JPH0478441A - Catalyst for purification of exhaust gas - Google Patents
Catalyst for purification of exhaust gasInfo
- Publication number
- JPH0478441A JPH0478441A JP2191192A JP19119290A JPH0478441A JP H0478441 A JPH0478441 A JP H0478441A JP 2191192 A JP2191192 A JP 2191192A JP 19119290 A JP19119290 A JP 19119290A JP H0478441 A JPH0478441 A JP H0478441A
- Authority
- JP
- Japan
- Prior art keywords
- catalyst
- carrier
- catalyst layer
- layer
- rare earth
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000003054 catalyst Substances 0.000 title claims abstract description 80
- 238000000746 purification Methods 0.000 title claims description 18
- 229910052761 rare earth metal Inorganic materials 0.000 claims abstract description 11
- 150000002910 rare earth metals Chemical class 0.000 claims abstract description 11
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims abstract description 10
- 229910017052 cobalt Inorganic materials 0.000 claims abstract description 6
- 239000010941 cobalt Substances 0.000 claims abstract description 6
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 claims abstract description 6
- 229910052759 nickel Inorganic materials 0.000 claims abstract description 5
- 229910000420 cerium oxide Inorganic materials 0.000 claims abstract description 4
- BMMGVYCKOGBVEV-UHFFFAOYSA-N oxo(oxoceriooxy)cerium Chemical compound [Ce]=O.O=[Ce]=O BMMGVYCKOGBVEV-UHFFFAOYSA-N 0.000 claims abstract description 4
- CETPSERCERDGAM-UHFFFAOYSA-N ceric oxide Chemical compound O=[Ce]=O CETPSERCERDGAM-UHFFFAOYSA-N 0.000 claims abstract description 3
- 229910000422 cerium(IV) oxide Inorganic materials 0.000 claims abstract description 3
- 238000007254 oxidation reaction Methods 0.000 claims abstract description 3
- MRELNEQAGSRDBK-UHFFFAOYSA-N lanthanum(3+);oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[La+3].[La+3] MRELNEQAGSRDBK-UHFFFAOYSA-N 0.000 claims abstract 4
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 claims description 21
- 229910052763 palladium Inorganic materials 0.000 claims description 9
- 239000002131 composite material Substances 0.000 claims description 4
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 claims description 4
- PLDDOISOJJCEMH-UHFFFAOYSA-N neodymium(3+);oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[Nd+3].[Nd+3] PLDDOISOJJCEMH-UHFFFAOYSA-N 0.000 claims 2
- 230000000694 effects Effects 0.000 abstract description 8
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 abstract description 5
- 229910052878 cordierite Inorganic materials 0.000 abstract description 4
- 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 abstract description 4
- 239000000203 mixture Substances 0.000 abstract description 4
- 239000011572 manganese Substances 0.000 abstract description 2
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 abstract 1
- 229910052748 manganese Inorganic materials 0.000 abstract 1
- MWUXSHHQAYIFBG-UHFFFAOYSA-N nitrogen oxide Inorganic materials O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 description 24
- 239000010410 layer Substances 0.000 description 21
- 239000007789 gas Substances 0.000 description 15
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 6
- 239000010948 rhodium Substances 0.000 description 5
- 238000002485 combustion reaction Methods 0.000 description 4
- 229930195733 hydrocarbon Natural products 0.000 description 4
- 150000002430 hydrocarbons Chemical class 0.000 description 4
- 229910000510 noble metal Inorganic materials 0.000 description 4
- 230000003197 catalytic effect Effects 0.000 description 3
- 239000002002 slurry Substances 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 230000002378 acidificating effect Effects 0.000 description 2
- 239000007864 aqueous solution Substances 0.000 description 2
- 229910002090 carbon oxide Inorganic materials 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
- 238000000576 coating method Methods 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 2
- 229910017604 nitric acid Inorganic materials 0.000 description 2
- RVTZCBVAJQQJTK-UHFFFAOYSA-N oxygen(2-);zirconium(4+) Chemical compound [O-2].[O-2].[Zr+4] RVTZCBVAJQQJTK-UHFFFAOYSA-N 0.000 description 2
- 229910052697 platinum Inorganic materials 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 229910001928 zirconium oxide Inorganic materials 0.000 description 2
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical class [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 1
- 230000010718 Oxidation Activity Effects 0.000 description 1
- 238000000498 ball milling Methods 0.000 description 1
- 238000006555 catalytic reaction Methods 0.000 description 1
- 239000011247 coating layer Substances 0.000 description 1
- -1 for example Substances 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000003801 milling Methods 0.000 description 1
- 229910000480 nickel oxide Inorganic materials 0.000 description 1
- GNRSAWUEBMWBQH-UHFFFAOYSA-N oxonickel Chemical compound [Ni]=O GNRSAWUEBMWBQH-UHFFFAOYSA-N 0.000 description 1
- GPNDARIEYHPYAY-UHFFFAOYSA-N palladium(ii) nitrate Chemical compound [Pd+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O GPNDARIEYHPYAY-UHFFFAOYSA-N 0.000 description 1
- 239000010970 precious metal Substances 0.000 description 1
- 229910052703 rhodium Inorganic materials 0.000 description 1
- MHOVAHRLVXNVSD-UHFFFAOYSA-N rhodium atom Chemical compound [Rh] MHOVAHRLVXNVSD-UHFFFAOYSA-N 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 239000007858 starting 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
本発明は、内燃機関の排気中の有害成分を餘去するため
の排気浄化用触媒に関する。DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an exhaust gas purification catalyst for removing harmful components from the exhaust gas of an internal combustion engine.
