TiN diffusion barrier interlayer for enhancing the durability of Pt/Ti anodes for molten carbonate electrolysis

Abstract

The corrosion behavior and durability of platinum-coated titanium (Pt/Ti) anodes in molten carbonate electrolysis were systematically studied across a temperature range of 450–650°C. The main cause of anode degradation was identified as rapid oxygen diffusion from the platinum coating to the titanium substrate, resulting in excessive passivation and the formation of a rutile TiO₂ layer. This passivation process led to coating breakage and spallation. To mitigate these issues, a TiN_x interlayer was introduced as an oxygen diffusion barrier to form a Pt/TiN_x/Ti electrode. The TiN_x layer significantly reduced substrate oxidation, thereby improving the anode’s corrosion resistance and extending its service life under harsh electrolysis conditions. These findings provide crucial insights into the corrosion mechanism of Pt/Ti anodes and offer a promising strategy to enhance their performance and longevity in industrial molten carbonate electrolysis applications for CO₂ reduction and green metallurgy.