JPS63137753A - Catalyst for purifying exhaust gas - Google Patents
Catalyst for purifying exhaust gasInfo
- Publication number
- JPS63137753A JPS63137753A JP61286251A JP28625186A JPS63137753A JP S63137753 A JPS63137753 A JP S63137753A JP 61286251 A JP61286251 A JP 61286251A JP 28625186 A JP28625186 A JP 28625186A JP S63137753 A JPS63137753 A JP S63137753A
- Authority
- JP
- Japan
- Prior art keywords
- catalyst
- alumina layer
- ultrafine
- powder
- 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
- 239000003054 catalyst Substances 0.000 title claims abstract description 120
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims abstract description 82
- 239000000843 powder Substances 0.000 claims abstract description 56
- GWXLDORMOJMVQZ-UHFFFAOYSA-N cerium Chemical compound [Ce] GWXLDORMOJMVQZ-UHFFFAOYSA-N 0.000 claims abstract description 38
- 229910052684 Cerium Inorganic materials 0.000 claims abstract description 37
- 229910052761 rare earth metal Inorganic materials 0.000 claims abstract description 25
- 150000002910 rare earth metals Chemical class 0.000 claims abstract description 23
- 229910052746 lanthanum Inorganic materials 0.000 claims abstract description 20
- FZLIPJUXYLNCLC-UHFFFAOYSA-N lanthanum atom Chemical compound [La] FZLIPJUXYLNCLC-UHFFFAOYSA-N 0.000 claims abstract description 20
- 239000002245 particle Substances 0.000 claims abstract description 17
- 229910052751 metal Inorganic materials 0.000 claims abstract description 16
- 239000002184 metal Substances 0.000 claims abstract description 16
- 238000000746 purification Methods 0.000 claims description 35
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 abstract description 14
- 229910052697 platinum Inorganic materials 0.000 abstract description 7
- 239000003381 stabilizer Substances 0.000 abstract description 5
- 229910052703 rhodium Inorganic materials 0.000 abstract description 4
- 239000010948 rhodium Substances 0.000 abstract description 4
- MHOVAHRLVXNVSD-UHFFFAOYSA-N rhodium atom Chemical compound [Rh] MHOVAHRLVXNVSD-UHFFFAOYSA-N 0.000 abstract description 4
- 230000003197 catalytic effect Effects 0.000 abstract description 2
- 229910052878 cordierite Inorganic materials 0.000 abstract description 2
- 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 2
- 230000000052 comparative effect Effects 0.000 description 26
- 239000007789 gas Substances 0.000 description 23
- 238000004519 manufacturing process Methods 0.000 description 14
- 239000002002 slurry Substances 0.000 description 12
- 238000000034 method Methods 0.000 description 10
- 238000005259 measurement Methods 0.000 description 8
- 229910001593 boehmite Inorganic materials 0.000 description 6
- HSJPMRKMPBAUAU-UHFFFAOYSA-N cerium(3+);trinitrate Chemical compound [Ce+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O HSJPMRKMPBAUAU-UHFFFAOYSA-N 0.000 description 6
- FAHBNUUHRFUEAI-UHFFFAOYSA-M hydroxidooxidoaluminium Chemical compound O[Al]=O FAHBNUUHRFUEAI-UHFFFAOYSA-M 0.000 description 6
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 6
- 229910001868 water Inorganic materials 0.000 description 6
- 239000003426 co-catalyst Substances 0.000 description 5
- 230000000694 effects Effects 0.000 description 5
- 239000002253 acid Substances 0.000 description 4
- 239000007864 aqueous solution Substances 0.000 description 4
- 238000003756 stirring Methods 0.000 description 4
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 3
- 238000007664 blowing Methods 0.000 description 3
- 150000002739 metals Chemical class 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- SONJTKJMTWTJCT-UHFFFAOYSA-K rhodium(iii) chloride Chemical compound [Cl-].[Cl-].[Cl-].[Rh+3] SONJTKJMTWTJCT-UHFFFAOYSA-K 0.000 description 3
- 229910052782 aluminium Inorganic materials 0.000 description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 239000000446 fuel Substances 0.000 description 2
- MRELNEQAGSRDBK-UHFFFAOYSA-N lanthanum(3+);oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[La+3].[La+3] MRELNEQAGSRDBK-UHFFFAOYSA-N 0.000 description 2
- 230000035699 permeability Effects 0.000 description 2
- -1 rare earth compound Chemical class 0.000 description 2
- 229910001404 rare earth metal oxide Inorganic materials 0.000 description 2
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 1
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 230000032683 aging Effects 0.000 description 1
- 229910002091 carbon monoxide Inorganic materials 0.000 description 1
- 229910000420 cerium oxide Inorganic materials 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- FYDKNKUEBJQCCN-UHFFFAOYSA-N lanthanum(3+);trinitrate Chemical compound [La+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O FYDKNKUEBJQCCN-UHFFFAOYSA-N 0.000 description 1
- 239000002923 metal particle Substances 0.000 description 1
- 229910017604 nitric acid Inorganic materials 0.000 description 1
- 229910000510 noble metal Inorganic materials 0.000 description 1
- BMMGVYCKOGBVEV-UHFFFAOYSA-N oxo(oxoceriooxy)cerium Chemical compound [Ce]=O.O=[Ce]=O BMMGVYCKOGBVEV-UHFFFAOYSA-N 0.000 description 1
- 229910052698 phosphorus Inorganic materials 0.000 description 1
- 239000011574 phosphorus Substances 0.000 description 1
- 231100000572 poisoning Toxicity 0.000 description 1
- 230000000607 poisoning effect Effects 0.000 description 1
- 239000010970 precious metal Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000011882 ultra-fine particle 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、排気ガス浄化用触媒に関し、例えば自動車の
排気ガス浄化用としてエンジンから排出される有害物質
＜１−ＩＣ，ＣＯ，Ｎｏ）を除去するために、また一般
の工業用の排気ガス浄化用としても利用されるものの改
良に関する。Detailed Description of the Invention (Industrial Application Field) The present invention relates to a catalyst for purifying exhaust gas, and is used to purify exhaust gas of automobiles, for example, to reduce harmful substances (<1-IC, CO, No.) emitted from the engine. This invention relates to improvements in products used for purification of exhaust gases in general industrial use.
