CATHODIC PROCESSES IN MOLTEN ALKALI-METAL CARBONATES

Cathodic processes were studied on noble (Au, Pt) and electrochemicall y negative (Al, Zr) metals in eutectic mixtures of alkali metal carbon ates at 600-800 degrees C. The effect of the cationic composition of a melt and the gas above it (CO2, CO2 + 1/2O(2), He) on the sequence of cathodic reactions was studied. The preliminary cathodic treatment is shown to significantly affect the intensity of the subsequent anodic processes. X-ray diffraction analysis of the zirconium electrode surfa ce after its cathodic polarization showed partial ZrO2 reduction to Zr 3O and the presence of ZrC (in lithium and sodium carbonate melts) and Na2ZrO3 (in potassium and sodium carbonate melts) under a helium atmo sphere.