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Model structures of molten salt-promoted MgO to probe the mechanism of MgCO(3) formation during CO(2) capture at a solid–liquid interface

MgO is a promising solid oxide-based sorbent to capture anthropogenic CO(2) emissions due to its high theoretical gravimetric CO(2) uptake and its abundance. When MgO is coated with alkali metal salts such as LiNO(3), NaNO(3), KNO(3), or their mixtures, the kinetics of the CO(2) uptake reaction is s...

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Autores principales: Bork, Alexander. H., Ackerl, Norbert, Reuteler, Joakim, Jog, Sachin, Gut, David, Zboray, Robert, Müller, Christoph. R.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: The Royal Society of Chemistry 2022
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9383051/
https://www.ncbi.nlm.nih.gov/pubmed/36092378
http://dx.doi.org/10.1039/d2ta02897b
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author Bork, Alexander. H.
Ackerl, Norbert
Reuteler, Joakim
Jog, Sachin
Gut, David
Zboray, Robert
Müller, Christoph. R.
author_facet Bork, Alexander. H.
Ackerl, Norbert
Reuteler, Joakim
Jog, Sachin
Gut, David
Zboray, Robert
Müller, Christoph. R.
author_sort Bork, Alexander. H.
collection PubMed
description MgO is a promising solid oxide-based sorbent to capture anthropogenic CO(2) emissions due to its high theoretical gravimetric CO(2) uptake and its abundance. When MgO is coated with alkali metal salts such as LiNO(3), NaNO(3), KNO(3), or their mixtures, the kinetics of the CO(2) uptake reaction is significantly faster resulting in a 15 times higher CO(2) uptake compared to bare MgO. However, the underlying mechanism that leads to this dramatic increase in the carbonation rate is still unclear. This study aims to determine the most favourable location for the nucleation and growth of MgCO(3) and more specifically, whether the carbonation occurs preferentially at the buried interface, the triple phase boundary (TPB), and/or inside the molten salt of the NaNO(3)–MgO system. For this purpose, a model system consisting of a MgO single crystal that is structured by ultra-short pulse laser ablation and coated with NaNO(3) as the promoter is used. To identify the location of nucleation and growth of MgCO(3), micro X-ray computed tomography, scanning electron microscopy, Raman microspectroscopy and optical profilometry were applied. We found that MgCO(3) forms at the NaNO(3)/MgO interface and not inside the melt. Moreover, there was no preferential nucleation of MgCO(3) at the TPB when compared to the buried interface. Furthermore, it is found that there is no observable CO(2) diffusion limitation in the nucleation step. However, it was observed that CO(2) diffusion limits MgCO(3) crystal growth, i.e. the growth rate of MgCO(3) is approximately an order of magnitude faster in shallow grooves compared to that in deep grooves.
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spelling pubmed-93830512022-09-08 Model structures of molten salt-promoted MgO to probe the mechanism of MgCO(3) formation during CO(2) capture at a solid–liquid interface Bork, Alexander. H. Ackerl, Norbert Reuteler, Joakim Jog, Sachin Gut, David Zboray, Robert Müller, Christoph. R. J Mater Chem A Mater Chemistry MgO is a promising solid oxide-based sorbent to capture anthropogenic CO(2) emissions due to its high theoretical gravimetric CO(2) uptake and its abundance. When MgO is coated with alkali metal salts such as LiNO(3), NaNO(3), KNO(3), or their mixtures, the kinetics of the CO(2) uptake reaction is significantly faster resulting in a 15 times higher CO(2) uptake compared to bare MgO. However, the underlying mechanism that leads to this dramatic increase in the carbonation rate is still unclear. This study aims to determine the most favourable location for the nucleation and growth of MgCO(3) and more specifically, whether the carbonation occurs preferentially at the buried interface, the triple phase boundary (TPB), and/or inside the molten salt of the NaNO(3)–MgO system. For this purpose, a model system consisting of a MgO single crystal that is structured by ultra-short pulse laser ablation and coated with NaNO(3) as the promoter is used. To identify the location of nucleation and growth of MgCO(3), micro X-ray computed tomography, scanning electron microscopy, Raman microspectroscopy and optical profilometry were applied. We found that MgCO(3) forms at the NaNO(3)/MgO interface and not inside the melt. Moreover, there was no preferential nucleation of MgCO(3) at the TPB when compared to the buried interface. Furthermore, it is found that there is no observable CO(2) diffusion limitation in the nucleation step. However, it was observed that CO(2) diffusion limits MgCO(3) crystal growth, i.e. the growth rate of MgCO(3) is approximately an order of magnitude faster in shallow grooves compared to that in deep grooves. The Royal Society of Chemistry 2022-07-08 /pmc/articles/PMC9383051/ /pubmed/36092378 http://dx.doi.org/10.1039/d2ta02897b Text en This journal is © The Royal Society of Chemistry https://creativecommons.org/licenses/by-nc/3.0/
spellingShingle Chemistry
Bork, Alexander. H.
Ackerl, Norbert
Reuteler, Joakim
Jog, Sachin
Gut, David
Zboray, Robert
Müller, Christoph. R.
Model structures of molten salt-promoted MgO to probe the mechanism of MgCO(3) formation during CO(2) capture at a solid–liquid interface
title Model structures of molten salt-promoted MgO to probe the mechanism of MgCO(3) formation during CO(2) capture at a solid–liquid interface
title_full Model structures of molten salt-promoted MgO to probe the mechanism of MgCO(3) formation during CO(2) capture at a solid–liquid interface
title_fullStr Model structures of molten salt-promoted MgO to probe the mechanism of MgCO(3) formation during CO(2) capture at a solid–liquid interface
title_full_unstemmed Model structures of molten salt-promoted MgO to probe the mechanism of MgCO(3) formation during CO(2) capture at a solid–liquid interface
title_short Model structures of molten salt-promoted MgO to probe the mechanism of MgCO(3) formation during CO(2) capture at a solid–liquid interface
title_sort model structures of molten salt-promoted mgo to probe the mechanism of mgco(3) formation during co(2) capture at a solid–liquid interface
topic Chemistry
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9383051/
https://www.ncbi.nlm.nih.gov/pubmed/36092378
http://dx.doi.org/10.1039/d2ta02897b
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