Formation of manganese dioxide coating with catalytic activity on thick boehmite film by hydrothermal method

Abstract

Aluminum has excellent workability and surface finishing, but it corrodes easily and has low hardness. Therefore, in this study, an excellent high corrosion resistance oxide film was prepared by hydrothermal treatment on aluminum in the primary treatment. In the secondary treatment, MnO 2 was immobilized on high corrosion resistance oxide film by hydrothermal treatment. Aluminum was treated by hydrothermal treatment for 30 min under 483 K (2.0 MPa) conditions in a 0.04 kmol/m 3 aluminum nitrate aqueous solution. Adding aluminum nitrate to prepared thick boehmite film (20 μm) by formed globules in the primary treatment, and it possessed a wide surface area. The primary processing film was treated for 30 min under 453-483 K (1.0-2.0 MPa) conditions in a potassium permanganate aqueous solution by hydrothermal treatment, and nanoorder MnO 2 (30 nm) was immobilized onto the boehmite film. MnO 2-boehmite film with wide surface area and high oxidation activity was prepared. © 2005 The Japan Institute of Metals.