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Promotional effect of Co or Ni impurity in the catalytic activity of MoS 2 : An electronic structure study
Author(s) -
GómezBalderas R.,
MartínezMagadán J. M.,
Santamaria R.,
Amador C.
Publication year - 2000
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/1097-461x(2000)80:3<406::aid-qua10>3.0.co;2-b
Subject(s) - hydrodesulfurization , bimetallic strip , catalysis , electronic structure , chemistry , reactivity (psychology) , density functional theory , impurity , metal , atom (system on chip) , molybdenum , supercell , chemical physics , computational chemistry , inorganic chemistry , physics , medicine , thunderstorm , biochemistry , alternative medicine , organic chemistry , pathology , meteorology , computer science , embedded system
It has been observed that the catalytic activity of MoS 2 crystals is enhanced when either Co or Ni atoms are added. The presence of these atoms leads to electronic rearrangements, which are considered the source of catalytic improvement. However, the relation between the electronic properties and the enhancement of the catalytic activity is not yet fully understood. In order to get insight into the electronic‐level changes that affect the catalyst performance, a solid‐state density functional study has been carried out for Mo, Co/Mo, and Ni/Mo sulfides, using bulk and surface models. The MoS 2 crystallize in a well‐known layered structure, which has been used together with the supercell model to simulate the \documentclass{article}\pagestyle{empty}\begin{document}$(10\ \bar{1}\ 0)$\end{document} edge surface of MoS 2 . The binary sulfides were obtained substituting Co or Ni by Mo from the original MoS 2 bulk model. The electronic structure in a nonmagnetic state is analyzed and, in particular, the density of states of metal and sulfur atoms for the surface and bulk are compared. Finally, we discuss the important role that these properties play in the hydrodesulfurization reaction and concluded that Mo at the surface remains the relevant reactive atomic center in the bimetallic systems, whereas Co and Ni are responsible for increasing the Mo reactivity at the surface. © 2000 John Wiley & Sons, Inc. Int J Quant Chem 80: 406–415, 2000