Thermal decomposition kinetics of potassium iodate

The thermal decomposition of potassium iodate (KIO₃) has been studied by both non-isothermal and isothermal thermogravimetry (TG). The non-isothermal simultaneous TG–differential thermal analysis (DTA) of the thermal decomposition of KIO₃ was carried out in nitrogen atmosphere at different heating rates. The isothermal decomposition of KIO₃ was studied using TG at different temperatures in the range 790–805 K in nitrogen atmosphere. The theoretical and experimental mass loss data are in good agreement for the thermal decomposition of KIO₃. The non-isothermal decomposition of KIO₃ was subjected to kinetic analyses by model-free approach, which is based on the isoconversional principle. The isothermal decomposition of KIO₃ was subjected to both conventional (model fitting) and model-free (isoconversional) methods. It has been observed that the activation energy values obtained from all these methods agree well. Isothermal model fitting analysis shows that the thermal decomposition kinetics of KIO₃ can be best described by the contracting cube equation.