Exploring mechanisms of hydration and carbonation of MgO and Mg(OH)₂ in reactive magnesium oxide-based cements
|Author:||Gardeh, Mina Ghane1; Kistanov, Andrey A.2; Nguyen, Hoang1;|
1Fibre and Particle Engineering Research Unit, University of Oulu, Pentti Kaiteran katu 1, 90014 Oulu, Finland
2Nano and Molecular Systems Research Unit, University of Oulu, Pentti Kaiteran katu 1, 90014 Oulu, Finland
3Departament of Condensed Matter Physics, University of the Basque Country (UPV/EHU), Barrio Sarriena, s/n, 48940 Leioa, Spain
|Online Access:||PDF Full Text (PDF, 7.4 MB)|
|Persistent link:|| http://urn.fi/urn:nbn:fi-fe2022042630463
American Chemical Society,
|Publish Date:|| 2022-04-26
Reactive magnesium oxide (MgO)-based cement (RMC) can play a key role in carbon capture processes. However, knowledge on the driving forces that control the degree of carbonation and hydration and rate of reactions in this system remains limited. In this work, density functional theory-based simulations are used to investigate the physical nature of the reactions taking place during the fabrication of RMCs under ambient conditions. Parametric indicators such as adsorption energies, charge transfer, electron localization function, adsorption/dissociation energy barriers, and the mechanisms of interaction of H₂O and CO₂ molecules with MgO and brucite (Mg(OH)₂) clusters are considered. The following hydration and carbonation interactions relevant to RMCs are evaluated: (i) carbonation of MgO, (ii) hydration of MgO, carbonation of hydrated MgO, (iii) carbonation of Mg(OH)₂, (iv) hydration of Mg(OH)₂, and (v) hydration of carbonated Mg(OH)₂. A comparison of the energy barriers and reaction pathways of these mechanisms shows that the carbonation of MgO is hindered by the presence of H₂O molecules, while the carbonation of Mg(OH)₂ is hindered by the formation of initial carbonate and hydrate layers as well as presence of excessed H₂O molecules. To compare these finding to bulk mineral surfaces, the interactions of the CO₂ and H₂O molecules with the MgO(001) and Mg(OH)₂ (001) surfaces are studied. Therefore, this work presents deep insights into the physical nature of the reactions and the mechanisms involved in hydrated magnesium carbonates production that can be beneficial for its development.
The journal of physical chemistry. C
|Pages:||6196 - 6206|
|Type of Publication:||
A1 Journal article – refereed
|Field of Science:||
1172 Environmental sciences
M.G.G., H.N., and P.K. are grateful for the support of the Academy of Finland grant CCC (329477) and the University of Oulu and the Academy of Finland Profi5 funding (326291). K.A.A. and W.C acknowledge funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (Grant Agreement No. 101002219). H.M. acknowledges funding from “Departamento de Educación, Política Lingüística y Cultura del Gobierno Vasco” (Grant No. IT1358-22). The authors acknowledge the CSC-IT Center for Science, Finland, for providing computational resources.
|EU Grant Number:||
(101002219) CATCH - Cross-dimensional Activation of Two-Dimensional Semiconductors for Photocatalytic Heterojunctions
|Academy of Finland Grant Number:||
329477 (Academy of Finland Funding decision)
© 2022 The Authors. Published by American Chemical Society. Published under the CC-BY license.