JP3916197B2 - Method for producing exhaust gas purification catalyst - Google Patents
Method for producing exhaust gas purification catalyst Download PDFInfo
- Publication number
- JP3916197B2 JP3916197B2 JP08611599A JP8611599A JP3916197B2 JP 3916197 B2 JP3916197 B2 JP 3916197B2 JP 08611599 A JP08611599 A JP 08611599A JP 8611599 A JP8611599 A JP 8611599A JP 3916197 B2 JP3916197 B2 JP 3916197B2
- Authority
- JP
- Japan
- Prior art keywords
- noble metal
- platinum
- exhaust gas
- supported
- chloride
- 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.)
- Expired - Fee Related
Links
Description
【0001】
【発明の属する技術分野】
本発明は、吸水担持法で用いる排ガス浄化触媒の製造方法に関する。
【0002】
【従来の技術】
近年、地球環境の保護の観点より、地球温暖化を招く原因として、自動車等の内燃機関より排出される排ガス中の二酸化炭素の問題が指摘されている。その解決策の一つとして、酸素過剰雰囲気において燃料と空気との混合比を調節し、いわゆる希薄燃焼を応用したリーンバーンエンジンが注目を集めている。
【0003】
このリーンバーンエンジンの排ガスの浄化には、特開平5−261287及び特開平6−262040にあるように、アルカリ金属、アルカリ土類金属及び希土類金属の中から選ばれた金属元素(以下、「アルカリ金属元素等」と称する。)と、白金、ロジウム又は白金−ロジウムの複合金属である貴金属元素とを組み合わせてアルミナ等の多孔質体に担持した排ガス浄化触媒が用いられる。
【0004】
これらの排ガス浄化用触媒は、リーン側では担持したアルカリ金属元素等の酸化物がNOxの吸蔵を行い、ストイキ又はリッチ側でHCやCOなどの還元成分と反応し、NOxを還元することで、優れたNOxの浄化性能を示すものである。
【0005】
従来より、上述の排ガス浄化触媒を製造するには、コージェライト質やメタル等のハニカム担体基材に、NOx吸蔵材が均質分散している複合酸化物担体(ウオッシュコート)のスラリーを付着、焼成して、ウオッシュコート層を形成する。続いて、ジニトロジアンミン白金水溶液又はアンミン白金溶液等に所定時間浸漬(吸水)して、乾燥、焼成し、白金を担持する等の、いわゆる吸水担持法が採られてきた。
【0006】
【発明が解決しようとする課題】
しかしながら、ジニトロジアンミン白金溶液を用いて、吸水担持法で白金等の貴金属を担持すると、ウオッシュコートに均一に分散しているNOx吸蔵材が溶液中に溶出し、NOx吸蔵材が減少してしまうという現象が生じていた。また、アンミン白金溶液を用いると、NOx吸蔵材の溶出は抑制できても、必要量の貴金属の担持が出来なかった。
【0007】
しかも、ジニトロジアンミン白金溶液を用いる場合でも、ウオッシュコートに均一に分散しているNOx吸蔵材が溶液中に溶出すると、水溶液がアルカリ性になり、ジニトロジアンミン白金の担持を阻害するという現象が生じることも判明してきた。
【0008】
この結果、目的量の白金等の貴金属の担持が出来ず、この触媒をリーンバーンエンジンの排ガス浄化触媒として用いても、十分なHC、COの酸化浄化性能及びNOx吸蔵能及び還元能までも低下してしまうことになる。
【0009】
【課題を解決するための手段】
そこで、本発明者らは、鋭意研究の結果、吸水担持法における、貴金属担持に用いる化合物であって、NOx吸蔵材の溶出することのない貴金属担持用の化合物を用いた排ガス浄化触媒の製造方法として、以下の発明を行うに至った。
【0010】
本発明は、コージェライト又はメタルのハニカム担体基材に、NOx吸蔵材であるアルカリ金属、アルカリ土類金属、ランタンの1種又は2種以上を均質分散させたウオッシュコートのスラリーを付着させ、焼成して、ウオッシュコート層を形成した後、貴金属担持用の化合物の水溶液を吸水させて、乾燥、焼成し、貴金属触媒を担持する排ガス浄化触媒の製造方法において、貴金属担持用の化合物は、貴金属を含む原料化合物と、エタノールアミンと、を接触させて得られるもので、エタノールアミンを含有することを特徴とする排ガス浄化触媒の製造方法に関する。
【0011】
ここで、「コージェライト又はメタルのハニカム担体基材」としているが、特に、これらのハニカムに拘るものではなく、ハニカムを構成するモノリスの状態であっても、更には、その材質がセラミック等他の材質に分類されるものであっても何ら問題はないことをここに明記しておく。
【0012】
