Effect of steam content on nickel nano-particle sintering and methane reforming activity of Ni–CZO anode cermets for internal reforming SOFCs

摘要: Abstract In this work, the reforming activity of Ni–Ce 0.75 Zr 0.25 O 2 (Ni–CZO) solid oxide fuel cell (SOFC) cermet anodes for steam methane has been investigated in absence electrochemical effects and results were compared with 0.9 Gd 0.1 (Ni–CGO) anodes. From X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission microscopy/energy dispersive spectroscopy (TEM/EDS) CHN analysis on spent Ni–CZO anode cermets, it was found that a decrease at higher steam-to-carbon ratios (S/C) due to sintering nickel nano-particles rather than re-oxidation or bulk carbon formation. Time-on-stream demonstrated Ni–CGO While initial sizes similar (5–10 nm) both anodes, after operation under steam-rich conditions (S/C = 1.5) be significantly larger (20–40 nm) those (15–25 nm). Under steam-lean (S/C = 0.5), size remained below 10 nm during operations, indicating effect Ni performance negligible. The is still which could attributed concentration ex-solved as well lower Ce 4+ /Ce 3+ reduction energy CZO CGO support.