| 摘要 |
PURPOSE:To obtain a catalyst for purifying an exhaust gas having extremely high heat resistance without the need for washcoat by impregnating a cordierite carrier with an aq. soln. of Pd nitrate, iron nitrate, and tartaric acid to carry the soln., drying, and calcining. CONSTITUTION:The cordierite carrier is impregnated with an aq. soln. of Pd nitrate, iron nitrate, and tartaric acid to carry the soln., dried, and calcined. And a finished catalyst is obtained. Said soln. is regulated to contain 10g/l Pd nitrate as Pd, 8g/l iron nitrate as iron, and 25g/l tartaric acid and to have 1.48 (regulated) pH (25 deg.C) and 1.11sp.gr. (25 deg.C). The catalyst has 33.3% water absorption ratio and contains 0.38wt% iron and 0.24wt% Pd. The pH is regulated with NH4OH, and the impregnation is carried out at 60 deg.C for 3hr. The purification ratio of CO and HC is not significantly decreased under such conditions as severe as 950 deg.C for 100hr in the air. |