（従来の技術）
従来より、この種の排気ガス浄化用触媒として、例えば
特開昭５９−１２７６４９号公報に開示されるように、
触媒担体の表面に段りられるアルミｊ−Ｍに、白金等の
員金属を主触媒として担持させるだけでなく、浄化性能
および耐久性の向上を図るだめにセリウムやランタン等
の希土類金属を助触媒および安定剤として担持させてな
るものは知られている。(Prior Art) Conventionally, as this type of exhaust gas purifying catalyst, for example, as disclosed in Japanese Unexamined Patent Publication No. 127649/1982,
The aluminum J-M layered on the surface of the catalyst carrier not only carries member metals such as platinum as a main catalyst, but also supports rare earth metals such as cerium and lanthanum as co-catalysts in order to improve purification performance and durability. And those supported as stabilizers are known.
そして、上記希土類金属をアルミナ層に担持させる場合
、アルミナ層が予め設けられた触媒担体を希土類化合物
の水溶液（例えば硝酸セリウムや６１！１ｍランタン等
）に浸漬することにより、希土類金属をイオン状態で担
持させたり、あるいはアルミナスラリー中に希土類金属
の酸化物を一定割合で添加し、このアルミナスラリーに
触媒担体を浸漬することにより、触媒担体の表面に設け
られるアルミナ層に希土類金属を酸化物の状態で担持さ
せることが一般に行われるでいる。When the rare earth metal is supported on the alumina layer, the catalyst carrier on which the alumina layer is previously provided is immersed in an aqueous solution of a rare earth compound (for example, cerium nitrate or 61!1m lanthanum), so that the rare earth metal is in an ionized state. By supporting the alumina layer on the surface of the catalyst carrier, or by adding rare earth metal oxides at a certain ratio to the alumina slurry and immersing the catalyst carrier in this alumina slurry, the rare earth metals are added to the alumina layer provided on the surface of the catalyst carrier in an oxide state. Generally, it is supported by
（発明が解決しようとする問題点）
ところが、上記前者の場合つまり希土類金属をアルミナ
層にイオン状態で担持さＵた場合、イオン状態の希土類
金属は、その粒径が小さくかつ浸透性が非常に高いため
、アルミナ層の表面にのみ担持されることなく、排気ガ
スが拡散し難いアルミナ層内部にまで担持されることに
なる。このため、浄化反応への希土類金属の助触媒とし
ての影響が少なくむるとともに、主触媒金属たる貴金属
が担持されるアルミナ層表面での希土類金属の担持沿が
少なく、アルミナ等の触媒担体に対する安定化に効果的
に寄与することができない。(Problem to be Solved by the Invention) However, in the former case, that is, when the rare earth metal is supported in the alumina layer in an ionic state, the rare earth metal in the ionic state has a small particle size and very low permeability. Because of its high content, it is not only supported on the surface of the alumina layer, but is also supported inside the alumina layer, where exhaust gas is difficult to diffuse. For this reason, the influence of rare earth metals as promoters on purification reactions is reduced, and the amount of rare earth metals supported on the surface of the alumina layer, which supports precious metals as the main catalytic metals, is small, making it more stable for catalyst supports such as alumina. unable to contribute effectively to
また、後右の場合つまり希土類金属をアルミナ層に酸化
物として担持させた場合、該希土類金属の酸化物は、そ
の粒径が比較的大きく（１μ以上）かつ比表面積（単位
体積当りの全表面積）が小さいため、助触媒としての機
能が少なく、また安定剤としての効果も少ないのが実情
である。In the case on the back right, that is, when a rare earth metal is supported as an oxide on an alumina layer, the rare earth metal oxide has a relatively large particle size (1μ or more) and a specific surface area (total surface area per unit volume). ) is small, so the actual situation is that it has little function as a co-catalyst and also has little effect as a stabilizer.
本発明はかかる点に鑑みてなされたものであり、その目
的とするところは、特に、粒径が極めて小さいいわゆる
超微粉金属の場合、比表面積が非常に大きく、また表面
活性が高いなどの特性を有することにＭ目し、この特性
を有効に利用した希土類金属でもって、排気ガス浄化用
触媒の浄化性能および耐久性を効果的に高め得るように
するものである。The present invention has been made in view of these points, and its purpose is particularly to improve the properties of so-called ultrafine powder metals, which have extremely small particle sizes, such as extremely large specific surface areas and high surface activity. The purpose of the present invention is to effectively improve the purification performance and durability of an exhaust gas purification catalyst by using a rare earth metal that effectively utilizes this property.
（問題点を解決するための手段）
上記目的を達成するため、本発明の解決手段は、排気ガ
ス浄化用触媒として、触媒担体の表面に、平均粒径が５
０００Å以下の希土類金属の超微粒を担持したアルミナ
層を設ける構成としたものである。(Means for Solving the Problems) In order to achieve the above object, the solving means of the present invention provides an exhaust gas purifying catalyst having an average particle diameter of 5.
The structure is such that an alumina layer supporting ultrafine particles of rare earth metal of 000 Å or less is provided.
（作用）
上記の構成により、本発明では、触媒担体表面のアルミ
ナ層に担持された超微粒の希土類金属は、比表面積が大
きく、かつ表面活性が強いという特性を有するとともに
、イオン状態の希土類金属に比べて浸透性が強くなく、
アルミナ層表面にほとんど担持されるので、助触媒とし
て主触媒金属（白金等の貴金属）による浄化反応を効果
的に促進することができ、また安定剤としてアルミナ等
の触媒担体に対する安定化に十分に寄与することができ
る。(Function) With the above configuration, in the present invention, the ultrafine rare earth metal particles supported on the alumina layer on the surface of the catalyst carrier have the characteristics of a large specific surface area and strong surface activity, and the rare earth metal in an ionic state The permeability is not as strong as that of
Since most of the alumina is supported on the surface of the alumina layer, it can effectively promote the purification reaction by the main catalyst metal (noble metal such as platinum) as a co-catalyst, and can be used as a stabilizer to sufficiently stabilize the catalyst support such as alumina. can contribute.
