.
比（酸化物換算重量比）が、１００：２〜１００：６０
である請求項１又は２記載の触媒。3. The ratio of cerium oxide to zirconium oxide (weight ratio in terms of oxide) is 100: 2 to 100: 60.
The catalyst according to claim 1 or 2, which is
セリウム酸化物、及びジルコニウム酸化物のうち少なく
とも一種に担持されてなる請求項１記載の触媒。4. The lanthanum oxide is a refractory inorganic oxide,
The catalyst according to claim 1, which is supported on at least one of cerium oxide and zirconium oxide.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4042920A JP2755513B2 (en) | 1992-02-28 | 1992-02-28 | Exhaust gas purification catalyst |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4042920A JP2755513B2 (en) | 1992-02-28 | 1992-02-28 | Exhaust gas purification catalyst |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH05237384A true JPH05237384A (en) | 1993-09-17 |
| JP2755513B2 JP2755513B2 (en) | 1998-05-20 |
Family
ID=12649461
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4042920A Expired - Lifetime JP2755513B2 (en) | 1992-02-28 | 1992-02-28 | Exhaust gas purification catalyst |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2755513B2 (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0721796A1 (en) | 1995-01-11 | 1996-07-17 | Institut Français du Pétrole | Catalyst for the selective reduction of nitrogen oxides in a oxidising atmosphere, process for preparation and utilisation |
| JP2000084405A (en) * | 1998-08-24 | 2000-03-28 | Degussa Huels Ag | Nitrogen oxides-accumulating material and nitrogen oxides-accumulating catalyst to be prepared therefrom |
| US6500392B2 (en) | 1996-12-20 | 2002-12-31 | Ngk Insulators, Ltd. | Catalyst for exhaust gas purification and system for exhaust gas purification |
| JP2012016681A (en) * | 2010-07-09 | 2012-01-26 | Ict:Kk | Catalyst for purifying exhaust gas and method of manufacturing the same, as well as exhaust gas purifying method |
| CN105636673A (en) * | 2013-10-22 | 2016-06-01 | 优美科股份公司及两合公司 | Catalyst for the oxidation of CO and HC at low temperatures |
| JP2021507804A (en) * | 2017-09-26 | 2021-02-25 | ジョンソン、マッセイ、パブリック、リミテッド、カンパニーＪｏｈｎｓｏｎ Ｍａｔｔｈｅｙ Ｐｕｂｌｉｃ Ｌｉｍｉｔｅｄ Ｃｏｍｐａｎｙ | Exhaust gas purification catalyst |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6411643A (en) * | 1987-07-06 | 1989-01-17 | Toyota Central Res & Dev | Catalyst for exhaust purification |
-
1992
- 1992-02-28 JP JP4042920A patent/JP2755513B2/en not_active Expired - Lifetime
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6411643A (en) * | 1987-07-06 | 1989-01-17 | Toyota Central Res & Dev | Catalyst for exhaust purification |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0721796A1 (en) | 1995-01-11 | 1996-07-17 | Institut Français du Pétrole | Catalyst for the selective reduction of nitrogen oxides in a oxidising atmosphere, process for preparation and utilisation |
| US6500392B2 (en) | 1996-12-20 | 2002-12-31 | Ngk Insulators, Ltd. | Catalyst for exhaust gas purification and system for exhaust gas purification |
| JP2000084405A (en) * | 1998-08-24 | 2000-03-28 | Degussa Huels Ag | Nitrogen oxides-accumulating material and nitrogen oxides-accumulating catalyst to be prepared therefrom |
| JP2012016681A (en) * | 2010-07-09 | 2012-01-26 | Ict:Kk | Catalyst for purifying exhaust gas and method of manufacturing the same, as well as exhaust gas purifying method |
| CN105636673A (en) * | 2013-10-22 | 2016-06-01 | 优美科股份公司及两合公司 | Catalyst for the oxidation of CO and HC at low temperatures |
| JP2021507804A (en) * | 2017-09-26 | 2021-02-25 | ジョンソン、マッセイ、パブリック、リミテッド、カンパニーＪｏｈｎｓｏｎ Ｍａｔｔｈｅｙ Ｐｕｂｌｉｃ Ｌｉｍｉｔｅｄ Ｃｏｍｐａｎｙ | Exhaust gas purification catalyst |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2755513B2 (en) | 1998-05-20 |
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