High-Temperature CO2 and H2O Electrolysis with an Electrolyte-Supported Solid Oxide Cell

High-temperature CO2 and H2O co-electrolysis using solid oxide cells can produce efficiently syngas that in turn can be converted to synfuel through technologically mature technologies like the Fischer-Tropsch (F-T) process. It can be used to convert renewable electrical energy to chemical energy stored in liquid fuels to support a sustainable transport in the future. In the present paper a commercial electrolyte-supported solid oxide cell has been operated under CO2/H2O-electrolysis conditions. It has been found that the product gas composition can be well predicted by assuming that the reverse water-gas shift (RWGS) reaction reaches a thermodynamic equilibrium. In comparison to wet CO2 electrolysis (CO2 with H2O or H2), the cell ASR is only slightly increased under dry CO2 electrolysis conditions, indicating that, besides the RWGS reaction, electrochemical reduction of CO2 could also play an important role for CO formation under CO2/H2O co-electrolysis conditions.