Electrical characterization and water sensitivity of Sr2Fe1.5Mo0.5O6−δ as a possible solid oxide fuel cell electrode

Sr2Fe1.5Mo0.5O6−δ (SFMO) powders were synthesized by combustion synthesis. Porous samples were formed by uniaxial pressing of powder compacts and sintering in air. Electrical conductivity was measured by a four-point DC technique over a temperature range from 200 °C to 800 °C in air and in hydrogen. Crystal structures were investigated by X-ray diffractometry. Stability of powder samples was investigated in H2O-containing atmospheres. It was observed that Sr2Fe1.5Mo0.5O6−δ was stable at 800 °C in water-containing atmospheres. However, it reacts with water at low temperatures. Reaction of Sr2Fe1.5Mo0.5O6−δ (SFMO) with water at low temperatures is a potential shortcoming of this material for application in solid oxide fuel cells (SOFC) due to concerns regarding degradation of the electrodes at low temperatures during cycling.

► Synthesized Sr2Fe1.5Mo0.5O6−δ by combustion synthesis.
► Electrical conductivity measured on porous samples.
► Sr2Fe1.5Mo0.5O6−δ reacts with H2O at low temperatures.
► Lack of stability of Sr2Fe1.5Mo0.5O6−δ is an impediment to its incorporation in fuel cells.