Use of Transition Metals to Reduce Cold Start Emissions

摘要

A hydrocarbon trap catalyst and method of forming the same are disclosed. The method may include introducing copper into a zeolite at 10% to 75% of an ion-exchange level of the zeolite, introducing at least one of nickel and manganese into a zeolite at 50% to 100% total of an ion-exchange level of the zeolite, and applying a three-way catalyst layer. The copper and nickel and/or manganese may be introduced into a single zeolite or the copper may be introduced into a first zeolite layer and the nickel and/or manganese may be introduced into a second zeolite layer. If copper and another metal are introduced into the same zeolite, copper may be introduced first. The disclosed trap catalyst may increase the release temperature of hydrocarbons such as ethanol, propylene and toluene, and thus reduce vehicle cold start tailpipe emissions.

主权项

1. A hydrocarbon trap catalyst, comprising:
a first zeolite layer of a first zeolite material and including copper present at 15% to 75% of an ion-exchange level of the first zeolite material; a second zeolite layer of a second zeolite material and including at least one of nickel and manganese present at 50% to 100% total of an ion-exchange level of the second zeolite material; and a three-way catalyst layer.