Catalyst for treating exhaust gas
AssigneeJohnson Matthey Public Limited Company
InventorsGuy Richard Chandler, Hai-Ying Chen, Jillian Elaine Collier, Joseph Michael Fedeyko, Alexander Nicholas Michael Green
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Abstract
Provided is a method for reducing N2O emissions in an exhaust gas comprising contacting an exhaust gas containing NH3 and an inlet NO concentration with an SCR catalyst composition containing small pore zeolite having an SAR of about 3 to about 15 and having about 1-5 wt. % of an exchanged transition metal.
Claims11
A method for reducing N2O emissions in an exhaust gas comprising contacting an exhaust gas containing NH3 and an inlet NO concentration with an SCR catalyst composition containing small pore zeolite having an AEI framework and an SAR of about 3 to about 15 and having about 1-5 wt. % of an exchanged transition metal to produce a purified gas containing an outlet NO concentration and an outlet N2O concentration,
- a. wherein the inlet NO concentration and outlet NO concentration have a relative ratio of >about 4, and
- b. wherein the inlet NO concentration and outlet N2O concentration have a relative ratio of >about 50.
A system for treating an exhaust gas comprising, in series and in fluid communication, a diesel oxidation catalyst, a source of nitrogen-based reductant, and an SCR catalyst, wherein the SCR catalyst comprises a small pore zeolite having an AEI framework and an SAR of about 3 to about 15 and having about 1-5 wt. % of an exchanged transition metal, and wherein the SCR catalyst is coated on a honeycomb wall-flow filter or flow-through monolith or is an extruded honeycomb body.
Dependencies are inferred from the claim text.