scholarly journals Impact of Solvation on the Structure and Reactivity of the Co3O4 (001)/H2O Interface: Insights From Molecular Dynamics Simulations

2020 ◽  
Vol 8 ◽  
Author(s):  
T. Kox ◽  
E. Spohr ◽  
S. Kenmoe
Keyword(s):  
Molecular Dynamics ◽  
Contact Layer ◽  
Ab Initio Molecular Dynamics ◽  
Water Dissociation ◽  
Degree Of Dissociation ◽  
Water Films ◽  
Dissociation Degree ◽  
In Operando ◽  
Dynamics Simulations ◽  
Potential Use

The spinel Co3O4 has many beneficial properties for potential use in catalysis. In operando, water is always present and alters the properties of the catalyst. We have used ab initio molecular dynamics to understand the effect of water and solvation on the structure and reactivity of the Co3O4 (001) A-type and B-type surface terminations. Water adsorbs on both terminations via a partial dissociative mode, and the A-termination is seen to be more reactive. On this surface, a higher degree of dissociation is observed in the topmost layers of the crystal in contact with water. Water dissociates more frequently on the Co2+ sites (about 75%) than on the adjacent Co3+ sites, where the degree of dissociation is about 50%. Increasing water coverage does not change the degree of water dissociation significantly. OH− adsorption on the Co2+ sites leads to a reduction of the amount of reconstruction and relaxation of the surface relative to the clean surface at room temperature. Proton transfer within the water films and between water molecules and surface has localized character. The B-terminated interface is less dynamic, and water forms epitactic layers on top of the Co3+ sites, with a dissociation degree of about 25% in the contact layer.

Ab initio molecular dynamics study of an aqueous NaCl solution under an electric field

2016 ◽  
Vol 18 (33) ◽  
pp. 23164-23173 ◽  
Author(s):  
Giuseppe Cassone ◽  
Fabrizio Creazzo ◽  
Paolo V. Giaquinta ◽  
Franz Saija ◽  
A. Marco Saitta
Keyword(s):  
Molecular Dynamics ◽  
Electric Field ◽  
Proton Transfer ◽  
Ab Initio ◽  
Strong Field ◽  
Ab Initio Molecular Dynamics ◽  
Water Dissociation ◽  
Nacl Solution ◽  
Salty Water ◽  
Dynamics Simulations

Ab initio molecular dynamics simulations of salty water under an electric field reveal two regimes of the relative mobilities of chlorine and sodium ions. When water dissociation and proton transfer are actived at strong field intensities, the presence of the ions hinders the efficiency of the proton transfer mechanism.

Adsorption of Water on TiO2 and SnO2 Surfaces: Molecular Dynamics Study

2008 ◽  
Vol 73 (4) ◽  
pp. 575-589 ◽  
Author(s):  
Lukáš Vlček ◽  
Peter T. Cummings
Keyword(s):  
Molecular Dynamics ◽  
Analysis Data ◽  
Water Dissociation ◽  
Gravimetric Analysis ◽  
Free Energies ◽  
Degree Of Dissociation ◽  
Density Distributions ◽  
Adsorption Of Water ◽  
Additional Water ◽  
Dynamics Simulations

The structure and thermodynamics of water adsorbed at the (110) surface of rutile (α-TiO2) and cassiterite (α-SnO2) were studied by means of molecular dynamics simulations with atomic interactions represented by a classical forcefield based on the SPC/E model of water. To investigate the effect of surface water dissociation on the adsorption of additional layers of water, two extreme cases of completely hydroxylated and nonhydroxylated surfaces were considered. Axial density distributions and adsorption Helmholtz free energies of water for different types of surfaces were compared and related to thermal gravimetric analysis data from literature. We found that the dissociation of water in the first layer considerably changes the affinity of additional water to the surface, weakening hydrogen bonding between the first and second layer and strengthening cohesion between the second and third layer. Comparison with the experimental measurements of adsorption indicates that water dissociates on cassiterite while it stays associated on rutile. The degree of dissociation in the first layer is not strongly affected by the adsorption of additional water.

scholarly journals Spontaneous liquid water dissociation on hybridised boron nitride and graphene atomic layers from ab initio molecular dynamics simulations

2020 ◽  
Vol 22 (19) ◽  
pp. 10710-10716 ◽  
Author(s):  
Benoît Grosjean ◽  
Anton Robert ◽  
Rodolphe Vuilleumier ◽  
Marie-Laure Bocquet
Keyword(s):  
Molecular Dynamics ◽  
Boron Nitride ◽  
Water Molecule ◽  
Ab Initio ◽  
Liquid Water ◽  
High Reactivity ◽  
Ab Initio Molecular Dynamics ◽  
Water Dissociation ◽  
Interfacial Water ◽  
Dynamics Simulations

By means of ab initio simulations we unveil the high reactivity of boron nitride–graphene planar heterostructure immersed in liquid water: an interfacial water molecule is found to spontaneously chemisorb and deprotonate at one composite border.

scholarly journals Proton Transport Mechanism and Pathways in the Superprotonic Phase of M3H(AO4)2 Solid Acids from Ab Initio Molecular Dynamics Simulations

2021 ◽  
Author(s):  
Boris Merinov ◽  
Sergey Morozov
Keyword(s):  
Molecular Dynamics ◽  
Ab Initio ◽  
Proton Transport ◽  
Transport Mechanism ◽  
Solid Acids ◽  
Ab Initio Molecular Dynamics ◽  
Theoretical Studies ◽  
Dynamics Simulations ◽  
Experimental And Theoretical Studies ◽  
Superprotonic Phase

The proton transport mechanism in superprotonic phases of solid acids is a subject of experimental and theoretical studies for a number of years. Despite this, details of the mechanism still...

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