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Catalytic water dissociation by greigite Fe(3)S(4) surfaces: density functional theory study

The iron sulfide mineral greigite, Fe(3)S(4), has shown promising capability as a hydrogenating catalyst, in particular in the reduction of carbon dioxide to produce small organic molecules under mild conditions. We employed density functional theory calculations to investigate the {001},{011} and {...

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Detalles Bibliográficos
Autores principales: Roldan, A., de Leeuw, N. H.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: The Royal Society Publishing 2016
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4892285/
https://www.ncbi.nlm.nih.gov/pubmed/27274698
http://dx.doi.org/10.1098/rspa.2016.0080
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author Roldan, A.
de Leeuw, N. H.
author_facet Roldan, A.
de Leeuw, N. H.
author_sort Roldan, A.
collection PubMed
description The iron sulfide mineral greigite, Fe(3)S(4), has shown promising capability as a hydrogenating catalyst, in particular in the reduction of carbon dioxide to produce small organic molecules under mild conditions. We employed density functional theory calculations to investigate the {001},{011} and {111} surfaces of this iron thiospinel material, as well as the production of hydrogen ad-atoms from the dissociation of water molecules on the surfaces. We systematically analysed the adsorption geometries and the electronic structure of both bare and hydroxylated surfaces. The sulfide surfaces presented a higher flexibility than the isomorphic oxide magnetite, Fe(3)O(4), allowing perpendicular movement of the cations above or below the top atomic sulfur layer. We considered both molecular and dissociative water adsorption processes, and have shown that molecular adsorption is the predominant state on these surfaces from both a thermodynamic and kinetic point of view. We considered a second molecule of water which stabilizes the system mainly by H-bonds, although the dissociation process remains thermodynamically unfavourable. We noted, however, synergistic adsorption effects on the Fe(3)S(4){001} owing to the presence of hydroxyl groups. We concluded that, in contrast to Fe(3)O(4), molecular adsorption of water is clearly preferred on greigite surfaces.
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spelling pubmed-48922852016-06-03 Catalytic water dissociation by greigite Fe(3)S(4) surfaces: density functional theory study Roldan, A. de Leeuw, N. H. Proc Math Phys Eng Sci Research Articles The iron sulfide mineral greigite, Fe(3)S(4), has shown promising capability as a hydrogenating catalyst, in particular in the reduction of carbon dioxide to produce small organic molecules under mild conditions. We employed density functional theory calculations to investigate the {001},{011} and {111} surfaces of this iron thiospinel material, as well as the production of hydrogen ad-atoms from the dissociation of water molecules on the surfaces. We systematically analysed the adsorption geometries and the electronic structure of both bare and hydroxylated surfaces. The sulfide surfaces presented a higher flexibility than the isomorphic oxide magnetite, Fe(3)O(4), allowing perpendicular movement of the cations above or below the top atomic sulfur layer. We considered both molecular and dissociative water adsorption processes, and have shown that molecular adsorption is the predominant state on these surfaces from both a thermodynamic and kinetic point of view. We considered a second molecule of water which stabilizes the system mainly by H-bonds, although the dissociation process remains thermodynamically unfavourable. We noted, however, synergistic adsorption effects on the Fe(3)S(4){001} owing to the presence of hydroxyl groups. We concluded that, in contrast to Fe(3)O(4), molecular adsorption of water is clearly preferred on greigite surfaces. The Royal Society Publishing 2016-04 /pmc/articles/PMC4892285/ /pubmed/27274698 http://dx.doi.org/10.1098/rspa.2016.0080 Text en © 2016 The Authors. http://creativecommons.org/licenses/by/4.0/ Published by the Royal Society under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/4.0/, which permits unrestricted use, provided the original author and source are credited.
spellingShingle Research Articles
Roldan, A.
de Leeuw, N. H.
Catalytic water dissociation by greigite Fe(3)S(4) surfaces: density functional theory study
title Catalytic water dissociation by greigite Fe(3)S(4) surfaces: density functional theory study
title_full Catalytic water dissociation by greigite Fe(3)S(4) surfaces: density functional theory study
title_fullStr Catalytic water dissociation by greigite Fe(3)S(4) surfaces: density functional theory study
title_full_unstemmed Catalytic water dissociation by greigite Fe(3)S(4) surfaces: density functional theory study
title_short Catalytic water dissociation by greigite Fe(3)S(4) surfaces: density functional theory study
title_sort catalytic water dissociation by greigite fe(3)s(4) surfaces: density functional theory study
topic Research Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4892285/
https://www.ncbi.nlm.nih.gov/pubmed/27274698
http://dx.doi.org/10.1098/rspa.2016.0080
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