Daiichi Kigenso Kagaku Kogyo Co., Ltd.

Toyota Jidosha Kabushiki Kaisha

Sumitomo Dow Limited

Daiichi Kigenso Kagaku Kogyo Co., Ltd.a

Yoshikazu Hirose

Hiroyuki Hayashida

Hiromasa Nishioka

Shigeki Nakayama

Kenji Sakurai

Naoyoshi Kawamoto

Shigeharu Suzuki

Provided is an alumina-based composite oxide having a large initial specific surface area and a small initial mean pore size, with excellent heat resistance of the specific surface area and pore volume; and a production method therefor. Specifically, provided is an alumina-based composite oxide wherein the initial crystallite diameter is 10 nm or less and the initial specific surface area is 80 m/ml or more; after calcination at 1200° C. for 3 hours in air, the specific surface area is 10 m/ml or more; the initial mean pore size is 10 nm or more and 50 nm or less; and after calcination at 1200° C. for 3 hours in air, the pore volume retention rate is 10% or more, which is determined by (P/P)×100 wherein Prepresents an initial pore volume (ml/g), and Prepresents a pore volume (ml/g) after calcination at 1200° C. for 3 hours in air.

Alumina-based composite oxide and production method for same

Provided is an alumina-based composite oxide having a large initial specific surface area and a small initial mean pore size, with excellent heat resistance of the specific surface area and pore volume; and a production method therefor. Specifically, provided is an alumina-based composite oxide wherein the initial crystallite diameter is 10 nm or less and the initial specific surface area is 80 m/ml or more; after calcination at 1200&#xb0; C. for 3 hours in air, the specific surface area is 10 m/ml or more; the initial mean pore size is 10 nm or more and 50 nm or less; and after calcination at 1200&#xb0; C. for 3 hours in air, the pore volume retention rate is 10% or more, which is determined by (P/P)&#xd7;100 wherein Prepresents an initial pore volume (ml/g), and Prepresents a pore volume (ml/g) after calcination at 1200&#xb0; C. for 3 hours in air.

An exhaust gas purifying catalyst of the present invention includes: a first metal oxide selected from the group of praseodymium oxide, terbium oxide, and a combination thereof; a second metal oxide that is neodymium oxide; a third metal oxide that is zirconia or a combination of zirconia and ceria; and a fourth metal oxide selected from the group of lanthanum oxide, yttrium oxide, barium oxide, calcium oxide, strontium oxide, silicon oxide and a combination thereof.

Catalyst composition and exhaust gas purifying method

Ionizing radiation-resistant polycarbonate resin composition and medical

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Osaka, Japan

Yoshikazu Hirose