Improvement of anode performance by surface modification for solid oxide fuel cell running on hydrocarbon fuel

A Ni/ yttria-stabilized zirconia (YSZ) cermet anode was modified by coating with samaria-doped ceria (SDC, Sm0.2Ce0.8O2) sol within the pores of the anode for a solid oxide fuel cell (SOFC) running on hydrocarbon fuel. The surface modification of Ni/YSZ anode resulted in an increase of structural stability and enlargement of the triple phase boundary (TPB), which can serve as a catalytic reaction site for oxidation of carbon or carbon monoxide. Consequently, the SDC coating on the pores of anode made it possible to have good stability for long-term operation due to low carbon deposition and nickel sintering. The maximum power density of an anode-supported cell (electrolyte; 8 mol% YSZ and thickness of 30 μm, and cathode; La0.85Sr0.15MnO3) with the modified anode was about 0.3 W/cm2 at 700 °C in the mixture of methane (25%) and air (75%) as the fuel and air as the oxidant. The cell was operated for 500 h without significant degradation of cell performance.