Cargando…
The Structure of the Electric Double Layer of the Protic Ionic Liquid [Dema][TfO] Analyzed by Atomic Force Spectroscopy
Protic ionic liquids are promising electrolytes for fuel cell applications. They would allow for an increase in operation temperatures to more than 100 °C, facilitating water and heat management and, thus, increasing overall efficiency. As ionic liquids consist of bulky charged molecules, the struct...
Autores principales: | , , , , , , , |
---|---|
Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
MDPI
2021
|
Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8658030/ https://www.ncbi.nlm.nih.gov/pubmed/34884462 http://dx.doi.org/10.3390/ijms222312653 |
_version_ | 1784612637169942528 |
---|---|
author | Rodenbücher, Christian Chen, Yingzhen Wippermann, Klaus Kowalski, Piotr M. Giesen, Margret Mayer, Dirk Hausen, Florian Korte, Carsten |
author_facet | Rodenbücher, Christian Chen, Yingzhen Wippermann, Klaus Kowalski, Piotr M. Giesen, Margret Mayer, Dirk Hausen, Florian Korte, Carsten |
author_sort | Rodenbücher, Christian |
collection | PubMed |
description | Protic ionic liquids are promising electrolytes for fuel cell applications. They would allow for an increase in operation temperatures to more than 100 °C, facilitating water and heat management and, thus, increasing overall efficiency. As ionic liquids consist of bulky charged molecules, the structure of the electric double layer significantly differs from that of aqueous electrolytes. In order to elucidate the nanoscale structure of the electrolyte–electrode interface, we employ atomic force spectroscopy, in conjunction with theoretical modeling using molecular dynamics. Investigations of the low-acidic protic ionic liquid diethylmethylammonium triflate, in contact with a platinum (100) single crystal, reveal a layered structure consisting of alternating anion and cation layers at the interface, as already described for aprotic ionic liquids. The structured double layer depends on the applied electrode potential and extends several nanometers into the liquid, whereby the stiffness decreases with increasing distance from the interface. The presence of water distorts the layering, which, in turn, significantly changes the system’s electrochemical performance. Our results indicate that for low-acidic ionic liquids, a careful adjustment of the water content is needed in order to enhance the proton transport to and from the catalytic electrode. |
format | Online Article Text |
id | pubmed-8658030 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2021 |
publisher | MDPI |
record_format | MEDLINE/PubMed |
spelling | pubmed-86580302021-12-10 The Structure of the Electric Double Layer of the Protic Ionic Liquid [Dema][TfO] Analyzed by Atomic Force Spectroscopy Rodenbücher, Christian Chen, Yingzhen Wippermann, Klaus Kowalski, Piotr M. Giesen, Margret Mayer, Dirk Hausen, Florian Korte, Carsten Int J Mol Sci Article Protic ionic liquids are promising electrolytes for fuel cell applications. They would allow for an increase in operation temperatures to more than 100 °C, facilitating water and heat management and, thus, increasing overall efficiency. As ionic liquids consist of bulky charged molecules, the structure of the electric double layer significantly differs from that of aqueous electrolytes. In order to elucidate the nanoscale structure of the electrolyte–electrode interface, we employ atomic force spectroscopy, in conjunction with theoretical modeling using molecular dynamics. Investigations of the low-acidic protic ionic liquid diethylmethylammonium triflate, in contact with a platinum (100) single crystal, reveal a layered structure consisting of alternating anion and cation layers at the interface, as already described for aprotic ionic liquids. The structured double layer depends on