The effect of catalyst nanostructure on the performance of solid oxide fuel cell (SOFC) anodes prepared by infiltration of an electronic conductor (45 wt % La0.8Sr0.2Cr0.5Mn0.5O3, LSCM) and a catalyst (1 wt % Pd and 9 wt % CeO2) into porous yttria-stabilized zirconia (YSZ) scaffolds was examined. When Pd and CeO2 were added by classical infiltration with nitrate salts, the initial electrode impedance in 97% H-2-3% H2O at 973 K was similar to 0.1 Omega cm(2); however, the impedance was found to increase significantly with time at 973 K and with heating to 1173 K. SEM images showed that the loss of performance coincided with a large increase in the size of the Pd crystallites. When Pd@CeO2 dispersible core-shell structures obtained through self-assembly were infiltrated into the anode and used as the catalytic component, the initial performance was excellent and the activity was remarkably stable with time at 973 K and upon heating to 1173 K. The improved stability is shown to be the result of greatly suppressed particle-size growth for Pd@CeO2 within the electrode structure. This study highlights the potential use of core-shell materials as stable structures in various fields of materials science and heterogeneous catalysis. (C)2011 The Electrochemical Society. [DOI: 10.1149/1.3571039]