JP2006255610A - Catalyst for cleaning exhaust gas and its manufacturing method - Google Patents

Catalyst for cleaning exhaust gas and its manufacturing method Download PDF

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JP2006255610A
JP2006255610A JP2005077618A JP2005077618A JP2006255610A JP 2006255610 A JP2006255610 A JP 2006255610A JP 2005077618 A JP2005077618 A JP 2005077618A JP 2005077618 A JP2005077618 A JP 2005077618A JP 2006255610 A JP2006255610 A JP 2006255610A
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particles
noble metal
particle
exhaust gas
base material
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Hiroto Kikuchi
博人 菊地
Toru Sekiba
徹 関場
Katsuo Suga
克雄 菅
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Nissan Motor Co Ltd
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Abstract

<P>PROBLEM TO BE SOLVED: To provide a catalyst for cleaning exhaust gas, which is manufactured by a simple process in a short time at a low cost and to provide a method for manufacturing the catalyst for cleaning exhaust gas. <P>SOLUTION: The catalyst 1 for cleaning exhaust gas comprises: a noble metal particle 3; an involving particle group 7 consisting of a plurality of involving particles 5 for surrounding the periphery of the noble metal particle 3; and a base material 9 on which the noble metal particle 3 involved by the involving particle group 7 is deposited. The method for manufacturing the catalyst for cleaning exhaust gas comprises the steps of: producing the noble metal particle 3 and the involving particle group 7 consisting of the plurality of involving particles 5 for surrounding the periphery of the noble metal particle 3 by using a method for vaporizing in a gas; and depositing the noble metal particle 3 surrounded by the involving particle group 7 on the base material 9. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

本発明は、排気ガス浄化用触媒及びその製造方法に関する。 The present invention relates to an exhaust gas purification catalyst and a method for producing the same.

近年、自動車用の排出ガス規制は益々厳しくなる一方であり、排気ガス浄化用触媒には、排ガス中に含まれる有害な成分、例えば、未燃焼炭化水素（ＨＣ）や一酸化炭素（ＣＯ）の浄化をより高効率で行なうことが要求されている。排ガス浄化触媒は、アルミナ等の基材の表面に貴金属粒子を担持したものであり、排ガス中に含まれる有害な成分、例えば未燃焼炭化水素（ＨＣ）や一酸化炭素（ＣＯ）を貴金属粒子で酸化し、無害な成分である水やガスに変換する。そして、一般に、触媒の浄化性能は貴金属粒子の表面積が大きいほど向上するため、貴金属粒子の粒径を小さくすることにより、貴金属粒子の表面積を大きくして表面エネルギーを増大させることが行われている。   In recent years, exhaust gas regulations for automobiles are becoming more and more stringent, and exhaust gas purification catalysts include harmful components contained in exhaust gas, such as unburned hydrocarbons (HC) and carbon monoxide (CO). There is a demand for more efficient purification. An exhaust gas purification catalyst is a catalyst in which noble metal particles are supported on the surface of a substrate such as alumina, and harmful components contained in the exhaust gas, such as unburned hydrocarbon (HC) and carbon monoxide (CO), are used as noble metal particles. Oxidizes and converts to water and gas which are harmless components. And generally, since the purification performance of the catalyst is improved as the surface area of the noble metal particles is increased, the surface energy is increased by increasing the surface area of the noble metal particles by reducing the particle size of the noble metal particles. .

ここで、排気ガス浄化用触媒の貴金属粒子は、初期段階では数ｎｍ以下の超微粒子状態になっている。しかし、高温の酸化雰囲気中に排気ガス浄化用触媒が晒されているうちに、貴金属粒子の表面が酸化され、近傍の貴金属粒子同士が合体して数十ｎｍに粗大化してしまい、貴金属粒子の表面積が低下して有害物質の浄化率が低下するという問題がある。   Here, the noble metal particles of the exhaust gas purifying catalyst are in an ultrafine particle state of several nm or less in the initial stage. However, while the exhaust gas purification catalyst is exposed to a high-temperature oxidizing atmosphere, the surface of the noble metal particles is oxidized, and the noble metal particles in the vicinity coalesce and become coarse to several tens of nanometers. There is a problem in that the surface area decreases and the purification rate of harmful substances decreases.

この貴金属粒子の粗大化による表面積低下を防止すべく、逆ミセル法などのような表面積の大きい貴金属粒子の製法に関する開発が進んでいる。この逆ミセル法とは、まず、有機溶媒中に界面活性剤と触媒活性な成分（例えば、貴金属元素）を含む水溶液とを混合する。その後、有機溶媒中に、貴金属を含む水溶液を含有する逆ミセルが形成されたエマルジョン溶液を調製し、貴金属を沈殿させた後、還元又は不溶化し、逆ミセルの中で微粒化した貴金属を析出させる方法である。   In order to prevent a decrease in the surface area due to the coarsening of the noble metal particles, development relating to a method for producing noble metal particles having a large surface area such as a reverse micelle method has been advanced. In the reverse micelle method, first, an aqueous solution containing a surfactant and a catalytically active component (for example, a noble metal element) is mixed in an organic solvent. Thereafter, an emulsion solution in which reverse micelles containing an aqueous solution containing a noble metal are formed in an organic solvent is prepared, and after precious metal is precipitated, it is reduced or insolubilized to precipitate the precious metal atomized in the reverse micelle. Is the method.

また、特開２０００−４２４１１号公報には、エマルジョン溶液調製工程において、逆ミセルの中に酸素吸蔵作用を有する元素を含有させて触媒を製造する方法が開示されている。この逆ミセル法では、エマルジョン溶液中に含まれる逆ミセルの中で、基材に触媒活性な成分を担持した後、逆ミセルを崩壊させて、得られた沈殿物を濾過、乾燥、粉砕、焼成する各工程を経て触媒としている。本製造方法を用いて製造された触媒は、基材に酸素吸蔵作用を有する元素を担持できるだけではなく、基材の最表面及び基材中に形成された孔部表面にも触媒活性な成分を担持するため、触媒の活性を高めることができる。
特開２０００−４２４１１号公報 Japanese Patent Application Laid-Open No. 2000-42411 discloses a method for producing a catalyst by incorporating an element having an oxygen storage function into reverse micelles in an emulsion solution preparation step. In this reverse micelle method, after supporting the catalytically active component on the base material in the reverse micelle contained in the emulsion solution, the reverse micelle is disintegrated, and the resulting precipitate is filtered, dried, pulverized, and calcined. Each step is used as a catalyst. The catalyst produced using this production method not only supports an element having an oxygen storage effect on the base material, but also has a catalytically active component on the outermost surface of the base material and the surface of the pores formed in the base material. Since it is supported, the activity of the catalyst can be increased.
JP 2000-42411 A

しかしながら、前述した逆ミセル法では、逆ミセルが形成されたエマルジョン溶液を噴霧焼成して触媒を製造するため、製造工程の複雑化、製造時間の増大、製造コストの上昇を招くという問題があった。   However, in the reverse micelle method described above, since the catalyst is manufactured by spray firing the emulsion solution in which the reverse micelle is formed, there is a problem in that the manufacturing process is complicated, the manufacturing time is increased, and the manufacturing cost is increased. .

そこで、本発明は、製造工程が簡易で、製造時間が短く、製造コストが安価な排気ガス浄化用触媒及びその製造方法を提供することを目的とする。   SUMMARY OF THE INVENTION An object of the present invention is to provide an exhaust gas purifying catalyst having a simple manufacturing process, a short manufacturing time, and a low manufacturing cost, and a manufacturing method thereof.

前記目的を達成するために、本発明に係る排気ガス浄化用触媒は、貴金属粒子と、該貴金属粒子の周囲を取り囲む複数の内包粒子からなる内包粒子群と、該内包粒子群に内包された貴金属粒子を担持する基材とを含んでなる。   In order to achieve the above object, an exhaust gas purifying catalyst according to the present invention includes a noble metal particle, an inclusion particle group including a plurality of inclusion particles surrounding the noble metal particle, and a noble metal included in the inclusion particle group. And a substrate carrying particles.

また、本発明に係る排気ガス浄化用触媒の製造方法は、貴金属粒子と該貴金属粒子の周囲を取り囲む複数の内包粒子からなる内包粒子群とを、ガス中蒸発法を用いて生成する工程、及び前記内包粒子群で取り囲まれた貴金属粒子を基材に担持する工程を含んでなる。   Further, the method for producing an exhaust gas purifying catalyst according to the present invention includes a step of generating noble metal particles and an inclusion particle group composed of a plurality of inclusion particles surrounding the noble metal particles using a gas evaporation method, and And a step of supporting a noble metal particle surrounded by the inclusion particle group on a base material.

本発明に係る排気ガス浄化用触媒によれば、貴金属粒子の周囲を内包粒子群によって取り囲んでいるため、担体上における貴金属粒子の移動による凝集化を抑制することができ、貴金属の表面積を大きい状態に保持することができる。   According to the exhaust gas purifying catalyst of the present invention, the surroundings of the noble metal particles are surrounded by the inclusion particle group, so that aggregation due to movement of the noble metal particles on the carrier can be suppressed, and the surface area of the noble metal is increased. Can be held in.

また、本発明に係る排気ガス浄化用触媒の製造方法によれば、ガス中蒸発法を用いて貴金属粒子の周囲を内包粒子群によって覆うことができるため、製造工程が簡易で、製造時間が短く、製造コストが安価な排気ガス浄化用触媒を得ることができる。   Further, according to the method for producing an exhaust gas purifying catalyst according to the present invention, the surroundings of the noble metal particles can be covered with the encapsulated particle group by using the gas evaporation method, so that the production process is simple and the production time is short. Thus, an exhaust gas purifying catalyst having a low production cost can be obtained.

以下、本発明の実施形態を図面に基づき説明する。   Hereinafter, embodiments of the present invention will be described with reference to the drawings.

図１は、本発明に係る排気ガス浄化用触媒の表面の状態を拡大して示す概略図である。   FIG. 1 is an enlarged schematic view showing the state of the surface of an exhaust gas purifying catalyst according to the present invention.

この図１に示すように、本発明に係る排気ガス浄化用触媒１は、排気ガスに接触して排気ガスを浄化させる活性金属である貴金属粒子３と、該貴金属粒子３の外周を取り囲む複数の内包粒子５からなる内包粒子群７と、これらの内包粒子群７によって内包された貴金属粒子１を担持する基材９とを備えている。なお、図１は触媒の構成が判りやすくなるように簡略化したため、貴金属粒子３が基材９から離れているように示されているが、実際には、貴金属粒子３は基材９に直接に担持されている。   As shown in FIG. 1, an exhaust gas purifying catalyst 1 according to the present invention includes a plurality of noble metal particles 3 that are active metals that contact exhaust gas and purify the exhaust gas, and a plurality of surroundings of the noble metal particles 3. An encapsulated particle group 7 composed of encapsulated particles 5 and a base material 9 supporting the noble metal particles 1 encapsulated by these encapsulated particle groups 7 are provided. FIG. 1 is simplified so that the structure of the catalyst can be easily understood, so that the noble metal particles 3 are shown as being separated from the base material 9. It is carried on.

