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 includes a passive NOx adsorber (PNA), and an ammonia slip catalyst (ASC) comprising a platinum group metal on a support and a first SCR catalyst; where the second zone includes 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 with a blend of: (1) the platinum group metal on a support and (2) the first SCR catalyst; and a top layer with a second SCR catalyst, the top layer located over the bottom layer.

The present invention is directed towards the use of an ion-exchanged zeolite containing ASC as a trap for volatile vanadium compounds in a downstream position of a vanadium containing SCR-catalyst.

A catalytic article for treating an exhaust gas stream containing particulate matter, hydrocarbons, CO, and ammonia, the article may include: (a) a substrate having an inlet end and an outlet end defining an axial length; (b) a first catalyst coating including: 1) a platinum group metal distributed on a molecular sieve, and 2) a base metal distributed on a molecular sieve; and (c) a second catalyst coating including: 1) a platinum group metal distributed on a molecular sieve, and 2) a base metal distributed on a molecular sieve.

In an exhaust system for a motor vehicle having an exhaust treatment device for after-treating exhaust gas of a combustion engine of the motor vehicle, the exhaust gas treatment device includes a first SCR catalyst, which has a zeolite material containing copper, an ammonia slip catalyst, which is arranged downstream of the first SCR catalyst, and a particulate filter. A second SCR catalyst, which has an SCR catalyst material containing vanadium, is arranged upstream of the first SCR catalyst.

A method for operating an exhaust system of an internal combustion engine of a motor vehicle, in which exhaust gas from the internal combustion engine flows through a first SCR catalytic converter, which is followed by an ammonia barrier catalytic converter, and flows through a second SCR catalytic converter which is disposed downstream of the ammonia barrier catalyst, includes introducing a reducing agent introduced into the exhaust gas by a first metering device upstream of the first SCR catalytic converter and by a second metering device upstream of the second SCR catalytic converter. When a predetermined threshold value of a temperature of a region of the exhaust system is exceeded, a quantity of reducing agent introduced into the exhaust gas by the first metering device is increased.

A selective catalytic reduction catalyst composition for converting oxides of nitrogen (NO.sub.x) in an exhaust gas using a nitrogenous reductant, which catalyst composition comprising a mixture of a first component and a second component, wherein the first component is the H-form of an aluminosilicate chabazite zeolite (CHA); or an admixture of the H-form of an aluminosilicate mordenite zeolite (MOR) and the H-form of an aluminosilicate chabazite zeolite (CHA); and the second component is a vanadium oxide supported on a metal oxide support, which is titania, silica-stabilized titania or a mixture of titania and silica-stabilized titania, wherein the weight ratio of the first component to the second component is 10:90 to 25:75.

Catalyst and use of the catalyst comprising a molecular sieve belonging to the ABC-6 framework family with disorder in the ABC stacking sequence essentially composed of double-six-ring periodic building units and having a mole ratio of silicon oxide to aluminum oxide from about 8 to about 60.

A method for the preparation of a molecular sieve belonging to the ABC-6 framework family with disorder in the ABC stacking sequence essentially composed of double-six-ring periodic building units and having a mole ratio of silicon oxide to aluminum oxide from about 8 to about 60.

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 includes a passive NOx adsorber (PNA), and an ammonia slip catalyst (ASC) comprising a platinum group metal on a support and a first SCR catalyst; where the second zone includes 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 with a blend of: (1) the platinum group metal on a support and (2) the first SCR catalyst; and a top layer with a second SCR catalyst, the top layer located over the bottom layer.

The present invention relates to a catalytic article comprising a substrate having a catalyst composition disposed thereon, wherein the catalyst composition comprises a platinum group metal impregnated onto a porous support and a selective catalytic reduction catalyst, wherein the catalyst composition is substantially free of platinum; and wherein the catalytic article is effective in the abatement of nitrogen oxides (NOx) and hydrocarbons (HCs). The present invention further relates to exhaust gas treatment systems for treating an exhaust gas stream exiting a diesel engine.