10.1021/jp510899m.s001
Kulbir
Kaur Ghuman
Kulbir
Kaur
Ghuman
Shwetank Yadav
Shwetank
Yadav
Chandra Veer Singh
Chandra Veer
Singh
Adsorption
and Dissociation of H<sub>2</sub>O on Monolayered
MoS<sub>2</sub> Edges: Energetics and Mechanism from <i>ab Initio</i> Simulations
American Chemical Society
2015
desorbed H 2
OH
2 D monolayer molybdenum disulfide
eV
activation energy barrier
Monolayered MoS 2 Edges
AIMD
activation barrier results
H 2O H
ab Initio SimulationsThe dissociation
water dissociation
MoS 2 edges
species
mechanism
adsorption
kJ
reaction rate calculations
water dissociation reaction
2015-03-26 00:00:00
Journal contribution
https://acs.figshare.com/articles/journal_contribution/Adsorption_and_Dissociation_of_H_sub_2_sub_O_on_Monolayered_MoS_sub_2_sub_Edges_Energetics_and_Mechanism_from_i_ab_Initio_i_Simulations/2182387
The dissociation of water on 2D monolayer
molybdenum disulfide
(MoS<sub>2</sub>) edges was studied with density functional theory.
The catalytically active sites for H<sub>2</sub>O, H, and OH adsorption
on MoS<sub>2</sub> edges with 0% (Mo-edge), 50% (S50-edge), and 100%
(S100-edge) sulfur coverage were determined, and the Mo-edge was found
to be the most favorable for adsorption of all species. The water
dissociation reaction was then simulated on all edges using the climbing
image nudged elastic band (CI-NEB) technique. The reaction was found
to be endothermic on the S100-edge and exothermic for the S50- and
Mo-edges, with the Mo-edge having the lowest activation energy barrier.
Water dissociation was then explored on the Mo-edge using metadynamics
biased <i>ab initio</i> molecular dynamics (AIMD) methods
to explore the reaction mechanism at finite temperature. These simulations
revealed that water dissociation can proceed by two mechanisms: the
first by splitting into adsorbed OH and H species produced a particularly
small activation free energy barrier of 0.06 eV (5.89 kJ/mol), and
the second by formation of desorbed H<sub>2</sub> and adsorbed O atom
had a higher activation barrier of 0.36 eV (34.74 kJ/mol) which was
nevertheless relatively small. These activation barrier results, along
with reaction rate calculations, suggest that water dissociation will
occur spontaneously at room temperature on the Mo-edge.