Enhanced electrochemical performance and CO2 tolerance of Ba(0.9)5La(0.05)Fe(0.85)Cu(0.15)O(3-delta) as Fe-based cathode electrocatalyst for solid oxide fuel cells

摘要

The perovskite oxide Ba0.95La0.05Fe0.85Cu0.15O3-delta (BLFC) was evaluated as a Fe-based cathode electrocatalyst for solid oxide fuel cells (SOFCs). The crystal structure, electrocatalytic activity for the oxygen reduction reaction (ORR), and CO2 tolerance property of BLFC cathode are systematically investigated. BLFC is found to form a cubic symmetry perovskite oxide with space group Pm (3) over bar m. The introduction of Cu reduces the average binding energy (ABE) value of Ba0.95La0.05FeO3.delta and increases the oxygen vacancy concentration. The polarization resistance (Re) of the BLFC cathode is 0.091 Omega cm(2) and the power density of the single cell with BLFC cathode is 1.05 W cm(-2) under an output voltage of 0.53 V at 700 degrees C. The BLFC cathode shows satisfactory CO2 tolerance and chemical stability in the presence of 10 % CO2. Furthermore, the relationship of Rp, with oxygen partial pressure indicates that the oxygen surface adsorption-diffusion process is the rate-limiting step of the electrode.