| 摘要 |
PURPOSE:To provide a highly heat resistant catalyst having a long life used in simultaneous removal of NOx CO and HC, and obtd. by supporting Rh or Rh and one or more kinds of other platinum group metals, and one or more kinds of metals showing a plurality of oxidized states on a transitive alumina carrier in which at least alpha-alumina is detected through X-rays. CONSTITUTION:alpha-alumina base carrier or activated alumina with a relatively large specific area is calcined to prepare a spherical transitive alumina carrier in which at least alpha-alumina is detected through X-rays. On this carrier are then supported 0.01g of Rh to 1l of packed catalyst or more than 0.02g of Rh and other platinum group metals, and more than 0.01mol of O2 storage components such as Ce, Fe, Cu and Co. The resulting catalyst is used in simultaneous removal of NOx, CO, HC, etc. contained in exhaust gas of car esp. equipped with an internal combustion engine and it has superior heat resistance. |
