Patent ID: 7622096

Claim:
An exhaust gas treatment system comprising: a catalytic material deposited on a carrier, the carrier comprising a longitudinal axis, an upstream end, a downstream end, having a length extending between the inlet end to the outlet end; the catalytic material comprising: an inner layer having an inner layer upstream zone and an inner layer downstream zone deposited on the carrier, the inner layer comprising a first support, being substantially free of precious metals, and, optionally, comprising a first oxygen storage component; a middle layer having a middle layer upstream zone and a middle layer downstream zone, the middle layer comprising a second support, a palladium component, and, optionally, a second oxygen storage component; and an outer layer having an outer layer upstream zone and an outer layer downstream zone, the outer layer comprising a third support, a rhodium component, and, optionally, a third oxygen storage component; wherein at least two of the first oxygen storage component, the second oxygen storage component, and the third oxygen storage component are present in the inner layer downstream zone, the middle layer downstream zone, and the outer layer downstream zone, respectively, in amounts greater than in the inner layer upstream zone, the middle layer upstream zone, and the outer layer upstream zone, respectively.