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Clarifications regarding the use of model-fitting methods of kinetic analysis for determining the activation energy
Pedro E Sánchez-Jiménez1, Luis A Pérez-Maqueda, Antonio Perejón
1Instituto de Ciencia de Materiales de Sevilla, C,S,I,C,-Universidad de Sevilla, C, Américo Vespucio nº49, Sevilla 41092, Spain. pedro.enrique@icmse.csic.es.
Background:
This paper provides some clarifications regarding the use of model-fitting methods of kinetic analysis for estimating the activation energy of a process, in response to some results recently published in Chemistry Central journal.
Findings:
The model fitting methods of Arrhenius and Savata are used to determine the activation energy of a single simulated curve. It is shown that most kinetic models correctly fit the data, each providing a different value for the activation energy. Therefore it is not really possible to determine the correct activation energy from a single non-isothermal curve. On the other hand, when a set of curves are recorded under different heating schedules are used, the correct kinetic parameters can be clearly discerned.
Conclusions:
Here, it is shown that the activation energy and the kinetic model cannot be unambiguously determined from a single experimental curve recorded under non isothermal conditions. Thus, the use of a set of curves recorded under different heating schedules is mandatory if model-fitting methods are employed.
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