Abstract: Methods and systems related to an exhaust gas treatment system including, in order: (i) a first means for injecting a nitrogenous reductant; (ii) a first selective catalytic reduction (SCR) catalyst; (iii) an ammonia slip catalyst (ASC); and (iv) a second selective catalytic reduction (SCR) catalyst, wherein the ASC comprises an SCR catalyst and a supported palladium (Pd) component.

Abstract: Exhaust purification system and methods for the reduction of emissions from an exhaust stream, including an upstream catalyst coupled with a passive NOx adsorber catalyst; means to contact the exhaust stream with ozone, to react NO in the exhaust stream with the ozone to produce NO2; and an SCR catalyst.

Abstract: An exhaust system for treating an exhaust gas produced by a diesel engine comprises: (a) an emissions control device (ECD) for oxidizing carbon monoxide (CO) and/or hydrocarbons (HCs), wherein the emissions control device comprises a platinum group metal (PGM) and a substrate, wherein the PGM is platinum, palladium or a combination thereof; (b) an injector for introducing an ammonia precursor into the exhaust gas, which is downstream of the ECD; (c) a first selective catalytic reduction (SCR) catalyst downstream of the injector, wherein the first SCR catalyst comprises a substrate and a first SCR composition, wherein the substrate is either a flow-through substrate or a filtering substrate; (d) a second SCR catalyst downstream of the first SCR catalyst, wherein the second SCR catalyst comprises a flow-through substrate and a second SCR composition; and wherein at least one of the ECD and the first SCR reduction catalyst has a filtering substrate.

Abstract: Exhaust purification system and methods for the reduction of emissions from an exhaust stream, including an upstream catalyst coupled with a passive NOx adsorber catalyst; means to contact the exhaust stream with ozone, to react NO in the exhaust stream with the ozone to produce NO2; and an SCR catalyst.

Abstract: An exhaust system for treating an exhaust gas produced by a diesel engine comprises: (a) an emissions control device (ECD) for oxidising carbon monoxide (CO) and/or hydrocarbons (HCs), wherein the emissions control device comprises a platinum group metal (PGM) and a substrate, wherein the PGM is platinum, palladium or a combination thereof; (b) an injector for introducing an ammonia precursor into the exhaust gas, which is downstream of the ECD; (c) a first selective catalytic reduction (SCR) catalyst downstream of the injector, wherein the first SCR catalyst comprises a substrate and a first SCR composition, wherein the substrate is either a flow-through substrate or a filtering substrate; (d) a second SCR catalyst downstream of the first SCR catalyst, wherein the second SCR catalyst comprises a flow-through substrate and a second SCR composition; and wherein at least one of the ECD and the first SCR reduction catalyst has a filtering substrate.