화학공학소재연구정보센터
Thermochimica Acta, Vol.487, No.1-2, 60-64, 2009
Thermal and thermo-oxidative decomposition of ammonium-iron(II) phosphate monohydrate
The thermal and thermo-oxidative decompositions of NH4FePO4 center dot H2O were studied by means of a combination of classical thermal analysis techniques (TG and DSC) with MS and powder XRD analysis. The experiment Was run in two different (inert and oxidizing) atmospheres. In an inert (N-2) atmosphere, thermal decomposition occurs in three steps at 265, 350 and 420 C related to the evacuation of H2O (steps 1 and 3) and NH3 (steps 1-3). In an oxidizing (O-2) atmosphere, thermal evacuation is coupled with the oxidation from Fe(II) to Fe(III). In addition, application of Vyazovkin's model-free kinetic method to three TG Curves obtained at different heating rates (5, 10 and 20 C/min) allows the activation energy to be calculated as a function of the extent of conversion. This helps to disclose the kinetic scheme that facilitates understanding of the mechanism of these reactions. (C) 2009 Elsevier B.V. All rights reserved.