| 摘要 |
A method of using a catalyst comprises exposing a catalyst to at least one reactant in a chemical process, wherein the catalyst comprises copper and a small pore molecular sieve having a maximum ring size of eight tetrahedral atoms, the chemical process includes 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, wherein the final activity is within 30% of the initial activity at a temperature between 200 and 500°C. The reactant may include nitrogen oxides and a selective catalytic reductant. The reductant may be ammonia or ammonia and oxygen. The molecular sieve may be selected from the group consisting of aluminosilicates, metal-substituted aluminosilicates and aluminophophates. |
