| 摘要 |
PURPOSE:To enhance decomposition efficiency and durability in the catalyst for exhaust gas of an automobile by making so ruthenium and iridium carried on alpha-Al2O3 that the mol ratio thereof is regulated to the prescribed amount. CONSTITUTION:Ruthenium Ru and iridium Ir are carried alpha-Al2O3 in a range within 0.30-5.00 as the mol ratio of Ru to Ir. When the mol ratio is 0.30 or below, a catalyst is made iridiumlike and durability is enhanced but initial activity is lowered. When the mol ratio is 5.00 or more, the catalyst is reversely made rutheniumlike and initial activity is good but durability is deteriorated. The catalyst is prepared by immersing alpha-Al2O3 in the ethanol solution of ruthenium and iridium which are regulated to the prescribed mol ratio and coimpregnating alpha-Al2O3 with these noble metals, drying alpha-Al2O3 and thereafter burning it at about 300-500 deg.C and performing reducing treatment in H2 flow. |
