Probing oxygen reduction and water uptake kinetics of BaCo0.4Fe0.4Zr0.1Y0.1-xZnxO3-δ cathodes for protonic ceramic fuel cells

A key challenge in the development of advanced protonic ceramic fuel cells (PCFCs) is to exploit efficient and robust cathode electrocatalysts for proton involved oxygen reduction reaction. Herein, we propose Zn-doped BaCo0.4Fe0.4Zr0.1Y0.1-xZnxO3-δ as promising triple-conducting cathodes for PCFCs. As disclosed, Zn incorporation induces the increased concentration of oxygen vacancies, and thereby facilitates both oxygen reduction and water uptake kinetics. Benefiting from the enhanced oxygen reduction and water uptake kinetics, the BaCo0.4Fe0.4Zr0.1Zn0.1O3-δ (BCFZZn) cathode delivers the lowered polarization resistance. Moreover, the PCFCs single cell with BCFZZn cathode exhibits a high power density of 0.49 W cm−2 at 600 °C and a robust durability for 50 h, suggesting a prospective cathode material for PCFCs.