Enhanced sulfur and carbon coking tolerance of novel co-doped ceria based anode for solid oxide fuel cells

Doubly doped CeO2 based anode with Y and Yb is first reported for direct methane solid oxide fuel cells. The power output of the cell with Ni–Ce0.8Y0.1Yb0.1O1.9 anode and stability at various temperatures are investigated when air is used as oxidant and pure H2, 5 ppm H2S containing H2 and dry CH4 as fuel, respectively. At 750 °C, the cell displays stable power output for 120 h at 200 mA cm−2 when fueled with dry CH4, suggesting the carbon deposit is largely absent on the anode, which is confirmed by the SEM observation and EDS results. The results also prove that the rare earth elements Y and Yb affect the sulfur tolerance performance of the anode in a cooperative fashion leading to good anode stability in the contaminated fuel. The SEM and EDS results provide evidence that the cell with Ni–Ce0.8Y0.1Yb0.1O1.9 anode is tolerant toward the H2S contamination. The remarkable performances suggest that co-doped CeO2 anode is an attractive electrode component for direct hydrocarbon solid oxide fuel cells and might also be used as a catalyst for reforming of hydrocarbon fuels and for removal of fuel gas contaminations such as sulfur.

► Doped CeO2 based anode with Y and Yb was first reported for direct methane SOFCs.
► The cell with Ni–Ce0.8Y0.1Yb0.1O1.9 in dry methane displayed stable power output.
► The co-dopants affected the sulfur tolerance performance in a cooperative fashion.
► This material can also be used for removal of fuel gas contaminations such as sulfur.