Abstract
This Study used perovskite La0.58Sr0.4Co0.2Fe0.8O3-δ (L58SCF) as cathode material for the solid oxide fuel cells (SOFCs). The mixing of gadolinia-doped ceria (GDC) with LSCF to form the LSCF－GDC composite and it can perform better than pure LSCF as the SOFC cathode.The effects of adding Cu, Ag and Pt to LSCF and the LSCF－GDC composite all increases the maximum power density over that of pure L58SCF cathode. The cathode reduction activity has been shown to follow a trend Cu >Ag > Pt. This can be explained by the oxygen affinities of the metals, which have a trend Cu >Ag > Pt. With 2~6% NO over the LSCF-GDC-V2O5, LSCF-GDC-Cu cathodes, the maximum power density increase with increasing NO concentration. That means direct electrochemical NO reduction can occur over those cathodes when oxygen is not present.Using LSCF-GDC-Cu cathode to reduce CO2, we found that the CO formation rate, the CO2 conversion and the generated current density increase with increasing CO2 concentration. The CO2 conversion rate equals exactly the CO formation rate and no carbon deposition occurs. The activation energy is about 2.72 kcal/mol.