Mitigating Carbon Formation with Al2TiO5-Enhanced Solid Oxide Fuel Cell Anodes

Spectroscopic and electrochemical techniques were used to examine the benefits of adding small amounts of aluminum titanate (Al2TiO5 or ALT) to standard NiO–yttria-stabilized zirconia (YSZ)-based solid oxide fuel cell anodes operating with methane at 800 °C. Combining small amounts (4% by mass) of ALT with NiO–YSZ leads to the formation of secondary phases that improve anode carbon tolerance via multiple reaction mechanisms. Raman data show that carbon forms on both ALT-doped and undoped anodes at open-circuit voltage and with applied bias as evidenced by the vibrational band of highly ordered graphite at 1560 cm–1. However, ALT-doped anodes limited the amount of carbon that forms on both the surface and within the bulk, resulting in improved performance for up to 12 h of exposure to CH4. Results show that ALT-enhanced anodes accumulate ∼25% less carbon on the surface under open-circuit conditions and that increasing polarizations to 50% of the maximum current and beyond results in no observable carbon ac...