Document Type

Article

Publication Date

2010

Publisher

American Chemical Society

Source Publication

Journal of Physical Chemistry A

Source ISSN

1089-5639

Abstract

Anion exchange reactions of nanodimensional layered metal hydroxide compounds are utilized to create materials with targeted physical and chemical properties and also as a means for controlled release of intercalated anions. The kinetics of this important class of reaction are generally characterized by model-based approaches. In this work, a different approach based on isothermal, isoconversional analysis was utilized to determine effective activation energies with respect to extent of reaction. Two different layered metal hydroxide materials were chosen for reaction with chloride anions, using a temperature range of 30−60 °C. The concentrations of anions released into solution and the changes in polycrystalline solid phases were evaluated using model-based (Avrami-Erofe’ev nucleation−growth model) and model-free (integral isoconversional) methods. The results demonstrate the utility of the isoconversional approach for identifying when fitting to a single model is not appropriate, particularly for characterizing the temperature dependence of the reaction kinetics.

Comments

Accepted version. Journal of Physical Chemistry A, Volume 114, No. 49 (2010): 12858-12869. DOI. © 2010 American Chemical Society. Used with permission.

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