from first principles PP-I-1

PP-III-39Nature of Low Bond Oxygen Form in La 1-x Sr x FeO 3 PerovskitesIsupova L.A. 1 , Prosvirin I. 1 , Pavlyukhin Yu.T. 21 Boreskov Institute of Catalysis SB RAS, pr. Lavrentieva, 5, Novosibirsk, Russia2 Institute of Solid State Chemistry SB RAS, ul. Kutateladze, 18, Novosibirsk, Russiaisupova@catalysis.ruPerovskite-like oxides ABO 3±y (A = La; B = Mn, Co, Fe) due to their unique physical andchemical properties and stability in reaction mediums are very promising for application inmany high temperature processes with oxygen participation as catalysts, catalyst membranes,cathodes and anodes in SOFC, and so on [1,2]. It is well known that catalytic properties ofperovskites depend on nature of 3d cations, their coordination and charge state, which dependon preparation route and substitution degrees in A and B sublattices, that in final influence thenumber of oxygen forms, their mobility and reactivity. For example, substitution oflanthanum for strontium in LaFeO 3 leads to formation of low bond oxygen form (its quantityincreases in proportion to substitution degree) that removes during H 2 - TPR experiments at400-600 о С. Usually based on electroneutrality principle and using H 2 -TPR data the quantityof iron cations in oxidation state +4 (due to substitution) may be calculated [3].The main goal of the paper is investigation of charge and coordination states of iron andoxygen ions in La 1-x Sr x FeO 3-y (0 ≤ x < 1.0) perovskites with Mossbauer and XPS.According to H 2 -TPR perovskites with x