TRANSITION METAL/ZEOLITE SCR CATALYSTS

An exhaust system (10) for a vehicular lean burn internal combustion engine (12), which system comprising a conduit (14) for carrying a flowing exhaust gas, a source of nitrogenous reductant (26), a zeolite catalyst (20) containing at least one transition metal disposed in a flow path of the exhaust...

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Bibliographic Details
Main Authors FEDEYKO, JOSEPH MICHAEL, COLLIER, JILLIAN ELAINE, CASCI, JOHN LEONELLO, ANDERSEN, PAUL JOSEPH, CHEN, HAI-YING
Format Patent
LanguageEnglish
French
Published 06.11.2008
Subjects
PERFORMING OPERATIONS
PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
SEPARATION
TRANSPORTING
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Summary:An exhaust system (10) for a vehicular lean burn internal combustion engine (12), which system comprising a conduit (14) for carrying a flowing exhaust gas, a source of nitrogenous reductant (26), a zeolite catalyst (20) containing at least one transition metal disposed in a flow path of the exhaust gas and means (22, 28, 30) for metering nitrogenous reductant into a flowing exhaust gas upstream of the zeolite catalyst, wherein the zeolite catalyst is a small pore zeolite containing a maximum ring size of eight tetrahedral atoms, wherein the zeolite is a synthetic zeolite having the CHA Framework Type Code, wherein the at least one transition metal is copper, wherein an oxidation catalyst (16) comprising at least one platinum group metal for oxidising nitrogen monoxide to nitrogen dioxide is located upstream of the means (22) for metering the nitrogenous reductant into a flowing exhaust gas.
Bibliography:Application Number: CA20082939726