(Ni0.75Fe0.25-xMgO)/YSZ anode for direct methane solid-oxide fuel cells

(Ni0.75Fe0.25-xMgO)/YSZ samples-with a varying weight percentage x (0, 5%. 10%) of MgO with respect to Ni0.75Fe0.25-were prepared and studied as anodes for intermediate temperature solid oxide fuel cells (SOFCs) operated on humidified methane (3% H2O). Among the cells with different anode compositions, it was found that the cell with the (Ni0.75Fe0.25-5%MgO)/YSZ anode showed the highest power density, giving 648 mW cm(-2) at 800 degrees C. The cells with MgO-doped anodes were able to operate stably for 20 h under a current density of 0.53 A cm(-2) at 700 degrees C without observed degradation, while the cells without MgO degraded rapidly. The mechanisms responsible for the superior performance and duration of the (Ni0.75Fe0.25-xMgO)/YSZ anode were analyzed. (C) 2011 Elsevier B.V. All rights reserved.