Ce_0.8Sr_0.2Co_xFe_1-xO_3-δ (x=0.2, 0.5, 0.8) – A Perovskite-type Nanocomposite for Application in the Oxygen Evolution Reaction in Alkaline Media

Three perovskite-type nanocomposites, i. e. Ce_0.8Sr_0.2Co_xFe_1-xO_3-δ (x=0.2, CSCF1; 0.5, CSCF2; 0.8, CSCF3), were synthesized employing the sol-gel technique, subsequent to which they were physically and electrochemically evaluated for their electrocatalytic activity towards the oxygen evolution reaction (OER) in alkaline medium (0.1 M KOH) at room temperature (25 °C). Electrochemical characterisation revealed Ce_0.8Sr_0.2Co_0.8Fe_0.2O_3-δ (CSCF3) to be the most active having the lowest overpotential at 10 mA cm⁻² (440 mV), the lowest Tafel slope (40.7 mV dec⁻¹), the highest mass activity (20.11 mA mg⁻¹) and highest specific activity (2.22 mA cm⁻²).