| 摘要 |
The present invention has as its object the provision of a platinum-rhodium catalyst for automotive exhaust gas wherein the exhaust gas purification catalyst is provided with resistance to lean conditions due to fluctuations in the exhaust gas atmosphere due to fuel cuts of the automobile engine and the catalyst itself is provided with heat resistance due to mounting in the high temperature region right near the engine. Further, the platinum-rhodium catalyst for automotive exhaust gas of the present invention is formed with a catalyst layer from a mixture of a platinum catalyst carrier substance comprised of 95 to 99.9 wt % of a first catalyst carrier substance comprised of either first cerium oxide or activated alumina stabilized by zirconium carrying 0.1 to 5 wt % of platinum, a rhodium catalyst-carrying powder comprised of a second catalyst carrier substance of a rare earth metal element-stabilized zirconium oxide carrying 0.1 to 5 wt % of rhodium, a zirconium-stabilized second cerium oxide not carrying any catalytic precious metal, and a heat resistant inorganic oxide and a binder and is comprised of the catalyst layer and a catalyst carrier substrate carrying the catalyst layer on its surface.
|
