| abstract |
This invention aims at achieving early activation by use of a catalytic body having a low thermal capacity, and a low pressure loss, without using a coating layer to reduce exhaust emission. The invention is directed also to improve exhaust purification performance by improving the combination of catalytic bodies and performance of each catalytic body. In the invention, a start catalyst 1 is arranged at an upstream portion of an exhaust pipe P of a car engine E and a three way catalyst 2 is disposed on the downstream side. The start catalyst 1 can directly support catalytic components through chemical bonds by incorporating replacing elements into a substrate ceramic having high heat resistance such as cordierite. Because a coating layer is not necessary, the catalyst of the invention has a low heat capacity and a large open area and achieves reduction of exhaust emission, and reduction of a pressure loss, through early activation. |