このように、本発明に係る排気ガス浄化用触媒においては、貴金属粒子３の周囲を内包粒子群７によって取り囲んでいるため、基材９上における貴金属粒子３の移動による凝集化を抑制することができ、貴金属粒子３の表面積を大きい状態に保持することができる。   Thus, in the exhaust gas purifying catalyst according to the present invention, since the periphery of the noble metal particles 3 is surrounded by the inclusion particle group 7, it is possible to suppress aggregation due to the movement of the noble metal particles 3 on the substrate 9. And the surface area of the noble metal particles 3 can be kept large.

貴金属粒子３の生成に用いる貴金属粒子用原料は、白金（Ｐｔ）、パラジウム（Ｐｄ）、ロジウム（Ｒｈ）、イリジウム（Ｉｒ）、金（Ａｕ）、銀（Ａｇ）、ルテニウム（Ｒｕ）の群から選択される一又は二以上の金属が好ましい。   The raw material for the noble metal particles used for producing the noble metal particles 3 is selected from the group consisting of platinum (Pt), palladium (Pd), rhodium (Rh), iridium (Ir), gold (Au), silver (Ag), and ruthenium (Ru). One or more metals selected are preferred.

また、これらの貴金属粒子３の粒径は、１〜５ｎｍが好ましく、後述するガス中蒸発法を用いて生成することができる。   Moreover, the particle diameter of these noble metal particles 3 is preferably 1 to 5 nm, and can be generated using a gas evaporation method described later.

内包粒子５の生成に用いる内包粒子用原料は、アルミニウム（Ａｌ）、セリウム（Ｃｅ）、ジルコニウム（Ｚｒ）、マンガン（Ｍｎ）、コバルト（Ｃｏ）、鉄（Ｆｅ）、ニッケル（Ｎｉ）、スズ（Ｓｎ）、チタン（Ｔｉ）、モリブデン（Ｍｏ）、イットリウム（Ｙ）、ランタン（Ｌａ）、ネオジム（Ｎｄ）の群から選択される一又は二以上の金属又はその金属の酸化物が好ましい。   The raw materials for the encapsulated particles used to produce the encapsulated particles 5 are aluminum (Al), cerium (Ce), zirconium (Zr), manganese (Mn), cobalt (Co), iron (Fe), nickel (Ni), tin ( One or more metals selected from the group consisting of Sn), titanium (Ti), molybdenum (Mo), yttrium (Y), lanthanum (La), and neodymium (Nd), or oxides of the metals are preferred.

これらの内包粒子５も、ガス中蒸発法を用いて生成することができる。即ち、前述した内包粒子用原料をガス中蒸発法用装置中に収容し、該装ガス中蒸発法用装置内を真空状態とし、内包粒子用原料を蒸発及び凝縮させることにより、複数の内包粒子５からなる内包粒子群７を生成することができる。このように、貴金属粒子３及び内包粒子５をガス中蒸発法を用いて生成することによって、従来の逆ミセル法の場合よりも、大幅に製造工程の簡素化及び製造時間の短縮を図ることができる。   These encapsulated particles 5 can also be generated using a gas evaporation method. That is, the above-mentioned encapsulated particle raw material is accommodated in a gas evaporation method apparatus, the inside of the gas evaporation method apparatus is evacuated, and the encapsulated particle raw material is evaporated and condensed. An encapsulated particle group 7 consisting of 5 can be generated. Thus, by producing the noble metal particles 3 and the encapsulated particles 5 by using the gas evaporation method, it is possible to greatly simplify the manufacturing process and shorten the manufacturing time as compared with the conventional reverse micelle method. it can.

また、内包粒子群７は、内包粒子５が複数集合したクラスターに形成し、このクラスターの状態で前記貴金属粒子３を取り囲むようにすることが好ましい。このように、内包粒子群７をクラスター状に形成することによって、貴金属粒子３を効率的に覆うことができ、ひいては貴金属粒子３同士の凝集を好適に抑制することができる。   The inclusion particle group 7 is preferably formed in a cluster in which a plurality of inclusion particles 5 are aggregated, and surrounds the noble metal particles 3 in this cluster state. In this way, by forming the encapsulated particle group 7 in a cluster shape, the noble metal particles 3 can be efficiently covered, and as a result, aggregation of the noble metal particles 3 can be suitably suppressed.

なお、これらの内包粒子５の粒径は、０ｎｍを超えて４０ｎｍ以下が好ましい。内包粒子５の粒径が４０ｎｍより大きい場合は、貴金属粒子３へのガス拡散が低下するため、排気ガス浄化効果も低下する。   The particle size of these encapsulated particles 5 is preferably more than 0 nm and 40 nm or less. When the particle size of the encapsulated particles 5 is larger than 40 nm, gas diffusion to the noble metal particles 3 is reduced, and the exhaust gas purification effect is also reduced.

基材９は、アルミナ(Ａｌ２Ｏ３)、セリア（ＣｅＯ２）、ジルコニア（ＺｒＯ２）、マグネシア（ＭｇＯ）、シリカ（ＳｉＯ２）、ＴｉＯ２、シリカアルミナ、酸化バナジウム及び酸化タングステンの群から選択される一又は二以上の元素からなる多孔質酸化物を好適に用いることができる。 The substrate 9 is made of alumina (Al 2 O 3 ), ceria (CeO 2 ), zirconia (ZrO 2 ), magnesia (MgO), silica (SiO 2 ), TiO 2 , silica alumina, vanadium oxide, and tungsten oxide. A porous oxide composed of one or more selected elements can be suitably used.

図２は、ガス中蒸発法用装置の概要を示す概略図である。   FIG. 2 is a schematic view showing an outline of an apparatus for gas evaporation.

このガス中蒸発法用装置１１は、外気から遮蔽された密閉性を有する真空槽１３と、該真空槽１３の内部に収容された抵抗加熱ボード１５，１７及び冷却手段２９とを備えている。   This in-gas evaporation method apparatus 11 includes a vacuum chamber 13 having a sealing property shielded from outside air, and resistance heating boards 15 and 17 and a cooling means 29 accommodated in the vacuum chamber 13.

前記真空槽１３の下端部には、開閉自在に構成された酸素（Ｏ２）ガス導入口１９及びヘリウム（Ｈｅ）ガス導入口２１が設けられている。また、真空槽１３の高さ方向中央部には、試料投入口２３及び試料回収口２５が配設されており、真空槽１３の上部には、排気口２７が設けられている。 An oxygen (O 2 ) gas introduction port 19 and a helium (He) gas introduction port 21 configured to be openable and closable are provided at the lower end of the vacuum chamber 13. In addition, a sample insertion port 23 and a sample recovery port 25 are provided at the center of the vacuum chamber 13 in the height direction, and an exhaust port 27 is provided at the top of the vacuum chamber 13.

そして、抵抗加熱ボード１５，１７は、上下に間隔をおいて２つ配置されており、それぞれの抵抗加熱ボード１５，１７の上面は、湾曲して凹部に形成されている。   And two resistance heating boards 15 and 17 are arrange | positioned at intervals up and down, and the upper surface of each resistance heating board 15 and 17 is curving and formed in the recessed part.

さらに、冷却手段２９は、液体窒素（Ｎ２）を用いて冷却するものであり、液体窒素導入口３１を真空槽１３を貫通して上方に延設し、この液体窒素導入口３１に冷却板３３を接続すると共に、該冷却板３３の下部に試料回収皿３５を配置している。 Further, the cooling means 29 is cooled by using liquid nitrogen (N 2 ), and the liquid nitrogen inlet 31 extends upward through the vacuum chamber 13, and a cooling plate is connected to the liquid nitrogen inlet 31. 33 is connected, and a sample collection tray 35 is disposed below the cooling plate 33.

次に、前記ガス中蒸発法用装置１１を用いて排気ガス浄化用触媒１を製造する方法を説明する。   Next, a method for producing the exhaust gas purifying catalyst 1 using the in-gas evaporation method apparatus 11 will be described.

図３は本発明の実施形態による排気ガス浄化用触媒の製造手順を示す概略図であり、このうちの（ａ）は貴金属粒子を示す概略図、（ｂ）は貴金属粒子の周囲を内包粒子群によって取り囲んだ状態を示す概略図、（ｃ）は内包粒子群によって取り囲んだ貴金属粒子を基材に担持した排気ガス浄化用触媒を示す概略図である。   FIG. 3 is a schematic view showing a manufacturing procedure of an exhaust gas purifying catalyst according to an embodiment of the present invention, in which (a) is a schematic view showing noble metal particles, and (b) is a group of encapsulated particles around the noble metal particles. FIG. 3C is a schematic diagram showing an exhaust gas purification catalyst in which noble metal particles surrounded by inclusion particles are supported on a base material.

排気ガス浄化用触媒１の製造工程は、貴金属粒子３をガス中蒸発法で生成する貴金属粒子生成工程と、複数の内包粒子５からなる内包粒子群７をガス中蒸発法で生成しつつ、該内包粒子群７によって前記貴金属粒子３の周囲を取り囲む内包粒子群生成工程と、この内包粒子群７で取り囲まれた貴金属粒子３を基材９に担持する担持工程とを含んでいる。   The manufacturing process of the exhaust gas purifying catalyst 1 includes a noble metal particle generating step for generating the noble metal particles 3 by a gas evaporation method, and an inclusion particle group 7 composed of a plurality of inclusion particles 5 by the gas evaporation method. An encapsulated particle group generating step for enclosing the periphery of the noble metal particle 3 with the encapsulated particle group 7 and a supporting step for supporting the noble metal particle 3 surrounded by the encapsulated particle group 7 on the base material 9 are included.

貴金属粒子３は、ガス中蒸発法を用いて生成することができる。低圧のアルゴン（Ａｒ）やヘリウム（Ｈｅ）等の不活性ガス中で貴金属粒子用原料を溶解及び蒸発させることにより蒸発金属が生成され、該蒸発金属の原子とガス分子との衝突、及び蒸発金属の原子同士の衝突が起こり、金属原子同士が合体して貴金属粒子３が生成される。具体的には、前記真空蒸着装置１１内に貴金属粒子用原料と不活性ガスを入れて、真空状態とすることにより、貴金属粒子用原料を蒸発及び凝縮させて貴金属粒子３を生成することができる。   The noble metal particles 3 can be generated using an in-gas evaporation method. Evaporated metal is generated by dissolving and evaporating the raw material for noble metal particles in an inert gas such as low-pressure argon (Ar) or helium (He), and collisions between atoms of the evaporated metal and gas molecules, and evaporated metal The atoms collide with each other, and the metal atoms coalesce to generate noble metal particles 3. Specifically, the noble metal particles 3 can be generated by evaporating and condensing the noble metal particles raw material by putting the noble metal particles raw material and the inert gas into the vacuum vapor deposition apparatus 11 and bringing them into a vacuum state. .

また、内包粒子５及び内包粒子群７もガス中蒸発法を用いて生成することができる。この場合も、前記貴金属粒子３と同様に、低圧の不活性ガス中で原料を溶解及び蒸発させることにより、図３（ｂ）に示すように、前記貴金属粒子３の周囲を取り囲みながら複数の内包粒子５からなる内包粒子群７が成長する。即ち、貴金属粒子３を核として、該貴金属粒子３の周囲に複数の内包粒子５が成長するため、貴金属粒子３の周囲がクラスター状の内包粒子群７によって覆われる。   Further, the encapsulated particles 5 and the encapsulated particle group 7 can also be generated using a gas evaporation method. Also in this case, as in the case of the noble metal particles 3, by dissolving and evaporating the raw material in a low-pressure inert gas, a plurality of inclusions are surrounded while surrounding the noble metal particles 3 as shown in FIG. An encapsulated particle group 7 composed of the particles 5 grows. That is, since the plurality of inclusion particles 5 grow around the noble metal particles 3 with the noble metal particles 3 as nuclei, the periphery of the noble metal particles 3 is covered with the cluster-like inclusion particle group 7.

