Thermochimica Acta, Vol.567, 35-39, 2013
Non isothermal decomposition of lanthanum titanates precursors prepared by sol gel process: A kinetic and thermodynamic study
The single phase La0.8Sr0.2TiO3+delta was prepared via the sol gel process using propionic acid. Kinetics of the thermal decomposition of the precursors has been studied using differential thermogravimetry under non-isothermal conditions in different atmospheres (air and helium). Non isothermal kinetic (A and Delta E) and thermodynamic parameters (Delta H, Delta S and Cp) were determined using different heating rates. La2O3, SrO and TiO2 products crystallized at temperatures of ca. 730, 960 and 470 degrees C respectively while pure La0.8Sr0.2TiO3+delta phase was obtained at 1200 degrees C, temperature substantially lower than that used for the preparation of La0.8Sr0.2TiO3+delta by conventional solid state method. Precursors and/or final solids were characterized by thermogravimetric analysis (TG), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction, diffuse reflectance ultraviolet-visible spectroscopy (DR-UV-vis) and methane steam reforming under water deficient conditions. (C) 2013 Elsevier B.V. All rights reserved.