| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for hardening treatment of a catalyst end part by which wear resistance strength of a coating layer can be remarkably increased by surely preventing ceramic small pieces divided by minute cracks from being scraped from a catalyst surface. SOLUTION: A ceramic coating layer having hardness higher than the catalyst is formed on a surface of a gas flowing-in end part of a planar catalyst or a honeycomb-shaped catalyst. At this time, the coating layer is formed by dipping the catalyst end part into an immersion slurry for forming a coating and drying the same. Then, the coating part is dipped into a metallic salt aqueous solution and is subjected to drying/sintering. As the metallic salt, a water-soluble salt of V, W, Mo and/or Fe is preferable. Preferable metallic salt concentration is between 50% and 100% of saturated concentration at room temperature. It is preferable that the coating part is sintered after drying, and then is dipped into the metallic salt aqueous solution.
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