A kinetic study of the thermal degradation of ammonium species inside a 3D zincophosphate(Article)
- aFaculty of Technology and Metallurgy, University of Belgrade, 11000 Belgrade, Yugoslavia
- bNational Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia
Abstract
Ammonium ions remain inside the 3D zincophosphate framework after the hydrothermal crystallization. These species in co-operation with sodium cations exert a specific templating role in the formation of the open-framework lattice. The decomposition of the ammonium species under non-isothermal conditions has been studied by the non-parametric kinetics (NPK) method. The process is characterized by a complex kinetic mechanism and a relatively high activation energy for the main reaction step, Ea = 336 kJ/mol. These reflect the fact that the decomposition of the ammonium ions inside the zincophosphate framework involves not only the diffusion of the liberated species through the narrow channels of the microporous framework but also a prior overcoming of strong electrostatic interactions and the breaking of hydrogen bonds. © 2006 Elsevier B.V. All rights reserved.
Indexed keywords
| Engineering controlled terms: | Activation energyCrystallizationHydrothermal synthesisIonsPyrolysisReaction kineticsThermogravimetric analysisZinc compounds |
|---|---|
| Engineering uncontrolled terms: | 3D zinc phosphateNon-isothermal kineticsNPK methodOpen-framework |
| Engineering main heading: | Ammonium compounds |
Funding details
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1
This work was supported by the bilateral project “By rational synthesis towards smart materials” financed by the Serbian Ministry of Science and Environmental Protection and the Slovenian Ministry of Higher Education Science and Technology.
- ISSN: 00406031
- CODEN: THACA
- Source Type: Journal
- Original language: English
- DOI: 10.1016/j.tca.2006.07.013
- Document Type: Article
Stojakovic, D.; Faculty of Technology and Metallurgy, University of Belgrade, Yugoslavia;
© Copyright 2008 Elsevier B.V., All rights reserved.
Cited by 2 documents
(2012) Journal of Thermal Analysis and Calorimetry
(2007) Journal of the Serbian Chemical Society