Application of BaTiO_3 as anode materials for H_2S-containing CH_4 fueled solid oxide fuel cells

摘要

Undoped BaTiO_3 perovskite oxide is more effective than SrTiO_3 and La_2Ti_2O_7 oxide as anode catalyst in SOFC fueled with H_2S-containing methane. Electrochemical performance, impedance spectroscopy and other characterizations show that pure BaTiO_3 is a good anode catalyst for conversion of methane in SOFC, especially in H_2S-containing atmospheres. Compared with SrTiO_3 and La_2Ti_2O_7 samples, the BaTiO_3-based fuel cell has higher resistance to carbon deposition, better electrochemical performance and much higher stability during long term operation. A maximum power density of 135 mW cm~(-2) was achieved at 900 ℃ with 0.5% H_2S-CH_4 in a fuel cell having a 300 μm thick YSZ electrolyte. High catalytic activity for methane conversion, mixed electronic and ionic conductivity, and the surface basicity of BaTiO_3 unexpectedly provides promising performance as anodes in SOFC.