Determination of pre-exponential factors and of the mathematical functions f(α) or G(α) that describe the reaction mechanism in a model-free way

The study compared the accuracy of several model-fitting methods for the computation of compensation parameters. Two methods were presented for the model-free computation of the pre-exponential factor dependency using kinetic compensation parameters and isoconversional methods. These methods give accurate results for both single and multi-step kinetics. Once the pre-exponential factors have been evaluated in a model-free way, three model-free methods were proposed to compute the values of the mathematical function that describes the reaction mechanism for multi-step kinetics. These methods can be preferred according to the type of data available (i.e. differential or integral). Accurate results were obtained for both single and multi-step kinetics using two sets of simulated data and an experimental example. (C) 2013 Elsevier B.V. All rights reserved.