この場合も、具体的には、前記ガス中蒸発法用装置１１内に内包粒子用原料と不活性ガスを入れて、真空状態とすることにより、貴金属粒子用原料を蒸発及び凝縮させて貴金属粒子３を生成することができる。   Also in this case, specifically, the encapsulated particle raw material and the inert gas are put into the gas evaporation method apparatus 11 and are brought into a vacuum state to evaporate and condense the noble metal particle raw material, thereby precious metal particles. 3 can be generated.

このように、貴金属粒子３を核として、該貴金属粒子３の周囲に複数の内包粒子５を成長させる生成方法を用いることによって、貴金属粒子３の外周に効率的に複数の内包粒子５を生成させることができる。   As described above, by using the generation method in which the plurality of inclusion particles 5 are grown around the noble metal particles 3 using the noble metal particles 3 as nuclei, the plurality of inclusion particles 5 are efficiently generated on the outer periphery of the noble metal particles 3. be able to.

担持工程は、図３（ｃ）に示すように、その周囲を内包粒子群７によって覆われている触媒活性な成分である貴金属粒子３を基材９に付着させる工程である。具体的には、基材９を形成する多孔質酸化物と、内包粒子群７によって覆われた貴金属粒子３とを混合して、貴金属粒子３を分散させたスラリを作成し、このスラリを担体（支持体）に塗布して乾燥させる。   As shown in FIG. 3 (c), the supporting step is a step in which the noble metal particles 3, which are catalytically active components whose periphery is covered with the inclusion particle group 7, are attached to the base material 9. Specifically, the porous oxide forming the base material 9 and the noble metal particles 3 covered with the inclusion particle group 7 are mixed to prepare a slurry in which the noble metal particles 3 are dispersed, and this slurry is used as a carrier. It is applied to (support) and dried.

次いで、実施例を用いて、本発明の実施形態を更に具体的に説明する。   Next, embodiments of the present invention will be described more specifically with reference to examples.

まず、その外周が内包粒子群７で覆われた貴金属粒子３（Ｐｔ粒子Ａ〜Ｉ）の製造方法を説明する。なお、Ｐｔ粒子の粒径は１ｎｍ〜５ｎｍであり、内包粒子５の粒径は５ｎｍ〜４０ｎｍである。   First, the manufacturing method of the noble metal particle 3 (Pt particles A to I) whose outer periphery is covered with the inclusion particle group 7 will be described. The Pt particles have a particle size of 1 nm to 5 nm, and the encapsulated particles 5 have a particle size of 5 nm to 40 nm.

Ｐｔ粒子Ａの調製（Ｐｔ粒子径：１ｎｍ、ＣｅＯ２粒子径：５ｎｍ）
前述した構成を有する図２のガス中蒸発法用装置１１を用いたガス中蒸発法により、粒径が１ｎｍ〜５ｎｍであるＰｔ粒子（貴金属粒子）と、該Ｐｔ粒子を内包する、粒径が５ｎｍ〜４０ｎｍのＣｅＯ２粒子（内包粒子）とを調製した。 Preparation of Pt particles A (Pt particle size: 1 nm, CeO 2 particle size: 5 nm)
By the gas evaporation method using the gas evaporation method apparatus 11 of FIG. 2 having the above-described configuration, the Pt particles (noble metal particles) having a particle size of 1 nm to 5 nm and the particle size including the Pt particles are 5 nm to 40 nm of CeO 2 particles (encapsulated particles) were prepared.

まず、図２に示す真空槽１３内の下側抵抗加熱ボード（蒸発源）１５にＰｔ、上側抵抗加熱ボード（蒸発源）１７にＣｅを各々載置した。なお、Ｐｔを載置した下側抵抗加熱ボード１５は、Ｃｅを載置した上側抵抗加熱ボード１７よりも低い位置に配置されており、下側抵抗加熱ボード１５と上側抵抗加熱ボード１７との高さの差違を距離Ｘに設定した。   First, Pt was placed on the lower resistance heating board (evaporation source) 15 in the vacuum chamber 13 shown in FIG. 2, and Ce was placed on the upper resistance heating board (evaporation source) 17, respectively. The lower resistance heating board 15 on which Pt is placed is disposed at a lower position than the upper resistance heating board 17 on which Ce is placed. The difference was set to the distance X.

次に、真空槽１３内の圧力を５．０×１０−８Ｔｏｒｒになるまで図外の真空ポンプにより排気した後、真空槽１３内に酸素ガスとヘリウムガスとを導入して1Ｔｏｒｒ付近とした。このときの酸素分圧は４０ｍｏｌ％であり、真空ポンプを作動させて一定のガス圧を保ち、液体窒素導入口３１を介して液体窒素を導入し、冷却板３３を冷却した。なお、上側抵抗加熱ボード１７と冷却板３３の高さの差違を距離Ｙに設定した。 Next, after evacuating with a vacuum pump (not shown) until the pressure in the vacuum chamber 13 becomes 5.0 × 10 −8 Torr, oxygen gas and helium gas are introduced into the vacuum chamber 13 to make it around 1 Torr. . The oxygen partial pressure at this time was 40 mol%, the vacuum pump was operated to maintain a constant gas pressure, liquid nitrogen was introduced through the liquid nitrogen inlet 31, and the cooling plate 33 was cooled. The difference in height between the upper resistance heating board 17 and the cooling plate 33 was set to the distance Y.

その後、下側抵抗加熱ボード１５と上側抵抗加熱ボード１７でＰｔとＣｅとを同時に蒸発させると共に、酸素ガス導入口１９を介して真空槽１３内に導入した酸素によりＣｅを酸化してＣｅＯ２を生成した。 Thereafter, Pt and Ce are evaporated at the same time by the lower resistance heating board 15 and the upper resistance heating board 17, and Ce is oxidized by oxygen introduced into the vacuum chamber 13 through the oxygen gas inlet 19 to obtain CeO 2 . Generated.

下側抵抗加熱ボード１５にセットされたＰｔはＣｅよりも先に凝縮してＰｔ粒子となり、このＰｔ粒子の周囲を取り囲むように前記ＣｅＯ２粒子が複数生成された。このＰｔ粒子の周囲をＣｅＯ２粒子によって被覆されたＰｔ粒子は冷却板３３に付着し、これを掻き落として、Ｐｔ粒子Ａを得た。 Pt set on the lower resistance heating board 15 was condensed before Ce to become Pt particles, and a plurality of the CeO 2 particles were generated so as to surround the periphery of the Pt particles. The Pt particles having the Pt particles coated with CeO 2 particles adhered to the cooling plate 33 and scraped off to obtain Pt particles A.

このＰｔ粒子ＡをＴＥＭで観察したところ、Ｐｔ粒子の粒径は１ｎｍ程度であり、ＣｅＯ２の粒子は５ｎｍ程度であった。このＰｔ粒子ＡをＩＣＰ分析したところ、Ｐｔが３．０％含有されていた。 When this Pt particle A was observed by TEM, the particle size of the Pt particle was about 1 nm, and the particle of CeO 2 was about 5 nm. When this Pt particle A was analyzed by ICP, it contained 3.0% of Pt.

Ｐｔ粒子Ｂの調製（Ｐｔ粒子径：１ｎｍ、ＣｅＯ２粒子径：７ｎｍ）
真空槽１３内の下側抵抗加熱ボード１５にＰｔ、上側抵抗加熱ボード１７にＣｅを各々セットした。なお、Ｐｔをセットした下側抵抗加熱ボード１５は、Ｃｅをセットした上側抵抗加熱ボード１７よりも、距離Ｘだけ低い位置に設定した。 Preparation of Pt particles B (Pt particle size: 1 nm, CeO 2 particle size: 7 nm)
Pt was set on the lower resistance heating board 15 in the vacuum chamber 13, and Ce was set on the upper resistance heating board 17. The lower resistance heating board 15 on which Pt was set was set at a position lower by the distance X than the upper resistance heating board 17 on which Ce was set.

次に、図外の真空ポンプを用いて真空槽１３内の空気を排気して圧力を5.0×10-８Ｔｏｒｒにまで低下させた後、真空槽１３内に酸素ガスとヘリウムガスとを導入して圧力を1Ｔｏｒｒ付近とした。このときの酸素分圧は４０ｍｏｌ％であり、真空ポンプを作動させて一定のガス圧を保ち、液体窒素導入口３１を介して真空槽１３の内部に液体窒素を導入し、冷却板３３を冷却した。 Next, after evacuating the air in the vacuum chamber 13 using a vacuum pump (not shown) and reducing the pressure to 5.0 × 10 −8 Torr, oxygen gas and helium gas are introduced into the vacuum chamber 13. The pressure was about 1 Torr. The oxygen partial pressure at this time is 40 mol%, the vacuum pump is operated to maintain a constant gas pressure, liquid nitrogen is introduced into the vacuum chamber 13 through the liquid nitrogen inlet 31, and the cooling plate 33 is cooled. did.

上側抵抗加熱ボード１７と冷却板３３の高さの差違を距離１．５Ｙに設定した。その後、下側抵抗加熱ボード１５のＰｔと上側抵抗加熱ボード１７のＣｅとを同時に蒸発させると共に、真空槽１３内に導入した酸素によりＣｅを酸化してＣｅＯ２を生成した。 The difference in height between the upper resistance heating board 17 and the cooling plate 33 was set to a distance of 1.5Y. Thereafter, Pt of the lower resistance heating board 15 and Ce of the upper resistance heating board 17 were simultaneously evaporated, and Ce was oxidized by oxygen introduced into the vacuum chamber 13 to generate CeO 2 .

下側抵抗加熱ボード１５にセットされたＰｔはＣｅよりも先に凝縮してＰｔ粒子となり、このＰｔ粒子の周囲を取り囲むように前記ＣｅＯ２粒子が複数生成された。このＰｔ粒子の周囲をＣｅＯ２粒子によって被覆されたＰｔ粒子は冷却板３３に付着し、これを掻き落として、Ｐｔ粒子Ｂを得た。 Pt set on the lower resistance heating board 15 was condensed before Ce to become Pt particles, and a plurality of the CeO 2 particles were generated so as to surround the periphery of the Pt particles. The Pt particles having the Pt particles coated with CeO 2 particles adhered to the cooling plate 33 and scraped off to obtain Pt particles B.

このＰｔ粒子ＢをＴＥＭで観察したところ、Ｐｔ粒子の粒径は１ｎｍ程度であり、ＣｅＯ２の粒子は7ｎｍ程度であった。このＰｔ粒子ＢをＩＣＰ分析したところ、Ｐｔが1.1％含有されていた。 When the Pt particles B were observed with a TEM, the Pt particles had a particle size of about 1 nm and the CeO 2 particles had a size of about 7 nm. When this Pt particle B was analyzed by ICP, it contained 1.1% of Pt.

