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Non-isothermal kinetics of the thermal decomposition of sodium oxalate Na2C2O4
Author(s)
Chaiyo, Nopsiri
Niemcharoen, Surasak
Date Issued
March 1, 2012
Type
Article
Abstract
The thermal transformation of Na2C2O4 was studied in N2 atmosphere using thermo gravimetric (TG) analysis and differential thermal analysis (DTA). Na2C2O4 and its decomposed product were characterized using a scanning electron microscope (SEM) and the X-ray diffraction technique (XRD). The non-isothermal kinetic of the decomposition was studied by the mean of Ozawa and Kissinger-Akahira-Sunose (KAS) methods. The activation energies (Eα) of Na2C2O4 decomposition were found to be consistent. Decreasing Eα at increased decomposition temperature indicated the multi-step nature of the process. The possible conversion function estimated through the Liqing-Donghua method was 'cylindrical symmetry (R 2 or F1/2)' of the phase boundary mechanism. Thermodynamic functions (DH*, DG* and DS*), calculated by the Activated complex theory and kinetic parameters, indicated that the decomposition step is a high energy pathway and revealed a very hard mechanism. © Akadémiai Kiadó, Budapest, Hungary 2011.
Citation
Journal of Thermal Analysis and Calorimetry, 107(3), 1023-1029, 2012