| 摘要 |
PURPOSE:To obtain a three-component catalyst for purifying an exhaust gas having high activity and high durability, by a method wherein a specific cerium stock material and a specific iron stock material are used to be dissolved in water and, after the resulting solution is subjected in water and, after the resulting solution is subjected to pH adjustment with squeous ammonia, it is mixed with an aqueous solution containing a noble metal element. CONSTITUTION:An org. cerium salt is used as a cerium stock material and an aqueous iron salt is used as an iron stock material and both of them are dissolved in water. After the pH of the resulting aqueous solution is adjusted to 6-9 with aqueous ammonia and, according to necessity, an org. ammonium salt is added to said aqueous solution, the obtained solution is mixed with an aqueous solution containing a noble metal element such as platinum or palladium and the resulting mixed solution is supported by a durable carrier based on alumina. Thus obtained three-component catalyst for purifying the exhaust gas of an internal combustion engine has both high activity and high durability. |