Ｐｔ粒子Ｃの調製（Ｐｔ粒子径：２ｎｍ、ＣｅＯ２粒子径：１０ｎｍ）
Ｐｔをセットした下側抵抗加熱ボード１５は、Ｃｅをセットした上側抵抗加熱ボード１７よりも、距離１．５Ｘだけ低い位置に設定した。また、上側抵抗加熱ボード１７と冷却板３３の高さの差違を距離２Ｙに設定した。その他の条件は、全てＰｔ粒子Ａの調製の場合と同様にしてＰｔ粒子Ｃを生成した。このＰｔ粒子ＣをＴＥＭで観察したところ、Ｐｔ粒子の粒径は２ｎｍ程度であり、ＣｅＯ２の粒子は１０ｎｍ程度であった。このＰｔ粒子ＣをＩＣＰ分析したところ、Ｐｔが３．０％含有されていた。 Preparation of Pt particles C (Pt particle size: 2 nm, CeO 2 particle size: 10 nm)
The lower resistance heating board 15 on which Pt was set was set at a position lower by a distance 1.5X than the upper resistance heating board 17 on which Ce was set. Further, the difference in height between the upper resistance heating board 17 and the cooling plate 33 was set to the distance 2Y. Other conditions were the same as in the preparation of Pt particles A, and Pt particles C were generated. When the Pt particles C were observed with a TEM, the Pt particles had a particle size of about 2 nm and the CeO 2 particles had a size of about 10 nm. When this Pt particle C was analyzed by ICP, it contained 3.0% of Pt.

Ｐｔ粒子Ｄの調製（Ｐｔ粒子径：２ｎｍ、ＣｅＯ２粒子径：１５ｎｍ）
Ｐｔをセットした下側抵抗加熱ボード１５は、Ｃｅをセットした上側抵抗加熱ボード１７よりも、距離１．５Ｘだけ低い位置に設定した。また、上側抵抗加熱ボード１７と冷却板３３の高さの差違を距離３Ｙに設定した。その他の条件は、全てＰｔ粒子Ａ の調製の場合と同様にしてＰｔ粒子内包ＣｅＯ２粒子Ｄを生成した。 Preparation of Pt particles D (Pt particle size: 2 nm, CeO 2 particle size: 15 nm)
The lower resistance heating board 15 on which Pt was set was set at a position lower by a distance 1.5X than the upper resistance heating board 17 on which Ce was set. Further, the difference in height between the upper resistance heating board 17 and the cooling plate 33 was set to the distance 3Y. Other conditions were the same as in the preparation of Pt particles A 2, and Pt particle-containing CeO 2 particles D were generated.

このＰｔ粒子ＤをＴＥＭで観察したところ、Ｐｔ粒子の粒径は２ｎｍ程度であり、ＣｅＯ２の粒子は１５ｎｍ程度であった。このＰｔ粒子ＤをＩＣＰ分析したところ、Ｐｔが０．９％含有されていた。 When this Pt particle D was observed by TEM, the particle size of the Pt particle was about 2 nm, and the particle of CeO 2 was about 15 nm. As a result of ICP analysis of the Pt particles D, 0.9% Pt was contained.

Ｐｔ粒子Ｅの調製（Ｐｔ粒子径：３ｎｍ、ＣｅＯ２粒子径：２０ｎｍ）
Ｐｔをセットした下側抵抗加熱ボード１５は、Ｃｅをセットした上側抵抗加熱ボード１７よりも、距離２Ｘだけ低い位置に設定した。また、上側抵抗加熱ボード１７と冷却板３３の高さの差違を距離４Ｙに設定した。その他の条件は、全てＰｔ粒子Ａ の調製の場合と同様にして生成した。 Preparation of Pt particles E (Pt particle size: 3 nm, CeO 2 particle size: 20 nm)
The lower resistance heating board 15 on which Pt was set was set at a position lower by a distance 2X than the upper resistance heating board 17 on which Ce was set. Further, the difference in height between the upper resistance heating board 17 and the cooling plate 33 was set to the distance 4Y. Other conditions were all generated in the same manner as in the preparation of Pt particles A 2.

このＰｔ粒子ＥをＴＥＭで観察したところ、Ｐｔ粒子の粒径は3ｎｍ程度であり、ＣｅＯ２の粒子は２０ｎｍ程度であった。このＰｔ粒子ＥをＩＣＰ分析したところ、Ｐｔが１．３％含有されていた。 When this Pt particle E was observed with a TEM, the particle size of the Pt particle was about 3 nm, and the particle of CeO 2 was about 20 nm. When this Pt particle E was analyzed by ICP, it contained 1.3% of Pt.

Ｐｔ粒子Ｆの調製（Ｐｔ粒子径：３ｎｍ、ＣｅＯ２粒子径：２５ｎｍ）
Ｐｔをセットした下側抵抗加熱ボード１５は、Ｃｅをセットした上側抵抗加熱ボード１７よりも、距離２Ｘだけ低い位置に設定した。また、上側抵抗加熱ボード１７と冷却板３３の高さの差違を距離５Ｙに設定した。その他の条件は、全てＰｔ粒子Ａ の調製の場合と同様にしてＰｔ粒子Ｆを生成した。 Preparation of Pt particles F (Pt particle size: 3 nm, CeO 2 particle size: 25 nm)
The lower resistance heating board 15 on which Pt was set was set at a position lower by a distance 2X than the upper resistance heating board 17 on which Ce was set. Further, the difference in height between the upper resistance heating board 17 and the cooling plate 33 was set to the distance 5Y. All other conditions were the same as in the preparation of Pt particles A to produce Pt particles F.

このＰｔ粒子ＦをＴＥＭで観察したところ、Ｐｔ粒子の粒径は３ｎｍ程度であり、ＣｅＯ２の粒子は２５ｎｍ程度であった。このＰｔ粒子ＦをＩＣＰ分析したところ、Ｐｔが０．６６％含有されていた。 When the Pt particles F were observed with a TEM, the Pt particles had a particle size of about 3 nm, and the CeO 2 particles had a size of about 25 nm. When this Pt particle F was analyzed by ICP, it was found to contain 0.66% Pt.

Ｐｔ粒子Ｇの調製（Ｐｔ粒子径：５ｎｍ、ＣｅＯ２粒子径：３０ｎｍ）
Ｐｔをセットした下側抵抗加熱ボード１５は、Ｃｅをセットした上側抵抗加熱ボード１７よりも、距離３Ｘだけ低い位置に設定した。また、上側抵抗加熱ボード１７と冷却板３３の高さの差違を距離６Ｙに設定した。その他の条件は、全てＰｔ粒子Ａ の調製の場合と同様にしてＰｔ粒子Ｇを生成した。 Preparation of Pt particles G (Pt particle size: 5 nm, CeO 2 particle size: 30 nm)
The lower resistance heating board 15 on which Pt was set was set at a position lower by a distance 3X than the upper resistance heating board 17 on which Ce was set. Further, the difference in height between the upper resistance heating board 17 and the cooling plate 33 was set to a distance 6Y. All other conditions were the same as in the preparation of Pt particles A 1 to generate Pt particles G.

このＰｔ粒子ＧをＴＥＭで観察したところ、Ｐｔ粒子の粒径は5ｎｍ程度であり、ＣｅO2の粒子は30ｎｍ程度であった。このＰｔ粒子ＧをＩＣＰ分析したところ、Ｐｔが1.7％含有されていた。   When the Pt particles G were observed with a TEM, the Pt particles had a particle size of about 5 nm and the CeO2 particles had a size of about 30 nm. When this Pt particle G was analyzed by ICP, it contained 1.7% of Pt.

Ｐｔ粒子Ｈの調製（Ｐｔ粒子径：５ｎｍ、ＣｅＯ２粒子径：４０ｎｍ）
Ｐｔをセットした下側抵抗加熱ボード１５は、Ｃｅをセットした上側抵抗加熱ボード１７よりも、距離３Ｘだけ低い位置に設定した。また、上側抵抗加熱ボード１７と冷却板３３の高さの差違を距離７Ｙに設定した。その他の条件は、全てＰｔ粒子Ａ の調製の場合と同様にしてＰｔ粒子Ｈを生成した。 Preparation of Pt particles H (Pt particle size: 5 nm, CeO 2 particle size: 40 nm)
The lower resistance heating board 15 on which Pt was set was set at a position lower by a distance 3X than the upper resistance heating board 17 on which Ce was set. Further, the difference in height between the upper resistance heating board 17 and the cooling plate 33 was set to the distance 7Y. All other conditions were the same as in the preparation of Pt particles A to produce Pt particles H.

このＰｔ粒子ＨをＴＥＭで観察したところ、Ｐｔ粒子の粒径は５ｎｍ程度であり、ＣｅO2の粒子は４０ｎｍ程度であった。このＰｔ粒子ＨをＩＣＰ分析したところ、Ｐｔが０．７４％含有されていた。   When the Pt particles H were observed with a TEM, the Pt particles had a particle size of about 5 nm and the CeO2 particles had a size of about 40 nm. When this Pt particle H was analyzed by ICP, it contained 0.74% of Pt.

Ｐｔ粒子Iの調製（Ｐｔ粒子径：６ｎｍ、ＣｅＯ２粒子径：５０ｎｍ）
Ｐｔをセットした下側抵抗加熱ボード１５は、Ｃｅをセットした上側抵抗加熱ボード１７よりも、距離４Ｘだけ低い位置に設定した。また、上側抵抗加熱ボード１７と冷却板３３の高さの差違を距離８Ｙに設定した。その他の条件は、全てＰｔ粒子Ａ の調製の場合と同様にしてＰｔ粒子Ｉを生成した。 Preparation of Pt particles I (Pt particle size: 6 nm, CeO 2 particle size: 50 nm)
The lower resistance heating board 15 on which Pt was set was set at a position lower by a distance 4X than the upper resistance heating board 17 on which Ce was set. Further, the difference in height between the upper resistance heating board 17 and the cooling plate 33 was set to a distance 8Y. All other conditions were the same as in the preparation of Pt particles A to produce Pt particles I.

このＰｔ粒子ＩをＴＥＭで観察したところ、Ｐｔ粒子の粒径は6ｎｍ程度であり、ＣｅＯ２粒子は５０ｎｍ程度であった。このＰｔ粒子ＩをＩＣＰ分析したところ、Ｐｔが０．６６％含有されていた。 When this Pt particle I was observed with a TEM, the particle size of the Pt particle was about 6 nm, and the CeO 2 particle was about 50 nm. When this Pt particle I was analyzed by ICP, it was found to contain 0.66% Pt.

実施例１
前述したＰｔ粒子Ａを２４．３３ｇと、アルミナ基材（γ-アルミナに酸化セリウム９％、酸化ジルコニウム９％、酸化ランタン６％を複合化したもの）１００．６５ｇと、セリア基材（セリアに酸化ジルコニウムを２５％複合化したもの）４８．４２ｇと、ベーマイトアルミナ１．６ｇと、をボールミルに加えた。その後、ボールミルに、水３０７．５ｇと１０％硝酸水溶液１７．５ｇとを加えて、Ｐｔ粒子Ａを分散させると共に粉末を粉砕し、平均粒径３μｍのスラリａを作成した。 Example 1
24.33 g of the Pt particles A described above, an alumina base material (composite of γ-alumina with 9% cerium oxide, 9% zirconium oxide, and 6% lanthanum oxide), and a ceria base material (on ceria) 48.42 g of 25% zirconium oxide) and 1.6 g of boehmite alumina were added to a ball mill. Thereafter, 307.5 g of water and 17.5 g of a 10% nitric acid aqueous solution were added to the ball mill to disperse the Pt particles A and pulverize the powder to prepare slurry a having an average particle diameter of 3 μm.

