Patent ID: 7189376

Claim:
An exhaust gas treatment catalyst, comprising: a substrate comprising a longitudinal axis, an inlet end, an outlet end, having a length extending between the inlet end to the outlet end, a plurality of passages, wherein each of the passages is tubularly enclosed by an internal surface of the substrate; wherein the plurality of passages comprise a first group of passages and a second group of passages, wherein the internal surfaces of the first and second groups of passages have a trap layer and a first catalytic layer; wherein the second group of passages further has a second catalytic layer; wherein: the trap layer comprises a hydrocarbon trap segment and a NOx trap segment, wherein the hydrocarbon trap segment comprises a hydrocarbon adsorbent; and wherein the NOx trap segment comprises a NOx adsorbent; the first catalytic layer comprises an inlet catalytic segment and an outlet catalytic segment; wherein the inlet catalytic segment comprises an inlet platinum component and an inlet rhodium component; and wherein the outlet catalytic segment comprises an outlet platinum component and an outlet rhodium component; and the second catalytic layer comprises a second platinum component; wherein: the trap layer is interposed between the internal surfaces of the substrate and the first catalytic layer; and the second catalytic layer is disposed on the first catalytic layer, and wherein the second catalytic layer begins from the outlet end and extends for no more than 50% of the substrate's length.