Basf Corporation

Basf Mobile Emissions Catalysts LLC

David M Youngren

Kevin A Hallstrom

Kenneth Edwin Voss

Yuejin Li

Sanath V Kumar

Robert Dorner

Sandip D Shah

Weiyong Tang

M Shahjahan Kazi

Andrew Thoms

Provided are catalyst articles, methods and systems for treating lean burn engine exhaust. Catalyst articles include selective catalytic reduction catalyst on a particulate filter. The SCR catalyst on the particulate filter provides limited NOx conversion so that unconverted NOis available to facilitate passive oxidation of soot trapped on the particulate filter by reaction with NO. Systems and methods utilize such catalytic articles, and further include, e.g., a downstream selective catalytic reduction catalyst on a flow through substrate.

Filter catalyzed with SCR catalyst, systems and methods

The present disclosure is directed to a system for treating an exhaust gas stream from an engine, which includes a diesel oxidation catalyst (DOC) located downstream of the engine and adapted for oxidation of hydrocarbons and carbon monoxide, an injector adapted for the addition of a reductant to the exhaust gas stream located downstream of the DOC, a catalyzed soot filter (CSF) located downstream of the injector, and a selective catalytic reduction component adapted for the oxidation of nitrogen oxides located downstream of the CSF. The CSF is adapted for oxidizing hydrocarbons and includes a selective oxidation catalyst composition on a filter with high selectivity ratio for hydrocarbon oxidation:ammonia oxidation (e.g., at least 0.6).

Catalyzed soot filter with reduced ammonia oxidation

A system for treatment of an exhaust gas stream from an engine is provided, containing an upstream selective catalytic reduction (SCR) catalyst, which receives the exhaust gas stream without any intervening catalyst, a diesel oxidation catalyst (DOC) positioned downstream thereof; a catalyzed soot filter (CSF) downstream of the diesel oxidation catalyst; a second SCR catalyst positioned downstream of the catalyzed soot filter; and an ammonia oxidation (AMOx) catalyst. The application also describes use of such systems to reduce nitrogen oxides (NOx) and hydrocarbons (HC) in an exhaust gas stream.

Exhaust gas treatment system with upstream SCR catalyst

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Union, NJ, United States of America

David M Youngren