Electrochemical performance and stability of LSFMn+NiSDC anode in dry methane

Anode deactivation over prolonged SOFC operation represents a major issue towards stable and reliable energy production from hydrocarbon-containing fuels. In this respect, Ni-YSZ replacement with oxide- based anodes, less prone to coking, is commonly regarded as a viable solution. Nevertheless, most stud- ied oxides cannot compete with Ni-based state-of-the-art anodes in terms of conductivity and catalytic activity. In this work a novel MIEC anodic composite based on La 0.6 Sr 0.4 Fe 0.8 Mn 0.2 O 3- δ(LSFMn) perovskite and Ce 0.85 Sm 0.15 O 2- δcontaining 5 wt.% of Ni (NiSDC) was tested in dry methane. In reducing conditions, LSFMn undergoes phase transformation to Ruddlesden-Popper structure, exsolving Fe 0 nanoparticles and retaining proper conductivity. The small amount of Ni, well-dispersed on the SDC matrix, forms a Ni-Fe alloy with the exsolved iron from the perovskite. While Ni-Fe alloy activates CH 4 , SDC provides enough O 2 −ions to electrochemically oxidize any cracking products. Endurance cell test at 800 °C in dry CH 4 shows a stable current density output for over 33h and both SEM and Raman Spectroscopy do not reveal any anode fouling.