A Superior Catalytic and Thermal Durable R‐P 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 protons 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, Sr 3 EuFe 2.5 Co 0.5 O 10-δ (3-SEFC 0.5 ), is developed as a potential single-phase cathode for PCFCs, which possesses high oxygen non-stoichiometry, and desirable structural thermal stability. Employing this highly active and stable single-phase cathode, PCFC demonstrates unprecedented low polarization resistances and exceptionally great peak power densities, which are about 0.030 Ω cm 2 and 900 mWcm -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.