次に、ジルコニウムとして３％を含むγ-アルミナと、酸化ジルコニウム複合化合物に硝酸ロジウムを含浸し、ロジウム０．６％担持粉末を調製した。また、酸化ジルコニウムに酸化セリウムを２４％復合化してジルコニア基材を調製した。   Next, γ-alumina containing 3% as zirconium and a zirconium oxide composite compound were impregnated with rhodium nitrate to prepare a 0.6% rhodium-supported powder. Moreover, zirconia base material was prepared by recombining cerium oxide with zirconium oxide 24%.

ロジウム０．６％担持粉末１１６．５ｇと、ジルコニア基材４４．４５ｇと、アルミナ基材１１ｇと、ベーマイトアルミナ３ｇと、をボールミルに加えた後、さらに、水３０７．５ｇと、１０％硝酸水溶液１７．５ｇとを加えて粉砕し、平均粒径３μｍのスラリＲを作成した。   After adding 116.5 g of rhodium 0.6% supported powder, 44.45 g of zirconia base material, 11 g of alumina base material, and 3 g of boehmite alumina to a ball mill, 307.5 g of water and a 10% nitric acid aqueous solution were further added. 17.5 g was added and pulverized to prepare a slurry R having an average particle size of 3 μm.

直径３６ｍｍφ、４００セル６ミルのハニカム担体（容量０．０４Ｌ）にスラリａを１４１ｇ／Ｌコーティングして乾燥した後、スラリＲを５９ｇ／Ｌコーティングして乾燥した後、４００℃で焼成して実施例１の試料とした。この実施例１の試料は、Ｐｔ：０．５８７ｇ／Ｌ、Ｒｈ：０．２３６ｇ／Ｌを各々担持した触媒である。   A honeycomb carrier (capacity 0.04 L) with a diameter of 36 mmφ and a 400 cell 6 mil was coated with 141 g / L of slurry a, dried, then coated with 59 g / L of slurry R, dried, and then fired at 400 ° C. The sample of Example 1 was obtained. The sample of Example 1 is a catalyst carrying Pt: 0.587 g / L and Rh: 0.236 g / L.

実施例２
前述したＰｔ粒子Ｂを６６．３６ｇと、アルミナ基材（γ−アルミナに酸化セリウム９％、酸化ジルコニウム９％、酸化ランタン６％を複合化したもの）５８．６２ｇと、セリア基材（セリアに酸化ジルコニウムを２５％複合化したもの）４８．４２ｇと、ベーマイトアルミナ１．６ｇと、をボールミルに加えた。その後、ボールミルに、水３０７．５ｇと１０％硝酸水溶液１７．５ｇとを加えて、Ｐｔ粒子Ｂを分散させると共に粉末を粉砕し、平均粒径３μｍのスラリｂを作成した。 Example 2
66.36 g of the Pt particles B described above, 58.62 g of alumina base material (composite of γ-alumina with 9% cerium oxide, 9% zirconium oxide, and 6% lanthanum oxide), ceria base material (with ceria) 48.42 g of 25% zirconium oxide) and 1.6 g of boehmite alumina were added to a ball mill. Thereafter, 307.5 g of water and 17.5 g of a 10% nitric acid aqueous solution were added to the ball mill to disperse the Pt particles B and pulverize the powder to prepare slurry b having an average particle diameter of 3 μm.

次に、ジルコニウムとして３％を含むγ−アルミナと、酸化ジルコニウム複合化合物に硝酸ロジウムを含浸し、ロジウム０．６％担持粉末を調製した。また、酸化ジルコニウムに酸化セリウムを２４％複合化してジルコニア基材を調製した。   Next, γ-alumina containing 3% as zirconium and a zirconium oxide composite compound were impregnated with rhodium nitrate to prepare a 0.6% rhodium supported powder. A zirconia base material was prepared by compounding 24% of cerium oxide with zirconium oxide.

ロジウム０．６％担持粉末１１６．５５ｇと、ジルコニア基材４４．４５ｇと、アルミナ基材１１ｇと、ベーマイトアルミナ３ｇと、をボールミルに加えた後、さらに、水３０７．５ｇと、１０％硝酸水溶液１７．５ｇとを加えて粉砕し、平均粒径３μｍのスラリＲを作成した。   After adding 116.55 g of rhodium 0.6% supported powder, 44.45 g of zirconia base material, 11 g of alumina base material, and 3 g of boehmite alumina to a ball mill, 307.5 g of water and a 10% nitric acid aqueous solution were further added. 17.5 g was added and pulverized to prepare a slurry R having an average particle size of 3 μm.

直径３６ｍｍφ、４００セル６ミルのハニカム担体（容量０．０４Ｌ）にスラリｂを１４１ｇ／Ｌコーティングして乾燥した後、スラリＲを５９ｇ／Ｌコーティングして乾燥し、その後、４００℃で焼成して実施例２の試料とした。この得られた実施例２の試料は、Ｐｔ：０．５８７ｇ／Ｌ、Ｒｈ：０．２３６ｇ／Ｌを各々担持した触媒である。   A honeycomb carrier (capacity 0.04 L) with a diameter of 36 mmφ and a 400 cell 6 mil is coated with 141 g / L of slurry b and dried, then coated with 59 g / L of slurry R, dried, and then fired at 400 ° C. The sample of Example 2 was obtained. The obtained sample of Example 2 is a catalyst carrying Pt: 0.587 g / L and Rh: 0.236 g / L.

実施例３
前述したＰｔ粒子Ｃを２４．３３ｇと、アルミナ基材（γ−アルミナに酸化セリウム９％、酸化ジルコニウム９％、酸化ランタン６％を複合化したもの）１００．６５ｇと、セリア基材（セリアに酸化ジルコニウムを２５％複合化したもの）４８．４２ｇと、ベーマイトアルミナ１．６ｇと、をボールミルに加えた。その後、ボールミルに、水３０７．５ｇと１０％硝酸水溶液１７．５ｇとを加えて、前述したＰｔ粒子Ｃを分散させると共に粉末を粉砕し、平均粒径３μｍのスラリｃを作成した。 Example 3
24.33 g of the Pt particles C described above, 100.65 g of an alumina base material (composite of γ-alumina with 9% cerium oxide, 9% zirconium oxide, and 6% lanthanum oxide) and a ceria base material (with ceria) 48.42 g of 25% zirconium oxide) and 1.6 g of boehmite alumina were added to a ball mill. Thereafter, 307.5 g of water and 17.5 g of a 10% nitric acid aqueous solution were added to the ball mill to disperse the Pt particles C described above and pulverize the powder to prepare slurry c having an average particle diameter of 3 μm.

次に、ジルコニウムとして３％を含むγ−アルミナと、酸化ジルコニウム複合化合物に硝酸ロジウムを含浸し、ロジウム０．６％担持粉末を調製した。また、酸化ジルコニウムに酸化セリウムを２４％複合化してジルコニア基材を調製した。   Next, γ-alumina containing 3% as zirconium and a zirconium oxide composite compound were impregnated with rhodium nitrate to prepare a 0.6% rhodium supported powder. A zirconia base material was prepared by compounding 24% of cerium oxide with zirconium oxide.

ロジウム０．６％担持粉末１１６．５５ｇと、ジルコニア基材４４．４５ｇと、アルミナ基材１１ｇと、ベーマイトアルミナ３ｇと、をボールミルに加えた後、さらに、水３０７．５ｇと、１０％硝酸水溶液１７．５ｇとを加えて粉砕し、平均粒径３μｍのスラリＲを作成した。   After adding 116.55 g of rhodium 0.6% supported powder, 44.45 g of zirconia base material, 11 g of alumina base material, and 3 g of boehmite alumina to a ball mill, 307.5 g of water and a 10% nitric acid aqueous solution were further added. 17.5 g was added and pulverized to prepare a slurry R having an average particle size of 3 μm.

直径３６ｍｍφ、４００セル６ミルのハニカム担体（容量０．０４Ｌ）にスラリｃを１４１ｇ／Ｌコーティングして乾燥した後、スラリＲを５９ｇ／Ｌコーティングして乾燥し、その後、４００℃で焼成して実施例３の試料とした。この得られた実施例３の試料は、Ｐｔ：０．５８７ｇ／Ｌ、Ｒｈ：０．２３６ｇ／Ｌを各々担持した触媒である。   A honeycomb carrier (capacity 0.04 L) having a diameter of 36 mmφ and a 400 cell 6 mil is coated with 141 g / L of slurry c and dried, and then coated with 59 g / L of slurry R and dried, and then fired at 400 ° C. The sample of Example 3 was obtained. The obtained sample of Example 3 is a catalyst carrying Pt: 0.587 g / L and Rh: 0.236 g / L.

実施例４
前述したＰｔ粒子Ｄを８１．１１ｇと、アルミナ基材（γ−アルミナに酸化セリウム９％、酸化ジルコニウム９％、酸化ランタン６％を複合化したもの）４３．８７ｇと、セリア基材（セリアに酸化ジルコニウムを２５％複合化したもの）４８．４２ｇと、ベーマイトアルミナ１．６ｇと、をボールミルに加えた。その後、ボールミルに、水３０７．５ｇと１０％硝酸水溶液１７．５ｇとを加えて、Ｐｔ粒子Ｄを分散すると共に粉末を粉砕し、平均粒径３μｍのスラリｄを作成した。 Example 4
81.11 g of the Pt particles D described above, 43.87 g of an alumina base material (composite of γ-alumina with 9% cerium oxide, 9% zirconium oxide and 6% lanthanum oxide), and a ceria base material (with ceria) 48.42 g of 25% zirconium oxide) and 1.6 g of boehmite alumina were added to a ball mill. Thereafter, 307.5 g of water and 17.5 g of a 10% nitric acid aqueous solution were added to the ball mill to disperse the Pt particles D and pulverize the powder to prepare a slurry d having an average particle diameter of 3 μm.

次に、ジルコニウムとして３％を含むγ−アルミナと、酸化ジルコニウム複合化合物に硝酸ロジウムを含浸し、ロジウム０．６％担持粉末を調製した。また、酸化ジルコニウムに酸化セリウムを２４％複合化してジルコニア基材を調製した。   Next, γ-alumina containing 3% as zirconium and a zirconium oxide composite compound were impregnated with rhodium nitrate to prepare a 0.6% rhodium supported powder. A zirconia base material was prepared by compounding 24% of cerium oxide with zirconium oxide.

ロジウム０．６％担持粉末１１６．５５ｇと、ジルコニア基材４４．４５ｇと、アルミナ基材１１ｇと、ベーマイトアルミナ３ｇと、をボールミルに加えた後、さらに、水３０７．５ｇと、１０％硝酸水溶液１７．５ｇとを加えて粉砕し、平均粒径３μｍのスラリＲを作成した。   After adding 116.55 g of rhodium 0.6% supported powder, 44.45 g of zirconia base material, 11 g of alumina base material, and 3 g of boehmite alumina to a ball mill, 307.5 g of water and a 10% nitric acid aqueous solution were further added. 17.5 g was added and pulverized to prepare a slurry R having an average particle size of 3 μm.

