Effects of infiltrated Pr0.6Sr0.4CoO3-delta (PSCo)electrocatalyst on SOFC cathode performance have been studied. Nano-sized particulate catalysts, deposited on surfaces of a composite cathode of Sm2O3 doped CeO2 (SDC) and La1-xSrxCo1-yFeyO3-delta (LSCF), are assumed to effectively widen active sites, or triple phase boundaries, for the oxygen reduction reaction. Area specific resistance of commercially available cells has been decreased by 36-40% with the addition of 23 wt% PSCo electrocatalyst on cathode. Analysis of the impedance spectra demonstrates that PSCo electrocatalyst plays a significant role in dissociation of oxygen molecules and adsorption of oxygen atoms into the cathode. A total of 200 h operation of the cells demonstrated that catalytic activity of PSCo has not been significantly degraded. Simultaneous operations of multiple cells using a parallel-cell testing system have made it possible to compare the performance of several cells with high reliability. (C) 2011 Elsevier Ltd. All rights reserved.