• Vibhu, Vaibhav
• Eyckeler, Niklas
• Vinke, Izaak
• Coll, Carla L.
• Wolf, Stephanie Elisabeth
• Eichel, Ruediger-A.
• De Haart, L. G. J.

Abstract

<jats:p>Severe performance loss of state-of-the-art Ni-cermet fuel electrodes has been observed due to Ni particle agglomeration and Ni migration away from the triple-phase boundary at the active electrode layer. Investigation of Ni-free perovskite Sr<jats:sub>2</jats:sub>Fe<jats:sub>2-x</jats:sub>Mo<jats:sub>x</jats:sub>O<jats:sub>6-δ </jats:sub>(SFM)–30 wt% Ce<jats:sub>0.8</jats:sub>Gd<jats:sub>0.2</jats:sub>O<jats:sub>2-δ</jats:sub> (GDC) as fuel electrode material showed good redox stability in oxidizing and reducing atmospheres. These characteristics meet exactly the targeted requirements for new solid oxide electrolyzer materials. A comparison of SFM and SFM-GDC fuel electrodes showed similar performance for H<jats:sub>2</jats:sub>O, CO<jats:sub>2</jats:sub>, and co-electrolysis between 750 °C and 900 °C. Long-term degradation measurements and post-test SEM-EDX analysis clarified that SFM-GDC exhibits good phase stability in comparison to pure SFM fuel electrodes. The composite fuel electrode Sr<jats:sub>2</jats:sub>Fe<jats:sub>1.1</jats:sub>Mo<jats:sub>1.0</jats:sub>O<jats:sub>6-δ</jats:sub>–30 wt% Ce<jats:sub>0.8</jats:sub>Gd<jats:sub>0.2</jats:sub>O<jats:sub>2-δ</jats:sub> (SFM15-GDC) reached polarization resistances (R<jats:sub>P</jats:sub>) in the same range as Sr<jats:sub>2</jats:sub>Fe<jats:sub>1.0</jats:sub>Mo<jats:sub>1.0</jats:sub>O<jats:sub>6-δ</jats:sub> with around 127 mΩ∙cm² and 137 mΩ∙cm at 900 °C in steam electrolysis.</jats:p>

Topics

• perovskite
• phase
• scanning electron microscopy
• composite
• Energy-dispersive X-ray spectroscopy
• phase boundary
• phase stability