In situ exsolved NiFe nanoparticles in Ni-doped Sr0.9Ti0.3Fe0.63Ni0.07O3‑δ anode with a three-dimensionally ordered macroporous structure for solid oxide fuel cells fueled by alkanes

Abstract

In this work, A-site deficient Ni-doped Sr0.9Ti0.3Fe0.63Ni0.07O3‑δ perovskite anode with ordered macroporous structures (STFN-3DOM) is designed to facilitate in-situ Ni-Fe exsolution for solid oxide fuel cells fueled by alkanes, e.g., methane and propane. The large specific surface area and A-site deficient of STFN-3DOM provide more exsolved Ni-Fe active sites and enhance the reaction kinetics of alkane reforming. Quasi-in-situ XPS is used to reveal the changes in the chemical state of elements during the exsolution and propane reforming process on the STFN-3DOM surface. The synergistic effect of A-site deficient, three-dimensional ordered macroporous structure, and in-situ Ni-Fe exsolution promotes the La0.8Sr0.2Ga0.83Mg0.17O3‑δ (LSGM) electrolyte-supported SOFC single cell to deliver advanced performance with both wet H2 (1.33 W cm−2) and wet C3H8 (0.838 W cm−2) at 850 °C, exhibiting satisfactory long-time stability in CH4 and redox stability. Density functional theory calculation confirms the low activation energy of STFN-3DOM for the rate-limiting step of C3H8* dissociation.