05010051 is referenced by 42 patents and cites 12 patents.

A catalyst composition has an upstream stage and a downstream stage, the upstream stage containing a catalytic material which is different from the catalytic material contained on the downstream stage and is characterized by having a low ignition temperature, e.g., 350.degree. C. to less than 400.degree. C., for the substantially simultaneous conversion of HC, CO and NO.sub.x pollutants contained in, e.g., the exhaust of an automobile engine operating at a substantially stoichiometric air-to-fuel weight ratio. The downstream catalytic material is characterized by having a higher conversion efficiency for substantially simultaneous conversion of HC, CO and NO.sub.x than the upstream catalytic material at elevated operation temperatures which may be, for example, from about 400.degree. to 800.degree. C. The method of the invention includes passing a gaseous exhaust stream containing HC, CO and NO.sub.x pollutants sequentially through first the upstream and then through the downstream catalytic materials.

Title
Staged three-way conversion catalyst and method of using the same
Application Number
7/433890
Publication Number
5010051
Application Date
November 8, 1989
Publication Date
April 23, 1991
Inventor
Wayne M Rudy
Morristown
NJ, US
Assignee
Engelhard Corporation
NJ, US
IPC
B01J 23/42
B01J 23/10
B01J 21/04
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