従来の技術
近年、内燃機関、特に自動車用内燃機関の排気浄化用触
媒は、耐久性、浄化性能等につき高度な性能が要求され
ている。この排気浄化用触媒としてはモノリス担体に白
金（Ｐ ｔ ） 、ロジウム（Ｒｈ）、パラジウム（Ｐ
ｄ）等の貴金属の一種又は二種以上担持したものが用い
られている。これらの触媒を充填した触媒コンバータに
排気を送入することにより、排気中の有害物質である炭
化水素（ＨＣ）、−酸化炭素（ＣＯ）および窒素酸化物
（ＮＯｘ）を酸化または還元して浄化する。排気中のこ
れらの３成分を一度に浄化処理できる触媒を三元触媒と
呼んでいる。従来、三元触媒としての触媒特性の向上を
図るために、酸化セリウム、酸化ニッケル、酸化ジルコ
ニウムを単独あるいは複合して用いることが行われてい
る。特に酸化セリウムと酸化ジルコニウムを混合した系
では触媒としての耐熱性が向上されるとされている。BACKGROUND OF THE INVENTION In recent years, exhaust gas purifying catalysts for internal combustion engines, particularly automobile internal combustion engines, are required to have high performance in terms of durability, purification performance, and the like. This exhaust purification catalyst uses platinum (Pt), rhodium (Rh), and palladium (Pt) on a monolithic carrier.
d), which supports one or more noble metals, is used. By sending exhaust gas to a catalytic converter filled with these catalysts, harmful substances in the exhaust gas, such as hydrocarbons (HC), -carbon oxides (CO), and nitrogen oxides (NOx), are oxidized or reduced and purified. do. A catalyst that can purify these three components in exhaust gas at once is called a three-way catalyst. Conventionally, in order to improve the catalytic properties of a three-way catalyst, cerium oxide, nickel oxide, and zirconium oxide have been used alone or in combination. In particular, a system containing a mixture of cerium oxide and zirconium oxide is said to have improved heat resistance as a catalyst.
発明が解決しようとする課題
しかしながら、従来の三元触媒においては、ＰＬ Ｐｄ
５Ｒｈ等の貴金属を用いるためコストが非常に高いとい
う問題がある。さらに安定供給の面からも問題がある。Problems to be Solved by the Invention However, in the conventional three-way catalyst, PL Pd
Since a noble metal such as 5Rh is used, there is a problem that the cost is extremely high. Furthermore, there are also problems in terms of stable supply.
このため貴金属以外のいわゆるヘースメタルを用いて触
媒を構成しようという努力がなされている。とりわけコ
バルト系のペロブスカイト構造をもつ複合酸化物が白金
系触媒に匹敵するＣ０１ＨＣの酸化活性を示すことが報
告されている。しかしながら、コバルト系のペロブスカ
イトは排気ガス中のＮＯｘについては浄化性能が従来の
貴金属に比較し、活性が低い欠点がある。ＮＯｘの浄化
にはＲｈが不可欠であるとされているが、Ｒｈは貴金属
の中でもとりわけコストが高いという問題がある。For this reason, efforts are being made to construct catalysts using so-called heath metals other than noble metals. In particular, it has been reported that a cobalt-based composite oxide having a perovskite structure exhibits C01HC oxidation activity comparable to that of a platinum-based catalyst. However, cobalt-based perovskites have a drawback in that their purifying performance for NOx in exhaust gas is lower than that of conventional precious metals. Rh is considered to be indispensable for purifying NOx, but Rh has a problem in that it is particularly expensive among noble metals.
