| 摘要 |
<P>PROBLEM TO BE SOLVED: To maintain durability high at a high temperature and develop the activity of noble metals to the utmost, and improve a low-temperature activity in a catalyst for cleaning exhaust gas. <P>SOLUTION: The catalyst for cleaning exhaust gas comprises an undercoat layer 2 formed by carrying Pt on a porous oxide, and an overcoat layer 1 formed on the surface of the under-coat layer 2 and formed by carrying Rh on a solid electrolyte with an electric conductivity of -2logδ(mho/cm) or more; and the undercoat layer includes an oxide having Ce as a constituting element but the overcoat layer does not include the oxide. Thus, a correlation between the entrance/exit of oxygen into/out of the solid electrolyte and the oxidation reaction by Rh becomes optimal by carrying Rh on a solid electrolyte with an electric conductivity of -2logδ(mho/cm) or more, and the oxidation activity in a low-temperature region is remarkably improved by developing the activity of Rh at the most. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
