ZONED CATALYST SYSTEM FOR REDUCING N2O EMISSIONS

摘要

A catalyst system for reducing N2O emissions in the exhaust system of a vehicle is provided and comprises a support in communication with the exhaust gas stream, with the support including an exhaust gas inlet and an exhaust gas outlet. The support has at least one exhaust gas passage therethrough. The support, which may be in the form of a monolithic, multi-cell honeycomb construction, comprises a first catalytic zone and a second catalytic zone positioned downstream from the first zone. The first catalytic zone includes rhodium or a rhodium-enriched catalyst, while the second catalytic zone includes palladium or a palladium-enriched catalyst.

主权项

1. A catalyst system for reducing N2O emissions in the exhaust system of a vehicle comprising, a support in communication with the exhaust gas stream, said support including an exhaust gas inlet and an exhaust gas outlet and having at least one exhaust gas passage therethrough, said support comprising a first catalytic zone and a second catalytic zone positioned downstream from said first zone, said first catalytic zone including a PGM catalyst comprising from about 50 to about 100 wt % rhodium, with the remainder comprising palladium and/or platinum in any weight ratio, and said second zone including a PGM catalyst comprising from about 50 to about 100 wt % palladium, with the remainder comprising rhodium and/or platinum in any weight ratio.