Solid oxide fuel cells (SOFCs), capable of operating in an intermediate temperature range with a high power density, are fabricated using Sn-doped Ni/YSZ as an anode catalyst with a functional layer between the anode and electrolyte The cell shows a high power density of 0 41 W cm(-2) at 650 degrees C when operated using humidified methane fuel A comparison of this cell with a single cell prepared without Sn shows that the long-term stability is greatly improved; the Sn-doped Ni/YSZ cell operates for 137 h, whereas the Ni/YSZ cell ceases operation within 27 h A minimal level of Sn-doping yields the best cell performance, higher levels of Sn-doping results in occupation of most catalytic active sites, causing poorer performance In the case that carbon deposited on the Sn-doped Ni/YSZ surface during operation is removed, the long-term stability of the cell is further improved, and the cell operates stably for 300 h without degradation The quantity and distribution of Sn on the anode surface remains nearly unchanged over the course of operation (C) 2010 Elsevier B V All rights reserved