Large presence of carbonic acid in CO$_2$-rich aqueous fluids under Earth's mantle conditions
The chemistry of carbon in aqueous fluids at extreme pressure and temperature conditions is of great importance to Earth's deep carbon cycle, which substantially affects the carbon budget at Earth's surface and global climate change. At ambient conditions, the concentration of carbonic aci...
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ftdatacite:10.48550/arxiv.1907.01833 2023-05-15T15:51:56+02:00 Large presence of carbonic acid in CO$_2$-rich aqueous fluids under Earth's mantle conditions Stolte, Nore Pan, Ding 2019 https://dx.doi.org/10.48550/arxiv.1907.01833 https://arxiv.org/abs/1907.01833 unknown arXiv https://dx.doi.org/10.1021/acs.jpclett.9b01919 arXiv.org perpetual, non-exclusive license http://arxiv.org/licenses/nonexclusive-distrib/1.0/ Chemical Physics physics.chem-ph Geophysics physics.geo-ph FOS Physical sciences article-journal Article ScholarlyArticle Text 2019 ftdatacite https://doi.org/10.48550/arxiv.1907.01833 https://doi.org/10.1021/acs.jpclett.9b01919 2022-03-10T16:41:39Z The chemistry of carbon in aqueous fluids at extreme pressure and temperature conditions is of great importance to Earth's deep carbon cycle, which substantially affects the carbon budget at Earth's surface and global climate change. At ambient conditions, the concentration of carbonic acid in water is negligible, so aqueous carbonic acid was simply ignored in previous geochemical models. However, by applying extensive ab initio molecular dynamics simulations at pressure and temperature conditions similar to those in Earth's upper mantle, we found that carbonic acid can be the most abundant carbon species in aqueous CO$_2$ solutions at ~10 GPa and 1000 K. The mole percent of carbonic acid in total dissolved carbon species increases with increasing pressure along an isotherm, while its mole percent decreases with increasing temperature along an isobar. In CO$_2$-rich solutions, we found significant proton transfer between carbonic acid molecules and bicarbonate ions, which may enhance the conductivity of the solutions. The effects of pH buffering by carbonic acid may play an important role in water-rock interactions in Earth's interior. Our findings suggest that carbonic acid is an important carbon carrier in the deep carbon cycle. Article in Journal/Newspaper Carbonic acid DataCite Metadata Store (German National Library of Science and Technology) |
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DataCite Metadata Store (German National Library of Science and Technology) |
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Chemical Physics physics.chem-ph Geophysics physics.geo-ph FOS Physical sciences |
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Chemical Physics physics.chem-ph Geophysics physics.geo-ph FOS Physical sciences Stolte, Nore Pan, Ding Large presence of carbonic acid in CO$_2$-rich aqueous fluids under Earth's mantle conditions |
topic_facet |
Chemical Physics physics.chem-ph Geophysics physics.geo-ph FOS Physical sciences |
description |
The chemistry of carbon in aqueous fluids at extreme pressure and temperature conditions is of great importance to Earth's deep carbon cycle, which substantially affects the carbon budget at Earth's surface and global climate change. At ambient conditions, the concentration of carbonic acid in water is negligible, so aqueous carbonic acid was simply ignored in previous geochemical models. However, by applying extensive ab initio molecular dynamics simulations at pressure and temperature conditions similar to those in Earth's upper mantle, we found that carbonic acid can be the most abundant carbon species in aqueous CO$_2$ solutions at ~10 GPa and 1000 K. The mole percent of carbonic acid in total dissolved carbon species increases with increasing pressure along an isotherm, while its mole percent decreases with increasing temperature along an isobar. In CO$_2$-rich solutions, we found significant proton transfer between carbonic acid molecules and bicarbonate ions, which may enhance the conductivity of the solutions. The effects of pH buffering by carbonic acid may play an important role in water-rock interactions in Earth's interior. Our findings suggest that carbonic acid is an important carbon carrier in the deep carbon cycle. |
format |
Article in Journal/Newspaper |
author |
Stolte, Nore Pan, Ding |
author_facet |
Stolte, Nore Pan, Ding |
author_sort |
Stolte, Nore |
title |
Large presence of carbonic acid in CO$_2$-rich aqueous fluids under Earth's mantle conditions |
title_short |
Large presence of carbonic acid in CO$_2$-rich aqueous fluids under Earth's mantle conditions |
title_full |
Large presence of carbonic acid in CO$_2$-rich aqueous fluids under Earth's mantle conditions |
title_fullStr |
Large presence of carbonic acid in CO$_2$-rich aqueous fluids under Earth's mantle conditions |
title_full_unstemmed |
Large presence of carbonic acid in CO$_2$-rich aqueous fluids under Earth's mantle conditions |
title_sort |
large presence of carbonic acid in co$_2$-rich aqueous fluids under earth's mantle conditions |
publisher |
arXiv |
publishDate |
2019 |
url |
https://dx.doi.org/10.48550/arxiv.1907.01833 https://arxiv.org/abs/1907.01833 |
genre |
Carbonic acid |
genre_facet |
Carbonic acid |
op_relation |
https://dx.doi.org/10.1021/acs.jpclett.9b01919 |
op_rights |
arXiv.org perpetual, non-exclusive license http://arxiv.org/licenses/nonexclusive-distrib/1.0/ |
op_doi |
https://doi.org/10.48550/arxiv.1907.01833 https://doi.org/10.1021/acs.jpclett.9b01919 |
_version_ |
1766387302358056960 |