A novel solid oxide electrolytic cell with reduced endothermic load for CO2 electrolysis using (La0.80Sr0.20)0.95MnO3-δ cathode

Abstract

CO2 conversion to CO via solid oxide electrolysis provides a potentially efficient method for converting CO2 into an industrially relevant product. A solid oxide electrolysis cell with (La0.80Sr0.20)0.95MnO3-δ (LSM) as the CO2 reduction cathode, yttrium stabilized zirconia (YSZ) as electrolyte, and nickel as the H2 oxidation anode was operated 800 °C and 850 °C. Thermogravimetric analysis of the LSM material showed no catalyst oxidation at operating temperatures allowing for CO2 electrolysis without reducing safe gas. In addition, no cathode material mass gain was observed in the presence of CO suggesting little to no carbon deposition occurred above 750 °C. The formation rates of CO for the cell reached 1.15 mL∙min−1∙ cm−2 for an applied current of 150 mA∙cm−2 achieving a faradaic efficiency of 100 %. Furthermore, the cell displayed good stability in the short-term CO2 electrolysis test with a nominal voltage drop of 4 mV h−1 for 10 h at 850 °C. This study shows the feasibility of operating a solid oxide CO2 electrolysis cell for CO production with H2 at the anode to reduce endothermic process load.