（実施例） 以下、本発明の実施例を図面に基づいて説明する。(Example) Embodiments of the present invention will be described below based on the drawings.
第１図は本発明の一つの実施態様に係る排気ガス浄化用
触媒の構造を示し、１はコージライト等からなるハニカ
ム型の触媒担体、２は該触媒担体１の表面に設けられた
アルミナ層であって、該アルミナ層２は、白金やロジウ
ム等の主触媒金属と、セリウムやランタン等の希土類化
合物の超微粉とを担持してなる。FIG. 1 shows the structure of an exhaust gas purifying catalyst according to one embodiment of the present invention, in which 1 is a honeycomb-shaped catalyst carrier made of cordierite or the like, and 2 is an alumina layer provided on the surface of the catalyst carrier 1. The alumina layer 2 supports a main catalyst metal such as platinum or rhodium, and ultrafine powder of a rare earth compound such as cerium or lanthanum.
次に、上記実施態様の触媒に対応した本発明の具体的な
実施例およびその比較例について、それらの製造方法を
述べるとともに、排気ガス浄化に関して行った試験の結
果を述べる。Next, with respect to specific examples of the present invention corresponding to the catalysts of the above embodiments and comparative examples thereof, a method for manufacturing them will be described, and the results of tests conducted regarding exhaust gas purification will be described.
本発明の第１実施例に係る触媒の製造方法は、先ず、γ
−アルミナ７０（＋１ベーマイト７０（Ｊ、水１８０ｃ
ｃおよび製鎖ｌｉ、６ｃｃをホモミキサーにより５時間
混合撹拌する。このアルミナスラリーに、平均粒径が５
００人のセリウムの超微粉を１６ｇ、メタノール２０Ｃ
Ｇをそれぞれ添加し、５時間混合撹拌する。次いで、こ
のアルミナスラリーに触媒担体を浸漬して引き上げた後
、余分のスラリーを高圧エアブロ−で除去し、１３０℃
で１時間乾燥し、しかる後、５５０℃で１．５時間焼成
をする。このアルミナコートを施した触媒担体を所定の
温度の塩化白金酸および塩化ロジウムの混合水溶液に浸
漬して引き上げ！、：後、１５０℃で３０分間乾燥し、
次いで、５５０℃で１．５時間焼成をする。そして、こ
のような方法で製造された触媒においては、アルミナ層
２に担持されたセリウム超微粉の含有ｈ１は、アルミナ
層２の仝重量に対し−Ｕ１１ｗｔ％（小量パーセント〉
である。また、白金および［１ジウムの含有量は、それ
ぞれ触媒の１リットル体積当す１ 、０（］ Ｊ３Ｊ：
ヒｏ、 ２ｇである。In the method for producing a catalyst according to the first embodiment of the present invention, firstly, γ
- Alumina 70 (+1 Boehmite 70 (J, water 180c)
C. and chain li, 6 cc were mixed and stirred for 5 hours using a homomixer. This alumina slurry has an average particle size of 5
00 people's cerium ultrafine powder 16g, methanol 20C
Add G respectively and mix and stir for 5 hours. Next, after immersing the catalyst carrier in this alumina slurry and pulling it up, excess slurry was removed by high-pressure air blowing, and the catalyst was heated to 130°C.
The sample was dried for 1 hour at 550°C, and then fired at 550°C for 1.5 hours. This alumina-coated catalyst carrier is immersed in a mixed aqueous solution of chloroplatinic acid and rhodium chloride at a predetermined temperature and then pulled out! , : After that, dry at 150°C for 30 minutes,
Next, baking is performed at 550° C. for 1.5 hours. In the catalyst manufactured by such a method, the content h1 of the ultrafine cerium powder supported on the alumina layer 2 is -U11wt% (small percentage) based on the weight of the alumina layer 2.
It is. In addition, the contents of platinum and [1dium] are 1 and 0(] per 1 liter volume of the catalyst, respectively) J3J:
Yes, it's 2g.
一方、上記第１大施例の触媒との比較のための第１比較
例に係る触媒の製造方法は、上記第１実施例の触媒の場
合におけるセリウムの超微粉の代わりに、平均粒径が１
μの通常のセリウム酸化物（Ｃｅ ０２ ）の粉末を用
い、他は同様な方法で触媒を製造するものである。On the other hand, in the method for producing the catalyst according to the first comparative example for comparison with the catalyst of the first example, the average particle size is 1
The catalyst was produced using a normal cerium oxide (Ce 02 ) powder of μ, but otherwise in the same manner.
また、第２比較例に係る触媒の製造方法は、先ず、γ−
アルミナ７０ｑ１ベーマイト７０ｑ、水１８０ｃｃおよ
び濃ｂｒ１酸１．（３ｃｃホモミキサーにより６時間混
合撹拌する。このアルミナスラリーに触媒担体を浸漬し
て引き上げた後、余分のスラリーを高圧エアブロ−で除
去し、１３０℃で１時間乾燥し、しかる後、５５０℃で
７．５時間焼成をＪ”る。このアルミナコートを施した
触媒担体を所定の１４度の塩化白金酸、塩化ロジウムお
よび硝酸セリウムの混合水溶液に浸漬して引き上げた後
、１５０℃で３０分間乾燥し、次いで、５５０℃で１．
５時間焼成をする。尚、このような方法で製造された触
媒におけるセリウム、白金Ｊ５よびロジウムの含有量は
、上記第１実施例の触媒の場合と同じになるように設定
されている。In addition, the method for manufacturing the catalyst according to the second comparative example first involves γ-
Alumina 70q1 boehmite 70q, water 180cc and concentrated br1 acid 1. (Mix and stir for 6 hours using a 3 cc homomixer. After immersing the catalyst carrier in this alumina slurry and pulling it up, remove the excess slurry with a high-pressure air blower, dry at 130°C for 1 hour, and then heat at 550°C. Calcinate for 7.5 hours. The alumina-coated catalyst carrier was immersed in a mixed aqueous solution of chloroplatinic acid, rhodium chloride, and cerium nitrate at a predetermined temperature of 14°C, pulled out, and then dried at 150°C for 30 minutes. and then 1. at 550°C.