ここで言うNOx吸蔵材とは、アルカリ金属、アルカリ土類金属及び希土類元素の中から選ばれた1種又は2種以上を組み合わせて用いたものである。これらのNOx吸蔵材を、ウオッシュコートに均一に分散させる方法としては、例えば、バリウムの場合を考えると、次のようになる。担体となる所定量のアルミナ(ウオッシュコート)を、酢酸バリウム、EDTAバリウム等の必要量を溶解させた水溶液中に加え、懸濁状態とし、数時間の撹拌吸着を行わせる。この溶液の中に、コージェライト質やメタル等のハニカム担体基材を浸漬し、バリウムが均一に分散したアルミナのスラリーを付着させ、乾燥、焼成して、ウオッシュコート層を形成することにより、NOx吸蔵材としてのバリウムの分散担持が完了する。他の元素を用いる場合も同様の手順が採られる。
【0013】
そして、本件の最大の特徴は、アミノアルコールを用いる点にある。このアミノアルコールを含有貴金属担持用の化合物の水溶液を用いて、NOx吸蔵材を均一分散させたコージェライト質やメタル等のハニカム担体基材に貴金属を吸水担持しても、均一分散したNOx吸蔵材の水溶液中への溶出は起こらない。これは、アミノアルコールを含有する貴金属担持用の化合物を用いた水溶液は、アルカリ性領域のpHを示すためである。
【0014】
また、アミノアルコールを含む貴金属担持用の化合物は、イソプロピルアルコール等のアルコール類にも容易に溶解するため、アルコール系溶液を用いた吸水担持法を用いることも可能であり、この方法であれば、NOx吸蔵材の溶出を完全に防止することも可能となる。
【0015】
更に、従来より用いてきた貴金属担持用の化合物であるジニトロジアンミン白金やアンミン白金では、十分な貴金属量が担持出来ないpH領域であっても、アミノアルコールを含有する貴金属担持用の化合物を用いることで、ウオッシュコートに必要な量の貴金属を担持することが可能となるのである。
【0016】
このアミノアルコールを含む貴金属担持用の化合物を製造するのに特に適したアミノアルコールは、エタノールアミン(2−アミノエタノール)、3−アミノ−1−プロパノール、2−アミノ−1−プロパノール、4−アミノ−1−ブタノール、2−アミノ−1−ブタノールの群より選ばれた一種又は二種以上からなるものである。
【0017】
ここに示したアミノアルコールを用いることで、アルカリ性領域のpHを示し、アルカリpH領域であっても、ウオッシュコートに必要な量の貴金属を担持することが可能となるのである。しかも、ここに列挙したアミノアルコールを用いた貴金属担持用の化合物は、化合物としての安定性に優れ、その保管時の取り扱いに、繊細な注意を払う必要が無く、保存管理が容易となるという利点がある。
【0018】
アミノアルコールを含有する貴金属担持用の化合物の対象となる貴金属とは、白金、ロジウム、パラジウム、イリジウム、ルテニウム、金及び銀を主な対象とすることが出来る。これらの貴金属元素の供給源としての原料としては、やはり貴金属化合物を用いる訳であるから、これを本明細書では、「貴金属を含む原料化合物」と称している。
【0019】
この貴金属を含む原料化合物として、単一貴金属の担持を行う場合の、貴金属を含む原料化合物には、白金の場合はヘキサヒドロキシ白金酸、塩化白金酸の一種又は二種、ロジウムの場合は塩化ロジウム、水酸化ロジウムの一種又は二種、パラジウムの場合はテトラヒドロキシパラジウム酸、塩化パラジウム、硝酸パラジウムの一種又は二種以上、イリジウムの場合は塩化イリジウム、ヘキサクロロイリジウム酸の一種又は二種、ルテニウムの場合は塩化ルテニウム、ヘキサクロロルテニウム酸の一種又は二種、金の場合は塩化金酸、塩化金の一種又は二種、銀の場合は硝酸銀、酢酸銀の一種又は二種を用いることが望ましい。前記アミノアルコールとの組み合わせにおいて安定した排ガス浄化触媒用貴金属担持用の化合物を生成できるからである。
【0020】
そして、本発明は、異なる貴金属を含む原料化合物を二種以上組み合わせて得られる貴金属担持用の化合物を用い、複数の貴金属を担持する排ガス浄化触媒の製造方法とすることが出来る。上記した貴金属担持用の化合物の組み合わせであれば、自由な組み合わせを選択しても、NOx吸蔵材を溶出させることなく、貴金属の触媒の担持性能に何ら問題は生じない。
【0021】
【発明の実施の形態】
以下、本発明に関する排ガス浄化触媒の製造方法の最良と考えられる実施の形態について説明する。
【0022】
第1実施形態: アミノアルコールを含有する貴金属担持用の化合物であるエタノールアミン白金の合成について説明する。1molのヘキサヒドロキシ白金酸に対し、2.5倍当量のエタノールアミンを加え、室温にて2時間撹拌した。撹拌終了後、更にエタノールアミン2.5倍当量を加え、淡黄色のエタノールアミン白金溶液が得られた。白金の濃度は10%、pH11であった。
【0023】
このエタノールアミン白金を用いて吸水担持法により、白金担持を行ったときのNOx吸蔵材の溶出量を求めた。このとき用いたのは、ウオッシュコート層のアルミナ100gに対し、NOx吸蔵材であるランタン0.2mol/l及びバリウム0.1mol/lを担持したアルミナを用いた。そして、上述のエタノールアミン白金溶液を用いて、ランタン及びバリウムを担持したアルミナへ、貴金属触媒である白金の目標担持量を5wt%と2wt%との2種類のものとして担持したそれぞれの場合で、NOx吸蔵材の溶出率を測定した。
【0024】
