Steam Electrolysis Characteristics for Various H2 and O2 Concentrations in Supply Gases

The steam electrolysis performance of a Ni-based electrode-supported tubular cell with a Sc2O3-stabilized ZrO2 electrolyte was evaluated at 650°C for various concentrations of H2 and O2 in the supply gases. It was found that an increase in the concentration of electrolytic products (H2 and O2) around the relevant electrode decreased the electrode polarization, and enhanced the electrolysis performance. This result suggests that the electrolysis can be performed with no carrier gases, and the direct storage of the steam electrolysis products H2 and O2 is feasible.