直径３６ｍｍφ、４００セル６ミルのハニカム担体（容量０．０４Ｌ）にスラリｄを１４１ｇ／Ｌコーティングして乾燥した後、スラリＲを５９ｇ／Ｌコーティングして乾燥し、その後、４００℃で焼成して実施例４の試料とした。得られた実施例４の試料は、Ｐｔ ０．５８７ｇ／Ｌ、Ｒｈ０．２３６ｇ／Ｌを各々担持した触媒である。   A honeycomb carrier (capacity 0.04 L) having a diameter of 36 mmφ and a 400 cell 6 mil is coated with 141 g / L of slurry d and dried, then coated with 59 g / L of slurry R and dried, and then fired at 400 ° C. The sample of Example 4 was obtained. The obtained sample of Example 4 is a catalyst carrying Pt 0.587 g / L and Rh 0.236 g / L, respectively.

実施例５
前述したＰｔ粒子Ｅを５７．０３ｇと、アルミナ基材（γ−アルミナに酸化セリウム９％、酸化ジルコニウム９％、酸化ランタン６％を複合化したもの）６７．９５ｇと、セリア基材（セリアに酸化ジルコニウムを２５％複合化したもの）４８．４２ｇと、ベーマイトアルミナ１．６ｇと、をボールミルに加えた。その後、ボールミルに、水３０７．５ｇと１０％硝酸水溶液１７．５ｇとを加えて、前述したＰｔ粒子Ｅを分散させると共に粉末を粉砕し、平均粒径３μｍのスラリeを作成した。 Example 5
57.03 g of the aforementioned Pt particles E, 67.95 g of alumina base material (composite of γ-alumina with 9% cerium oxide, 9% zirconium oxide and 6% lanthanum oxide), ceria base material (with ceria) 48.42 g of 25% zirconium oxide) and 1.6 g of boehmite alumina were added to a ball mill. Thereafter, 307.5 g of water and 17.5 g of a 10% nitric acid aqueous solution were added to the ball mill to disperse the above-described Pt particles E and pulverize the powder to prepare slurry e having an average particle diameter of 3 μm.

次に、ジルコニウムとして３％を含むγ−アルミナと、酸化ジルコニウム複合化合物に硝酸ロジウムを含浸し、ロジウム０．６％担持粉末を調製した。また、酸化ジルコニウムに酸化セリウムを２４％複合化してジルコニア基材を調製した。   Next, γ-alumina containing 3% as zirconium and a zirconium oxide composite compound were impregnated with rhodium nitrate to prepare a 0.6% rhodium supported powder. A zirconia base material was prepared by compounding 24% of cerium oxide with zirconium oxide.

ロジウム０．６％担持粉末１１６．５５ｇと、ジルコニア基材４４．４５ｇと、アルミナ基材１１ｇと、ベーマイトアルミナ３ｇと、をボールミルに加えた後、さらに、水３０７．５ｇと、１０％硝酸水溶液１７．５ｇとを加えて粉砕し、平均粒径３μｍのスラリＲを作成した。   After adding 116.55 g of rhodium 0.6% supported powder, 44.45 g of zirconia base material, 11 g of alumina base material, and 3 g of boehmite alumina to a ball mill, 307.5 g of water and a 10% nitric acid aqueous solution were further added. 17.5 g was added and pulverized to prepare a slurry R having an average particle size of 3 μm.

直径３６ｍｍφ、４００セル６ミルのハニカム担体（容量０．０４Ｌ）にスラリｅを１４１ｇ／Ｌコーティングして乾燥した後、スラリＲを５９ｇ／Ｌコーティングして乾燥し、その後、４００℃で焼成して実施例５の試料とした。得られた実施例５の試料は、Ｐｔ ０．５８７ｇ／Ｌ、Ｒｈ０．２３６ｇ／Ｌを各々担持した触媒である。 A honeycomb carrier (capacity 0.04 L) having a diameter of 36 mmφ and a 400 cell 6 mil is coated with 141 g / L of slurry e, dried, then coated with 59 g / L of slurry R, dried, and then fired at 400 ° C. The sample of Example 5 was obtained. The obtained sample of Example 5 is a catalyst carrying Pt 0.587 g / L and Rh 0.236 g / L, respectively.

実施例６
前述したＰｔ粒子Ｆを１１０．６ｇと、アルミナ基材（γ−アルミナに酸化セリウム９％、酸化ジルコニウム９％、酸化ランタン６％を複合化したもの）１４．３８ｇと、セリア基材（セリアに酸化ジルコニウムを２５％複合化したもの）４８．４２ｇと、ベーマイトアルミナ１．６ｇと、をボールミルに加えた。その後、ボールミルに、水３０７．５ｇと１０％硝酸水溶液１７．５ｇとを加えて、前述したＰｔ粒子Ｆを分散させると共に粉末を粉砕し、平均粒径３μｍのスラリｆを作成した。 Example 6
110.6 g of the Pt particles F described above, 14.38 g of alumina base material (composite of γ-alumina with 9% cerium oxide, 9% zirconium oxide, and 6% lanthanum oxide) and ceria base material (with ceria) 48.42 g of 25% zirconium oxide) and 1.6 g of boehmite alumina were added to a ball mill. Thereafter, 307.5 g of water and 17.5 g of a 10% nitric acid aqueous solution were added to the ball mill to disperse the above-described Pt particles F and pulverize the powder to prepare a slurry f having an average particle diameter of 3 μm.

次に、ジルコニウムとして３％を含むγ−アルミナと、酸化ジルコニウム複合化合物に硝酸ロジウムを含浸し、ロジウム０．６％担持粉末を調製した。また、酸化ジルコニウムに酸化セリウムを２４％複合化してジルコニア基材を調製した。   Next, γ-alumina containing 3% as zirconium and a zirconium oxide composite compound were impregnated with rhodium nitrate to prepare a 0.6% rhodium supported powder. A zirconia base material was prepared by compounding 24% of cerium oxide with zirconium oxide.

ロジウム０．６％担持粉末１１６．５５ｇと、ジルコニア基材４４．４５ｇと、アルミナ基材１１ｇと、ベーマイトアルミナ３ｇと、をボールミルに加えた後、さらに、水３０７．５ｇと、１０％硝酸水溶液１７．５ｇとを加えて粉砕し、平均粒径３μｍのスラリＲを作成した。   After adding 116.55 g of rhodium 0.6% supported powder, 44.45 g of zirconia base material, 11 g of alumina base material, and 3 g of boehmite alumina to a ball mill, 307.5 g of water and a 10% nitric acid aqueous solution were further added. 17.5 g was added and pulverized to prepare a slurry R having an average particle size of 3 μm.

直径３６ｍｍφ、４００セル６ミルのハニカム担体（容量０．０４Ｌ）にスラリｆを１４１ｇ／Ｌコーティングして乾燥した後、スラリＲを５９ｇ／Ｌコーティングして乾燥し、その後、４００℃で焼成して実施例６の試料とした。得られた実施例６の試料は、Ｐｔ：０．５８７ｇ／Ｌ、Ｒｈ：０．２３６ｇ／Ｌを各々担持した触媒である。 A honeycomb carrier (capacity 0.04 L) having a diameter of 36 mmφ and a 400 cell 6 mil is coated with 141 g / L of slurry f and dried, and then coated with 59 g / L of slurry R and dried, and then fired at 400 ° C. The sample of Example 6 was obtained. The obtained sample of Example 6 is a catalyst carrying Pt: 0.587 g / L and Rh: 0.236 g / L.

実施例７
前述したＰｔ粒子Ｇを４１．７ｇと、アルミナ基材（γ−アルミナに酸化セリウム９％、酸化ジルコニウム９％、酸化ランタン６％を複合化したもの）８３．２８ｇと、セリア基材（セリアに酸化ジルコニウムを２５％複合化したもの）４８．４２ｇと、ベーマイトアルミナ１．６ｇと、をボールミルに加えた。その後、ボールミルに、水３０７．５ｇと１０％硝酸水溶液１７．５ｇとを加えて、前述したＰｔ粒子Ｇを分散させると共に粉末を粉砕し、平均粒径３μｍのスラリｇを作成した。 Example 7
41.7 g of the aforementioned Pt particles G, 83.28 g of alumina base material (composite of 9% cerium oxide, 9% zirconium oxide and 6% lanthanum oxide in γ-alumina), ceria base material (ceria) 48.42 g of 25% zirconium oxide) and 1.6 g of boehmite alumina were added to a ball mill. Thereafter, 307.5 g of water and 17.5 g of a 10% nitric acid aqueous solution were added to the ball mill to disperse the aforementioned Pt particles G, and the powder was pulverized to prepare a slurry g having an average particle diameter of 3 μm.

次に、ジルコニウムとして３％を含むγ−アルミナと、酸化ジルコニウム複合化合物に硝酸ロジウムを含浸し、ロジウム０．６％担持粉末を調製した。また、酸化ジルコニウムに酸化セリウムを２４％複合化してジルコニア基材を調製した。   Next, γ-alumina containing 3% as zirconium and a zirconium oxide composite compound were impregnated with rhodium nitrate to prepare a 0.6% rhodium supported powder. A zirconia base material was prepared by compounding 24% of cerium oxide with zirconium oxide.

ロジウム０．６％担持粉末１１６．５５ｇと、ジルコニア基材４４．４５ｇと、アルミナ基材１１ｇと、ベーマイトアルミナ３ｇと、をボールミルに加えた後、さらに、水３０７．５ｇと、１０％硝酸水溶液１７．５ｇとを加えて粉砕し、平均粒径３μｍのスラリＲを作成した。   After adding 116.55 g of rhodium 0.6% supported powder, 44.45 g of zirconia base material, 11 g of alumina base material, and 3 g of boehmite alumina to a ball mill, 307.5 g of water and a 10% nitric acid aqueous solution were further added. 17.5 g was added and pulverized to prepare a slurry R having an average particle size of 3 μm.

直径３６ｍｍφ、４００セル６ミルのハニカム担体（容量０．０４Ｌ）にスラリｇを１４１ｇ／Ｌコーティングして乾燥した後、スラリＲを５９ｇ／Ｌコーティングして乾燥し、その後、４００℃で焼成して実施例７の試料とした。得られた実施例７の試料は、Ｐｔ ０．５８７ｇ／Ｌ、Ｒｈ０．２３６ｇ／Ｌを各々担持した触媒である。 A honeycomb carrier (capacity 0.04 L) having a diameter of 36 mmφ and a 400 cell 6 mil was coated with 141 g / L of slurry g, dried, then coated with 59 g / L of slurry R, dried, and then fired at 400 ° C. A sample of Example 7 was obtained. The obtained sample of Example 7 is a catalyst carrying Pt 0.587 g / L and Rh 0.236 g / L, respectively.

実施例８
前述したＰｔ粒子Ｈを９８．１ｇと、アルミナ基材（γ−アルミナに酸化セリウム９％、酸化ジルコニウム９％、酸化ランタン６％を複合化したもの）２６．８８ｇと、セリア基材（セリアに酸化ジルコニウムを２５％複合化したもの）４８．４２ｇと、ベーマイトアルミナ１．６ｇと、をボールミルに加えた。その後、ボールミルに、水３０７．５ｇと１０％硝酸水溶液１７．５ｇとを加えて、前述したＰｔ粒子Ｈを分散させると共に粉末を粉砕し、平均粒径３μｍのスラリｈを作成した。 Example 8
98.1 g of the Pt particles H described above, an alumina base material (composite of γ-alumina with 9% cerium oxide, 9% zirconium oxide and 6% lanthanum oxide) 26.88 g, and a ceria base material (ceria 48.42 g of 25% zirconium oxide) and 1.6 g of boehmite alumina were added to a ball mill. Thereafter, 307.5 g of water and 17.5 g of a 10% nitric acid aqueous solution were added to the ball mill to disperse the aforementioned Pt particles H, and the powder was pulverized to prepare a slurry h having an average particle diameter of 3 μm.

