Electrochemical activity of copper doped Sr2.7Pr0.3Fe2O7− cathode catalysts for solid oxide fuel cells

Due to their great efficiency, low cost and pollution, and flexible fuel choice, solid oxide fuel cells (SOFCs) have been applied to energy conversion filed. However, one challenge for developing SOFCs is sluggish oxygen reduction reaction (ORR) rate. Herein, a series of Ruddlesden-Popper-type Sr2.7Pr0.3Fe2–xCuxO7–δ (SPFCx) oxides are successfully synthesized and thoroughly assessed as potential SOFCs cathodes. Among all compositions, Sr2.7Pr0.3Fe1.9Cu0.1O7–δ (SPFC10) possesses the best electrocatalysis performance and improved oxygen reduction kinetics, with the lowest polarization resistance (Rp, 0.13 Ω cm2) at 700 °C. Cu-doping will contribute to improving oxygen transport kinetics, increasing oxygen vacancy concentration, and O 2p band centers close to the Fermi level, hence, enhancing the electrocatalysis performance. At 700 °C, the maximum output of the single cell with SPFC10 cathode is 704 mW cm−2. These results highlight a highly active SPFC10 cathode with Ruddlesden-Popper structure for SOFCs.