Patent ID: 7837953

Claim:
An article, comprising: a substrate comprising an inlet end, an outlet end, a length extending between the inlet end to the outlet end, wall elements and a plurality of cells defined by the wall elements; a first layer deposited on the wall elements from the inlet end and extending at least partially toward the outlet end, wherein the first layer comprises a preferential carbon monoxide oxidation catalyst, wherein the preferential carbon monoxide oxidation catalyst is a platinum-metal based catalyst, a palladium metal-based catalyst, or a mixture of thereof, the platinum-metal based catalyst consisting of about 1 to 5 wt. % of platinum, a support and an optional promoter, and the palladium metal-based catalyst consisting of about 1 to 5 wt. % of palladium, a support and an optional promoter; and a second layer deposited on at least part of the first layer from the outlet end and having a length that is about 10-70% of the wall elements' length beginning from the outlet end, the second layer comprises a methanation catalyst consisting of a ruthenium component and a support, wherein the first layer and the second layer are arranged to form three zones where a first zone extending from the inlet end has the first layer not overlaid by the second layer, a second zone downstream from the inlet end and upstream from the output end has the first layer overlaid by the second layer, and a third zone extending from the outlet end has the second layer not overlying the first layer, and the first layer extends from the inlet end and the second layer extends from the outlet end.