Journal of Power Sources, Vol.210, 374-380, 2012
Lanthanum promoted NiO-SDC anode for low temperature solid oxide fuel cells fueled with methane
A Ni0.95La0.05O-SDC composite was tested as solid oxide fuel cell (SOFC) anode fueled with methane at temperatures between 500 and 600 degrees C (i.e. for low temperature SOFC). It was found that NiO and La2O3 formed a solid solution and small amounts of La2NiO4 were also observed after sintering at 1340 degrees C. After subsequent reduction. NiO was reduced to Ni while La2O3 remained as oxide phase. The La modified NiO-SDC anode showed higher OCV, over 30% improved maximum power density and better stability in humidified methane fuel as compared with the NiO-SDC anode. Meanwhile, the Ni0.95La0.05O-SDC anode cell displayed lower polarization resistance (e.g. at 600 degrees C, 0.12 Omega cm(-2) versus 0.34 Omega cm(-2) for NiO-SDC) implying higher surface reaction activity than the NiO-SDC anode cell. At 600 degrees C. the Ni0.95La0.05O-SDC anode exhibited similar performance and activity in H-2 and CH4 fuels. The SEM results indicated that La effectively prevented NiO coarsening giving rise to a much finer structure with smaller particle size and more uniform distribution, which can contribute to the better performance with La. (C) 2011 Elsevier B.V. All rights reserved.