Synthesis, characterization and catalytic properties of La(Ni,Fe)O3–NiO nanocomposites

Nanocomposite structures involving LaNiO3 perovskite partially substituted with iron and segregated NiO are synthesized by sol–gel method using citric acid as chelating agent. Thermogravimetric and differential thermal analysis and X-ray diffraction (XRD) techniques are used to explore precursor decomposition and to establish adequate calcination temperature for the preparation of the nanocomposites. The samples obtained after calcination at 750 °C were characterized by XRD, X-ray photoelectronic spectroscopy, Brunauer–Emmett–Teller surface area analysis, Fourier transform infrared spectroscopy and powder size distribution, and tested for the catalytic oxidation reaction of CO. Optimum catalytic properties are shown to be achieved for nanocomposites with relatively weak Fe/Ni substitution degree in the perovskite interacting with well-dispersed small NiO entities.