High-Performance Anode for H[sub 2]S-Air SOFCs

A high-performance composite anode has been developed for solid oxide fuel cells (SOFCs). The anode design is based on the requirements of three-phase boundary theory. The anode material comprises a mixture of composite metal sulfide (Mo-Ni-S) catalyst prepared from and NiS (1:1 weight ratio), admixed with up to 10% each of Ag as electronic conductor and yttria-stabilized zirconia (YSZ) as ionic conductor. The optimum composition is about 90 wt % Mo-Ni-S, 5 wt % Ag, and 5 wt % YSZ. A fuel cell using a 0.2 mm thick YSZ membrane produced a maximum sustainable current density over 480 mA cm −2 at 750°C and over 800 mA cm −2 at 850°C, and maximum power density 50 mW cm −2 at 750°C and over 200 mW cm −2 at 850°C.