Electrochemical study of Ba0.5Sr0.5Co0.8Fe0.2O3 perovskite as bifunctional catalyst in alkaline media

Ba_0.5Sr_0.5Co_0.8Fe_0.2O₃ perovskite oxide has been synthesized by a sol–gel method, and characterized by XRD, SEM, BET. This oxide has a porous structure and a specific surface area of 2.78 m² g⁻¹. The catalytic activity of the oxide for the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER) in 0.1 M KOH solution has been studied by using a rotating ring-disk electrode (RRDE) technique. RRDE results show that the ORR mainly favors a direct four electron pathway, and a maximum cathodic current density of 6.25 mA cm⁻² at 2500 rpm was obtained, which is close to the behavior of Pt/C (20 wt% Pt on carbon) electrocatalyst in the same testing conditions. Compared with pure C electrode, BSCF is more active for OER, a lower onset potential for OER and a bigger anodic current at the same applied potential are observed.