Bake for 5 hours. The contents of cerium, platinum J5, and rhodium in the catalyst produced by this method are set to be the same as in the catalyst of the first embodiment.
本発明の第２実施例に係る触媒の製造方法は、上記第１
実施例の触媒の場合におけるセリウムの超微粉の代わり
に、平均粒径が５００人のランタンの超微粉を５ｇ添加
し、他は同様な方法で触媒を製造するものである。そし
て、このような方法で製造された触媒においては、アル
ミナ層２に担持されたランタン超微粉の含有量は、アル
ミナ層２の全ｆｆ１ｆｉに対して３．８ｗｔ％である。The method for producing a catalyst according to the second embodiment of the present invention includes the method for producing a catalyst according to the second embodiment of the present invention.
In place of the ultrafine cerium powder used in the catalyst of the example, 5 g of ultrafine lanthanum powder with an average particle size of 500 was added, and the catalyst was otherwise produced in the same manner. In the catalyst manufactured by such a method, the content of ultrafine lanthanum powder supported on the alumina layer 2 is 3.8 wt% with respect to the total ff1fi of the alumina layer 2.
一方、上記第２実施例の触媒との比較のための第３比較
例に係る触媒の製造方法は、上記第１比較例の触媒の場
合におけるセリウム酸化物＜Ｃａ０２）の粉末の代わり
に、平均粒径が１μの通常のランタン酸化物（Ｌａ ２
０３ ）の粉末を用い、他は同様な方法で触媒を製造す
るものである。On the other hand, in the method for producing a catalyst according to a third comparative example for comparison with the catalyst of the second example, an average Ordinary lanthanum oxide (La 2
The catalyst was produced using the powder of No. 03), but in the same manner as above.
また、第４比較例に係る触媒の！ｌ造方法は、上記第２
比較例の触媒の場合における硝酸セリウムの代わりに、
硝酸ランタンを用い、他は同様な方法で触媒を製造する
ものである。Moreover, the catalyst according to the fourth comparative example! The manufacturing method is the second one above.
Instead of cerium nitrate in the case of comparative catalysts,
The catalyst is produced using lanthanum nitrate, but otherwise in the same manner.
尚、上記第１・第２実施例および第１〜第４比較例の各
触媒は、いずれもその１？４造が第１図に示すようにな
るもので、外見上は全く同一である。The catalysts of the first and second embodiments and the first to fourth comparative examples have a 1-4 structure as shown in FIG. 1, and are completely the same in appearance.
そして、上記第１実施例および第１・第２比較例の各触
媒について、電気炉を用いて９５０℃で８０時間熱エー
ジングした後、以下の条件で排気ガス浄化試験を行った
。Then, each of the catalysts of the first example and the first and second comparative examples was thermally aged at 950° C. for 80 hours using an electric furnace, and then an exhaust gas purification test was conducted under the following conditions.
試験条件；
空燃比（空気５／燃利吊）１４．７
振幅 ±０．９
周波数 １．０ｌ−１ｚ
排気ガス温度 １００〜５００℃
空間速度 ６００００ｈｒ−１
触媒体Ｂ！１２４．ＯＣＣ
排気ガス浄化試験の測定結果は第３図（ａ）〜（Ｃ）に
示す。この図から判るように、本発明の第１実施例の触
媒によるｔ−＋ｃ、ｃｏおよびＮＯＸの各浄化率（Ａ１
線）は、いずれも従来例としての第１および第２比較例
の触媒による浄化率（Ｂ＋ｒＡおよび８２線）よりも大
巾に増大する。Test conditions: Air-fuel ratio (air 5/fuel lift) 14.7 Amplitude ±0.9 Frequency 1.0l-1z Exhaust gas temperature 100-500°C Space velocity 60000hr-1 Catalyst B! 124. The measurement results of the OCC exhaust gas purification test are shown in FIGS. 3(a) to 3(C). As can be seen from this figure, each purification rate (A1
line) are both greatly increased compared to the purification rates (B+rA and 82 lines) by the catalysts of the first and second comparative examples as conventional examples.
また、上記第２実施例および第３・第４比較例の各触媒
についても、電気炉を用いて１０００℃で８０時間熱エ
ージングした後、上述の第１実施例の触媒等の場合と同
じ条件で排気ガス浄化試験を行った。その試験の測定結
果は第４図（ａ）〜（Ｃ）に示す。この図から判るよう
に、本発明の第２実施例の触媒においＣも、ＨＣ，ＣＯ
おＪ、びＮＯｘの各浄化率（Ａ２線）は、いずれも従来
例としての第３および第４比較例の触媒による浄化率（
８３線およびＢ４ＶＡ）Ｊ：りも大巾に増大する。In addition, the catalysts of the second example and the third and fourth comparative examples were also heat aged at 1000°C for 80 hours using an electric furnace, and then subjected to the same conditions as the catalyst of the first example. An exhaust gas purification test was conducted. The measurement results of the test are shown in FIGS. 4(a) to (C). As can be seen from this figure, in the catalyst of the second example of the present invention, C, HC, CO
The respective purification rates (A2 line) of OJ, NOx, and NOx are the purification rates (A2 line) of the catalysts of the third and fourth comparative examples as conventional examples.
83 line and B4VA) J: Rimo increases greatly.
