Platinum group metal and base metal on a molecular sieve for PNA-SCR-ASC close-coupled system

摘要

A catalyst article including a substrate with an inlet side and an outlet side, a first zone and a second zone, where the first zone comprises a passive NOx adsorber (PNA) comprising a platinum group metal and a base metal, both on a molecular sieve, and an ammonia slip catalyst (ASC) comprising an oxidation catalyst comprising a platinum group metal on a support, and a first SCR catalyst; where the second zone comprises a catalyst selected from the group consisting of a diesel oxidation catalyst (DOC) and a diesel exotherm catalyst (DEC); and where the first zone is located upstream of the second zone. The first zone may include a bottom layer including a blend of: (1) the oxidation catalyst and (2) the first SCR catalyst; and a top layer including a second SCR catalyst, the top layer located over the bottom layer.