A Comparative Study of the Performance and Electrode Processes of Solid Oxide H2O Electrolysis and CO2 Electrolysis

The significance of converting CO2 into valuable feedstock is highly emphasized with the carbon neutrality vision and solid electrolysis cell has been regarded as a promising technology to convert CO2. However, it is far from its industrial application due to the severe degradation. In this paper, a degradation phenomenon was reported on both a button cell and an industrial size cell. Both cells suffered severe degradation during a short-time operating of CO2 electrolysis. The comparison of performance before and after degradation revealed significant differences between H2O electrolysis and CO2 electrolysis in terms of electrode processes and it was indicated that the interface of fuel electrode and electrolyte was the place that was severely damaged. Finally, a safety operating voltage interval was advocated to suppress the degradation.