Enhanced coking tolerance of a MgO-modified Ni cermet anode for hydrocarbon fueled solid oxide fuel cells

Abstract

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.