Engelhard Corporation

Englehard Corporation

Rudolf M Smaling

Shiang Sung

Ronald Marshall Heck

John Joseph Steger

Harold N Rabinowitz

Alan R Amundsen

Zhicheng Hu

An exhaust gas treatment apparatus and method for its use includes an upstream catalyst and a downstream catalyst. The upstream catalyst contains a catalytic metal effective at least for the oxidation of hydrocarbons in the exhaust gas stream, and preferably contains a palladium catalytic component and contains substantially no oxygen storage components, i.e., oxides of cerium, cobalt, iron, magnesium, molybdenum, nickel, praseodymium, tungsten and vanadium, but the downstream catalyst includes an oxygen storage component. Preferably, the upstream catalyst is a close-coupled catalyst. The downstream catalyst may be an underfloor catalyst or a close-coupled catalyst, in which case there is, preferably, an additional, underfloor catalyst.

Engine exhaust treatment apparatus and method of use

The present invention relates to an exhaust gas treatment catalytic article having an upstream catalytic zone and at least one downstream catalytic zone. The upstream catalytic zone has an upstream composition which has a first upstream support, and at least one first upstream palladium component. The upstream zone can have one or more layers. The downstream catalytic zone has a first downstream layer which has a first downstream support and a first downstream precious metal component. A second downstream layer has a second downstream support and a second downstream precious metal component.

Exhaust gas treatment system

A catalyst composition comprising at least one first support, at least one first precious metal component, at least one second support, and at least one second precious metal component. The total amount of the first precious metal component comprises from 1 to 99 weight percent based on the total of the first and second precious metal components. The average particle size of the second support is greater than the average particle size of the first support. The present invention includes a method to prepare the catalyst composition and a method to use the catalyst composition as a three-way catalyst. The composition results in a coated layer from a slurry where the more supported first precious metal component is in the bottom half and more supported second precious metal component is in the top half.

Catalyst composition

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Plainfield, NJ, United States of America

Rudolf M Smaling