Catalytic activity of infiltrated La_0.3Sr_0.7Ti_0.3Fe_0.7O_3−Δ–CeO₂ as a composite SOFC anode material for H₂ and CO oxidation

Finding cost-effective and efficient anode materials for solid oxide fuel cells (SOFCs) is of prime importance to develop renewable energy technologies. In this paper, La and Fe co-doped SrTiO₃ perovskite oxide, La_0.3Sr_0.7Ti_0.3Fe_0.7O_3−δ (LSTF0.7) composited with CeO₂ is prepared as a composite anode by solution infiltration method. The H₂ and CO oxidation behavior and the electrochemical performance (electrochemical impedance spectra, I–V and I–P curves) of the scandia-stabilized zirconia (ScSZ) electrolyte supported cells fabricated by tape casting with the LSTF0.7–CeO₂ composite anode are subsequently measured at various temperatures (700–850 °C). Electrochemical impedance spectra (EIS) of the prepared cells with the LSTF0.7–CeO₂|ScSZ|La_0.8Sr_0.2MnO₃ (LSM)–ScSZ configuration illustrate that the anode polarization resistance distinguished from the whole cell is 0.072 Ω cm² in H₂, whereas 0.151 Ω cm² in CO at 850 °C. The maximal power densities (MPDs) of the cell at 700, 750, 800 and 850 °C are 217, 462, 612, 815 mW cm⁻² in H₂ and 145, 349, 508, 721 mW cm⁻² in CO, respectively. Moreover, a significant decrease of anode activation energy towards H₂ oxidation is clearly demonstrated, indicating a better electrochemical performance in H₂ than in CO. These results demonstrate an alternative composite anode with high electrocatalytic activity for SOFC practical applications.