{"title":"Isoconversional methods: The many uses of variable activation energy","authors":"Sergey Vyazovkin","doi":"10.1016/j.tca.2024.179701","DOIUrl":null,"url":null,"abstract":"<div><p>In this review article, the author briefly shares his personal experience of exploring the phenomenon of variable activation energy. Isoconversional methods frequently yield variable activation energy, <em>E<sub>α</sub></em>, which depends on conversion, <em>α</em>. It is emphasized that isoconversional kinetic analysis should not be limited to simply evaluating and reporting the <em>E<sub>α</sub></em> dependencies. Deeper insights into the thermal kinetics are gained by exploiting the intrinsic properties of the <em>E<sub>α</sub></em> dependencies. These properties can be defined as diagnostic, exploratory, predictive, modelistic, and intermediary. Thanks to them one can generate mechanistic hypotheses, test the validity of assumed temperature dependencies of the process rates, forecast the kinetics beyond experimental conditions, determine parameters of kinetic models, and evaluate the preexponential factors and reaction rate constants. The article provides a practical overview of these properties of the <em>E<sub>α</sub></em> dependencies and illustrates their usage by instructive examples.</p></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":null,"pages":null},"PeriodicalIF":3.1000,"publicationDate":"2024-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Thermochimica Acta","FirstCategoryId":"92","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0040603124000406","RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, ANALYTICAL","Score":null,"Total":0}
引用次数: 0
Abstract
In this review article, the author briefly shares his personal experience of exploring the phenomenon of variable activation energy. Isoconversional methods frequently yield variable activation energy, Eα, which depends on conversion, α. It is emphasized that isoconversional kinetic analysis should not be limited to simply evaluating and reporting the Eα dependencies. Deeper insights into the thermal kinetics are gained by exploiting the intrinsic properties of the Eα dependencies. These properties can be defined as diagnostic, exploratory, predictive, modelistic, and intermediary. Thanks to them one can generate mechanistic hypotheses, test the validity of assumed temperature dependencies of the process rates, forecast the kinetics beyond experimental conditions, determine parameters of kinetic models, and evaluate the preexponential factors and reaction rate constants. The article provides a practical overview of these properties of the Eα dependencies and illustrates their usage by instructive examples.
期刊介绍:
Thermochimica Acta publishes original research contributions covering all aspects of thermoanalytical and calorimetric methods and their application to experimental chemistry, physics, biology and engineering. The journal aims to span the whole range from fundamental research to practical application.
The journal focuses on the research that advances physical and analytical science of thermal phenomena. Therefore, the manuscripts are expected to provide important insights into the thermal phenomena studied or to propose significant improvements of analytical or computational techniques employed in thermal studies. Manuscripts that report the results of routine thermal measurements are not suitable for publication in Thermochimica Acta.
The journal particularly welcomes papers from newly emerging areas as well as from the traditional strength areas:
- New and improved instrumentation and methods
- Thermal properties and behavior of materials
- Kinetics of thermally stimulated processes