| abstract |
A catalyst having a nitrogen oxide-removingnactivity (DeNOx activity) in a low-temperature region ofnfrom 200 to 350°C, a method for removing nitrogennoxides using the catalyst, and a method for keeping thenDeNOx activity in a wide temperature region of from 200nto 600°C are provided. The low-temperature-activencatalyst is obtained by adding tellurium to a platinum-basedncatalyst and further adding thereto a zeolitenand/or at least one kind of element selected from alkalinmetals, alkaline earth metals, boron, zinc, phosphorus,ntungsten, molybdenum, tin and cerium. The DeNOxnactivity in the region of from low-temperature to high-temperaturenis achieved by combining the catalyst withnan Ag- or Cu-based catalyst having a high activity atn300°C and higher. |