BaCo_0.7Fe_0.22Y_0.08O_3-δ as an Active Oxygen Reduction Electrocatalyst for Low-Temperature Solid Oxide Fuel Cells below 600 °c

Solid oxide fuel cells (SOFCs) offer great promise as sustainable energy conversion devices due to their high chemical-to-electrical conversion efficiency, flexible fuel sources, and low pollutions. In recent years, much effort has been devoted to developing intermediate temperature SOFCs. Central to the devices is the availability of a highly effective electrocatalyst for oxygen reduction reaction with reduced temperature operation, especially below 600 °C. Here we present a novel B-site Y-doped perovskite-type oxide BaCo_0.7Fe_0.22Y_0.08O_3-δ (BCFY) with extremely low polarization resistances (e.g., 0.10 ω cm² at 550 °C), which is ascribed to high cubic symmetry structure and fast oxygen kinetics. The superior electrocatalytic activity and stability enable BCFY to be a promising cathode candidate toward the application of reduced temperature SOFCs.