Real-time analysis of anodic mixed gas generated on carbon electrodes during TiO reduction in a LiCl-based salt at 650 °C

The anode gas components produced during the electrolytic reduction of TiO was analyzed in this study in real time using a carbon anode in LiCl containing various Li 2 O and Li 2 CO 3 concentrations under high-potential operation at 650 °C. A molten salt with 0.3 wt% Li 2 O under 6 V cell voltage predominantly generated CO 2 until depletion of the initial oxygen ion source, after which Cl 2 gas began to form. A molten salt containing 0.2 and 1.3 wt% Li 2 O and 1.3 wt% Li 2 CO 3 , respectively, also generated CO 2 as the main anode gas, followed by CO, O 2 , and Cl 2 gas generation. In contrast, a molten salt with 0.8 and 0.5 wt% Li 2 O and Li 2 CO 3 , respectively, initially generated CO, leading to carbonate accumulation, which gradually decreased as the concentration of generated CO 2 increased and it became the dominant gas, while that of O 2 remained constant (6–9%). Cl 2 was predominantly generated upon depletion of the oxygen ion source in the salt. Cl 2 reacted with carbonate ions in the salt, thus releasing CO 2 gas and preventing carbonate accumulation in the salt. This study revealed that anode gas composition during electrolytic reduction with carbon anodes is critically influenced by the oxygen ion source concentration of the salt.