次に、上記第１実施例の触媒のように、アルミナ層２に
セリウムの超微粉を担持させる場合において、該セリウ
ム超微粉の含有量を如何に定めるべきかを検討するため
に、第３・第４実施例および第５・第６比較例としてセ
リウム超微粉の含有量を種々変えた。すなわち、第３４
３よび第４実施例に係る触媒は、それらの製造方法にお
いてセリウムの超微粉をそれぞれ３５．０（Ｊ 、５５
．０（１添加することにより、アルミナ層２に担持され
るセリウム超微粉の含有量を、アルミナ層２の全重量に
対して２２ｗｔ％、３Ｑｗｔ％としたものである。Next, in order to consider how to determine the content of ultrafine cerium powder in the case where ultrafine cerium powder is supported on the alumina layer 2 as in the catalyst of the first embodiment, the third In the fourth example and the fifth and sixth comparative examples, the content of ultrafine cerium powder was varied. That is, the 34th
The catalysts according to Examples 3 and 4 were manufactured using ultrafine cerium powder of 35.0 (J, 55
．． By adding 0 (1), the content of the ultrafine cerium powder supported on the alumina layer 2 was set to 22 wt% and 3 Qwt% with respect to the total weight of the alumina layer 2.
一方、第５および第６比較例に係る触媒は、それらの製
造方法においてセリウムの超微粉をそれぞれ１２．Ｏａ
、７５．４ｑ添加することにより、アルミナ層２に担
持されるセリウム超微粉の含有量を、アルミｔＰ２の全
重量に対してＢ、７ｗｔ％。On the other hand, the catalysts according to the fifth and sixth comparative examples were produced using ultrafine cerium powder of 12. Oa
, 75.4q, the content of ultrafine cerium powder supported on the alumina layer 2 is increased to 7wt% of the total weight of aluminum tP2.
３７ｗｔ％とじたものである。It is bound at 37wt%.
そして、上記第３・第４実施例および第５・第６比較例
の各触媒について、上記第１実施例の触媒の場合と同様
の排気ガス浄化試験を行った。その試験の測定結果は第
５図＜ａ ＞〜（Ｃ）に示す。Then, for each of the catalysts of the third and fourth examples and the fifth and sixth comparative examples, an exhaust gas purification test similar to that for the catalyst of the first example was conducted. The measurement results of the test are shown in Figures 5<a>-(C).
この図から判るように、第３および第４実施例の各触媒
による浄化率（Ａ３線およびＡ４線）は、第１実施例の
触媒による浄化率（Ａ＋線〉と同程度に大きくなるが、
第５および第６比較例の各触媒による浄化率（Ｂｓ線お
よびＢｓ１）は、これら実施例の触媒の場合と比べて著
しく小さくなる。As can be seen from this figure, the purification rates by the catalysts of the third and fourth embodiments (line A3 and line A4) are as large as the purification rate by the catalyst of the first embodiment (line A+), but
The purification rates (Bs line and Bs1) of the catalysts of the fifth and sixth comparative examples are significantly smaller than those of the catalysts of these examples.
従って、セリウムの超微粉を主触媒金属と同一のアルミ
ナ層２に担持させる場合、該セリウム超微粉の含有量は
、第１・第３・第４実施例の如くアルミナ層２の全重量
に対して１０〜３０ｗｔ％に設定することが好ましい。Therefore, when ultrafine cerium powder is supported on the same alumina layer 2 as the main catalyst metal, the content of the ultrafine cerium powder is relative to the total weight of the alumina layer 2 as in the first, third, and fourth embodiments. It is preferable to set it to 10 to 30 wt%.
つまり、セリウム超微粉の含有量が１ｏｗｔ％以下であ
る（第５比較例の触媒が相当する）と、セリウム超微粉
の助触媒としての機能が十分に発揮されず、浄化性能は
低くなる。また、セリウム超微粉の含有量が増加するに
つれて浄化機能は向上するが、３ｏｗｔ％以上どなると
く第６比較例が相当する）と、セリウムが主触媒金属と
の化合物をつくり、浄化性能に悪影響を及ぼすと考えら
れるからである。In other words, if the content of ultrafine cerium powder is 1 wt % or less (corresponding to the catalyst of the fifth comparative example), the ultrafine cerium powder will not function sufficiently as a co-catalyst, and the purification performance will be low. In addition, as the content of ultrafine cerium powder increases, the purification function improves, but if it exceeds 3 owt% (which corresponds to the 6th comparative example), cerium forms a compound with the main catalyst metal, which adversely affects the purification performance. This is because it is thought to have a negative effect.
また一方、上記第２実施例の触媒のように、アルミナＩ
Ｎ！ｉ２にランタンの超微粉を担持させる場合において
、該ランタン超微粉の含有量を如何に定めるべきかを検
討するために、第５・第６実施例および第７・第８比較
例としてランタン超微粉の含有（５）を種々変えた。す
なわち、第５および第６実施例に係る触媒は、それらの
’ＩＴｉｈ法においてランタンの超微粉をそれぞれ１．
４ｇ、５．３ｇ添加することにより、アルミナ層２に担
持されるランタン超微粉の含有量を、アルミナ層２の全
重層に対して１．０ｗｔ％、４．□ｗｔ％としたもので
ある。一方、第７および第８比較例に係る触媒は、それ
らの製造方法においてランタンの超微粉をそれぞれ１．
Ｏｏ 、６．６（ｌ添加することにより、アルミナ１１
！２に担持されるランタン超微粉の含有量を、アルミナ
層２の全重層に対して０．８ｗｔ％。On the other hand, like the catalyst of the second embodiment, alumina I
N! In order to examine how to determine the content of ultrafine lanthanum powder when i2 supports ultrafine lanthanum powder, ultrafine lanthanum powder was used as the fifth and sixth examples and the seventh and eighth comparative examples. The content (5) was varied. That is, in the catalysts according to the fifth and sixth examples, ultrafine lanthanum powder was added to 1.
By adding 4g and 5.3g, the content of ultrafine lanthanum powder supported on the alumina layer 2 is increased to 1.0wt% with respect to the total layer of the alumina layer 2, and 4. □wt%. On the other hand, the catalysts according to the seventh and eighth comparative examples were produced using ultrafine lanthanum powder of 1.
By adding Oo, 6.6(l), alumina 11
! The content of ultrafine lanthanum powder supported on the alumina layer 2 was 0.8 wt% with respect to the total layer of the alumina layer 2.
