Electrochemical oxygen separation using hydroxide ion conductive layered double hydroxides

This paper reports a novel electrochemical oxygen separation process using a hydroxide ion conductor as an electrolyte. In this study, we used Ni–Fe layered double hydroxide (LDH) intercalated with CO32 − (Ni–Fe CO32 − LDH) as a hydroxide ion conductive material. Ni–Fe CO32 − LDH was prepared using the co-precipitation method. Electrodes using Pt/C as a catalyst and Ni–Fe CO32 − LDH as an ionomer were prepared and a membrane reactor for oxygen separation using Ni–Fe CO32 − LDH as an electrolyte was fabricated. The electrochemical oxygen product flow was confirmed to be proportional to the external current density, and thus the membrane functioned at 50 °C under 70% of relative humidity and an electrical potential gradient.