Lithium and lanthanum promoted Ni-Al₂O₃ as an active and highly coking resistant catalyst layer for solid-oxide fuel cells operating on methane

Ni-Al₂O₃ catalyst is modified with Li ₂O₃, La₂O₃ and CaO promoters to improve its resistance to coking. These catalysts are used as the materials of the anode catalyst layer in solid-oxide fuel cells operating on methane. Their catalytic activity for the partial oxidation, steam reforming and CO₂ reforming of methane at 600-850 °C is investigated. Their catalytic stability and carbon deposition properties are also studied. The LiLaNi-Al ₂O₃ catalyst shows a catalytic activity that is comparable to those of LaNi-Al₂O₃ and LiNi-Al₂O ₃ catalysts for all three reactions. However, it displays a higher catalytic activity than those of CaLaNi-Al₂O₃ and CaNi-Al₂O₃ catalysts. Among the various catalysts, the LiLaNi-Al₂O₃ catalyst presents the highest catalytic stability. O₂-TPO profiles indicate that the modification of the Ni-Al₂O₃ catalyst with Li and La greatly reduces carbon deposition under pure methane atmosphere. The LiLaNi-Al₂O₃ catalyst is applied as the anode functional layer of a Ni + ScSZ anode-supported fuel cell. The cell is operated on methane-O₂, methane-H₂O or methane-CO₂ gas mixtures and yields peak power densities of 538, 532 and 529 mW cm^-2 at 850 °C, respectively, comparable to that of hydrogen fuel. In sum, the LiLaNi-Al ₂O₃ is highly promising as a highly coking resistant catalyst layer for solid-oxide fuel cells.