４．９ｗｔ％としたものである。The content was 4.9wt%.
そして、上記第５・第６実施例および第７・第８比較例
の各触媒について、上記第２実施例の触媒の場合と同様
の排気ガス浄化試験を行った。その試験の測定結果は第
６図（ａ ）〜（Ｃ）に示す。Then, for each of the catalysts of the fifth and sixth examples and the seventh and eighth comparative examples, an exhaust gas purification test similar to that for the catalyst of the second example was conducted. The measurement results of the test are shown in FIGS. 6(a) to (C).
この図から判るように、第５および第６実施例の各触媒
による浄化率（Ａｓ線およびへ〇線）は、第２実施例の
触媒による浄化率（Ａ２線）と同程度に大きくなるが、
第７および第８比較例の各触媒による浄化率（８７線お
よび８８線）は、これら実施例の触媒の場合と比べて著
しく小さくなる。As can be seen from this figure, the purification rates by the catalysts of the fifth and sixth embodiments (As line and circle) are as large as the purification rate by the catalyst of the second embodiment (line A2). ,
The purification rates (line 87 and line 88) of the catalysts of the seventh and eighth comparative examples are significantly smaller than those of the catalysts of these examples.
従って、ランタンの超微粉を主触媒金属と同一のアルミ
ナＷＪ２に担持させる場合、該ランタン超微粉の含有量
は、第２・第５・第６実施例の如くアルミナ層２の全重
層に対して１．０〜４．、Ｑｗｔ％に設定することが好
ましい。Therefore, when ultrafine lanthanum powder is supported on alumina WJ2, which is the same as the main catalyst metal, the content of the ultrafine lanthanum powder is limited to the entire layer of alumina layer 2 as in the second, fifth, and sixth embodiments. 1.0-4. , Qwt%.
第２図は本発明の別の実施態様に係る排気ガス浄化用触
媒の構造を示し、この触媒は、主触媒金属と希土類金属
の超微粉とが別のアルミナ層に担持されてなる。すなわ
ち、主触媒金属は、触媒担体１の表面に直接設けられた
第１アルミナｍ３に担持されている一方、希土類金属は
、該第１アルミナ層３にオーバコートされた第２アルミ
ナ層４に担持されている。尚、主触媒金属を担持した第
１アルミブ居３を第２アルミナ層４によりオーバコート
したのは、主触媒金属が排気ガス中に含まれる燐や鉛等
の被毒に弱いということなどをＭｒｔｈしたものぐある
。FIG. 2 shows the structure of an exhaust gas purifying catalyst according to another embodiment of the present invention, in which the main catalyst metal and ultrafine rare earth metal powder are supported on separate alumina layers. That is, the main catalyst metal is supported on the first alumina m3 provided directly on the surface of the catalyst carrier 1, while the rare earth metal is supported on the second alumina layer 4 overcoated on the first alumina layer 3. has been done. The reason why the first alumina layer 3 supporting the main catalyst metal is overcoated with the second alumina layer 4 is because the main catalyst metal is susceptible to poisoning by phosphorus, lead, etc. contained in exhaust gas. There are things to do.
次に、上記実施態様の触媒に対応した本発明の第７〜第
９実施例およびこれら実施例との比較のｔｃ メ（７）
ｍ ９・第１０比較例について、それらの製造方法を
述べるとともに、排気ガス浄化等に関して行った試験の
結果を述べる。Next, 7th to 9th Examples of the present invention corresponding to the catalysts of the above embodiments and tc method (7) for comparison with these Examples.
Regarding the 9th and 10th comparative examples, the manufacturing method thereof will be described, as well as the results of tests conducted regarding exhaust gas purification, etc.
本発明の第７実施例に係る触媒の製造方法は、先ず、γ
−アルミナ１６０９、べ−フィト１６０ｑ、水５００ｃ
ｃおよび濃硝酸４ｃｃをホ［ミキサーにより１０時間混
合撹拌する。このアルミナスラリーに触媒担体を浸漬し
で引き上げた後、余分のスラリーを高圧エアブロ−で除
去し、１３０℃で１時間乾燥し、しかる後、５５０℃で
１時間焼成をする。このアルミナコートを施した触媒担
体を所定の温度の塩化白金酸および塩化ロジウムの混合
水溶液に浸漬して引き上げたｊ炎、２００℃で１時間乾
燥し、しかる後、６００℃で１時間焼成をする。次いで
、平均粒径が５００人のセリウムの超微粉３０ｑ、ベー
マイト２０ｇおよび水５Ｑｃｃをホモミキサーにより５
時間混合撹拌する。このアルミナスラリーに、先に作っ
た触媒担体を浸漬して引き上げた後、余分なスラリーを
高圧エアブロ−により除去し、１３０℃で１時間乾燥し
、しかる後、５５０℃で１．５時間焼成をする。そして
、このような方法で製造された触媒において、第２アル
ミナ層４に担持されたセリウム超微粉の含イ１ｍは、第
２アルミナ層４の全重量に対して６５ｗｔ％である。ま
た、第１アルミナ層３に担持された白金およびロジウム
の含イＬｆｆｉは、それぞれ触媒の１リットル体積当り
１゜０９および０．２ｇである。In the method for producing a catalyst according to the seventh embodiment of the present invention, firstly, γ
-Alumina 1609, Bephyto 160q, Water 500c
C and 4 cc of concentrated nitric acid were mixed and stirred using a mixer for 10 hours. After the catalyst carrier is immersed in this alumina slurry and pulled up, excess slurry is removed by high-pressure air blowing, dried at 130°C for 1 hour, and then calcined at 550°C for 1 hour. This alumina-coated catalyst carrier is immersed in a mixed aqueous solution of chloroplatinic acid and rhodium chloride at a predetermined temperature, then pulled up with a flame, dried at 200°C for 1 hour, and then calcined at 600°C for 1 hour. . Next, 30 q of ultrafine cerium powder with an average particle size of 500, 20 g of boehmite, and 5 Qcc of water were mixed in a homomixer for 5 ml.
