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

Abstract

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.