Gm Global Technolgoy Operations, Inc.

Basf Corporation

Richard J Blint

Chang H Kim

Steven Jeffrey Schmieg

Byong Kwon Cho

Ayyappan Subbiah

Wei Ping Li

Ahmad Moini

Gerald Stephen Koermer

Michael B Viola

Christopher R Castellano

Howard Furbeck

Jong-Hwan Lee

Ling Deng

A method for catalytic oxidation of NO to NOin the sulfur-containing exhaust gases of lean-burn engines, such as diesel engines is disclosed. The catalysts are oxide perovskites with a credible likelihood of being sulfur-tolerant.

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A sulfur tolerant oxidation catalyst with appreciable NO and HC oxidation capabilities has been developed for use in any component of an exhaust aftertreatment system for a lean-burn engine where the oxidation of at least NO is desired. Several non-exclusive examples of such components where the oxidation catalyst may be employed include a DOC and a LNT. The oxidation catalyst may comprise perovskite oxide particles that support palladium particles. The ability of the palladium supported perovskite oxide particles to concurrently oxidize NO and HC's can significantly diminish or altogether eliminate the use of platinum in the exhaust aftertreatment system for at least NO oxidation. The oxidation catalyst, moreover, may exhibit superior thermal durability and better NO and HC oxidation activities than platinum in some instances.

Sulfur tolerant perovskite supported catalysts

A method and apparatus are described to selectively reduce NOemissions of an internal combustion engine. An exhaust aftertreatment system includes an injection device operative to dispense a hydrocarbon reductant upstream of a silver-alumina catalytic reactor device. A control system determines a NOconcentration and hydrocarbon/NOx ratio based upon selected parameters of the exhaust gas feedstream and dispenses hydrocarbon reductant during lean engine operation. Included is a method to control elements of the feedstream during lean operation. The hydrocarbon reductant may include engine fuel.

Catalysts, systems and methods are described to reduce NOemissions of an internal combustion engine. In one embodiment, an emissions treatment system for an exhaust stream is provided having a catalyst comprising silver and a platinum group metal on a particulate alumina support, the atomic fraction of the platinum group metal being less than or equal to about 0.25. Methods of manufacturing catalysts are described in which silver is impregnated on alumina particles.

Certain metal-exchanged SUZ-4 zeolites have been prepared that have catalytic activity for the reduction of NOx in the exhaust of a hydrocarbon or alcohol fueled engine operated under fuel lean conditions. Initially the SUZ-4 zeolite contains alkali metal cations such as Li, Na, Kand/or Cs. These alkali metal cation-containing zeolites are partially exchanged with at least one of copper (II), silver (I), iron (III) or cobalt (II) ions. The resulting partially exchanged SUZ-4 zeolites display such activity and are stable under extreme hydrothermal aging conditions.

Hydrothermally stable catalyst for improved lean NOx reduction

Certain metal-exchanged SUZ-4 zeolites have been prepared that have catalytic activity for the reduction of NOx in the exhaust of a hydrocarbon or alcohol fueled engine operated under fuel lean conditions. Initially the SUZ-4 zeolite contains alkali metal cations such as Li , Na , K and/or Cs . These alkali metal cation-containing zeolites are partially exchanged with at least one of copper (II), silver (I), iron (III) or cobalt (II) ions. The resulting partially exchanged SUZ-4 zeolites display such activity and are stable under extreme hydrothermal aging conditions.

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Shelby Township, MI, United States of America

Richard J Blint