LaMO3 (M=Mg, Ti, Fe) perovskite type oxides: Preparation, characterization and catalytic properties in methane deep oxidation

• Published in: Applied catalysis. B, Environmental Environmental, 2008-02, Vol.79 (2), p.186-198
• Main Authors: Petrović, S., Terlecki-Baričević, A., Karanović, Lj, Kirilov-Stefanov, P., Zdujić, M., Dondur, V., Paneva, D., Mitov, I., Rakić, V.
• Format: Article
• Language: English
• Subjects: Catalysis; Catalyst characterization; Chemistry; Exact sciences and technology; General and physical chemistry; Methane combustion; Perovskite catalysts; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry
• ISSN: 0926-3373; 1873-3883
• DOI: 10.1016/j.apcatb.2007.10.022

Two new series of perovskite-type oxides LaMO3 (M=Mg, Ti, Fe) with different ratio Mg/Fe (MF) and Ti/Fe (TF) in the B cation site were prepared by annealing the precursor, obtained by the mechanochemical activation (MCA) of constituent metal oxides, at 1000°C in air. In addition, two closely related perovskites LaFeO3 (LF) and LaTi0.5Mg0.5O3 (TM (50:50)) were synthesized in the similar way. Using MCA method, perovskites were obtained in rather short time and at room temperature. The samples were characterized by X-ray powder diffraction (XRPD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDS), temperature programmed desorption of oxygen (TPD), Mössbauer spectroscopy, BET surface area measurements and tested in methane deep oxidation. According to XRPD analysis all synthesized samples are almost single perovskite phase, with trace amounts of La2O3 phase. Data of Mössbauer spectroscopy identify Fe3+ in octahedral coordination. The activity of perovskite in methane deep oxidation increases in the order TM (50:50)