| 摘要 |
PROBLEM TO BE SOLVED: To provide an SCR system which shows high activity in a range from a low temperature region to a high temperature region and still has resistance to thermal deterioration.SOLUTION: The SCR system uses an SCR catalyst 20 for reducing NOx in exhaust gas with ammonia. The SCR catalyst 20 consists of a high-temperature active Fe catalyst 21i located on the front face at its center, and a low-temperature active Cu catalyst 21o located on the front face at its outer periphery and at its center behind the Fe catalyst. |
