Carbon dioxide transport in molten calcium carbonate occurs through an oxo-Grotthuss mechanism via a pyrocarbonate anion

Abstract : The reactivity, speciation and solvation structure of CO2 in carbonate melts are relevant both for the fate of carbon in deep geological formations and for its electroreduction to CO, to be used as fuel, by means of solvation in a molten carbonate electrolyte. In particular, the high solubility of CO2 in carbonate melts has been tentatively attributed to the formation of a new carbon species, the pyrocarbonate anion, C_2O_5^{2−}. In this work we study, by first principles molecular dynamics simulations, the behaviour of CO2 in molten calcium carbonate. We find that pyrocarbonate forms spontaneously and the identity of the CO2 molecule is quickly lost through O^{2−} exchange. The transport of CO2 in this molten carbonate thus occurs in a fashion similar to the Grotthuss mechanism in water, and is three times faster than molecular diffusion. This shows that Grotthuss-like transport is more general than thought so far.
Document type :
Journal articles
Complete list of metadatas

Cited literature [20 references]  Display  Hide  Download

https://hal.archives-ouvertes.fr/hal-02113318
Contributor : François-Xavier Coudert <>
Submitted on : Sunday, April 28, 2019 - 4:02:04 PM
Last modification on : Wednesday, May 15, 2019 - 3:48:59 AM

File

postprint.pdf
Files produced by the author(s)

Identifiers

Citation

Dario Corradini, François-Xavier Coudert, Rodolphe Vuilleumier. Carbon dioxide transport in molten calcium carbonate occurs through an oxo-Grotthuss mechanism via a pyrocarbonate anion. Nature Chemistry, Nature Publishing Group, 2016, 8 (5), pp.454-460. ⟨10.1038/nchem.2450⟩. ⟨hal-02113318⟩

Share

Metrics

Record views

43

Files downloads

88