このときの白金の担持方法は、水10ml及びランタン及びバリウムを担持したアルミナ100gに目標担持率に相当する上述のエタノールアミン白金溶液を加え、5分間撹拌後、濾別した。濾過後の上澄み液中の白金濃度を分析することで白金の担持率を計算し、上澄み液中のランタン及びバリウム濃度を分析することでNOx吸蔵材の溶出率を測定した。その結果、目標担持量5wt%の場合の実質白金担持量4.4wt%、目標担持量2wt%の場合の実質白金担持量2.0wt%と極めて良好な貴金属担持能を示した。そして、NOx吸蔵材の溶出率は、双方ともに1.0%であった。
【0025】
これに対し、エタノールアミン白金溶液に替えて、従来より用いられていたジニトロジアンミン白金溶液を用いて、上述したランタン及びバリウムを担持したアルミナに、貴金属触媒である白金の目標担持量を5wt%と2wt%との2種類のものを製造し、白金担持率とNOx吸蔵材の溶出率とを測定してみた。その結果、目標担持量5wt%の場合の実質白金担持量4.3wt%、目標担持量2wt%の場合の実質白金担持量2.0wt%であり、貴金属担持能においては、本実施形態に係るエタノールアミン白金溶液を用いる場合と遜色はない。
【0026】
ところが、本実施形態に係るエタノールアミン白金溶液を用いる場合に比べ、NOx吸蔵材の溶出率は、双方ともに10.0%と、極めて多くのNOx吸蔵材の溶出が認められた。従って、このことからしても、本実施形態に係るエタノールアミン白金溶液を用いる場合が技術的に優れていることが明らかとなる。
【0027】
第2実施形態: アミノアルコールを含有する貴金属担持用の化合物であるエタノールアミン白金アルコール溶液の合成について説明する。1molのヘキサヒドロキシ白金酸に対し、5倍モルのエタノールアミンを加え、室温にて2時間撹拌した。撹拌終了後、蒸発乾固し、更にイソプロピルアルコール数10mlを加え、加熱溶解して、エタノールアミン白金アルコール溶液が得られた。白金の濃度は5wt%であった。
【0028】
このエタノールアミン白金アルコールを用いて吸水担持法により、白金担持を行ったときのNOx吸蔵材の溶出量を求めた。このとき用いたのは、ウオッシュコート層のアルミナ100gに対し、NOx吸蔵材であるランタン0.2mol/l及びバリウム0.1mol/lを担持したアルミナを用いた。そして、上述のエタノールアミン白金アルコール溶液を用いて、ランタン及びバリウムを担持したアルミナへ、貴金属触媒である白金の目標担持量を5wt%と2wt%との2種類のものとして担持したそれぞれの場合で、NOx吸蔵材の溶出率を測定した。
【0029】
このときの白金の担持方法は、水10ml及びランタン及びバリウムを担持したアルミナ1gに目標担持率に相当する上述のエタノールアミン白金アルコール溶液を加え、5分間撹拌後、濾別した。濾過後の上澄み液中の白金濃度を分析することで白金の担持率を計算し、上澄み液中のランタン及びバリウム濃度を分析することでNOx吸蔵材の溶出率を測定した。その結果、目標担持量5wt%の場合の実質白金担持量4.6wt%、目標担持量2wt%の場合の実質白金担持量2.0wt%と極めて良好な貴金属担持能を示した。そして、NOx吸蔵材の溶出率は、双方ともに0.1%であった。
【0030】
これに対し、エタノールアミン白金アルコール溶液に替えて、従来より用いられていたヘキサアンミン白金水酸化塩溶液を用いて、上述したランタン及びバリウムを担持したアルミナに、貴金属触媒である白金の目標担持量を5wt%と2wt%の2種類のものを製造し、白金担持率とNOx吸蔵材の溶出率とを測定してみた。その結果、目標担持量5wt%の場合の実質白金担持量2.3wt%、目標担持量2wt%の場合の実質白金担持量1.4wt%であり、貴金属担持能においては、本実施形態に係るエタノールアミン白金アルコール溶液を用いる場合に比べ極めて低くなっている。
【0031】
一方、本実施形態に係るエタノールアミン白金アルコール溶液を用いる場合に比べ、NOx吸蔵材の溶出率は、双方ともに1.0%と、極めて多くのNOx吸蔵材の溶出が認められた。従って、このことからしても、本実施形態に係るエタノールアミン白金アルコール溶液を用いる場合が技術的に優れていることが明らかとなる。
【0032】
【発明の効果】
本発明に係る貴金属担持用の化合物を自動車排ガス浄化用触媒の製造に用いることで、貴金属触媒の吸水担持法で白金等の貴金属を担持する際の、NOx吸蔵材が溶液中に溶出することを防止し、しかも、必要量の貴金属触媒の担持が可能となった。この結果、この触媒をリーンバーンエンジンの排ガス浄化触媒として用いても、十分なHC、COの酸化浄化性能及びNOx吸蔵能及び還元能を確保することが可能となり、より環境に優しい自動車の供給が可能となる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing an exhaust gas purification catalyst used in a water absorption support method.
[0002]
[Prior art]
In recent years, from the viewpoint of protecting the global environment, the problem of carbon dioxide in exhaust gas discharged from internal combustion engines such as automobiles has been pointed out as a cause of global warming. As one of the solutions, a lean burn engine that adjusts the mixing ratio of fuel and air in an oxygen-excess atmosphere and applies so-called lean combustion attracts attention.
