New SrMo1-x,CrxO3-delta perovskites as anodes in solid-oxide fuel cells

作者：Martinez Coronado R^*; Alonso J A; Aguadero A; Fernandez Diaz M T

来源：International Journal of Hydrogen Energy, 2014, 39(8): 4067-4073.

DOI：10.1016/j.ijhydene.2013.04.149

• IT-SOFC
• Anode
• Perovskite
• SrMo(1-x)FexO(3)
• SrMoO3

Oxides of composition SrMo1-xCrxO3-delta (x = 0.1, 0.2) have been prepared, characterized and tested as anode materials in single solid-oxide fuel cells, yielding output powers higher than 700 mW cm(-2) at 850 degrees C with pure H-2 as a fuel. All the materials are suggested to present mixed ionic-electronic conductivity (mmq from neutron powder diffraction (NPD) experiments, complemented with transport measurements; the presence of a Mo4+/Mo5+ mixed valence at room temperature, combined with a huge metal-like electronic conductivity, as high as 340 S cm(-1) at T = 50 degrees C for x = 0.1, could make these oxides good materials for solid-oxide fuel cells. The magnitude of the electronic conductivity decreases with increasing Cr-doping content. The reversibility of the reduction-oxidation between the oxidized Sr(Mo,Cr)O4-delta scheelite and the reduced Sr(Mo,Cr)O-3 perovskite phases was studied by thermogravimetric analysis, which exhibit the required cyclability for fuel cells. An adequate thermal expansion coefficient, without abrupt changes, and a chemical compatibility with electrolytes make these oxides good candidates for anodes in intermediate-temperature SOFC (IT-SOFCs).

• 出版日期2014-3-6