Catalytic composition for treating a NOx-containing exhaust gas
A catalytic composition for treating a NOx-containing exhaust gas, wherein the composition comprises a copper-substituted zeolite comprising: i) Ce in a total amount of about 0.1 to about 200 g/ft 3 ; and ii) Mn in a total amount of about 0.1 to about 200 g/ft 3 .
1. A catalytic composition for treating a NOx-containing exhaust gas, wherein the composition comprises a copper-substituted zeolite comprising:
i) Ce in a total amount of about 0.1 to about 200 g/ft 3 ; and
ii) Mn in a total amount of about 0.1 to about 200 g/ft 3 .
2. The catalytic composition of claim 1 , wherein the copper is present in an amount of from about 1 to about 6 wt % of the catalytic composition.
3. The catalytic composition of claim 1 , wherein the copper is present in an amount of about 3 to about 5.5 wt % of the catalytic composition.
4. The catalytic composition of claim 1 , wherein the copper is present in an amount of about 3.2 to about 4.8 wt % of the catalytic composition.
5. The catalytic composition of claim 1 , wherein the copper-substituted zeolite is a small-pore zeolite.
6. The catalytic composition of claim 5 , wherein the small-pore zeolite has a CHA and/or AEI framework structure type.
7. The catalytic composition of claim 1 , wherein Mn is present in an amount of about 10 to about 70 g/ft 3 .
8. The catalytic composition of claim 1 , wherein Ce is present in an amount of about 80 to about 140 g/ft 3 .
9. The catalytic composition of claim 1 , wherein the composition comprises:
copper in an amount of from about 1 to about 6 wt % of the catalytic composition;
Mn in an amount of about 10 to about 70 g/ft 3 ; and
Ce in an amount of about 80 to about 140 g/ft 3 .
10. A catalyst article for an exhaust gas system, the catalyst article comprising the catalytic composition of claim 1 and a substrate.
11. An exhaust gas system comprising the catalyst article of claim 10 and a combustion engine.