| 摘要 |
PROBLEM TO BE SOLVED: To improve heat endurance under the presence of steam by depositing silica by vapor deposition of a silicone compound or zeolite supporting cobalt. SOLUTION: In the case where an exhaust gas cleaning catalyst suitable as various kinds of internal engines use such as an automobil engine or the like is manufactured, at first zeolite with which Co is supported is obtained, the Co-supporting zeolite is treated by hydration, and vapor of a silicon compound together with an inert gas is circulated to execute vapor deposition treatment at 200 deg.C to 400 deg.C. Then, the deposited silicon compound is hydrolyzed, and burnt at 400 deg.C to 700 deg.C under the presence of oxygen. Thereby decrease of activity after endurance treatment at 450 deg.C to 700 deg.C under steam existing atmosphere is enabled to be sharply inhibited. Further, a process wherein vapor deposition treatment of the silicon compound is executed, and a process of burning under the presence of oxygen are preferably repetitively several times executed. The silicon compound is preferably a compound easy to receive hydrolysis such as SiCl4, Si(OCH3)4, Si(OC2H5)4 or the like. |
