Platinizing

(1) The deposition of a layer of platinum 1–5 microns (μ) thick on the surface of metal objects to increase their corrosion resistance, reflectivity, and wear resistance, as well as to provide constancy of contact electrical conductivity. The coatings are deposited by electroplating from phosphate or, less frequently, diaminodinitrite electrolytes containing platinum salts. The anodes are thin platinum sheets, which remain virtually undissolved during the platinizing process.

Platinizing is used to make special laboratory and chemical apparatus, platinized titanium electrodes (used, for example, in the production of hydrogen peroxide), parts or subassemblies of electrotechnical devices (copper and copper-alloy contacts), and molybdenum wire for electron tubes, as well as in the jewelry and watchmaking industries.

(2) The impregnation of granules of alumina by chloroplatinic acid, with subsequent reduction of the platinum. Platinized alumina is used as a catalyst in the hydrogenation of unsaturated hydrocarbons and the polymerization and reforming of petroleum products.