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Long-Time Non-Debye Kinetics of Molecular Desorption from Substrates with Frozen Disorder
The experiments on the kinetics of molecular desorption from structurally disordered adsorbents clearly demonstrate its non-Debye behavior at “long” times. In due time, when analyzing the desorption of hydrogen molecules from crystalline adsorbents, attempts were made to associate this behavior with...
Autores principales: | , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
MDPI
2020
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7464774/ https://www.ncbi.nlm.nih.gov/pubmed/32796720 http://dx.doi.org/10.3390/molecules25163662 |
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author | Bondarev, Victor N. Kutarov, Volodymyr V. Schieferstein, Eva Zavalniuk, Vladimir V. |
author_facet | Bondarev, Victor N. Kutarov, Volodymyr V. Schieferstein, Eva Zavalniuk, Vladimir V. |
author_sort | Bondarev, Victor N. |
collection | PubMed |
description | The experiments on the kinetics of molecular desorption from structurally disordered adsorbents clearly demonstrate its non-Debye behavior at “long” times. In due time, when analyzing the desorption of hydrogen molecules from crystalline adsorbents, attempts were made to associate this behavior with the manifestation of second-order effects, when the rate of desorption is limited by the rate of surface diffusion of hydrogen atoms with their subsequent association into molecules. However, the estimates made in the present work show that the dominance of second-order effects should be expected in the region of times significantly exceeding those where the kinetics of H(2) desorption have long acquired a non-Debye character. To explain the observed regularities, an approach has been developed according to which frozen fluctuations in the activation energy of desorption play a crucial role in the non-Debye kinetics of the process. The obtained closed expression for the desorption rate has a transparent physical meaning and allows us to give a quantitative interpretation of a number of experiments on the desorption kinetics of molecules not only from crystalline (containing frozen defects) but also from amorphous adsorbents. The ways of further development of the proposed theory and its experimental verification are outlined. |
format | Online Article Text |
id | pubmed-7464774 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2020 |
publisher | MDPI |
record_format | MEDLINE/PubMed |
spelling | pubmed-74647742020-09-04 Long-Time Non-Debye Kinetics of Molecular Desorption from Substrates with Frozen Disorder Bondarev, Victor N. Kutarov, Volodymyr V. Schieferstein, Eva Zavalniuk, Vladimir V. Molecules Article The experiments on the kinetics of molecular desorption from structurally disordered adsorbents clearly demonstrate its non-Debye behavior at “long” times. In due time, when analyzing the desorption of hydrogen molecules from crystalline adsorbents, attempts were made to associate this behavior with the manifestation of second-order effects, when the rate of desorption is limited by the rate of surface diffusion of hydrogen atoms with their subsequent association into molecules. However, the estimates made in the present work show that the dominance of second-order effects should be expected in the region of times significantly exceeding those where the kinetics of H(2) desorption have long acquired a non-Debye character. To explain the observed regularities, an approach has been developed according to which frozen fluctuations in the activation energy of desorption play a crucial role in the non-Debye kinetics of the process. The obtained closed expression for the desorption rate has a transparent physical meaning and allows us to give a quantitative interpretation of a number of experiments on the desorption kinetics of molecules not only from crystalline (containing frozen defects) but also from amorphous adsorbents. The ways of further development of the proposed theory and its experimental verification are outlined. MDPI 2020-08-11 /pmc/articles/PMC7464774/ /pubmed/32796720 http://dx.doi.org/10.3390/molecules25163662 Text en © 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/). |
spellingShingle | Article Bondarev, Victor N. Kutarov, Volodymyr V. Schieferstein, Eva Zavalniuk, Vladimir V. Long-Time Non-Debye Kinetics of Molecular Desorption from Substrates with Frozen Disorder |
title | Long-Time Non-Debye Kinetics of Molecular Desorption from Substrates with Frozen Disorder |
title_full | Long-Time Non-Debye Kinetics of Molecular Desorption from Substrates with Frozen Disorder |
title_fullStr | Long-Time Non-Debye Kinetics of Molecular Desorption from Substrates with Frozen Disorder |
title_full_unstemmed | Long-Time Non-Debye Kinetics of Molecular Desorption from Substrates with Frozen Disorder |
title_short | Long-Time Non-Debye Kinetics of Molecular Desorption from Substrates with Frozen Disorder |
title_sort | long-time non-debye kinetics of molecular desorption from substrates with frozen disorder |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7464774/ https://www.ncbi.nlm.nih.gov/pubmed/32796720 http://dx.doi.org/10.3390/molecules25163662 |
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