Ag-Pr2O2SO4 is identified as a promising new composite material to enhance the cathodic oxygen reduction reaction in solid oxide fuel cells. Ag-Pr2O2SO4 was studied in terms of synthesis, stability of Pr2O2SO4 in CO2, and electrochemical behavior as a cathode. The performance of the composite cathode was assessed as a function of temperature by A.C. impedance using a symmetrical cell arrangement in oxygen. The global performance of an anode-supported fuel cell Ag-Pr2O2SO4/CGO/NiO-CGO was also assessed, the highest power density being 1.5 W cm(-2) at 800 degrees C. A longevity test of this cell performed at 800 degrees C under load for 24 days demonstrated high stability with Ag-Pr2O2SO4 cathode. (C) 2015 Elsevier B.V. All rights reserved.