次に、ジルコニウムとして３％を含むγ−アルミナと、酸化ジルコニウム複合化合物に硝酸ロジウムを含浸し、ロジウム０．６％担持粉末を調製した。また、酸化ジルコニウムに酸化セリウムを２４％複合化してジルコニア基材を調製した。   Next, γ-alumina containing 3% as zirconium and a zirconium oxide composite compound were impregnated with rhodium nitrate to prepare a 0.6% rhodium supported powder. A zirconia base material was prepared by compounding 24% of cerium oxide with zirconium oxide.

ロジウム０．６％担持粉末１１６．５５ｇと、ジルコニア基材４４．４５ｇと、アルミナ基材１１ｇと、ベーマイトアルミナ３ｇと、をボールミルに加えた後、さらに、水３０７．５ｇと、１０％硝酸水溶液１７．５ｇとを加えて粉砕し、平均粒径３μｍのスラリＲを作成した。   After adding 116.55 g of rhodium 0.6% supported powder, 44.45 g of zirconia base material, 11 g of alumina base material, and 3 g of boehmite alumina to a ball mill, 307.5 g of water and a 10% nitric acid aqueous solution were further added. 17.5 g was added and pulverized to prepare a slurry R having an average particle size of 3 μm.

直径３６ｍｍφ、４００セル６ミルのハニカム担体（容量０．０４Ｌ）にスラリｈを１４１ｇ／Ｌコーティングして乾燥した後、スラリＲを５９ｇ／Ｌコーティングして乾燥し、その後、４００℃で焼成して実施例８の試料とした。得られた実施例８の試料は、Ｐｔ ０．５８７ｇ／Ｌ、Ｒｈ０．２３６ｇ／Ｌを各々担持した触媒である。   A honeycomb carrier (capacity 0.04 L) having a diameter of 36 mmφ and 400 cells 6 mil was coated with 141 g / L of slurry h, dried, then coated with 59 g / L of slurry R, dried, and then fired at 400 ° C. The sample of Example 8 was obtained. The obtained sample of Example 8 is a catalyst carrying Pt 0.587 g / L and Rh 0.236 g / L, respectively.

比較例１
実施例１で調製したアルミナ担体にジニトロジアミン白金水溶液を含浸し、乾燥後、４００℃で焼成してＰｔを０．４４％含有したアルミナ粉末を調製した。また、実施例１で調製したセリア基材にジニトロジアミン白金水溶液を含浸し、乾燥後、４００℃で焼成し、Ｐｔを０．３７５％含有したセリア粉末を調製した。 Comparative Example 1
The alumina carrier prepared in Example 1 was impregnated with a dinitrodiamine platinum aqueous solution, dried, and then fired at 400 ° C. to prepare alumina powder containing 0.44% Pt. Further, the ceria substrate prepared in Example 1 was impregnated with a dinitrodiamine platinum aqueous solution, dried, and then fired at 400 ° C. to prepare a ceria powder containing 0.375% Pt.

Ｐｔを０．４４％含有したアルミナ粉末１２４．８ｇと、Ｐｔを０．３７５％含有したセリア粉末４８．６ｇと、ベーマイトアルミナ１．６ｇと、をボールミルに加え、さらに、水３０７．５ｇと１０％硝酸水溶液１７．５ｇとを加えて粉末を粉砕し、平均粒径３μｍのスラリＸを作成した。   124.8 g of alumina powder containing 0.44% of Pt, 48.6 g of ceria powder containing 0.375% of Pt, and 1.6 g of boehmite alumina were added to a ball mill, and further, 307.5 g of water and 10 17.5 g of an aqueous nitric acid solution was added and the powder was pulverized to prepare slurry X having an average particle size of 3 μm.

直径３６ｍｍφ、４００セル６ミルのハニカム担体（容量０．０４Ｌ）にスラリＸを１４１ｇ／Ｌコーティングし、乾燥後、さらに実施例１で調製したスラリＲを５９ｇ／Ｌコーティングし、乾燥後、４００℃で焼成して比較例１の試料とした。比較例１の試料は、Ｐｔ：０．５８７ｇ／Ｌ、Ｒｈ：０．２３６ｇ／Ｌを担持した触媒であり、いわゆる通常の貴金属を含浸した触媒である。   A honeycomb carrier (capacity 0.04 L) having a diameter of 36 mmφ and a 400 cell 6 mil was coated with 141 g / L of slurry X, dried, and further coated with 59 g / L of slurry R prepared in Example 1, and dried at 400 ° C. The sample of Comparative Example 1 was obtained by baking. The sample of Comparative Example 1 is a catalyst supporting Pt: 0.587 g / L and Rh: 0.236 g / L, and is a catalyst impregnated with a so-called normal noble metal.

比較例２
前述したＰｔ粒子Ｉを１１０．６ｇと、アルミナ基材（γ−アルミナに酸化セリウム９％、酸化ジルコニウム９％、酸化ランタン６％を複合化したもの）１４．３８ｇと、セリア基材（セリアに酸化ジルコニウムを２５％複合化したもの）４８．４２ｇと、ベーマイトアルミナ１．６ｇと、をボールミルに加えた。その後、ボールミルに、水３０７．５ｇと１０％硝酸水溶液１７．５ｇとを加えて、Ｐｔ粒子Ｉを分散させると共に粉末を粉砕し、平均粒径３μｍのスラリｉを作成した。 Comparative Example 2
110.6 g of the aforementioned Pt particles I, 14.38 g of alumina base material (composite of 9% cerium oxide, 9% zirconium oxide and 6% lanthanum oxide in γ-alumina) and ceria base material (ceria) 48.42 g of 25% zirconium oxide) and 1.6 g of boehmite alumina were added to a ball mill. Thereafter, 307.5 g of water and 17.5 g of a 10% nitric acid aqueous solution were added to the ball mill to disperse the Pt particles I and pulverize the powder to prepare slurry i having an average particle diameter of 3 μm.

次に、ジルコニウムとして３％を含むγ−アルミナと、酸化ジルコニウム複合化合物に硝酸ロジウムを含浸し、ロジウム０．６％担持粉末を調製した。また、酸化ジルコニウムに酸化セリウムを２４％複合化してジルコニア基材を調製した。   Next, γ-alumina containing 3% as zirconium and a zirconium oxide composite compound were impregnated with rhodium nitrate to prepare a 0.6% rhodium supported powder. A zirconia base material was prepared by compounding 24% of cerium oxide with zirconium oxide.

ロジウム０．６％担持粉末１１６．５５ｇと、ジルコニア基材４４．４５ｇと、アルミナ基材１１ｇと、ベーマイトアルミナ３ｇと、をボールミルに加えた後、さらに、水３０７．５ｇと、１０％硝酸水溶液１７．５ｇとを加えて粉砕し、平均粒径３μｍのスラリＲを作成した。   After adding 116.55 g of rhodium 0.6% supported powder, 44.45 g of zirconia base material, 11 g of alumina base material, and 3 g of boehmite alumina to a ball mill, 307.5 g of water and a 10% nitric acid aqueous solution were further added. 17.5 g was added and pulverized to prepare a slurry R having an average particle size of 3 μm.

直径３６ｍｍφ、４００セル６ミルのハニカム担体（容量０．０４Ｌ）にスラリiを１４１ｇ／Ｌコーティングして乾燥した後、スラリＲを５９ｇ／Ｌコーティングして乾燥し、その後、４００℃で焼成して比較例２の試料とした。得られた比較例２の試料は、Ｐｔ ０．５８７ｇ／Ｌ、Ｒｈ０．２３６ｇ／Ｌを各々担持した触媒である。   A honeycomb carrier (capacity 0.04 L) having a diameter of 36 mmφ and a 400 cell 6 mil is coated with 141 g / L of slurry i, dried, then coated with 59 g / L of slurry R, dried, and then fired at 400 ° C. A sample of Comparative Example 2 was obtained. The obtained sample of Comparative Example 2 is a catalyst carrying Pt 0.587 g / L and Rh 0.236 g / L, respectively.

前記実施例１〜実施例８及び比較例１〜比較例２により調製した触媒を用いて、排気量３５００ｃｃのＶ型エンジンの排気系に、片バンクあたり触媒を各５個ずつ装着した。国内レギュラーガソリンを使用して、触媒入口温度を６５０℃とし、３０時間運転して耐久により熱履歴を施した。   Using the catalysts prepared in Examples 1 to 8 and Comparative Examples 1 to 2, five catalysts were installed per bank in the exhaust system of a V-type engine with a displacement of 3500 cc. Using domestic regular gasoline, the catalyst inlet temperature was set to 650 ° C., and it was operated for 30 hours to give a heat history by durability.

さらに、耐久後の各触媒を模擬排ガス流通装置に組み込み、以下の表１に示す組成の模擬排ガスを模擬排ガス流通装置に流通させて、触媒温度を３０℃／分の速度で昇温させながら、ＮＯｘ、ＣＯ、ＨＣ（Ｃ３Ｈ６）の浄化率が５０％となる温度（Ｔ）を調べた。

Figure 2006255610
Furthermore, each catalyst after durability is incorporated into a simulated exhaust gas distribution device, and simulated exhaust gas having the composition shown in Table 1 below is distributed to the simulated exhaust gas distribution device while raising the catalyst temperature at a rate of 30 ° C./min. The temperature (T) at which the purification rate of NOx, CO, and HC (C 3 H 6 ) was 50% was examined.
Figure 2006255610

また、以下の表２に、実施例１〜実施例８及び比較例１〜比較例２の各触媒の評価結果を示すと共に、図４〜図６に、ＣＯ浄化率、ＮＯｘ浄化率及びＨＣ（Ｃ３Ｈ６）浄化率が５０％となる温度を比較したグラフを示した。

Figure 2006255610
Table 2 below shows the evaluation results of the catalysts of Examples 1 to 8 and Comparative Examples 1 to 2, and FIGS. 4 to 6 show the CO purification rate, NOx purification rate, and HC ( A graph comparing the temperatures at which the C 3 H 6 ) purification rate is 50% is shown.
Figure 2006255610

これらの評価結果から、比較例１は、通常使用される含浸法を用いて貴金属溶液を調製した触媒であるため、初期のＰｔ粒径は非常に小さく分散性が良かったが、耐久後のＰｔ粒子をＴＥＭで観察したところ、Ｐｔ粒径が約２０ｎｍ〜３０ｎｍとなりＰｔ粒子が凝集していた。   From these evaluation results, since Comparative Example 1 is a catalyst prepared with a noble metal solution using a commonly used impregnation method, the initial Pt particle size was very small and the dispersibility was good. When the particles were observed with a TEM, the Pt particle size was about 20 nm to 30 nm, and the Pt particles were aggregated.

