Synergistically improving electrocatalytic performance and CO2 tolerance of Fe-based cathode catalysts for solid oxide fuel cells

Fe-based pervoskite oxides Bi0.5Sr0.5Fe1−xZrxO3−δ (BSFZx, x = 0, 0.05, 0.10 and 0.15) were synthesized and developed by doping of cation Zr as possible cathodes for solid oxide fuel cells (SOFCs). Herein, we carefully investigated the effect of Zr-doped on BSFZx physicochemical property. The Bi0.5Sr0.5Fe0.90Zr0.10O3−δ (BSFZ0.10) cathode shows the lowest Rp values ranging from 0.52 to 0.11 Ω cm2 in the temperature range of 600–700 °C and the corresponding activation energy is about 1.135 eV. A single fuel cell with BSFZ0.10 cathode delivers a satisfactory electrocatalytic performance with a peak power density (PPD) as high as 1.2 W cm−2 at 700 °C. The BSFZ0.10 also exhibits unsurpassed stability by less change in Rp values under different CO2concentrations (5, 10 and 15 vol%). The excellent chemical stability and CO2 tolerance of BSFZx electrode material is mainly due to the doping of highly acidic Zr4+ and the increase of average metal bond energy (ABE). The present work highlights that BSFZx oxides are very promising candidate cathode catalysts for oxygen-conducting SOFCs.