the applied electrode potential and extends several nanometers into the liquid, whereby the stiffness decreases with increasing distance from the interface. The presence of water distorts the layering, which, in turn, significantly changes the system’s electrochemical performance. Our results indicate that for low-acidic ionic liquids, a careful adjustment of the water content is needed in order to enhance the proton transport to and from the catalytic electrode. MDPI 2021-11-23 /pmc/articles/PMC8658030/ /pubmed/34884462 http://dx.doi.org/10.3390/ijms222312653 Text en © 2021 by the authors. https://creativecommons.org/licenses/by/4.0/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 (https://creativecommons.org/licenses/by/4.0/). |
spellingShingle | Article Rodenbücher, Christian Chen, Yingzhen Wippermann, Klaus Kowalski, Piotr M. Giesen, Margret Mayer, Dirk Hausen, Florian Korte, Carsten The Structure of the Electric Double Layer of the Protic Ionic Liquid [Dema][TfO] Analyzed by Atomic Force Spectroscopy |
title | The Structure of the Electric Double Layer of the Protic Ionic Liquid [Dema][TfO] Analyzed by Atomic Force Spectroscopy |
title_full | The Structure of the Electric Double Layer of the Protic Ionic Liquid [Dema][TfO] Analyzed by Atomic Force Spectroscopy |
title_fullStr | The Structure of the Electric Double Layer of the Protic Ionic Liquid [Dema][TfO] Analyzed by Atomic Force Spectroscopy |
title_full_unstemmed | The Structure of the Electric Double Layer of the Protic Ionic Liquid [Dema][TfO] Analyzed by Atomic Force Spectroscopy |
title_short | The Structure of the Electric Double Layer of the Protic Ionic Liquid [Dema][TfO] Analyzed by Atomic Force Spectroscopy |
title_sort | structure of the electric double layer of the protic ionic liquid [dema][tfo] analyzed by atomic force spectroscopy |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8658030/ https://www.ncbi.nlm.nih.gov/pubmed/34884462 http://dx.doi.org/10.3390/ijms222312653 |
work_keys_str_mv | AT rodenbucherchristian thestructureoftheelectricdoublelayeroftheproticionicliquiddematfoanalyzedbyatomicforcespectroscopy AT chenyingzhen thestructureoftheelectricdoublelayeroftheproticionicliquiddematfoanalyzedbyatomicforcespectroscopy AT wippermannklaus thestructureoftheelectricdoublelayeroftheproticionicliquiddematfoanalyzedbyatomicforcespectroscopy AT kowalskipiotrm thestructureoftheelectricdoublelayeroftheproticionicliquiddematfoanalyzedbyatomicforcespectroscopy AT giesenmargret thestructureoftheelectricdoublelayeroftheproticionicliquiddematfoanalyzedbyatomicforcespectroscopy AT mayerdirk thestructureoftheelectricdoublelayeroftheproticionicliquiddematfoanalyzedbyatomicforcespectroscopy AT hausenflorian thestructureoftheelectricdoublelayeroftheproticionicliquiddematfoanalyzedbyatomicforcespectroscopy AT kortecarsten thestructureoftheelectricdoublelayeroftheproticionicliquiddematfoanalyzedbyatomicforcespectroscopy AT rodenbucherchristian structureoftheelectricdoublelayeroftheproticionicliquiddematfoanalyzedbyatomicforcespectroscopy AT chenyingzhen structureoftheelectricdoublelayeroftheproticionicliquiddematfoanalyzedbyatomicforcespectroscopy AT wippermannklaus structureoftheelectricdoublelayeroftheproticionicliquiddematfoanalyzedbyatomicforcespectroscopy AT kowalskipiotrm structureoftheelectricdoublelayeroftheproticionicliquiddematfoanalyzedbyatomicforcespectroscopy AT giesenmargret structureoftheelectricdoublelayeroftheproticionicliquiddematfoanalyzedbyatomicforcespectroscopy AT mayerdirk structureoftheelectricdoublelayeroftheproticionicliquiddematfoanalyzedbyatomicforcespectroscopy AT hausenflorian structureoftheelectricdoublelayeroftheproticionicliquiddematfoanalyzedbyatomicforcespectroscopy AT kortecarsten structureoftheelectricdoublelayeroftheproticionicliquiddematfoanalyzedbyatomicforcespectroscopy |