また、比較例２のＰｔ粒子の大きさには耐久前と耐久後とで変化が見られなかったが、比較例２のＰｔ粒子の粒径は初期から大きく、更にＰｔ粒子を内包するセリア粒子の径が５０ｎｍと大きく、Ｐｔの凝集は抑制されたが、セリア層が厚いため、ガスの拡散が阻害され、比較例２の触媒は、比較例１の触媒よりも性能が劣ったものと考えられる。   Further, the size of the Pt particles in Comparative Example 2 did not change before and after the endurance, but the particle size of the Pt particles in Comparative Example 2 was large from the beginning, and the ceria particles included in the Pt particles. The Pt agglomeration was as large as 50 nm and Pt aggregation was suppressed, but because the ceria layer was thick, gas diffusion was inhibited, and the catalyst of Comparative Example 2 was considered to be inferior to the catalyst of Comparative Example 1 It is done.

これに対して、実施例１〜実施例８の各触媒では、耐久前及び耐久後のＰｔ粒子径に大きな変化はなく、各実施例の触媒が熱履歴に対して耐久性に優れていることが判明した。特に、実施例２、実施例３、実施例４の各触媒は、いずれもＮＯｘ、ＣＯ、ＨＣの浄化率が５０％となる温度が低く、触媒活性が高いことが判明した。   On the other hand, in each catalyst of Examples 1 to 8, there is no significant change in the Pt particle diameter before and after durability, and the catalyst of each example is excellent in durability against thermal history. There was found. In particular, the catalysts of Examples 2, 3 and 4 were all found to have a low catalyst temperature and a high catalyst activity at a NOx, CO and HC purification rate of 50%.

なお、実施例３の耐久後の触媒について、ＴＥＭで観察したところ、Ｐｔ粒子の粒径は２〜３ｎｍであり、耐久前と後ではほとんど変化がなかった。   In addition, when the catalyst after durability of Example 3 was observed by TEM, the particle size of the Pt particles was 2 to 3 nm, and there was almost no change before and after the durability.

本発明の実施形態による排気ガス浄化用触媒の表面の状態を拡大して示す概略図である。It is the schematic which expands and shows the state of the surface of the catalyst for exhaust gas purification by embodiment of this invention. 本発明の実施形態による排気ガス浄化用触媒を製造する際に用いるガス中蒸発法用装置の概略図である。It is the schematic of the apparatus for gas evaporation methods used when manufacturing the exhaust gas purification catalyst by embodiment of this invention. 本発明の実施形態による排気ガス浄化用触媒の製造手順を示す概略図であり、このうちの（ａ）は貴金属粒子を示す概略図、（ｂ）は貴金属粒子の周囲を内包粒子群によって取り囲んだ状態を示す概略図、（ｃ）は内包粒子群によって取り囲んだ貴金属粒子を基材に担持した排気ガス浄化用触媒を示す概略図である。It is the schematic which shows the manufacturing procedure of the catalyst for exhaust gas purification by embodiment of this invention, (a) is the schematic which shows a noble metal particle, (b) is surrounding the noble metal particle by the inclusion particle group. FIG. 3C is a schematic diagram showing a state, and FIG. 3C is a schematic diagram showing an exhaust gas purification catalyst in which noble metal particles surrounded by a group of encapsulated particles are supported on a base material. 実施例１〜８及び比較例１，２における各触媒のＣＯ浄化率が５０％となる温度を比較したグラフである。It is the graph which compared the temperature from which the CO purification rate of each catalyst in Examples 1-8 and Comparative Examples 1 and 2 becomes 50%. 実施例１〜８及び比較例１，２における各触媒のＮＯｘ浄化率が５０％となる温度を比較したグラフである。It is the graph which compared the temperature from which the NOx purification rate of each catalyst in Examples 1-8 and Comparative Examples 1 and 2 becomes 50%. 実施例１〜８及び比較例１，２における各触媒のＨＣ（Ｃ３Ｈ６）浄化率が５０％となる温度を比較したグラフである。Examples 1-8 and HC of each catalyst in Comparative Example 1,2 (C 3 H 6) purification ratio is a graph comparing the temperature at which 50%.

符号の説明Explanation of symbols

３ 貴金属粒子
５ 内包粒子
７ 内包粒子群
９ 基材 3 Precious metal particles 5 Encapsulated particles 7 Encapsulated particles 9 Base material

Claims (9)

貴金属粒子と、該貴金属粒子の周囲を取り囲む複数の内包粒子からなる内包粒子群と、該内包粒子群に内包された貴金属粒子を担持する基材とを含んでなる排気ガス浄化用触媒。   An exhaust gas purifying catalyst comprising noble metal particles, an inclusion particle group including a plurality of inclusion particles surrounding the noble metal particle, and a base material supporting the noble metal particles contained in the inclusion particle group. 前記貴金属粒子は、白金、パラジウム、ロジウム、イリジウム、金、銀、ルテニウムの群から選択される一又は二以上の金属からなることを特徴とする請求項１に記載の排気ガス浄化用触媒。   The exhaust gas purifying catalyst according to claim 1, wherein the noble metal particles are made of one or more metals selected from the group consisting of platinum, palladium, rhodium, iridium, gold, silver and ruthenium. 前記内包粒子は、アルミニウム、セリウム、ジルコニウム、マンガン、コバルト、鉄、ニッケル、スズ、チタン、モリブデン、イットリウム、ランタン、ネオジムの群から選択される一又は二以上の金属又はその金属の酸化物からなることを特徴とする請求項１又は２に記載の排気ガス浄化用触媒。   The encapsulated particles are made of one or more metals selected from the group consisting of aluminum, cerium, zirconium, manganese, cobalt, iron, nickel, tin, titanium, molybdenum, yttrium, lanthanum, and neodymium, or oxides of the metals. The exhaust gas purifying catalyst according to claim 1 or 2. 前記貴金属粒子の粒径は、１〜５ｎｍであり、前記内包粒子の粒径は、４０ｎｍ以下であることを特徴とする請求項１〜３のいずれか１項に記載の排気ガス浄化用触媒。   The exhaust gas purifying catalyst according to any one of claims 1 to 3, wherein a particle diameter of the noble metal particles is 1 to 5 nm, and a particle diameter of the inclusion particles is 40 nm or less. 前記内包粒子群は、前記内包粒子が複数集合したクラスターに形成されていることを特徴とする請求項１〜４のいずれか１項に記載の排気ガス浄化用触媒。   The exhaust gas purifying catalyst according to any one of claims 1 to 4, wherein the inclusion particle group is formed in a cluster in which a plurality of the inclusion particles are aggregated. 貴金属粒子及び該貴金属粒子の周囲を取り囲む複数の内包粒子からなる内包粒子群を、ガス中蒸発法を用いて生成する工程と、前記内包粒子群で取り囲まれた貴金属粒子を基材に担持する工程とを含んでなる排気ガス浄化用触媒の製造方法。   A step of generating an encapsulated particle group composed of noble metal particles and a plurality of encapsulated particles surrounding the noble metal particle using a gas evaporation method, and a step of supporting the noble metal particles surrounded by the encapsulated particle group on a base material A method for producing an exhaust gas purifying catalyst comprising: 前記内包粒子群を生成する工程は、内包粒子を生成する内包粒子用原料をガス中蒸発法を用いて蒸発させて前記貴金属粒子の周囲に凝縮させることによって、貴金属粒子を核として内包粒子群を成長させることを特徴とする請求項６に記載の排気ガス浄化用触媒の製造方法。   The step of generating the encapsulated particle group includes evaporating the raw material for the encapsulated particle that generates the encapsulated particle by using a gas evaporation method and condensing the encapsulated particle group around the noble metal particle. The method for producing an exhaust gas purifying catalyst according to claim 6, wherein the catalyst is grown. 前記貴金属粒子は、白金、パラジウム、ロジウム、イリジウム、金、銀、ルテニウムの群から選択される一又は二以上の金属からなることを特徴とする請求項６又は７に記載の排気ガス浄化用触媒の製造方法。   The exhaust gas purifying catalyst according to claim 6 or 7, wherein the noble metal particles are made of one or more metals selected from the group consisting of platinum, palladium, rhodium, iridium, gold, silver and ruthenium. Manufacturing method. 前記内包粒子は、アルミニウム、セリウム、ジルコニウム、マンガン、コバルト、鉄、ニッケル、スズ、チタン、モリブデン、イットリウム、ランタン、ネオジムの群から選択される一又は二以上の金属又はその金属の酸化物からなることを特徴とする請求項６〜８のいずれか１項に記載の排気ガス浄化用触媒の製造方法。   The encapsulated particles are made of one or more metals selected from the group consisting of aluminum, cerium, zirconium, manganese, cobalt, iron, nickel, tin, titanium, molybdenum, yttrium, lanthanum, and neodymium, or oxides of the metals. The method for producing an exhaust gas purifying catalyst according to any one of claims 6 to 8.
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WO2007011062A1 (en) * 2005-07-21 2007-01-25 Kabushiki Kaisha Toyota Chuo Kenkyusho Composite material, composite material base, composite material dispersion liquid, and methods for producing those
WO2008135373A1 (en) * 2007-05-04 2008-11-13 Robert Bosch Gmbh Coating of ceramic carriers
US7718567B2 (en) * 2006-12-15 2010-05-18 Nissan Motor Co., Ltd. Exhaust gas purging catalyst and method for producing the exhaust gas purging catalyst
JP2010521277A (en) * 2006-09-22 2010-06-24 バーイラン ユニバーシティー Porous cluster of silver powder whose activity is enhanced by zirconium oxide, which can be used as a catalyst in a gas diffusion electrode, and a method for producing the same
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WO2007011062A1 (en) * 2005-07-21 2007-01-25 Kabushiki Kaisha Toyota Chuo Kenkyusho Composite material, composite material base, composite material dispersion liquid, and methods for producing those
US8475921B2 (en) 2005-07-21 2013-07-02 Kabushiki Kaisha Toyota Chuo Kenkyusho Composite material, composite material substrate, composite material dispersed fluid, and manufacturing methods thereof
JP5267841B2 (en) * 2005-07-21 2013-08-21 株式会社豊田中央研究所 COMPOSITE MATERIAL, COMPOSITE MATERIAL BASE, COMPOSITE MATERIAL DISPERSION AND METHOD FOR PRODUCING THEM
JP2010521277A (en) * 2006-09-22 2010-06-24 バーイラン ユニバーシティー Porous cluster of silver powder whose activity is enhanced by zirconium oxide, which can be used as a catalyst in a gas diffusion electrode, and a method for producing the same
US8900750B2 (en) 2006-09-22 2014-12-02 Bar-Ilan University Porous clusters of silver powder promoted by zirconium oxide for use as a catalyst in gas diffusion electrodes, and method for the production thereof
US9666874B2 (en) 2006-09-22 2017-05-30 Bar Ilan University Porous clusters of silver powder promoted by zirconium oxide for use as a catalyst in gas diffusion electrodes, and method for the production thereof
US9941516B2 (en) 2006-09-22 2018-04-10 Bar Ilan University Porous clusters of silver powder comprising zirconium oxide for use in gas diffusion electrodes, and methods of production thereof
US7718567B2 (en) * 2006-12-15 2010-05-18 Nissan Motor Co., Ltd. Exhaust gas purging catalyst and method for producing the exhaust gas purging catalyst
WO2008135373A1 (en) * 2007-05-04 2008-11-13 Robert Bosch Gmbh Coating of ceramic carriers
CN101362091B (en) * 2007-08-08 2012-05-30 比亚迪股份有限公司 Automobile tail gas cleaning catalyst and its preparation method
CN114160121A (en) * 2021-12-27 2022-03-11 山东亮剑环保新材料有限公司 Multi-dimensional particle denitration catalyst and production method thereof

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