Titanium Carbide Coating of Titanium by Cathodic Deposition from a Carbonate Melt

The deposition of a TiC coating on a Ti electrode in molten Li 2 CO 3 at 900°C due to cathodic bias is described. During the first 5–20 min of application of −3V bias with respect to open circuit voltage, the formation of graphite is minimal and the resulting TiC layer is ∼10 μm thick. Applying negative bias for longer time results in the formation of graphite dendrites. This behavior can be explained by the fact that the overpotential of CO is lower on TiC than on graphite. The resulting Ti\TiC structure can be employed to good advantage as the anode in the electrolysis of molten Li 2 CO 3 for CO 2 to CO conversion for energy storage. It has higher conductivity than the graphite electrode used previously and can be prepared in situ. The process described here can therefore make a valuable contribution to the practical implementation of the electrochemical production of CO. In addition, the fact that the TiC coating is perfectly conformal suggests that the same process can be used as a general method of coating Ti by TiC.