Iron nanoparticles (Fe2O3) were added to NiO/gadolinium-doped CeO2 (GDC) anode supported solid oxide fuel cell (SOFC) for the direct methane-water fuel operation. The cell was co-sintered at 1400 degrees C, and the anode porosity is 31.8%. The main size corresponding to peak volume is around 1.5 mu m. When steam and methane directly fed to the cell, the power density is about 0.57 W cm(-2) at 650 degrees C. It is the familiar performance for H-2 operation (4 times of flow rate) with same fuel utilization. Compare with the testing temperature of 600 and 650 degrees C. there is almost no carbon fiber deposition at 700 degrees C with steam/methane (S/C) of 5. At the same time, fuel operation of high value of S/C(=3.3) resulted in fiber-like deposition and degradation of power performance based on loading test results. (C) 2011 Elsevier B.V. All rights reserved.