| 摘要 |
An exhaust emission control catalyst disclosed herein is equipped with a rhodium catalytic layer and a platinum catalytic layer, and is characterized in that a relationship between a mole average (X) of a Pauling's electronegativity that is calculated as to elements included in the rhodium catalytic layer except platinum group elements and oxygen and a mole average (Y) of a Pauling's electronegativity that is calculated as to elements included in the platinum catalytic layer except platinum group elements and oxygen is 1.30 ‰¤ X ‰¤ 1.45 and 1.47 ‰¤ Y ‰¤ 2.0. According to this exhaust emission control catalyst, an interlayer transfer of platinum and/or rhodium and the alloying of platinum and/or rhodium are suppressed during use of the catalyst, and high exhaust gas purification performance can be exerted. |
