Compatibility evaluation between La2Mo2O9 fast oxide-ion conductor and Ni-based materials

The chemical reactivity of La2NiO4+δ and nickel metal or nickel oxide with fast oxide-ion conductor La2Mo2O9 is investigated in the annealing temperature range between 600 and 1000 °C, using room temperature X-ray powder diffraction. Within the La2NiO4+δ/La2Mo2O9 system, subsequent reaction is evidenced at relatively low annealing temperature (600 °C), with formation of La2MoO6 and NiO. The reaction is complete at 1000 °C. At reverse, no reaction occurs between Ni or NiO and La2Mo2O9 up to 1000 °C. Together with a previous work [G. Corbel, S. Mestiri, P. Lacorre, Solid State Sci. 7 (2005) 1216], the current study shows that Ni-CGO cermets might be chemically and mechanically compatible anode materials to work with LAMOX electrolytes in solid oxide fuel cells.