Manufacturing corrosion-resistant electrode materials on the basis of Ti, Ta, Nb, and W covered with thin electrodeposited platinum layers

The electrodeposition of thin platinum coatings onto Ti, Ta, Nb, and W supp orts with an ordered microstructure and reliable adhesion is studied. The c oatings can be applied in adverse electrolysis conditions for synthesizing oxidants and for other purposes. Optimum conditions for a support pretreatm ent and a platinum deposition from an electrolyte based on platinum diammin edinitrite are found. All other deposition conditions being the same, the s upport pretreatment affects the coating microstructure (ordering, size of P t crystallites, roughness coefficient). On polished Nb supports, the grain size of Pt crystallites is smaller, the coating is more compact, and the ro ughness coefficient drops to nearly 5-8, which is typical for bulk platinum . However, the Nb support must be preliminarily oxidized in a strictly spec ified mode, for preventing hydrogen sorption during platinum electrodeposit ion, if one is to deposit reliable poreless platinum coatings with strong a dhesion.