A new Gd-promoted nickel catalyst for methane conversion to syngas and as an anode functional layer in a solid oxide fuel cell

The effect of lanthanide promoters on a Ni-Al₂O₃ catalyst for methane partial oxidation, steam reforming and CO₂ reforming at 600-850 °C is systematically investigated. The promoters include La₂O₃, CeO₂, Pr₂O ₃, Sm₂O₃ and Gd₂O₃. GdNi-Al₂O₃ shows comparable catalytic activity to LaNi-Al₂O₃ and PrNi-Al₂O₃ but higher activity than CeNi-Al₂O₃ and SmNi-Al₂O ₃ for all three reactions. The O₂-TPO results show that GdNi-Al₂O₃ possesses the best coke resistance among those tested. It also displays good stability at 850 °C for 300 h. Raman spectroscopy indicates that the addition of lanthanide promoters can reduce the degree of graphitization of the carbon deposited on Ni-Al₂O ₃. The GdNi-Al₂O₃ is further applied as an anode functional layer in solid-oxide fuel cells operating on methane. The cell yields peak power densities of 1068, 996 and 986 mW cm^-2 at 850 °C, respectively, for operating on methane-O₂, methane-H ₂O and methane-CO₂ gas mixtures, which is comparable to operating on hydrogen fuel. GdNi-Al₂O₃ is promising as a highly coking-resistant catalyst layer for solid-oxide fuel cells.