| 摘要 |
PROBLEM TO BE SOLVED: To produce a catalyst for cleaning exhaust gas, which improves NOX conversion under a lean atmosphere using unburnt hydrocarbons or CO from the exhaust gas of a diesel engine where sufficient activities with a conventional catalyst cannot be obtained after endurance. SOLUTION: In the catalyst for cleaning NOX by reduction using the unburnt hydrocarbons and CO from the exhaust gas of the diesel engine, (1) an A composition in which 0.1-20 wt.% (in terms of a metal) of at least one metal selected from the group consisting of platinum, palladium, rhodium and iridium is carried on a W-Zr complex oxide where the metal atom ratio of W/Zr is 0.01-0.3, and (2) a B composition in which 0.1-5.0 wt.% (in terms of a metal) of copper is carried on an inorganic oxide are physically mixed, and the mixing ratio of the A composition to the B composition is in the range of 30:70-70:30 by weight. |