Mix and stir for an hour. After immersing the previously prepared catalyst carrier in this alumina slurry and pulling it up, excess slurry was removed by high-pressure air blowing, dried at 130°C for 1 hour, and then calcined at 550°C for 1.5 hours. do. In the catalyst manufactured by such a method, the content of 1 m of ultrafine cerium powder supported on the second alumina layer 4 is 65 wt% with respect to the total weight of the second alumina layer 4. Further, the platinum and rhodium content Lffi supported on the first alumina layer 3 are 1°09 and 0.2 g per 1 liter volume of the catalyst, respectively.
また、本発明の第８および第９実施例に係る触媒の製造
方法は、上記第７実施例の触媒のうｌ進方法においてセ
リウムの超微粉、ベーマイトおよび水をホモミキサーに
より混合撹拌してアルミナスラリーを製造ツる際、セリ
ウムの超微粉とベーマイトとのｆｆｌｆｉ割合をそれぞ
れ２．５ｇと５０９゜４４ｇと６ｇに変えるだけで、他
は同様な方法で触媒を製造するものである。そして、こ
のような方法で製造された触媒において、第２アルミナ
層４に担持されたセリウム超微粉の含イｉ吊は、第２ア
ルミナ層４の全ｍ位に対して、第８実施例の触媒の場合
５，８ｗｔ％であり、第９実施例の触媒の場合９０ｗｔ
％である。In addition, the method for producing a catalyst according to the eighth and ninth embodiments of the present invention is to mix and stir ultrafine powder of cerium, boehmite, and water using a homomixer in the method for producing a catalyst according to the seventh embodiment. When producing the slurry, the catalyst was produced in the same manner except that the fflfi ratios of ultrafine cerium powder and boehmite were changed to 2.5g, 509°44g, and 6g, respectively. In the catalyst manufactured by such a method, the content of the ultrafine cerium powder supported on the second alumina layer 4 is approximately the same as that of the eighth embodiment with respect to the total m of the second alumina layer 4. In the case of the catalyst, it is 5.8 wt%, and in the case of the catalyst of the ninth example, it is 90 wt%.
%.
一方、第９および第１０比較例に係る触媒の製造方法は
、上記第８および第９実施例の触媒の製造方法における
セリウムの超微粉とベーマイトとの重量割合をそれぞれ
１．５ｇと４’８．５ｇ、４６．５ｇと３．５ｇに変え
るだけで、他は同様な方法で触媒を製造するものである
。そして、このような方法で製造された触媒において、
第２アルミナ層４に担持されたセリウム超微粉の含有量
は、第２アルミナ層４の全重量に対して、第９比較例の
触媒の場合３．７ｗｔ％であり、第１０比較例の触媒の
場合９４ｗｔ％である。On the other hand, in the catalyst manufacturing methods according to the ninth and tenth comparative examples, the weight ratios of the ultrafine cerium powder and boehmite in the catalyst manufacturing methods of the eighth and ninth examples are 1.5 g and 4'8, respectively. The catalyst was produced in the same manner except that the amounts were changed to .5 g, 46.5 g, and 3.5 g. And in the catalyst manufactured by such a method,
The content of the ultrafine cerium powder supported on the second alumina layer 4 was 3.7 wt% in the case of the catalyst of the ninth comparative example, based on the total weight of the second alumina layer 4, and In this case, it is 94wt%.
そして、上記第７〜第９実施例および第９・第１０比較
例の各触媒について、電気炉を用いて９５０℃で１００
時間時間−ジングした後、上記第１実施例の触媒の場合
と同様の条件で排気ガス浄化試験および剥離試験を行っ
た。ここで、剥離試験としては、直径３インチ、高さ３
インチの円筒形テストピースを７００℃で３０分間加熱
し、次い′ｃ２５℃の水中で冷Ｗするという手順を３回
繰り返した後、１分乾燥し、剥離量を測定する方法を採
用した。The catalysts of the seventh to ninth examples and the ninth and tenth comparative examples were heated to 100°C at 950°C using an electric furnace.
After aging, an exhaust gas purification test and a peeling test were conducted under the same conditions as for the catalyst of the first example. Here, for the peel test, the diameter was 3 inches and the height was 3 inches.
A method of heating an inch cylindrical test piece for 30 minutes at 700°C, then cooling it in water at 25°C was repeated three times, followed by drying for 1 minute and measuring the amount of peeling.
、Ｌ記排気ガス浄化試験の測定結果は第７図（ａ）〜（
Ｃ）に示し、剥離試験の測定結果は第８図に示す。第７
図（ａ ）〜（Ｃ）から判るように、第７〜第９実施例
および第１０比較例の各触媒による浄１ヒ率（Ａｙａ、
ＡａｌＪ、第９図およびＢ ｔｏ 線）は、互いに同程
度に大きくなるが、セリウム超微粉の含有量が少ない第
９比較例の触媒による浄化率〈Ｂ・）線）は、他の触媒
の場合に比べてかなり小さく ’ｊＫる。また、第８図
から判るＪ：うに、セリウムの含有量が第２アルミナ層
４の全重量に対して９０ｗｔ％以上になると、剥離率が
急激に増加する。従って、主触媒全層を担持した第１ア
ルミナ層３にオーバコートされた第２アルミナ層４にセ
リウムの超微粉を担持させる場合、該セリウム超微粉の
含有聞は、第７〜第９実施例の如く第２アルミナ層４の
全車ａに対して５〜９０％に設定することが好ましい。, The measurement results of the exhaust gas purification test listed in L are shown in Figures 7(a) to (
C), and the measurement results of the peel test are shown in FIG. 7th
As can be seen from Figures (a) to (C), the purification rate (Aya,
AalJ, Fig. 9 and B to line) are almost as large as each other, but the purification rate (B.) line) by the catalyst of the 9th comparative example with a low content of ultrafine cerium powder is the same as that of other catalysts. It is quite small compared to 'jKru. Further, as can be seen from FIG. 8, when the cerium content becomes 90 wt% or more with respect to the total weight of the second alumina layer 4, the peeling rate increases rapidly. Therefore, when ultrafine cerium powder is supported on the second alumina layer 4 overcoated on the first alumina layer 3 supporting the entire main catalyst layer, the content of the ultrafine cerium powder is the same as in Examples 7 to 9. It is preferable to set the second alumina layer 4 to 5 to 90% of the entire vehicle a, as shown in FIG.
