Kinetics of thermal decomposition of som

The thermal decomposition kinetics of oxalates of Zn²⁺, K⁺, and Th⁴⁺ have been studied in air using isothermal and non-isothermal thermogravimetry methods. The isothermal kinetic results indicate that the decomposition mechanism of the zinc compound involves rapid nucleation followed by two-dimensional growth during the acceleratory phase, whereas for thorium oxalate, initial nucleation occurs through a chain mechanism at the surface, with product growth from the surface towards the interior. The kinetic data for nickel oxalate remain ambiguous. Activation energy and frequency factor derived from thermogravimetric (TG) curves align well with those obtained from the isothermal approach. Additionally, activation energies for the dehydration of these oxalates were evaluated from TG curves. In recent years, interest has surged in studying the kinetics and mechanisms of solid-state thermal dehydration and decomposition reactions of simple metal salts, including oxalates, acetates, perchlorates, and sulfates. Generally, the kinetics of solid-state thermal decomposition can be tracked using isothermal or non-isothermal methods, with isothermal data presented in terms of the fraction of decomposed reactant as a function of time, leading to characteristic sigmoid-shaped curves indicative of interface-leading decomposition mechanisms.