A Durable Ruddlesden-Popper Cathode for Protonic Ceramic Fuel Cells.

Protonic ceramic fuel cells (PCFCs) have been proved as an efficient energy converter at intermediate temperatures. To accelerate the kinetics of the proton-involved oxygen reduction reaction (p-ORR), developing efficient and durable cathodes is of great importance for improving PCFCs. In this work, a new triple-layered Ruddlesden-Popper (R-P) structure oxide, Sr3 EuFe2.5 Co0.5 O10-δ (3-SEFC0.5 ), was developed as a potential single-phase cathode for PCFCs, showing high oxygen non-stoichiometry and desirable structural thermal stability. By employing this highly active and stable single-phase cathode, the PCFC demonstrated unprecedented low polarization resistances and exceptionally great peak power densities, which were approximately 0.030 Ω cm2 and 900 mW cm-2 measured at 700 °C, respectively. These findings not only manifest the effectiveness of optimal doping in improving the structural stability and electrocatalytic activity in the multi-layered perovskite family, but also highlight the great potential of using multi-layered R-P series oxides as highly active and durable catalysts for PCFCs.