Electrochemical Decomposition of CO2 in a Fluoride Melt

The conversion of CO 2 into carbon materials and oxygen gas has great significance for reducing the greenhouse gas concentrations of Earth and realizing in situ utilization of Mars’ atmosphere. In this work, LiF-Li 2 O melts containing CO 2 were electrolyzed using a Ni cathode and Pt anode at 850°C. Carbon materials with different morphologies were deposited on the cathode and oxygen evolution was detected in anode gas. The products were characterized by Raman spectroscopy, x-ray diffraction, scanning electron microscopy and gas chromatography. The results demonstrated that CO 2 was firstly captured and converted into the carbonate in LiF-Li 2 O melts, and subsequently electrolyzed. The morphologies of the carbon material obtained on the cathode were dependent on the electrolysis potentials. The rate of CO 2 and O 2 production in the anode gas was related to the reaction process, current density, and potentials. Electrochemical decomposition of CO 2 into carbon materials and oxygen gas in a fluoride melt was proved to be feasible.