Nb-doped TiO2 inert anodes for electrolytic production of magnesium metal

The synthesis and performance of polycrystalline niobium-doped titanium dioxide mixtures for use as potential inert anodes in magnesium electrowinning cells were investigated. The anode materials were prepared by solid-state reaction between niobium pentoxide and titanium dioxide. The results indicate that a 3% Nb-doped TiO2 anode sintered at 1300 degrees C offers an acceptable anode performance during 16 h electrolysis tests at different current densities (0.75-1.25 A/cm(2)). Post-electrolysis characterization showed an increase in the porosity at the surface of the anodes. Deterioration in anode performance is believed to be caused by grain boundary phase segregation. This work was undertaken as part of the CSIRO Light Metals Flagship.