[0003]
As described in JP-A-5-261287 and JP-A-6-262040, the purification of the exhaust gas from the lean burn engine is performed using a metal element selected from alkali metals, alkaline earth metals, and rare earth metals (hereinafter referred to as “alkaline”). An exhaust gas purifying catalyst that is supported on a porous body such as alumina in combination with platinum, rhodium, or a noble metal element that is a composite metal of platinum-rhodium is used.
[0004]
In these exhaust gas purification catalysts, oxides such as alkali metal elements carried on the lean side occlude NOx, react with reducing components such as HC and CO on the stoichiometric or rich side, and reduce NOx, It exhibits excellent NOx purification performance.
[0005]
Conventionally, in order to produce the above-described exhaust gas purification catalyst, a slurry of a composite oxide carrier (wash coat) in which NOx occlusion material is homogeneously dispersed is attached to a honeycomb carrier base material such as cordierite or metal, and fired. Then, a washcoat layer is formed. Subsequently, a so-called water absorption supporting method has been adopted, in which the substrate is immersed (absorbed) in a dinitrodiammine platinum aqueous solution or an ammine platinum solution for a predetermined time, dried, fired, and supported with platinum.
[0006]
[Problems to be solved by the invention]
However, when a noble metal such as platinum is supported by a water absorption method using a dinitrodiammine platinum solution, the NOx occlusion material uniformly dispersed in the washcoat is eluted into the solution, and the NOx occlusion material decreases. The phenomenon occurred. Moreover, when an ammine platinum solution was used, the required amount of noble metal could not be supported even though elution of the NOx storage material could be suppressed.
[0007]
Moreover, even when a dinitrodiammine platinum solution is used, if the NOx occlusion material uniformly dispersed in the washcoat elutes in the solution, the aqueous solution becomes alkaline and a phenomenon may occur in which the loading of dinitrodiammine platinum is inhibited. It turns out.
