Patent ID: 7767163

Claim:
A treatment device, comprising: a treatment element for treating exhaust gas comprising a substrate and a catalyst, wherein the catalyst comprises: (a) an NOx adsorber disposed on the substrate, wherein the NOx adsorber has a zirconium component in solid solution or as a complex oxide with at least one of an alkali element component and an alkaline earth metal component; and a precious metal component, and is capable of adsorbing NOx and converting NOx to NHx when contacted with H 2 , and (b) an NH 3 adsorber is an overlayer disposed over the NOx adsorber and is a base adsorber which comprises a zirconium component in solid solution with a transition metal oxide component selected from the group consisting of vanadium oxide, niobium oxide, molybdenum oxide, tungsten oxide, rhenium oxide, nickel oxide, and mixtures thereof and, a precious metal component wherein the NH 3 adsorber is capable of adsorbing NH 3 and converting NH 3 to N 2 ; and a housing disposed around the substrate.