Methane synthesis from CO and HO using a phosphate-based electrochemical cell at 210-270 °C with oxide-supported Ru catalysts

The conversion of electricity to chemical energy is a key technology for absorbing the fluctuations of electricity and utilizing solar and wind-powered electricities as chemical fuels. An electrochemical system equipped with a phosphate-based electrolyte has been reported as a promising method to efficiently obtain CH 4 from CO 2 and H 2 O in a single electrochemical cell. Electrochemical cells with 10 wt%-Ru/ZrO 2 , Ru/Al 2 O 3 , and Ru/TiO 2 were examined for CH 4 synthesis from CO 2 and H 2 O at 210-270 °C and 10 mA cm −2 . Approximately 13 and 1 nmol s −1 cm −2 of CH 4 and H 2 , respectively, were formed using the Ru/ZrO 2 cell at 270 °C, and the current efficiencies for CH 4 and H 2 formation were 97 and 3%, respectively. The cells with Ru/Al 2 O 3 and Ru/TiO 2 produced lower CH 4 yields. An H-permeable membrane (Pd-Ag) cathode cell, which was designed in a previous study, and a newly designed PTFE membrane filter cell was investigated with Ru/ZrO 2 . Both cells demonstrated similar formation rates and current efficiencies, which means that the Pd-Ag membrane is not essential for the synthesis of CH 4 from CO 2 and H 2 O. The catalysts were analyzed using transmission electron microscopy and temperature-programmed desorption of H 2 . The conversion of electricity to chemical energy is a key technology for absorbing the fluctuations of electricity and utilizing solar and wind-powered electricities as chemical fuels.