[0008]
As a result, the target amount of noble metals such as platinum cannot be supported, and even if this catalyst is used as an exhaust gas purification catalyst for lean burn engines, the HC and CO oxidation purification performance, NOx occlusion ability and reduction ability are also reduced. Will end up.
[0009]
[Means for Solving the Problems]
Therefore, as a result of earnest research, the present inventors have made a method for producing an exhaust gas purification catalyst using a compound for supporting a noble metal that does not elute the NOx occlusion material in the water absorption supporting method. As a result, the inventors have made the following invention.
[0010]
In the present invention, a wash coat slurry in which one or more of alkali metal, alkaline earth metal, and lanthanum, which are NOx occlusion materials, are homogeneously dispersed is attached to a cordierite or metal honeycomb carrier base material, and fired. Then, after the formation of the washcoat layer, the aqueous solution of the compound for supporting the noble metal is absorbed, dried and fired, and in the method for producing an exhaust gas purification catalyst for supporting the noble metal catalyst, The present invention relates to a method for producing an exhaust gas purifying catalyst, which is obtained by bringing a raw material compound and ethanolamine into contact with each other and containing ethanolamine.
[0011]
Here, “the honeycomb carrier base material of cordierite or metal” is not particularly concerned with these honeycombs, and even in the state of the monolith constituting the honeycomb, the material is ceramic or the like. It should be noted here that there is no problem even if it is classified as a material.
[0012]
The NOx occlusion material referred to here is one used in combination of one or more selected from alkali metals, alkaline earth metals and rare earth elements. As a method for uniformly dispersing these NOx occlusion materials in the washcoat, for example, considering the case of barium, the method is as follows. A predetermined amount of alumina (wash coat) serving as a carrier is added to an aqueous solution in which a necessary amount of barium acetate, EDTA barium or the like is dissolved, and the suspension is brought into a suspended state for several hours of stirring and adsorption. In this solution, a honeycomb carrier base material such as cordierite or metal is immersed, an alumina slurry in which barium is uniformly dispersed is adhered, dried and fired to form a washcoat layer, thereby forming a NOx coating layer. Dispersion and loading of barium as an occlusion material is completed. The same procedure is used when other elements are used.
[0013]
The greatest feature of this case is that amino alcohol is used. Using an aqueous solution of a compound for supporting a precious metal containing amino alcohol, a NOx storage material in which the NOx storage material is uniformly dispersed even if the precious metal is absorbed and supported on a honeycomb carrier base material such as cordierite or metal in which the NOx storage material is uniformly dispersed. Elution into the aqueous solution does not occur. This is because an aqueous solution using a noble metal-supporting compound containing an amino alcohol exhibits a pH in the alkaline region.
[0014]
In addition, since the compound for supporting a noble metal containing amino alcohol is easily dissolved in alcohols such as isopropyl alcohol, it is possible to use a water absorption supporting method using an alcohol-based solution. It is also possible to completely prevent elution of the NOx storage material.
[0015]
Furthermore, dinitrodiammine platinum and ammine platinum, which are conventionally used noble metal loading compounds, should use a noble metal loading compound containing an amino alcohol even in a pH range where a sufficient amount of noble metal cannot be supported. Thus, it becomes possible to carry the amount of noble metal necessary for the washcoat.
[0016]
Particularly suitable amino alcohols for producing a compound for supporting a noble metal containing amino alcohol are ethanolamine (2-aminoethanol), 3-amino-1-propanol, 2-amino-1-propanol, 4-amino. It consists of one or more selected from the group of -1-butanol and 2-amino-1-butanol.
[0017]
By using the amino alcohol shown here, the pH in the alkaline region is shown, and even in the alkaline pH region, it is possible to carry the amount of noble metal necessary for the washcoat. In addition, the compounds for supporting noble metals using amino alcohols listed here have the advantages of excellent stability as a compound, no need to pay close attention to handling during storage, and easy storage management. There is.
[0018]
The noble metal which is the target of the noble metal-supporting compound containing amino alcohol can mainly be platinum, rhodium, palladium, iridium, ruthenium, gold and silver. Since a noble metal compound is still used as a raw material as a supply source of these noble metal elements, it is referred to as a “raw material compound containing a noble metal” in this specification.
