The electrochemical performance of anode-supported single-chamber solid oxide fuel cells (SC-SOFCs) with and without SDC-impregnated cathodes was compared in a diluted methane-oxygen mixture. These cells were made of conventional materials including yttrium-stabilized zirconia (YSZ) thin film, a Ni + YSZ anode and a La0.7Sr0.3MnO3 (LSM) cathode. Our results showed that the cell performance was greatly enhanced with the SDC-impregnated LSM cathode. At a furnace temperature of 750 degrees C, the maximum power density was as high as 404 mW cm(-2) for a CH4 to O-2 ratio of 2:1, which was 4.0 times higher than the cell with a pure LSM cathode (100 mW cm(-2)). The overall polarization resistance of the impregnated cell was 1.6 ohm cm(2), which was much smaller than that of the non-impregnated one (4.2 ohm cm2). The impregnation introduced SDC nanoparticles greatly extended the electrochemical active zone and hence greatly improved the cell performance. (C) 2007 Elsevier B.V. All rights reserved.