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

摘要

Strontium-doped lanthanum vanadate, La_(0.7)Sr_(0.3)VO4, 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 7h in 10 H2-Ar, LSV is chemically and electrochemically stable in H2S-containing syngas (40 H2, 60 CO, and 5000 ppm H2S), LSV is an active anode catalyst for use in solid oxide fuel cells (SOFCs), and a H2-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 H2. The ohmic and polarization resistance of the cell decreased with increase in temperature.