Georgi Rusev, Velyana Georgieva, Svetlana Genieva, Ivaylo Tankov
{"title":"Non-Isothermal Decomposition Kinetics of Hafnium and Zirconyl Hydrogentellurates","authors":"Georgi Rusev, Velyana Georgieva, Svetlana Genieva, Ivaylo Tankov","doi":"10.1002/kin.21773","DOIUrl":null,"url":null,"abstract":"<div>\n \n <p>The thermal characteristics of zirconyl and hafnium hydrogentellurates, ZrO(HTeO<sub>4</sub>)<sub>2</sub> × 4H<sub>2</sub>O (ZrOTe) and Hf(HTeO<sub>4</sub>)<sub>4</sub> × 8H<sub>2</sub>O (HfTe), were investigated via non-isothermal decomposition kinetics in this paper for the first time. Important kinetic parameters such as activation energy (<i>E<sub>A</sub></i>), pre-exponential factor (<i>A</i>) and <i>g</i>(<i>α</i>) function were determined using Coats-Redfern integral method. The latter was verified by means of <i>z</i>(<i>α</i>) master plots. In addition, plausible decomposition mechanisms for the title compounds were offered. Based on the <i>E<sub>A</sub></i> values, less thermal stability for ZrOTe (633.69 kJ/mol) with respect to HfTe (872.24 kJ/mol) was observed. Thermodynamic functions (Δ<i>S</i><sup>≠</sup>, Δ<i>H</i><sup>≠</sup>, and Δ<i>G</i><sup>≠</sup>) of the activated complexes generated during the thermal decomposition steps were studied as well. A high positive Δ<i>H</i><sup>≠</sup> value (855.70 kJ/mol) for the thermal decomposition of HfTe indicated formation of high-ordered activated complexes. In contrast, lower Δ<i>H</i><sup>≠</sup> (612.50 kJ/mol) for ZrOTe suggested easier formation the transition states in that case.</p>\n </div>","PeriodicalId":13894,"journal":{"name":"International Journal of Chemical Kinetics","volume":"57 4","pages":"254-262"},"PeriodicalIF":1.5000,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"International Journal of Chemical Kinetics","FirstCategoryId":"92","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1002/kin.21773","RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
引用次数: 0
Abstract
The thermal characteristics of zirconyl and hafnium hydrogentellurates, ZrO(HTeO4)2 × 4H2O (ZrOTe) and Hf(HTeO4)4 × 8H2O (HfTe), were investigated via non-isothermal decomposition kinetics in this paper for the first time. Important kinetic parameters such as activation energy (EA), pre-exponential factor (A) and g(α) function were determined using Coats-Redfern integral method. The latter was verified by means of z(α) master plots. In addition, plausible decomposition mechanisms for the title compounds were offered. Based on the EA values, less thermal stability for ZrOTe (633.69 kJ/mol) with respect to HfTe (872.24 kJ/mol) was observed. Thermodynamic functions (ΔS≠, ΔH≠, and ΔG≠) of the activated complexes generated during the thermal decomposition steps were studied as well. A high positive ΔH≠ value (855.70 kJ/mol) for the thermal decomposition of HfTe indicated formation of high-ordered activated complexes. In contrast, lower ΔH≠ (612.50 kJ/mol) for ZrOTe suggested easier formation the transition states in that case.
期刊介绍:
As the leading archival journal devoted exclusively to chemical kinetics, the International Journal of Chemical Kinetics publishes original research in gas phase, condensed phase, and polymer reaction kinetics, as well as biochemical and surface kinetics. The Journal seeks to be the primary archive for careful experimental measurements of reaction kinetics, in both simple and complex systems. The Journal also presents new developments in applied theoretical kinetics and publishes large kinetic models, and the algorithms and estimates used in these models. These include methods for handling the large reaction networks important in biochemistry, catalysis, and free radical chemistry. In addition, the Journal explores such topics as the quantitative relationships between molecular structure and chemical reactivity, organic/inorganic chemistry and reaction mechanisms, and the reactive chemistry at interfaces.