Mazda Motor Corporation

Yuki Murakami

Masaaki Akamine

Akihide Takami

Masahiko Shigetsu

Hideharu Iwakuni

Hisaya Kawabata

Yasuhiro Ochi

Hiroshi Yamada

Seiji Miyoshi

Yasuhiro Matsumura

Susumu Mineoi

An exhaust gas purification catalyst includes a Rh-containing catalyst layer provided on a base material. The Rh-containing catalyst layer includes a binder material of Rh-doped CeZr-based composite oxide containing Ce and Zr and doped with Rh. The binder material has been previously subjected to a reduction treatment.

Exhaust gas purification catalyst and method for producing the same

An exhaust gas purification catalyst includes a catalytic layer containing a particle component A-1 and a particle component A-2 with different catalytic metal contents, each of which is composed of catalytic-metal-doped CeZr-based mixed oxide powder. The particle component A-1 having the lower catalytic metal content is supported on a particle component B composed of Zr-based-oxide-supported alumina powder, and the particle component A-2 having the higher catalytic metal content is supported on a particle component C composed of CeZr-based mixed oxide powder in which catalytic metal is not solid-dissolved.

Exhaust gas purification catalyst

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

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.

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Hiroshima, Japan

Yuki Murakami