Gold particle effect on high temperature oxygen reduction reaction via lanthanum strontium cobaltite ferrite electrocatalyst

Gold is generally considered to be inert for electrochemical reactions in solid oxide fuel cells (SOFCs). It is thus used as the standard current collector to characterize the catalytic activity of various cathode materials including the state-of-the-art lanthanum strontium cobalt iron oxide (LSCF). This work shows that gold is not inert but active for oxygen reduction reaction (ORR) via LSCF. Electrical conductivity relaxation measurement shows that scattered gold particles on LSCF surface can greatly increase the ORR rate. Gold improves the chemical oxygen surface exchange coefficient by a factor up to 27.5. The improvement is much high at reduced temperature from 800 to 650 °C. In addition, gold particles with smaller size show better performance in enhancing the ORR activity.