Exsolved Fe–Ni nano-particles from Sr2Fe1.3Ni0.2Mo0.5O6 perovskite oxide as a cathode for solid oxide steam electrolysis cells

Abstract

A stable and catalytically active cathode consisting of homogeneously dispersed nano-socketed Fe–Ni particles has been elegantly fabricated in single-step treatment for solid oxide steam electrolysis cells via the in situ reduction of the Sr₂Fe_1.3Ni_0.2Mo_0.5O₆ (SFMNi) material in a humidified H₂ (3 vol% H₂O) atmosphere at 800 °C. The SFMNi–SDC/LCO/LSGM/SDC–LSCF electrolysis cell exhibits a high electrolysis current density of 1257 mA cm⁻² and a high hydrogen production rate of 525 mL cm⁻² h⁻¹ at an applied voltage of 1.3 V at 850 °C. Moreover, the in situ grown nano-structured cathode shows a good short-term stability at a constant electrolysis current of −300 mA cm⁻², resulting from the strong interface between the exsolved particles and the parent perovskite.