Modified iron perovskites as catalysts precursors for the conversion of syngas to low molecular weight alkenes

• Published in: Journal of molecular catalysis. A, Chemical Chemical, 2003-02, Vol.193 (1), p.227-236
• Main Authors: Goldwasser, M.R., Dorantes, V.E., Pérez-Zurita, M.J., Sojo, P.R., Cubeiro, M.L., Pietri, E., González-Jiménez, F., Lee, Y.Ng, Moronta, D.
• Format: Article
• Language: English
• Subjects: Catalysis; Catalytic reactions; Chemistry; Exact sciences and technology; General and physical chemistry; Iron perovskites; Low alkenes production; Manganese promotion; Mössbauer spectroscopy; Potassium promotion; Syngas conversion; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry
• ISSN: 1381-1169; 1873-314X
• DOI: 10.1016/S1381-1169(02)00472-7

Five perovskite oxides La 1− x K x Mn y Fe 1− y O 3 (0≤ x, y≤0.2) were synthesized. The activity strongly depended on the presence of Hägg carbides. K promotes reducibility to α-Fe and to more carbide phases. Mn increases alkenes production. The presence of both K and Mn (La 0.9K 0.1Fe 0.9Mn 0.1O 2.9) strongly modified the selectivity and stability of catalysts with high yield of C 2C 4 alkenes. Five perovskite oxides with the composition La 1− x K x Mn y Fe 1− y O 3 (0≤ x, y≤0.2) were synthesized by the co-precipitation method. Techniques such as chemical and XR fluorescence analysis, powder X-ray diffraction (XRD), BET surface area, IR, EPR and Mössbauer spectroscopy were applied to characterize the structural features of the perovskites. The activity of the solids was strongly dependent on the presence of iron carbides. It was observed that K promotes the reducibility of the solid to α-Fe giving rise to more carbide phases. Mn produces a significant increase in alkenes production. The combined presence of both K and Mn (La 0.9K 0.1Fe 0.9Mn 0.1O 2.9) strongly modified the selectivity of the oxides, giving rise to a stable catalyst with high yield of C 2C 4 alkenes.