Study of microtubular membranes based on strontium ferrite doped with lanthanum and molybdenum, used in catalytic membrane reactors for the partial oxidation of methane
O. A. BRAGINA, M. O. KHOKHLOVA, E. V. SHUBNIKOVA, M. V. ARAPOVA, A. P. NEMUDRY
Institute of Solid State Chemistry and Mechanochemistry, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
Keywords: microtubular membranes, partial oxidation of methane, perovskite
Abstract
La0.4Sr0.6Fe0.95Mo0.05O3-δ microtubular membranes were prepared by the phase inversion method followed by sintering. Porous catalytic layers consisting of 1) 30%LaFe0.7Ni0.3O3-δ/(30%Ce0.9Gd0.1O2-δ-40%NiO), 2) LaFe0.4Ni0.6O3-δ were applied onto their inner surface. Preliminarily synthesised components of the membrane catalytic layers were studied by X-ray diffraction, revealing a monophasic composition of the studied complex oxides, without any impurities. The absence of chemical interaction between the membrane material La0.4Sr0.6Fe0.95Mo0.05O3-δ oxide and catalytic layers was established. According to the data of scanning electron microscopy, microtubular membranes, obtained by phase inversion followed by sintering, possess complex microstructure characterised by the presence of a gas-tight layer about 200 μm thick, surrounded by porous catalytic layers 10 m thick, with the uniform distribution of elements over the surface. It was demonstrated that the obtained microtubular membranes with deposited porous layers effectively activate methane when atmospheric oxygen and carbon dioxide are used as oxygen sources on the feed side of the membrane.
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