Modeling the active sites of Co-promoted MoS₂ particles by DFT

TY - JOUR

T1 - Modeling the active sites of Co-promoted MoS2 particles by DFT

AU - Šarić, Manuel

AU - Rossmeisl, Jan

AU - Moses, Poul Georg

PY - 2017

Y1 - 2017

N2 - The atomic-scale structure of the Co-promoted MoS2 catalyst (CoMoS), used for hydrodesulfurization and as a potential replacement for platinum in the acidic hydrogen evolution reaction has been analyzed by modeling its sites using density functional theory and applying thermochemical corrections to account for different reaction conditions. The equilibrium structures of the edges, basal plane and corners have been found and used to obtain a picture of an ideal CoMoS nanoparticle under hydrodesulfurization and hydrogen evolution reaction conditions. Under hydrodesulfurization conditions small energy differences between structures having an additional or missing sulfur atom relative to the equilibrium structures have been observed for the edges and corners explaining their activity towards hydrodesulfurization at the atomic scale. The lack of these small energy differences at the basal plane explains why it is inert towards hydrodesulfurization. The adsorption free energy of hydrogen was calculated and used as a descriptor for qualifying each site in the context of hydrogen evolution, finding that the corner site should perform better than the edges.

AB - The atomic-scale structure of the Co-promoted MoS2 catalyst (CoMoS), used for hydrodesulfurization and as a potential replacement for platinum in the acidic hydrogen evolution reaction has been analyzed by modeling its sites using density functional theory and applying thermochemical corrections to account for different reaction conditions. The equilibrium structures of the edges, basal plane and corners have been found and used to obtain a picture of an ideal CoMoS nanoparticle under hydrodesulfurization and hydrogen evolution reaction conditions. Under hydrodesulfurization conditions small energy differences between structures having an additional or missing sulfur atom relative to the equilibrium structures have been observed for the edges and corners explaining their activity towards hydrodesulfurization at the atomic scale. The lack of these small energy differences at the basal plane explains why it is inert towards hydrodesulfurization. The adsorption free energy of hydrogen was calculated and used as a descriptor for qualifying each site in the context of hydrogen evolution, finding that the corner site should perform better than the edges.

U2 - 10.1039/c6cp06881b

DO - 10.1039/c6cp06881b

M3 - Journal article

C2 - 28009026

AN - SCOPUS:85009874483

SN - 1463-9076

VL - 19

SP - 2017

EP - 2024

JO - Physical Chemistry Chemical Physics

JF - Physical Chemistry Chemical Physics

IS - 3

ER -