Mazda Motor Corporation

Toda Kogyo Corporation

Other

Tokyo Roki Co., Ltd.

Hideharu Iwakuni

Akihide Takami

Hiroshi Yamada

Makoto Kyogoku

Seiji Miyoshi

Kenji Okamoto

Masaaki Akamine

Hiroshi Murakami

Takahiro Kurokawa

Kenichi Yamamoto

Takashi Takemoto

Koji Minoshima

Masahiko Shigetsu

Hirosuke Sumida

Koichiro Harada

Kazunari Komatsu

Hisaya Kawabata

Yasuto Watanabe

Tomoaki Urai

Satoshi Ichikawa

Tomohiro Honda

Yuki Murakami

Tadashi Tokuyama

Katsuyuki Fujita

Hirofumi Nishimura

Junichi Taga

Tomomi Watanabe

Youichi Kuji

Tadataka Nakazumi

Tsutomu Shimizu

Motoshi Kataoka

Masayuki Kuroki

Yasuhumi Kawado

Yuki Koda

Katsuaki Kurata

Shinichi Tanioka

Jiro Kondo

Susumu Mineoi

Yasuhiro Ochi

Yoko Kawakami

Hirosou Oda

Kazuhiro Furukawa

Tadashi Isobe

Ryota Fujimoto

Asako Sadai

Tomohiko Kawamoto

A catalyst layer includes: a first mixed oxide particle componentwhich contains Ce and Rhand in which Rh is partially exposed at particle surfaces; and a second mixed oxide particle componentcontaining Ce, Zr, and a rare earth metal except Ce. The particle size distribution of the first mixed oxide particle componenthas a peak in the particle size range from 100 nm to 300 nm, both inclusive. The particle size distribution of the second mixed oxide particle componenthas a peak in a particle size range larger than the particle size range in which the first mixed oxide particle componenthas the peak. At least part of particles of the first mixed oxide particle componentis attached to at least part of particles of the second mixed oxide particle component

Exhaust gas purification catalyst

Disclosed is an exhaust gas purifying catalyst, which comprises a catalyst layer formed on a honeycomb-shaped support. The catalyst layer is formed by mixing a catalyst powder (A) consisting of a composite oxide (RhZrCeNdO) which contains at least Ce, Zr, and a catalytic noble metal composition, and a catalyst powder (B) consisting of a Zr-based oxide (RhZrXO) which contains at least Zr and has Rh existing on a surface thereof. A ratio (RhZrXO/RhZrCeNdO) of a mass of the catalyst powder (B) to a total mass of the catalyst powder (A) and the catalyst powder (B) may be set in the range of 1 to 50%. Further, the catalyst powder (B) may consist of a composite oxide which contains Zr as a primary component, a rare-earth metal except Ce, and Rh. The exhaust gas purifying catalyst of the present invention can provide enhanced exhaust gas conversion efficiency.

Exhaust gas purifying catalyst and exhaust gas purifying method

An upstream catalyst and a downstream catalyst are disposed in an exhaust passage of an engine. The downstream catalyst contains in the same catalyst layer thereof. Rh-doped CeZrNd mixed oxide particles on which Rh is supported and active alumina particles on which Pt is supported. The upstream catalyst is a three-way catalyst containing an oxygen storage component having a lower oxygen storage capacity than the Rh-doped CeZrNd mixed oxide.

Exhaust gas catalytic conversion system

Disclosed is an exhaust gas purifying catalyst, which comprises a CeZr-based composite oxide capable of maintaining a hollow structure to ensure an oxygen absorbing/releasing capability, even after being exposed to high-temperature exhaust gas. The exhaust gas purifying catalyst comprises a honeycomb-shaped substrate, and a catalyst layer formed on a surface of the substrate. The catalyst layer contains a composite oxide which includes cerium (Ce) and zirconium (Zr) and has a hollow structure, and a catalytic metal supported by the composite oxide. The composite oxide having the hollow structure includes, in a state after being subjected to a thermal aging in Air at 1000&#xb0; C. for 24 hours, a particle with a shape having an outer diameter of 750 to 1000 nm and a shell thickness of 80 to 120 nm.

Exhaust gas purifying catalyst

An exhaust gas purification catalyst comprises: an oxygen storage component constituted by a mixed oxide containing cerium and zirconium; and a catalytic metal carried on the oxygen storage component. The oxygen storage component is in the form of hollow secondary particles each formed so that primary particles of an average particle size of less than 10 nm cohere into a shell.

