Sulfur-Tolerant Anode Catalyst for Solid Oxide Fuel Cells Operating on H₂S-Containing Syngas

Strontium-doped lanthanum vanadate, La 0.7 Sr 0.3 VO 4, LSV, was prepared via a nitrate-citrate combustion method. The phase formation process of LSV was studied using thermogravimetric analysis and X-ray diffraction (XRD). A pure phase of LSV was formed during baking at 900 °C for 7 h in 10% H 2 −Ar. LSV is chemically and electrochemically stable in H 2 S-containing syngas (40% H 2, 60% CO, and 5000 ppm H 2 S). LSV is an active anode catalyst for use in solid oxide fuel cells (SOFCs), and a H 2 -air fuel cell with configuration LSV/YSZ/Pt provided maximum power density of 210 mW cm −2 at 900 °C and a current density close to 400 mA cm −2 . Impedance measurements showed that the anodic polarization resistance depended on the fuel gas, and was highest for CO and lowest for H 2 . The ohmic and polarization resistance of the cell decreased with increase in temperature.