[0019]
In the case of carrying a single noble metal as a raw material compound containing this noble metal, the raw material compound containing a noble metal includes hexahydroxyplatinic acid, one or two kinds of chloroplatinic acid in the case of platinum, and rhodium chloride in the case of rhodium. 1 or 2 types of rhodium hydroxide, in the case of palladium, tetrahydroxypalladium acid, palladium chloride, 1 or 2 types of palladium nitrate, in the case of iridium, 1 or 2 types of iridium chloride and hexachloroiridate, in the case of ruthenium It is desirable to use one or two of ruthenium chloride and hexachlororuthenic acid, one or two of chloroauric acid and gold chloride in the case of gold, one or two of silver nitrate and silver acetate in the case of silver. This is because a stable compound for supporting a noble metal for an exhaust gas purification catalyst can be produced in combination with the amino alcohol.
[0020]
And this invention can be set as the manufacturing method of the exhaust gas purification catalyst which carry | supports several noble metals using the compound for noble metal carrying | support obtained by combining 2 or more types of raw material compounds containing a different noble metal. As long as the combination of the above-mentioned compounds for supporting the noble metal is used, no problem arises in the performance of supporting the catalyst of the noble metal without eluting the NOx occlusion material even if any combination is selected.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment considered to be the best method for producing an exhaust gas purification catalyst according to the present invention will be described.
[0022]
1st Embodiment : The synthesis | combination of ethanolamine platinum which is a compound for noble metal carrying | support containing amino alcohol is demonstrated. 2.5 times equivalent of ethanolamine was added to 1 mol of hexahydroxyplatinic acid and stirred at room temperature for 2 hours. After the stirring, 2.5 times equivalent of ethanolamine was further added to obtain a pale yellow ethanolamine platinum solution. The platinum concentration was 10% and pH 11.
[0023]
Using this ethanolamine platinum, the elution amount of the NOx occlusion material when platinum was supported was determined by a water absorption method. At this time, alumina carrying 0.2 mol / l of lanthanum and 0.1 mol / l of barium as NOx occlusion materials was used for 100 g of alumina of the washcoat layer. In each case of using the ethanolamine platinum solution described above, the target loading amount of platinum, which is a noble metal catalyst, was supported as two types of 5 wt% and 2 wt% on alumina supporting lanthanum and barium, The dissolution rate of the NOx storage material was measured.
[0024]
At this time, platinum was supported by adding the above-mentioned ethanolamine platinum solution corresponding to the target loading rate to 100 g of alumina supporting 10 ml of water and lanthanum and barium, stirring for 5 minutes, and then filtering. By analyzing the platinum concentration in the supernatant liquid after filtration, the loading ratio of platinum was calculated, and by analyzing the lanthanum and barium concentrations in the supernatant liquid, the elution ratio of the NOx occlusion material was measured. As a result, the platinum support amount was 4.4 wt% when the target support amount was 5 wt%, and the platinum support amount was 2.0 wt% when the target support amount was 2 wt%. The elution rate of the NOx occlusion material was 1.0% for both.
[0025]
On the other hand, instead of the ethanolamine platinum solution, a conventionally used dinitrodiammine platinum solution is used, and the target loading amount of platinum as a noble metal catalyst is set to 5 wt% on the alumina carrying the lanthanum and barium described above. Two types of 2 wt% were manufactured, and the platinum loading rate and the elution rate of the NOx occlusion material were measured. As a result, the actual platinum support amount is 4.3 wt% when the target support amount is 5 wt%, and the actual platinum support amount is 2.0 wt% when the target support amount is 2 wt%. It is not inferior to the case of using ethanolamine platinum solution.
[0026]
However, compared with the case of using the ethanolamine platinum solution according to the present embodiment, the elution rate of the NOx occlusion material was 10.0% for both, and an extremely large amount of elution of the NOx occlusion material was recognized. Therefore, even from this, it is clear that the case of using the ethanolamine platinum solution according to the present embodiment is technically excellent.
[0027]
Second Embodiment : The synthesis of an ethanolamine platinum alcohol solution that is a compound for supporting a noble metal containing amino alcohol will be described. 5 mol of ethanolamine was added to 1 mol of hexahydroxyplatinic acid, and the mixture was stirred at room temperature for 2 hours. After completion of the stirring, the solution was evaporated to dryness, and further, 10 ml of isopropyl alcohol was added and dissolved by heating to obtain an ethanolamine platinum alcohol solution. The concentration of platinum was 5 wt%.
[0028]
Using this ethanolamine platinum alcohol, the elution amount of the NOx occlusion material when platinum was supported was determined by a water absorption method. At this time, alumina carrying 0.2 mol / l of lanthanum and 0.1 mol / l of barium as NOx occlusion materials was used for 100 g of alumina of the washcoat layer. In each case where the above-mentioned ethanolamine platinum alcohol solution was used, the target loading of platinum as a noble metal catalyst was supported as two types of 5 wt% and 2 wt% on alumina supporting lanthanum and barium. The elution rate of the NOx occlusion material was measured.
