| 摘要 |
PROBLEM TO BE SOLVED: To provide an exhaust emission control catalyst and a honeycomb catalyst structure for exhaust emission control which obtain enough lifetime and have excellent durability even under severe environment such as high temperature.SOLUTION: The exhaust emission control catalyst is provided which has a surface precipitation membrane on a base material particle carrying noble metal, and which is characterized in that:a component of the surface precipitation membrane contains cerium hydroxide alone or ceria alone, or yttrium and hydroxide of at least one or more rare-earth selected from rare-earth element with atomic number 57 to 71 (excluding cerium and promethium) or oxide of the rare-earth, aluminum hydroxide or alumina or silica; and the base material particle is ceria-zirconia-based complex oxide, zirconia, yttria-stabilized zirconia, or alumina. The honeycomb catalyst structure for exhaust emission control is provided in which metal or a ceramic honeycomb inner wall is coated with the exhaust emission control catalyst.SELECTED DRAWING: Figure 1 |
