Tongtong Yao,Nianjun Hou,Juanjuan Gan,Jun Wang,Xiaojing Zhi,Lijun Fan,Tian Gan,Yicheng Zhao,Yongdan Li
Sr 2-x Na x FeMo 0.65 Ni 0.35 O 6-δ is synthesized as an anode material for solid oxide fuel cells. The effects of Na on the crystalline phase and electrical properties are investigated. The main perovskite phase changes into a Ruddlesden-Popper structure after reduction when x is less than 0.1, while the material with a higher amount of Na keeps the perovskite structure. FeNi x alloy nanoparticles are exsolved during reduction, in which the content of Ni increases with the rise of Na amount. The surface oxygen vacancy concentration is also influenced by the doping of Na, and the highest value is reached when x is 0.1. Sr 1.9 Na 0.1 FeMo 0.65 Ni 0.35 O 6-δ anode exhibits the highest activity, and a single cell supported by a 300-μm-thick La 0.8 Sr 0.2 Ga 0.8 Mg 0.2 O 3-δ electrolyte layer shows maximum power densities of 1495 and 627 mW cm −2 at 850 °C with H 2 and wet CH 4 as fuels, respectively. The coking resistance of the anode is also improved with Na doping.
Excellent Cr diffusion resistance and interface stability is essential for coatings applied on the surface of ferrite stainless steel interconnect for SOFCs. Four kinds of materials, the equimolar (MnFeCoNiCu) 3 O 4 (Eq), non-equimolar (Mn 0·272 Fe 0·272 Co 0·272 Ni 0·092 Cu 0.092 ) 3 O 4 (Non-Eq), MnCo 2 O 4 (MC) and the Quaternary (MnFeCoNi) 3 O 4 (Quaternary), are combined with chromium oxide to form diffusion couples in order to study the interfacial reaction mechanism. The constitutes and morphologies of the samples are tested. Two different composition reaction layers are found in equimolar/Cr 2 O 3 diffusion couple. A slight Cr inward diffusion is detected in Quaternary/Cr 2 O 3 diffusion couple.