| 摘要 |
PURPOSE: To provide a catalytic material having an excellent heat resistance to purify NOx in an exhaust gas efficiently by making a specified amount of platinum or palladium be supported on a carrier which is a mixture of a complex oxide of a spinel structure composed mainly of nickel and gallium, and alumina. CONSTITUTION: Platinum or palladium are supported in 0.01-1.0 pts.wt. on a carrier of 100 pts.wt., wherein nickel and gallium are mainly contained, and complex oxide powder having a crystal phase of spinel structure and Al2 O3 powder are mixed. Thus, this catalytic material have an excellent NOx reducibility of course in an atmosphere containing steam, even in an atmosphere having a high oxygen concentration in the exhaust gas of >=3% or even at a high gas flow velocity and can remove NOx contained in the exhaust gas by reduction efficiently. NO2 generated on the carrier by oxidation of NO and hydrocarbon activated by the precious metal supported on the carrier react and exhibit NO reduction activity even at a low temperature area of <=350 deg.C. |
