Effect of Ni-loading on Sm-doped CeO2 anode for ammonia-fueled solid oxide fuel cell

Samaria-doped ceria, (SmO1.5)(0.2)(CeO2)(0.8) (SDC), containing nickel (Ni) was prepared as the anode of solid oxide fuel cell fueled with 6% ammonia (NH3). The Ni-free SDC powders prepared by the reverse co-precipitation method exhibited poor catalytic activities for NH3 decomposition in 6% NH3/Ar. Impregnation of Ni onto the SDC powders significantly enhanced its catalytic activity. The catalytic activity was highest at 10 wt% Ni-SDC, but it decreased with an increase in the Ni content. Contrary to expectation, the anodic performances were similar between 10 and 40 wt% of Ni loading and the highest maximum power densities were 98.8 and 96.5 mW.cm(-2) at 900 degrees C, respectively. Impedance analysis of the anodes revealed that the anodic performance was rate-controlled by the similar process in 4% H-2 fuel and that was electrochemical oxidation and diffusion processes. (C) 2018 The Ceramic Society of Japan. All rights reserved.