The optimization of electrolyte composition for CH4 and H2 generation via CO2/H2O co-electrolysis in eutectic molten salts

A huge number of carbon dioxide (CO2) emission is beyond the scope of the natural changes of the earth itself and destabilizes the carbon cycle, which leads to worsening global warming problem, and also seriously threats the survival and development of human. Herein, CO2 is captured and transformed electrochemically with H2O to controllably generate CH4 and H2 in an electrolyte comprising a eutectic of carbonates and hydroxides with equal-area Fe cathode and Ni anode. Gas chromatography (GC) is employed to analyze the content of gaseous products. Additionally, Faraday efficiency under different conditions is measured via the comparison between moles of obtained fuel gas (mainly composed of CH4 and H2) and the Faradays of charge passed during the electrolysis reaction. This article investigates the effect of molten salt compositions on gaseous product generation, and confirms the visible dependence of obtained products on the electrolytes.