A new nickel–ceria composite for direct-methane solid oxide fuel cells

Various Ni–LaxCe1−xOy composites were synthesized and their catalytic activity, catalytic stability and carbon deposition properties for steam reforming of methane were investigated. Among the catalysts, Ni–La0.1Ce0.9Oy showed the highest catalytic performance and also the best coking resistance. The Ni–LaxCe1−xOy catalysts with a higher Ni content were further sintered at 1400 °C and investigated as anodes of solid oxide fuel cells for operating on methane fuel. The Ni–La0.1Ce0.9Oy anode presented the best catalytic activity and coking resistance in the various Ni–LaxCe1−xOy catalysts with different ceria contents. In addition, the Ni–La0.1Ce0.9Oy also showed improved coking resistance over a Ni–SDC cermet anode due to its improved surface acidity. A fuel cell with a Ni–La0.1Ce0.9Oy anode and a catalyst yielded a peak power density of 850 mW cm−2 at 650 °C while operating on a CH4–H2O gas mixture, which was only slightly lower than that obtained while operating on hydrogen fuel. No obvious carbon deposition or nickel aggregation was observed on the Ni–La0.1Ce0.9Oy anode after the operation on methane. Such remarkable performances suggest that nickel and La-doped CeO2 composites are attractive anodes for direct hydrocarbon SOFCs and might also be used as catalysts for the steam reforming of hydrocarbons.

► Ni–LaxCe1−xOy (x = 0.0, 0.1, 0.3, 0.5, 0.7, 0.9 and 1.0) cermets were synthesized.
► Ni–La0.1Ce0.9Oy showed the best catalytic activity and highest coking resistance.
► Ni–La0.1Ce0.9Oy anode also showed excellent operational stability.
► High power output of 850 mW cm−2 was obtained with methane–steam as fuel at 650 °C.