| 摘要 |
PURPOSE:To produce a metallic denitration catalyst with no exfoliation and wear of the active layer by dipping rolled steel covered with a porours silica film in an etching soln. contg. an oxidizing agent to form an oxide layer inside the film. CONSTITUTION:The surface of rolled steel such as carbon steel or stainless steel is etched mechanically or chemically. Next the steel is dipped in a silica colloidal soln. or coated with the soln. and dried to form a tough porous silica film of three- dimensional structure on the surface of the steel. It is then dipped in an etching soln., a suitable concn. aq. soln. of mineral acide, acidic salts, etc. contg. an adequate concn. of an oxidizing agent such as H2O2, KMnO4 or K2CrO4. The soln. reaches the surface of the steel through the silica film and etches it, forming oxides. Thereafter, the steel is taken out from the soln., dried, and optionally calcined. The oxide layer, that is, the active layer of the resulting catalyst is formed inside the silica film, so there is no possibility of exfoliation and wear. |
