Electrochemical Reduction of Carbon Dioxide and Iron Oxide in Molten Salts to Fe/Fe3 C Modified Carbon for Electrocatalytic Oxygen Evolution

Abstract

Non-noble electrocatalyst for the oxygen evolution reaction (OER) is essential for water electrolysis and electrochemical conversion of CO₂ . Integrating electrochemical fixation of CO₂ and electrochemical metallurgy to prepare advanced OER electrocatalyst is a promising solution to promote carbon neutrality and renewable energy. Herein, the electrochemical reduction of CO₂ and Fe₂ O₃ are combined in molten salts to prepare cathodic Fe₃ C-based electrocatalyst and anodic oxygen at 600 °C with enhanced current efficiency. The resulting Fe₃ C-based electrocatalyst outperforms precious electrocatalyst towards the OER operation in 1 M KOH due to a dynamic structural evolution to form an interface of Fe₃ C-FeOOH.

Keywords: carbon dioxide conversion; electrochemical reduction; iron carbide; molten salts; oxygen evolution reaction.