A comparative study of electrodes in the direct synthesis of CH4 from CO2 and H2O in molten salts

Since the Industrial Revolution, the heavy reliance on the limited fossil energy has emitted huge number of CO2 into the air and led to a severely global warming. We propose a new green technology to moderate greenhouse gas CO2 emission and transform it into low-carbon renewable energy in this paper. Through this manner, electricity is transformed into chemical energy. CO2 and H2O is directly simultaneous electrolysis under constant 0.25 A with 30 cm2 nickel anode and 30 cm2 iron cathode in a 600 °C alkali carbonate with LiOH electrolyte in mole ratio of nH:nC = 0.15:1, achieving the storage of electricity to chemical energy. This electrolysis provides a gaseous product comprising 45.9% methane, 53.1% H2, 0.92% CO and trace amounts of longer (than methane) hydrocarbons. Simultaneously, the current efficiency is still ∼51% for 60 min.