[0029]
At this time, platinum was supported by adding 10 ml of water and 1 g of alumina supporting lanthanum and barium to the above ethanolamine platinum alcohol solution corresponding to the target supporting rate, stirring for 5 minutes, and then separating by filtration. By analyzing the platinum concentration in the supernatant liquid after filtration, the loading ratio of platinum was calculated, and by analyzing the lanthanum and barium concentrations in the supernatant liquid, the elution ratio of the NOx occlusion material was measured. As a result, the platinum support amount of 4.6 wt% when the target support amount was 5 wt% and the platinum support amount of 2.0 wt% when the target support amount was 2 wt% were shown to be extremely good. And the elution rate of the NOx occlusion material was 0.1% in both.
[0030]
On the other hand, instead of the ethanolamine platinum alcohol solution, the previously supported hexaammine platinum hydroxide solution, using the above-mentioned alumina supporting lanthanum and barium, the target supported amount of platinum as a noble metal catalyst Two types of 5 wt% and 2 wt% were manufactured, and the platinum loading rate and the elution rate of the NOx occlusion material were measured. As a result, the actual platinum loading amount is 2.3 wt% when the target loading amount is 5 wt%, and the actual platinum loading amount is 1.4 wt% when the target loading amount is 2 wt%. Compared with the case of using ethanolamine platinum alcohol solution, it is extremely low.
[0031]
On the other hand, as compared with the case of using the ethanolamine platinum alcohol solution according to the present embodiment, the elution rate of the NOx occlusion material was 1.0% in both cases, and elution of an extremely large amount of NOx occlusion material was recognized. Therefore, even from this, it is clear that the case of using the ethanolamine platinum alcohol solution according to the present embodiment is technically excellent.
[0032]
【The invention's effect】
By using the noble metal-supporting compound according to the present invention for the production of an automobile exhaust gas purification catalyst, the NOx occlusion material elutes in the solution when the noble metal such as platinum is supported by the water absorption supporting method of the noble metal catalyst. In addition, the required amount of noble metal catalyst can be supported. As a result, even when this catalyst is used as an exhaust gas purification catalyst for a lean burn engine, it is possible to ensure sufficient HC and CO oxidation purification performance, NOx storage capacity and reduction capacity, and to supply more environmentally friendly vehicles. It becomes possible.
Claims (3)
貴金属担持用の化合物は、貴金属を含む原料化合物と、エタノールアミンと、を接触させて得られるもので、エタノールアミンを含有することを特徴とする排ガス浄化触媒の製造方法。 A wash coat slurry in which one or more of alkali metal, alkaline earth metal and lanthanum, which are NOx occlusion materials , are uniformly dispersed is attached to a cordierite or metal honeycomb carrier base material, fired, and washed. after forming the coating layer, by water absorption of the aqueous solution of a compound for the noble metal-supported, drying and baking, in the method for manufacturing the exhaust gas purifying catalyst carrying a noble metal catalyst,
Compounds for the noble metal-supported includes a raw material compound containing a noble metal, and ethanolamine, those obtained by contacting a method of manufacturing an exhaust gas purifying catalyst which is characterized by containing the ethanolamine.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP08611599A JP3916197B2 (en) | 1999-03-29 | 1999-03-29 | Method for producing exhaust gas purification catalyst |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP08611599A JP3916197B2 (en) | 1999-03-29 | 1999-03-29 | Method for producing exhaust gas purification catalyst |
Publications (2)
Publication Number | Publication Date |
---|---|
JP2000279811A JP2000279811A (en) | 2000-10-10 |
JP3916197B2 true JP3916197B2 (en) | 2007-05-16 |
Family
ID=13877711
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP08611599A Expired - Fee Related JP3916197B2 (en) | 1999-03-29 | 1999-03-29 | Method for producing exhaust gas purification catalyst |
Country Status (1)
Country | Link |
---|---|
JP (1) | JP3916197B2 (en) |
Families Citing this family (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2005206931A (en) | 2003-12-26 | 2005-08-04 | Sumitomo Electric Ind Ltd | Method for producing metal powder |
CA2565113A1 (en) | 2004-06-10 | 2005-12-22 | Sumitomo Electric Industries, Ltd. | Metal catalyst and method for preparation thereof |
JP5812392B2 (en) * | 2011-05-10 | 2015-11-11 | スズキ株式会社 | Method for stabilizing the size of a platinum hydroxide polymer |