尚、上記第１〜第９実施例では、いずれもセリウムまた
はランタンの超微粉として、平均粒径が５００人のちの
を使用してアルミナ層に担持させるようにしたが、本発
明において使用するセリウムまたはランタンの超微粉は
、平均粒径が２０〜５０００人であればよく、特にｉ適
な粒径は１００〜１０００人である。In the first to ninth embodiments described above, ultrafine cerium or lanthanum powder with an average particle size of 500 mm was used to be supported on the alumina layer, but the cerium used in the present invention Alternatively, the ultrafine lanthanum powder may have an average particle size of 20 to 5,000 particles, and a particularly suitable particle size is 100 to 1,000 particles.
（発明の効果）
以上の如く、本発明の排気ガス浄化用触媒によれば、触
媒担体表面のアルミナ層に担持さむる希土類金属が平均
粒径５０００Å以下の超微粉として担持されているので
、超微粉の特性によって希土類金属の助触媒および安定
性としての機能を有効に発揮させることができ、浄化性
能および耐久性の向上を効果的に図ることができるもの
である。(Effects of the Invention) As described above, according to the exhaust gas purification catalyst of the present invention, the rare earth metal supported on the alumina layer on the surface of the catalyst carrier is supported as ultrafine powder with an average particle size of 5000 Å or less. The characteristics of the fine powder allow the rare earth metal to effectively exhibit its functions as a co-catalyst and stabilizer, thereby making it possible to effectively improve purification performance and durability.
図面は本発明の実施態様を示すもので、第１図および第
２図はそれぞれ排気ガス浄化用触媒の構造を示す拡大断
面図、第３図〜第７図はそれぞれ排気ガス浄化試験の測
定結果を示す図、第８図は剥離試験の測定結果を示す図
である。
１・・・触媒担体、２・・・アルミナ層、３・・・第１
アルミナ層、４・・・第２アルミナ層。The drawings show embodiments of the present invention, and FIGS. 1 and 2 are enlarged sectional views showing the structure of an exhaust gas purification catalyst, and FIGS. 3 to 7 show measurement results of an exhaust gas purification test. FIG. 8 is a diagram showing the measurement results of a peel test. 1... Catalyst carrier, 2... Alumina layer, 3... First
Alumina layer, 4... second alumina layer.
Claims (5)
希土類金属の超微粉を担持したアルミナ層が設けられて
いることを特徴とする排気ガス浄化用触媒。(1) A catalyst for exhaust gas purification, characterized in that an alumina layer supporting ultrafine rare earth metal powder with an average particle size of 5000 Å or less is provided on the surface of a catalyst carrier.
請求の範囲第（１）項記載の排気ガス浄化用触媒。(2) The exhaust gas purifying catalyst according to claim (1), wherein the rare earth metal is cerium or lanthanum.
層に担持されており、該セリウム超微粉の含有量は、ア
ルミナ層の全重量に対して１０〜３０重量％である特許
請求の範囲第（２）項記載の排気ガス浄化用触媒。(3) A claim in which ultrafine cerium powder is supported on the same alumina layer as the main catalyst metal, and the content of the ultrafine cerium powder is 10 to 30% by weight based on the total weight of the alumina layer. The exhaust gas purifying catalyst described in item (2).
層に担持されており、該ランタン超微粉の含有量は、ア
ルミナ層の全重量に対して１．０〜４．０重量％である
特許請求の範囲第（２）項記載の排気ガス浄化用触媒。(4) Ultrafine lanthanum powder is supported on the same alumina layer as the main catalyst metal, and the content of the ultrafine lanthanum powder is 1.0 to 4.0% by weight based on the total weight of the alumina layer. An exhaust gas purifying catalyst according to claim (2).
ナ層にオーバコートされた別のアルミナ層に担持されて
おり、該セリウム超微粉の含有量は、オーバコート側の
アルミナ層の全重量に対して５〜９０重量％である特許
請求の範囲第（２）項記載の排気ガス浄化用触媒。(5) Ultrafine cerium powder is supported on another alumina layer overcoated on the alumina layer supporting the main catalyst metal, and the content of the ultrafine cerium powder is based on the total weight of the alumina layer on the overcoat side. The exhaust gas purifying catalyst according to claim (2), wherein the amount is 5 to 90% by weight.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61286251A JPH07114960B2 (en) | 1986-12-01 | 1986-12-01 | Exhaust gas purification catalyst |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61286251A JPH07114960B2 (en) | 1986-12-01 | 1986-12-01 | Exhaust gas purification catalyst |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS63137753A true JPS63137753A (en) | 1988-06-09 |
| JPH07114960B2 JPH07114960B2 (en) | 1995-12-13 |
Family
ID=17701942
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61286251A Expired - Lifetime JPH07114960B2 (en) | 1986-12-01 | 1986-12-01 | Exhaust gas purification catalyst |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH07114960B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001000864A (en) * | 1999-06-22 | 2001-01-09 | Toyota Motor Corp | Waste gas purifying catalyst and its production |
| US10906816B2 (en) | 2016-07-29 | 2021-02-02 | Sumitomo Chemical Company, Limited | Alumina and method for producing automotive catalyst using same |
-
1986
- 1986-12-01 JP JP61286251A patent/JPH07114960B2/en not_active Expired - Lifetime
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001000864A (en) * | 1999-06-22 | 2001-01-09 | Toyota Motor Corp | Waste gas purifying catalyst and its production |
| US10906816B2 (en) | 2016-07-29 | 2021-02-02 | Sumitomo Chemical Company, Limited | Alumina and method for producing automotive catalyst using same |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH07114960B2 (en) | 1995-12-13 |
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