| 摘要 |
PROBLEM TO BE SOLVED: To surely purify, at the time of desorbing, a hydrocarbon adsorbed at the start of an internal combustion engine to prevent it from releasing to the outside. SOLUTION: An adsorption catalytic device 13 for adsorbing the hydrocarbon in an exhaust gas is interposingly mounted in an exhaust passage 18 of the internal combustion engine 1. The adsorption catalytic device 13 has a double layer structure of an adsorption layer containing adsorbent as an upper layer and a catalytic layer as a surface layer and in the catalytic layer, an oxide or the like generating heat by the irradiation with electromagnetic wave is blended. An electromagnetic wave generator 12 for emitting electromagnetic wave is provided in the inlet side of the adsorption catalytic device 13. After the start of the internal combustion engine 1, the electromagnetic generator 12 is operated to selectively cause the catalytic layer to generate heat when the tamp. of the catalyst is low. Then the catalyst reaches activation temp. before the adsorption layer reaches desorption start temp., and after that, the desorbed hydrocarbon is surely treated. |
