Sr2Ni0.7Mg0.3MoO6-δ: Correlation between synthesis conditions and functional properties as anode material for intermediate-temperature SOFCs

• Published in: International journal of hydrogen energy 2021-10, Vol.46 (72), p.35910-35922
• Main Authors: Filonova, E.A., Russkikh, O.V., Skutina, L.S., Vylkov, A.I., Maksimchuk, T.Yu, Ostroushko, A.A.
• Format: Article
• Language: English
• Subjects: Charges generation; Double perovskite; Electrical conductivity; Solution combustion synthesis; Thermal expansion; Thermodynamic stability
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2021.02.008

The Sr2Ni0.7Mg0.3MoO6-δ double perovskites synthesis has been performed by a pyrolysis of organic-nitrate compositions with various ratios of ϕ (glycerol- or glycine content) and R (ammonium nitrate content). The solution combustion study revealed that the redox mixture composition for the Sr2Ni0.7Mg0.3MoO6-δ synthesis influenced the pyrolysis temperature, thermochemical charge generation, particles size, phase composition and physicochemical properties of the final oxide material. Investigations of thermodynamic stability, thermal expansion and electrical conductivity demonstrated that the Sr2Ni0.7Mg0.3MoO6-δ sample, obtained via pyrolysis synthesis with glycine triple excess without exothermic additive, may be considered as a prospective anode material for intermediate-temperature solid oxide fuel cells. It was confirmed by the sample stability in oxidative and reducing atmospheres, optimal values of linear coefficient of thermal expansion (14.4·10−6 K−1 in air; 13.1·10−6 K−1 in 50% H2/Ar) and the highest electrical conductivity value (0.53 S cm−1 at 800 °C in air) among glycine-samples. [Display omitted] •Redox synthetic ratios for Sr2Ni0·7Mg0.3MoO6-δ single phases were determined.•Process of thermochemical charge generation in solutions has been observed.•Stable sample was synthesised via glycine-nitrate route without exothermic additive.•For optimal Sr2Ni0.7Mg0.3MoO6-δ LCTE value was equal to 13.1·10−6 K−1 in H2/Ar.