本発明は、上記従来技術の問題点を解決するためになさ
れたもので、三元触媒としての活性も高くしかもコスト
の安い触媒を提供しようとするものである。The present invention has been made to solve the problems of the prior art described above, and aims to provide a catalyst that has high activity as a three-way catalyst and is inexpensive.
課題を解決するための手段
本発明は、内燃機関の排気中の炭化水素、−酸化炭素及
び窒素酸化物を浄化するための触媒であって、担体上に
酸化反応に有効な触媒成分からなる第１触媒層を設け、
更に該第１触媒層の上に混合希土、マンガン、ニッケル
及びパラジウムからなる第２触媒層を設けてなることを
特徴とする排気浄化用触媒にある０本発明にかかる触媒
は、酸化反応に有効な触媒成分からなる第１触媒層と混
合希土、マンガン、ニッケル及びパラジウムからなる第
２触媒層を有する。そして、両触媒層は、担体上に第１
触媒層を、更にその上に第２触媒層を設けるものである
。しかして、上記第１触媒層に用いる触媒成分としては
セリア、混合希土、コバルトからなり、混合希土及びコ
バルトはペロブスカイト構造を有している。Means for Solving the Problems The present invention provides a catalyst for purifying hydrocarbons, carbon oxides and nitrogen oxides in the exhaust gas of an internal combustion engine, the catalyst comprising a catalyst component effective for oxidation reaction on a carrier. 1 catalyst layer is provided,
Furthermore, the catalyst according to the present invention in the exhaust purification catalyst is characterized in that a second catalyst layer made of mixed rare earth, manganese, nickel, and palladium is provided on the first catalyst layer. It has a first catalyst layer made of effective catalyst components and a second catalyst layer made of mixed rare earth, manganese, nickel and palladium. Then, both catalyst layers are placed on the carrier.
The catalyst layer is further provided with a second catalyst layer thereon. The catalyst components used in the first catalyst layer are ceria, mixed rare earth, and cobalt, and the mixed rare earth and cobalt have a perovskite structure.
また上記第２触媒層は混合希王、マンガン、ニッケルで
構成されるペロブスカイト型複合酸化物（ＲＭｎ＋−ｙ
Ｎ ｉ ７０ｓ ）及びパラジウムで構成する。パラジ
ウムは硝酸パラジウム等の各積場を出発物質とし、ＲＭ
ｎ＋−ｙＮｉ ｙｏ３に対し０．０１〜０．１重量パー
セントの範囲で担持する。The second catalyst layer is made of a perovskite complex oxide (RMn+-y
N i 70s ) and palladium. Palladium is a starting material from various loading docks such as palladium nitrate, and RM
It is supported in a range of 0.01 to 0.1 weight percent based on n+-yNi yo3.
次に、第１触媒層を担持させる担体としては、コーディ
エライト、アルミナ、シリカ等の多孔質焼結体等がある
。また担体の形状としては、排気との触媒を向上させし
かも圧力損失を低くし、浄化率を向上させるにはハニカ
ム状体等の一体型担体とすることが好ましい。Next, examples of the carrier supporting the first catalyst layer include porous sintered bodies such as cordierite, alumina, and silica. As for the shape of the carrier, it is preferable to use an integral carrier such as a honeycomb-shaped body in order to improve the catalysis with the exhaust gas, lower the pressure loss, and improve the purification rate.
また、担体上への第１触媒層の担持量は、担体ｌＮに対
して１０ｇ〜１００ｇとすることが好ましい。Further, the amount of the first catalyst layer supported on the carrier is preferably 10 g to 100 g based on the carrier IN.
１０ｇ未満では本発明の効果を得難く、１００ｇを越え
ても担持量に見合うだけの効果を得難い。If it is less than 10 g, it is difficult to obtain the effect of the present invention, and even if it exceeds 100 g, it is difficult to obtain an effect commensurate with the supported amount.
