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Understanding the Behaviour of Real Metaborates in Solution
Alkali metal borohydrides are promising candidates for large‐scale hydrogen storage. They react spontaneously with water, generating dihydrogen and metaborate salts. While sodium borohydride is the most studied, potassium has the best chance of commercial application. Here we examine the physical an...
Autores principales: | , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
John Wiley and Sons Inc.
2022
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9825938/ https://www.ncbi.nlm.nih.gov/pubmed/36069265 http://dx.doi.org/10.1002/cphc.202200428 |
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author | Pope, Frances Watson, Noë I. Deblais, Antoine Rothenberg, Gadi |
author_facet | Pope, Frances Watson, Noë I. Deblais, Antoine Rothenberg, Gadi |
author_sort | Pope, Frances |
collection | PubMed |
description | Alkali metal borohydrides are promising candidates for large‐scale hydrogen storage. They react spontaneously with water, generating dihydrogen and metaborate salts. While sodium borohydride is the most studied, potassium has the best chance of commercial application. Here we examine the physical and chemical properties of such self‐hydrolysis solutions. We do this by following the hydrogen evolution, the pH changes, and monitoring the reaction intermediates using NMR. Most studies on such systems are done using dilute solutions, but real‐life applications require high concentrations. We show that increasing the borohydride concentration radically changes the system's microstructure and rheology. The changes are seen already at concentrations as low as 5 w/w%, and are critical above 10 w/w%. While dilute solutions are Newtonian, concentrated reaction solutions display non‐Newtonian behaviour, that we attribute to the formation and (dis)entanglement of metaborate oligomers. The implications of these findings towards using borohydride salts for hydrogen storage are discussed. |
format | Online Article Text |
id | pubmed-9825938 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2022 |
publisher | John Wiley and Sons Inc. |
record_format | MEDLINE/PubMed |
spelling | pubmed-98259382023-01-09 Understanding the Behaviour of Real Metaborates in Solution Pope, Frances Watson, Noë I. Deblais, Antoine Rothenberg, Gadi Chemphyschem Research Articles Alkali metal borohydrides are promising candidates for large‐scale hydrogen storage. They react spontaneously with water, generating dihydrogen and metaborate salts. While sodium borohydride is the most studied, potassium has the best chance of commercial application. Here we examine the physical and chemical properties of such self‐hydrolysis solutions. We do this by following the hydrogen evolution, the pH changes, and monitoring the reaction intermediates using NMR. Most studies on such systems are done using dilute solutions, but real‐life applications require high concentrations. We show that increasing the borohydride concentration radically changes the system's microstructure and rheology. The changes are seen already at concentrations as low as 5 w/w%, and are critical above 10 w/w%. While dilute solutions are Newtonian, concentrated reaction solutions display non‐Newtonian behaviour, that we attribute to the formation and (dis)entanglement of metaborate oligomers. The implications of these findings towards using borohydride salts for hydrogen storage are discussed. John Wiley and Sons Inc. 2022-09-07 2022-11-18 /pmc/articles/PMC9825938/ /pubmed/36069265 http://dx.doi.org/10.1002/cphc.202200428 Text en © 2022 The Authors. ChemPhysChem published by Wiley-VCH GmbH https://creativecommons.org/licenses/by-nc/4.0/This is an open access article under the terms of the http://creativecommons.org/licenses/by-nc/4.0/ (https://creativecommons.org/licenses/by-nc/4.0/) License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes. |
spellingShingle | Research Articles Pope, Frances Watson, Noë I. Deblais, Antoine Rothenberg, Gadi Understanding the Behaviour of Real Metaborates in Solution |
title | Understanding the Behaviour of Real Metaborates in Solution |
title_full | Understanding the Behaviour of Real Metaborates in Solution |
title_fullStr | Understanding the Behaviour of Real Metaborates in Solution |
title_full_unstemmed | Understanding the Behaviour of Real Metaborates in Solution |
title_short | Understanding the Behaviour of Real Metaborates in Solution |
title_sort | understanding the behaviour of real metaborates in solution |
topic | Research Articles |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9825938/ https://www.ncbi.nlm.nih.gov/pubmed/36069265 http://dx.doi.org/10.1002/cphc.202200428 |
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