Catalyzed substrate and exhaust system for internal combustion engine

Abstract

An exhaust system, and a catalyzed substrate for use in an exhaust system, is disclosed. The exhaust system comprises a lean NOx trap and the catalyzed substrate. The catalyzed substrate has a first zone, having a platinum group metal loaded on a support, and a second zone, having copper or iron loaded on a zeolite. The first zone or second zone additionally comprises a base metal oxide or a base metal loaded on an inorganic oxide. Also provided are methods for treating an exhaust gas from an internal combustion engine using the exhaust system. The exhaust system is capable of storing NH3 generated in rich purging, reacting the NH3 with slip NOx, controlling H2S released from NOx trap desulfation, and oxidizing slip hydrocarbons and carbon monoxide. When the catalyzed substrate is a filter substrate, it is also capable of removing soot from exhaust system.

Dependencies are inferred from the claim text.