Ceramics-Silikáty 52, (1) 1 - 7 (2008)

This study focuses on the elaboration of the oxidation mechanism of molybdenum in a molten glass. More specifically it was sought to examine whether the anodic dissolution of molybdenum occurs in one or more steps and what the reaction products are. The work was performed in two steps. First the reaction of molybdenum ions in a glass melt at a platinum electrode was investigated. This was followed by the study of the corrosion reactions at a molybdenum electrode in this molten glass. Experiments showed that the oxidation of metallic molybdenum occurs in three steps: Mo → Mo³⁺(glass) + 3e⁻ (I); Mo³⁺ (glass) → Mo⁴⁺(surface/glass) + e⁻ or Mo → Mo⁴⁺(surface/glass) + 4e⁻ (II); Mo⁴⁺ (surface/glass) → Mo⁶⁺(glass) + 2e⁻ or Mo → Mo⁶⁺(glass) + 6e⁻ (III).