Mazda Motor Corporation

Toda Kogyo Corporation

Koji Minoshima

Akihide Takami

Hiroshi Yamada

Hideharu Iwakuni

Seiji Miyoshi

Masaaki Akamine

Koichiro Harada

Tomoaki Urai

Hirosuke Sumida

Tomohiro Honda

Ryota Fujimoto

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

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.

Exhaust gas purification catalyst

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.

Exhaust gas purifying catalyst

Growing community of inventors

Hiroshima, Japan

Koji Minoshima