Catalytic composition with added copper trapping component for NOx abatement
AssigneeBASF Mobile Emissions Catalysts LLC
InventorYuejin Li
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Abstract
The present disclosure provides catalyst compositions for NOx conversion and wall-flow filter substrates comprising such catalyst compositions. Certain catalyst compositions include a zeolite with sufficient Cu exchanged into cation sites thereof to give a Cu/Al ratio of 0.1 to 0.5 and a CuO loading of 1 to 15 wt. %; and a copper trapping component (e.g., alumina) including a plurality of particles having a D90 particle size of about 0.5 to 20 microns in a concentration of about 1 to 20 wt. %. The zeolite and copper trapping component can be in the same washcoat layer or can be in different washcoat layers (such that the copper trapping component serves as a “pre-coating” on the wall-flow filter substrate).
Claims23
A catalyst article comprising:
- a wall-flow filter substrate;
- and
- a catalyst composition coated on the wall-flow filter substrate,
- wherein the catalyst composition comprises:
- a zeolite with sufficient copper (Cu) exchanged into cation sites of the zeolite such that the zeolite has a Cu/Al ratio ranging from 0.1 to 0.5 and a CuO loading ranging from 1 wt. % to 15 wt. % based on a total weight of the zeolite;
- and
- a copper trapping component in an amount ranging from about 1 wt. % to about 20 wt. % based on the weight of the Cu-exchanged zeolite;
- and
- wherein the copper trapping component comprises a plurality of particles having a D90 particle size ranging from about microns 0.5 to about 20 microns, and the copper trapping component comprises non-dispersible alumina having an agglomerate size of D10>0.1 microns and is substantially free of any active metal associated therewith.
Dependencies are inferred from the claim text.