Improved solid oxide fuel cell anodes for the direct utilization of methane using Sn-doped Ni/YSZ catalysts

A single solid oxide fuel cell is fabricated using Sn-doped Ni/YSZ as the anode catalyst. A power density of 0.39 W/cm2 was obtained using a Sn-doped Ni/YSZ cell with methane fuel at 800 °C, which is equivalent to that obtained using a Ni/YSZ cell (0.40 W/cm2). Stability tests reveal that the stability of the Sn-doped Ni/YSZ cell is an order of magnitude higher than that of the Ni/YSZ cell. The Sn-doped Ni/YSZ cell operates for 49.0 h, whereas the Ni/YSZ cell stops after 2.3 h. The Ni/YSZ fuel cell is destroyed by cell expansion caused by the rapid accumulation of graphitic coke. In contrast, much less graphitic carbon is deposited on Sn-doped Ni/YSZ, leading to improved stability.