SrMo_0.9O_3-δ Perovskite with Segregated Ru Nanoparticles Performing as Anode in Solid Oxide Fuel Cells

A new anode material, Ru-SrMo_0.9O_3-δ, with a perovskite structure and segregated metallic Ru, has been tested in an intermediate-temperature solid oxide fuel cell (IT-SOFC) in an electrolyte-supported configuration giving substantial power densities as high as 840 mW/cm² at 850 °C using pure H₂ as fuel. This material has been prepared by the citrate method and structurally and microstructurally characterized at room temperature by different techniques such as X-ray diffraction (XRD), neutron powder diffraction (NPD), scanning electron microscopy (SEM), and scanning transmission electron microscopy (STEM). NPD was very useful to determine oxygen positions and vacancies, unveiling a cubic and oxygen-deficient perovskite SrMo_0.9O_3-δ oxide with a Pm-3m space group and potential ionic mobility. On the other hand, SEM and STEM studies have allowed to identify metallic segregated Ru nanoparticles providing the material with an excellent catalytic activity. Other properties such as the thermal expansion coefficient (TEC) and chemical compatibility with other cell components or electrical conductivity have also been studied to understand the excellent performance of this material as anode in IT-SOFC and correlate it with the crystallographic structure.