| 摘要 |
PROBLEM TO BE SOLVED: To adsorb efficiently HC and SOF in a low temperature zone, prevent the discharge of HC and SOF and control further the formation of sulfate by mixing acidic carrier powder on which a catalyst metal is carried with basic carrier powder of more basic than the acidic carrier powder. SOLUTION: Mixed powder formed by mixing acidic carrier 20 powder on which a catalyst metal such as platinum, palladium or silver, or iron or copper and with basic carrier 21 powder more basic than the acidic carrier 20 powder can be applied for coating a honeycomb type or a pellet type shaped carrier base 1. As for the acidic carrier 20, a carrier of low adsorptivity of SO2 in exhaust gas is discharged out, and at least one kind selected out of SiO2 -TiO2 , ZrO2 -SiO2 and SiO2 is used desirably. As the base carrier 21, any carrier of more basic, even slightly more, than the acidic carrier 20 can be used, and a carrier of high adsorptivity of SOF and SO2 is desirably used, and at least one kind selected out of Al2 O3 , ZrO2 and TiO2 is desirably used. |
