LAUSR

Abstract Sluggish oxygen reduction reaction (ORR) activity and poor CO2-tolerance has been the long-standing limitations for the application of alkaline earth metal oxide cathode for solid oxide fuel cells (SOFCs). Here we report this situation can be ameliorated with a composite cathode based on Ba0.9Co0.7Fe0.3O3-δ (B90CF) by surface-decorated Pr6O11 (PO) particles. A halved polarization resistance is obtained by B90CF-15PO (PO of 15 wt%) cathode (0.033 Ω cm2 at 700 °C) compared to blank B90CF, suggesting boosted oxygen reduction reaction activity owing to the accelerated oxygen surface exchange kinetics introduced by PO particles. PO protective layer also brings up desirable CO2-tolerance for B90CF cathode due to the more stable fluorite cubic structure of PO and higher acidity of Pr3+/Pr4+ than Ba2+, which ensures the stable operation of cells. This work demonstrates the positive potential of surface-decoration with PO in developing cathodes with high performance and CO2-tolerance.