次に、前記第１触媒層の上に第２触媒層を設ける方法と
しては、例えば先ず前記第１触媒層を形成した担体上に
ＲＭ ｎ １．□ｙＮｉｙｏｓにパラジウムを担持した
ものをスラリーにし、コーティングすることにより行う
、しかして、担体に対する第２触媒層の担持量としては
、担体１）に対して１ｇ〜５０ｇとすることが好ましい
、１ｇ以下では本発明の効果を得難＜、５０ｇを越えて
もそれに見合う効果を得難い。Next, as a method for providing a second catalyst layer on the first catalyst layer, for example, RM n 1. □It is carried out by making a slurry of palladium supported on yNiyos and coating it.The amount of the second catalyst layer supported on the carrier is preferably 1 g to 50 g with respect to carrier 1), and is 1 g or less. If the amount exceeds 50 g, it is difficult to obtain the effects of the present invention.
なお、本発明にかかる排気浄化用触媒は２００〜８００
℃において用いることが好ましい、また触媒層へ導入す
る排気の空間速度としては、Ｇ）（ＳＶ１万〜１２万／
時とすることが好ましい。Note that the exhaust purification catalyst according to the present invention has a molecular weight of 200 to 800
The space velocity of the exhaust gas introduced into the catalyst layer is preferably G) (SV 10,000 to 120,000/
It is preferable to do it once in a while.
作用
本発明においては、担体上に第１触媒層を設け、更にそ
の上に出し２触媒層を設けて触媒を構成しているので、
従来困難であったＮＯｘの浄化も高率よく行うことがで
きる。したがって、優れた三元触媒を提供することがで
きる０本発明の触媒がかかる優れた効果を発揮する理由
は明らかでないが、大路次のようであると考えられる。Function In the present invention, the catalyst is constructed by providing the first catalyst layer on the carrier and further providing the second catalyst layer on top of the first catalyst layer.
It is also possible to purify NOx, which has been difficult in the past, with a high efficiency. Therefore, it is not clear why the catalyst of the present invention exhibits such excellent effects as an excellent three-way catalyst, but it is thought to be as follows.
即ち、排気が上記触媒と接触した時、ガス中のＮＯｘは
ＮｌとＭｎからなるペロブスカイト型複合酸化物と接触
した時、同じくガス中のＨＣと選択的に反応し、ＮＯｘ
は還元される。これによりＮＯｘは無害物質に浄化され
る。That is, when the exhaust gas comes into contact with the above catalyst, NOx in the gas selectively reacts with HC in the gas when it comes into contact with the perovskite-type composite oxide consisting of Nl and Mn, and NOx
will be returned. This purifies NOx into harmless substances.
また、上記ＮＯｘと反応しなかった残りのＨＣｌ及びＣ
Ｏは第１触媒層によって排気中のＭ素と反応して、Ｈ，
Ｏ，Ｃｏ、となる。In addition, the remaining HCl and C that did not react with the NOx
O reacts with M element in the exhaust gas by the first catalyst layer, and becomes H,
O, Co.
実施例
以下本発明の排気ガス浄化触媒の実施例について述べる
。４００セル／ｉｎ”のコーディエライト製一体型担体
をＲ６，９Ｃｅｏ、＋ ＣＯ０，１００部とＣｅＯ□
１００部、さらにアルミナゾル５０部を水と共にボール
ミリングすることにより作製したスラリー中に浸漬した
。続いて、圧縮空気により過剰液を吹き去り、この一体
化物を乾燥して、遊離の水を除去した後、７００℃で１
時間焼成し、・担体１Ｎ当り２０ｇのコート層を担持し
た０次にＲＭｎｏ、＊Ｎ ｉ−、−Ｏｓ １００部と
アルミナゾル５０部を水と共にホールミリングすること
により作製したスラリー中に上記担持物を浸漬し、上記
第１層と同様にして担体ｌｌ当り２０ｇのコーティング
を行った。Examples Examples of the exhaust gas purification catalyst of the present invention will be described below. A 400 cell/in'' cordierite integrated carrier was mixed with R6,9Ceo, +0,100 parts of CO and CeO□
It was immersed in a slurry prepared by ball milling 100 parts of alumina sol and 50 parts of alumina sol together with water. Subsequently, the excess liquid was blown off with compressed air, the combined product was dried to remove free water, and then heated at 700°C for 1 hour.
The above-mentioned material was baked in a slurry prepared by hole-milling 100 parts of 0-order RMno, *N i-, -Os and 50 parts of alumina sol with water, carrying a coating layer of 20 g per 1 N of carrier. 20 g of coating was applied per 1 liter of carrier in the same manner as for the first layer above.
続いて、該担体をジニトロジアンミンパラジウムの硝酸
酸性水溶液に浸漬し、乾燥後、４００°Ｃで１時間焼成
して担体上に担体Ｉ Ｌに対し０．３ ｇ ／ ｉ−の
Ｐｄを担持した。Subsequently, the carrier was immersed in an acidic nitric acid aqueous solution of dinitrodiammine palladium, dried, and then calcined at 400°C for 1 hour to support 0.3 g/i− of Pd on the carrier IL.
