Infiltrated Ni_0.08Co_0.02CeO_2-x@Ni_0.8Co_0.2 catalysts for a finger-like anode in direct methane-fueled solid oxide fuel cells

Direct utilization of methane in solid oxide fuel cells (SOFCs) is greatly impeded by the grievous carbon deposition and the much depressed catalytic activity. In this work, a promising anode, taking finger-like porous YSZ as the anode substrate and impregnated Ni_0.08Co_0.02Ce_0.9O₂-_δ@Ni_0.8Co_0.2O as the novel catalyst, is fabricated via the phase conversion-combined tape-casting technique. This anode shows commendable mechanical strength and excellent catalytic activity and stability toward the methane conversion reactions, which is attributed to the exsolved alloy nanoparticles and the active oxygen species on the reduced Ni_0.08Co_0.02Ce_0.9O₂-_δ catalyst as well as the facilitated methane transport rooting in the special open-pore microstructure of the anode substrate. Strikingly, this button cell delivers an excellent peak power density of 730 mW cm^-2 at 800 °C in 97% CH₄/3% H₂O fuel, only 9% lower than that in 97% H₂/3% H₂O. Our work shed new light on the SOFC anode developments.