Preparation and characterization of an solid oxide fuel cell tubular cell for direct use with sour gas

The first metal-free membrane assembly for tubular solid oxide fuel cells efficient in conversion of either sour gas or H2S-containing hydrogen is fabricated and characterized. To achieve high performance, a porous layer of YSZ impregnated with LSBT, LSBT/YSZ (LSBT is La0.4Sr0.5Ba0.1TiO3), was selected as the composite anode material for the fully ceramic SOFC with the established catalyst LSM/YSZ as the cathode. The anode has a high performance and is stable in conversion of sulfur-containing fuels. The tubular fuel cell was characterized electrochemically using impedance spectroscopy (EIS) and potentiodynamic tests performed at 800, 850, and 900 °C with various fuels to determine the effect of H2S content in the following feeds: H2, H2/H2S (5000 ppm), and CH4/H2S (5000 ppm). Encouraging total power densities were obtained: 110, 105, and 41 mW cm−2, respectively using H2/H2S, H2, and dry CH4/H2S at 900 °C, despite high ohmic resistances.