Catalytic oxidation of CO on LaMn1-xFexO3 perovskites solid solution

Catalytic CO oxidation was studied over LaMn1-xFexO3 perovskites prepared by co-precipitation and rotor-vapor citrate method. The catalysts were characterized by X-ray diffraction (XRD), Transmission electron microscope (TEM) and X-ray photoelectron spectroscopy (XPS). XRD analysis showed that LaMn1-xFexO3 samples prepared by rotor-vapor citrate method were single-phase perovskite-type oxides, but not prepared by co-precipitation. XPS results indicated that Mn element was mainly in Mn4+ state and Fe element was mainly in Fe3+ state on the surface of the catalysts. LaMn1-xFexO3 prepared by rotor-vapor citrate method exhibited higher activity for CO oxidation than which prepared by co-precipitation, and among the LaMn1-xFexO3 series prepared by rotor-vapor citrate method LaMn0.4Fe0.6O3 showed highest activity due to highest BET surface area. The lowest apparent activation energy (Ea) towards the oxidation of CO over LaMn0.4Fe0.0O3 dues to the highest dispersion of Mn4+-O-Fe3+ species on the surface of LaMn0.4Fe0.6O3. (C) 2014 Elsevier B.V. All rights reserved.