An exhaust gas purifying catalyst comprising: a honeycomb-like substrate disposed in an exhaust passage for an engine; and a catalytic layer formed on a cell wall of said substrate, said catalytic layer including a mixed oxide which contains Ce (cerium) and Zr (zirconium), and retains a catalytic noble metal in such a manner that said noble metal atoms are located at crystal lattice points or between the lattice points of the mixed oxide, wherein said mixed oxide includes a first mixed oxide containing CeOin a mass greater than that of ZrO, and a second mixed oxide containing ZrOin a mass greater than that of CeO.

Catalytic converter comprises a carrier having exhaust gas passages therein, a lower catalytic layer coated over the carrier and comprising hollow oxide powder loaded with catalytic metal, and an upper catalytic layer coated over the lower catalytic layer, directly exposed to exhaust gas flowing in the exhaust gas passages and comprising solid oxide powder loaded with catalytic metal. The hollow oxide powder may be ceria or alumina base oxide. Further it may be mixed oxide such as Ce&#x2014;Zr mixed oxide or La contained alumina as well.

The present invention relates to an exhaust gas purification catalytic material containing: (a) a mixed oxide containing Ce and Zr for storing and releasing oxygen; and (b) a precious metal catalyst made of one or more kinds of precious metals. The precious metal catalyst comprises a first precious metal catalyst component placed between atoms, at crystal lattice points and/or at oxygen defect sites of the mixed oxide and a second precious metal catalyst component loaded on the surface of the mixed oxide, thereby improving the thermal resistance, oxygen storage capacity and exhaust gas conversion performance of the catalytic material.

Exhaust gas purification catalytic material and method for fabricating the same

In an exhaust gas purification catalyst comprising a honeycomb support and a catalytic layer that is formed on wall surfaces of each cell of the honeycomb support and contains active alumina and a mixed oxide containing Ce, Zr and Nd and doped with catalytic precious metal, the mixed oxide has a CeO/ZrOmass ratio of 1.4 or more and the ratio of NdO/(CeO+ZrO+NdO) in the mixed oxide is 20 mass % or less.

Exhaust gas purification catalyst and oxygen storage component for the same

An exhaust gas purifying catalyst includes a carrier and a catalyst layer provided on the carrier. The catalyst layer includes active AlOon which a noble metal is carried, an oxygen storage agent on which Rh is carried, AlOcoated with ZrOon which Rh is carried, and a binder material.

An exhaust gas purifying catalyst contains a NOx absorbing component which comprises at least one kind of element selected from a group of alkaline earth metals, a group of alkaline metals and a group of rare earth elements and a component, other than the NOx absorbing component, selected between K and Na. The catalyst has a such a structure that the component other than the NOx absorbing component is brought into contact with an exhaust gas before the NOx absorbing component is brought into contact with the exhaust gas.

Method of producing exhaust gas purifying catalyst and catalyst produced thereby

An exhaust gas emission control catalyst includes an under catalyst layer containing at least one of barium and lanthanum and an over catalyst layer containing an agent for absorbing water in a gas, at least one of the under catalyst layer and over catalyst layer containing catalytic metal.

Burned gas purifying catalyst

An exhaust gas purifying catalyst is provided by coating a slurry of a mixture of a powdered first catalyst provided by carrying Pt on a mixture of alumina and ceria and a powdered second catalyst provided by carrying Rh on manganese oxide on a support member and then impregnating the coated layer with a solution of barium.

Catalyst for purifying exhaust gas and manufacturing method thereof

A catalytic base material for an exhaust gas purifying catalyst is produced by impregnating ceria powders with a barium contained solution and heating the ceria particles at approximately 400 to 1100&deg; C. to create and accumulate barium oxides fixed to surfaces of the ceria particles.

Material for exhaust gas purifying catalyst, exhaust gas purifying catalyst made of the material and method for producing the exhaust gas purifying catalyst

An exhaust gas purifying system includes an exhaust gas purifying catalyst having a nitrogen oxide absorbing material which is installed in an exhaust line of an engine and performs split fuel injection to inject fuel directly into each combustion chamber partly during a suction stroke and partly during a compression stroke to provide and supply an increased amount of carbon monoxide to the nitrogen oxide absorbing material so as thereby to desorb sulfur oxides from the nitrogen oxide absorbing material.

Exhaust gas purifying system for engine

Growing community of inventors

Hiroshima, Japan

Hideharu Iwakuni