OXIDATION CATALYST FOR INTERNAL COMBUSTION ENGINE EXHAUST GAS TREATMENT

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PROBLEM TO BE SOLVED : To provide an oxidation catalyst having treatment capability equivalent to a previous exhaust gas purification catalyst even when usage of expensive and rare noble metal is reduced. SOLUTION : This oxidation catalyst for exhaust gas treatment includes : a carrier base material and a plurality of catalyst layers supported to the carrier base material, wherein each of the plurality of catalyst layers includes a washcoat material, an active metal and a hydrocarbon adsorbent; one catalyst layer is present on a catalyst surface layer side; the other catalyst layers are present on lower layer sides relative to the one catalyst layer; the abundance of the hydrocarbon adsorbent in the one catalyst layer is larger than that of the hydrocarbon adsorbent in the other catalyst layers; and the presence concentration of the active metal in the one catalyst layer is smaller than that of the active metal in the other catalyst layers. Thereby, the oxidation catalyst can be provided by an oxidation catalyst having a characteristic of subjecting hydrocarbon (HC) and carbon monoxide (CO) in exhaust gas to oxidation treatment. COPYRIGHT : (C)2013, JPO&INPIT