Title :

Hydrogen activation on Mo-based sulfide catalysts, a periodic DFT study

Author(s) :

Travert, Arnaud [Auteur]
Nakamura, Hiroyuki [Auteur]
Van Santen, Rutger A. [Auteur]
Cristol, Sylvain [Auteur]
Unité de Catalyse et Chimie du Solide (UCCS) - UMR 8181
Paul, