| 摘要 |
PROBLEM TO BE SOLVED: To effectively suppress HC from delivering by improving the structure of an HC adsorbing catalyst obtained by coating catalytic converter rhodium layer on the upper layer of an HC adsorbing material so as to increase the HC conversion performance in low temperatures. SOLUTION: The internal surface of a cell 12 of a honeycomb carrier 11 is coated with HC adsorbing material 13 except for the downstream end of that surface in exhaust emission flow direction, the overall internal surface of the cell 12 coated with the HC adsorbing material 13 is coated with catalytic converter rhodium 14, and a part X having a catalytic converter rhodium layer part 14 on the upper layer of the HC adsorbing material 13 and a catalytic converter rhodium layer part Y positioned on the downstream side of the exhaust emission flow are formed on the internal surface of the cell 12 of the honeycomb carrier 11. By this, HC is peeled off from, adsorbed to, peeled off, and re-adsorbed repeatedly to a part positioned on the upstream side of the exhaust emission flow of the HC adsorbing catalyst and, finally, reaches the downstream end of the part X having a catalytic converter rhodium layer part 14 on the upper layer of the HC adsorbing material 13. Because the catalytic converter rhodium layer part Y is provided on the downstream end of the part X, HC is converted by the catalytic converter rhodium layer part 14 in the part Y. |
