Abstract: A method of using a catalyst comprises exposing a catalyst to at least one reactant in a chemical process. The catalyst comprises copper and a small pore molecular sieve having a maximum ring size of eight tetrahedral atoms. The chemical process undergoes at least one period of exposure to a reducing atmosphere. The catalyst has an initial activity and the catalyst has a final activity after the at least one period of exposure to the reducing atmosphere. The final activity is within 30% of the initial activity at a temperature between 200 and 500° C.
Type:
Grant
Filed:
May 2, 2012
Date of Patent:
January 8, 2013
Assignee:
Johnson Matthey Public Limited Company
Inventors:
Paul Joseph Andersen, Hai-Ying Chen, Joseph Michael Fedeyko, Erich Weigert
Abstract: A catalyst comprising: (a) a first layer comprising an oxidizing catalyst having an effective PGM loading such that oxidation of hydrocarbons generates sufficient heat to regenerate soot, wherein said effective amount of PGM is greater than about 10 g/ft3; and (b) a second layer adjacent to said first layer and comprising a reducing catalyst to selectively reduce NOx.