JP6216609B2 (en) * | 2013-10-29 | 2017-10-18 | 石福金属興業株式会社 | Method for producing supported catalyst production composition |
JP6263991B2 (en) * | 2013-11-28 | 2018-01-24 | マツダ株式会社 | A method for producing a catalyst material, a method for producing a particulate filter with a catalyst using the same, and a method for producing a three-way catalyst for a gasoline engine. |
-
1999
- 1999-03-29 JP JP08611599A patent/JP3916197B2/en not_active Expired - Fee Related
Also Published As
Publication number | Publication date |
---|---|
JP2000279811A (en) | 2000-10-10 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
KR890001301B1 (en) | Process for producing monolithic catalyst for purifying exhaust gases | |
JPH10235192A (en) | Catalyst for cleaning exhaust gas | |
JP4012320B2 (en) | Exhaust gas purification catalyst for lean combustion engine | |
JP2002535135A (en) | Catalyst composition containing oxygen storage component | |
US20040101452A1 (en) | Gas treatment device comprising SMSI material and methods for making and using the same | |
JPH07232064A (en) | Catalyst for purification of exhaust gas | |
JPH03207445A (en) | Multi-functional catalyst for conversion of contaminant containing ce and u as well as metal exhausted from internal combustion engine, and preparation of said catalyst | |
JPH01139144A (en) | Catalyst for controlling exhaust emission | |
JP3882627B2 (en) | Exhaust gas purification catalyst | |
JP3216858B2 (en) | Exhaust gas purification catalyst and method for producing the same | |
EP0963781B1 (en) | Catalyst for purifying exhaust gas and process for producing the same | |
JP2004057949A (en) | Catalyst for removing particulate | |
JP3916197B2 (en) | Method for producing exhaust gas purification catalyst | |
JPH08299793A (en) | Catalyst for purification of exhaust gas and its production | |
JP2006289301A (en) | Catalyst for clarifying exhaust gas | |
JP3766568B2 (en) | Exhaust gas purification catalyst and exhaust gas purification method | |
JPH10277389A (en) | Catalyst for cleaning exhaust gas | |
JP4382180B2 (en) | Exhaust gas purification catalyst | |
JPH10216514A (en) | Catalyst for exhaust gas purification | |
JP4303799B2 (en) | Method for producing lean NOx purification catalyst | |
JPH03196841A (en) | Catalyst for purification of exhaust gas | |
JP2001000862A (en) | NOx REMOVING CATALYST FOR LEAN-BURN ENGINE | |
JP4106762B2 (en) | Exhaust gas purification catalyst device and purification method | |
JP2000246103A (en) | Production of catalyst for cleaning exhaust gas | |
JP3534286B2 (en) | Exhaust gas purification catalyst and exhaust gas purification method |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20040513 |
|
A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20061016 |
|
A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20061018 |
|
A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20061215 |
|
TRDD | Decision of grant or rejection written | ||
A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20070129 |
|
A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20070205 |
|
R150 | Certificate of patent or registration of utility model |
Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130216 Year of fee payment: 6 |
|
FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130216 Year of fee payment: 6 |
|
S533 | Written request for registration of change of name |
Free format text: JAPANESE INTERMEDIATE CODE: R313533 |
|
R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130216 Year of fee payment: 6 |
|
S111 | Request for change of ownership or part of ownership |
Free format text: JAPANESE INTERMEDIATE CODE: R313115 |
|
FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130216 Year of fee payment: 6 |
|
R360 | Written notification for declining of transfer of rights |
Free format text: JAPANESE INTERMEDIATE CODE: R360 |
|
FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130216 Year of fee payment: 6 |
|
R370 | Written measure of declining of transfer procedure |
Free format text: JAPANESE INTERMEDIATE CODE: R370 |
|
FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130216 Year of fee payment: 6 |
|
S111 | Request for change of ownership or part of ownership |
Free format text: JAPANESE INTERMEDIATE CODE: R313115 |
|
FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130216 Year of fee payment: 6 |
|
R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130216 Year of fee payment: 6 |
|
FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20140216 Year of fee payment: 7 |
|
R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20140216 Year of fee payment: 7 |
|
S111 | Request for change of ownership or part of ownership |
Free format text: JAPANESE INTERMEDIATE CODE: R313117 |
|
R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
LAPS | Cancellation because of no payment of annual fees |