Enhanced coking tolerance of a MgO-modified Ni cermet anode for hydrocarbon fueled solid oxide fuel cells
A great deal of effort has been devoted to promoting the practical application of hydrocarbon fuels in solid oxide fuel cells (SOFCs). However, traditional SOFC cells with a Ni cermet anode have a serious carbon deposition problem in hydrocarbon fuels. Here we report a new method for improving the tolerance to carbon deposition of the Ni cermet anode in methane by impregnating a small amount of MgO (1.25–3.75 wt% with respect to Ni) into the porous Ni cermet anode. The cell with a MgO loading of 2.5 wt% exhibits a high power density of 714 mW cm−2 and excellent long-term stability for 330 h in humidified methane at 800 °C. The outstanding coking tolerance performance of the MgO-modified Ni cermet anode was attributed to the enhanced adsorption properties of H2O and CO2 on MgO, revealed by combined density function theory (DFT) calculations and experimental characterization. Our finding paves a new way for designing new hydrocarbon-fueled SOFCs and understanding the mechanism of coking tolerance of anodes.