Hydration Structures of MgO, CaO, and SrO (001) Surfaces

Ončák, Milan; Włodarczyk, Radosław; Sauer, Joachim

doi:10.1021/acs.jpcc.6b07434

Cited by 24 publications

(6 citation statements)

References 62 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Ab initio molecular dynamics simulations of multilayer water adsorption on BaO(100) have revealed facile cation dissolution and formation of hydroxylated structures . Similar phenomena were recently studied for MgO(100), where a Mg(OH) 2 ‐layered structure was predicted to be thermodynamically preferred at high chemical potentials of water . Although the barriers for Mg(OH) 2 formation or detachment of solvated Mg 2+ from the surface are unknown, it can be assumed that these processes are facile at room temperature.…”

Section: Resultssupporting

confidence: 52%

Thin water films and particle morphology evolution in nanocrystalline MgO

et al. 2018

View full text Add to dashboard Cite

A key question in the field of ceramics and catalysis is how and to what extent residual water in the reactive environment of a metal oxide particle powder affects particle coarsening and morphology. With X‐ray Diffraction (XRD) and Transmission Electron Microscopy (TEM), we investigated annealing‐induced morphology changes on powders of MgO nanocubes in different gaseous H2O environments. The use of such a model system for particle powders enabled us to describe how adsorbed water that originates from short exposure to air determines the evolution of MgO grain size, morphology, and microstructure. While cubic nanoparticles with a predominant abundance of (100) surface planes retain their shape after annealing to T = 1173 K under continuous pumping with a base pressure of water p(H2O) = 10−5 mbar, higher water partial pressures promote mass transport on the surfaces and across interfaces of such particle systems. This leads to substantial growth and intergrowth of particles and simultaneously favors the formation of step edges and shallow protrusions on terraces. The mass transfer is promoted by thin films of water providing a two‐dimensional solvent for Mg2+ ion hydration. In addition, we obtained direct evidence for hydroxylation‐induced stabilization of (110) faces and step edges of the grain surfaces.

show abstract

Section: Resultssupporting

confidence: 52%

Thin water films and particle morphology evolution in nanocrystalline MgO

et al. 2018

View full text Add to dashboard Cite

show abstract

“…In contrast to its ubiquity on Earth and a long history of experimental demonstration in small plants, − the details of the hydration mechanism on the surface of MgO remain elusive, and this fact prevents a practical introduction of TCHS technology into the social systems. Since alkaline earth metal oxide has characteristic features in its chemical properties and especially in the interface, − various kinds of experimental − and computational − ,− research have been reported so far, but the research aimed at the thermochemical application is limited at the present time. − …”

Section: Discussionmentioning

confidence: 99%

“…As for computational studies, many calculations have been reported on the physical/chemical properties of MgO due to its unique and interesting character. − Most of these calculations discussed the surface properties of the ideal MgO lattice, − ,− since the surface atoms of the MgO lattice were assumed to have potential catalytic activity. − Although some previous calculations discussed the surface hydration step on a specific MgO surface, − ,, the mechanistic details of the hydration process have not been elucidated until now. Apart from the thermal storage mechanism, Jug and co-workers reported on the water absorption structure on the MgO surface.…”

Section: Introductionmentioning

confidence: 99%

Chemical Heat Storage Mechanism in Alkaline Earth Metal Oxide: Ab Initio Modeling of the Initial Hydration Reaction on MgO(001) Surface

Ishida,

Ishimura

2024

J. Phys. Chem. C

View full text Add to dashboard Cite

Effective management of reusable waste heat is one of the most important technologies for reducing energy consumption and promoting energy conservation. In particular, chemical heat storage is a practical solution to the spatial and temporal mismatches of energy use. Among various chemical reactions, the reversible hydration process of periclase (MgO) to brucite [Mg(OH) 2 ] is a practical candidate for the future applications in various social systems. In this article, in order to clarify the atomistic reaction mechanism of thermochemical heat storage in the MgO hydration reaction, we calculated potential energy profiles to understand the complex thermochemical reaction on the solid surface. By assuming a series of elementary reaction processes in the early stage of the surface reaction, we have practically estimated the reaction energetics for the hydration reaction in both the MgO(001) terrace and step geometries. First, we calculate two important thermodynamic parameters that characterize the thermochemical reaction (the reaction heat and the transition temperature). Our computational results show good agreement with the available thermodynamic data. Then, to clarify the nature of the thermochemical heat storage process, we introduce the 2D potential energy diagram, which is determined by the dislocation distance of the Mg atoms and the coordination (solvation) number of the Mg atoms. This 2D potential energy diagram clearly shows that the activation energy is highly dependent on the surface geometry of MgO, while an atomistic process in this rate-determining step (an extraction of Mg atoms from the inner layer to the surface aqueous layer) is exactly the same in both the terrace and step surface. These computational results lead to a simple guideline for the design of thermochemical heat storage systems.

show abstract

“…In recent years, limited studies have been devoted to the synthesis of two-dimensional metallic materials. In recent years, Nair et al succeeded in synthesizing MgO, CuO, and CaO metal oxide monolayers by trapping an aqueous solution of corresponding salt in graphene nanoenclosures [5][6][7][8][9][10][11][12][13][14][15][16].…”

Section: Introductionmentioning

confidence: 99%

Electronic, optical and thermoelectric properties of CaO:F mono-layer: a DFT study

Salehi,

Arghavaninia,

Rezaeei

2023

Phys. Scr.

View full text Add to dashboard Cite

Based on density functional theory, structural, electronic, optical and thermoelectric properties of CaO and CaO:F mono-layer compounds have been investigated. Both structures have elastic stability and Young's and Shear's moduli of CaO:F are 57.78 (N/m) and 23.85(N/m), which shows the resistance of these compounds against stress and strain. The reduction of Poisson's ratio with the introduction of F atom indicates the tendency to ionic bonds between atoms, and its magnetic moment reaches to 0.84 µB. The CaO compound is a p-type semiconductor with 2.6 eV, and by adding a F atom to it, it has become a half-metal.In the CaO:F mono-layer, we see a red shift in the real- and imaginary-dielectric function compared to the CaO one. At a temperature of 50 K, the value of the Seebeck coefficient is

show abstract

Hydration Structures of MgO, CaO, and SrO (001) Surfaces

Cited by 24 publications

References 62 publications

Thin water films and particle morphology evolution in nanocrystalline MgO

Thin water films and particle morphology evolution in nanocrystalline MgO

Chemical Heat Storage Mechanism in Alkaline Earth Metal Oxide: Ab Initio Modeling of the Initial Hydration Reaction on MgO(001) Surface

Electronic, optical and thermoelectric properties of CaO:F mono-layer: a DFT study

Contact Info

Product

Resources

About