比較触媒とし、て上記触媒と同様にして４００セル／ｉ
ｎ”のコーディエライト製担体にＲｏ、ｗＣｅｏ、＋Ｃ
ｏ Ｏ，を担体Ｉｆ当り４０ｇコーティングした。As a comparative catalyst, 400 cells/i was prepared in the same manner as the above catalyst.
Ro, wCeo, +C on a cordierite carrier of n”
o O, was coated at 40 g per carrier If.
続いて該担体をジニトロジアンミンパラジウムの硝酸酸
性水溶液を用いて前記触媒と同様にして該担体上に担体
ＩＬに対し０．３ｇ／ＬのＰｄを担持した。Subsequently, 0.3 g/L of Pd was supported on the carrier IL using an acidic aqueous solution of dinitrodiammine palladium in nitric acid in the same manner as the catalyst described above.
上記２種の触媒をエンジンの排気系に装着して触媒活性
を調べた０本発明による触媒を隘１、比較触媒を胤２と
する。結果を次表に示す。The two types of catalysts mentioned above were installed in the exhaust system of an engine and their catalytic activity was examined. The catalyst according to the present invention is designated as No. 1, and the comparative catalyst is designated as No. 2. The results are shown in the table below.
表 浄化率
表から明らかなように本発明による排気浄化用触媒はＲ
ｈを用いなくとも高いＮＯｘ浄化率を持っている。As is clear from the purification rate table, the exhaust purification catalyst according to the present invention has R
It has a high NOx purification rate even without using h.
発明の効果
上記のごとく、本発明の排気浄化用触媒は優れた三元触
媒である。さらに高価なＲｈを用いていないのでコスト
的にも大巾に下げることが出来た。Effects of the Invention As described above, the exhaust purification catalyst of the present invention is an excellent three-way catalyst. Furthermore, since expensive Rh was not used, the cost could be significantly reduced.
さらに供給の変動がなく、安定供給が可能となった。Furthermore, there are no fluctuations in supply, making stable supply possible.
Claims (6)
触媒層を設け、この第１触媒層の上に混合希土、マンガ
ン、ニッケル及びパラジウムからなる第２触媒層を設け
た排気浄化用触媒。(1) A first layer comprising a catalyst component effective for oxidation reaction on a carrier.
A catalyst for exhaust purification, which includes a catalyst layer and a second catalyst layer made of mixed rare earth, manganese, nickel, and palladium on the first catalyst layer.
なる触媒である特許請求の範囲第１項記載の排気浄化用
触媒。(2) The exhaust purification catalyst according to claim 1, wherein the first catalyst layer is a catalyst made of ceria, mixed rare earth, and cobalt.
持した触媒である特許請求の範囲第１項記載の排気浄化
用触媒。(3) The exhaust purification catalyst according to claim 1, wherein the first catalyst layer is a catalyst supporting a perovskite type composite oxide.
成したペロブスカイト型複合酸化物である特許請求の範
囲第１項記載の排気浄化用触媒。(4) The exhaust purification catalyst according to claim 1, wherein the second catalyst layer is a perovskite-type composite oxide composed of mixed rare earth, manganese, and nickel.
オジウムである特許請求の範囲第１項記載の排気浄化用
触媒。(5) The exhaust purification catalyst according to claim 1, wherein the mixed rare earth is cerium oxide, lanthanum oxide, or neodymium oxide.
記載の排気浄化用触媒。(6) The exhaust purification catalyst according to claim 1, wherein the carrier is an integral carrier.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2191192A JPH0478441A (en) | 1990-07-18 | 1990-07-18 | Catalyst for purification of exhaust gas |
| CA 2046775 CA2046775C (en) | 1990-07-17 | 1991-07-11 | High frequency heating apparatus and electromagnetic wave detector for use in high frequency heating apparatus |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2191192A JPH0478441A (en) | 1990-07-18 | 1990-07-18 | Catalyst for purification of exhaust gas |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0478441A true JPH0478441A (en) | 1992-03-12 |
Family
ID=16270437
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2191192A Pending JPH0478441A (en) | 1990-07-17 | 1990-07-18 | Catalyst for purification of exhaust gas |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0478441A (en) |
-
1990
- 1990-07-18 JP JP2191192A patent/JPH0478441A/en active Pending
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