| 摘要 |
PROBLEM TO BE SOLVED: To obtain an exhaust gas purification catalyst capable of effectively diminishing NOx contained in exhaust gas from a diesel engine without causing deterioration even at high temp. in the presence of steam, etc. SOLUTION: Chloroplatinic acid is carried on alumina particles, dried and subjected to 1st firing preferably at 500-700 deg.C for 3-5hr in a nonreducing atmosphere and it is further subjected to 2nd firing at 300-1,000 deg.C for 0.1-12hr in a reducing atmosphere. This 2nd firing is preferably carried out in an atmosphere in which a reducing flame and/or an oxidizing flame exists. The resultant catalyst contains platinum finally fixed and carried by 0.01-20g, preferably 1-3g per the complete catalyst 11. |
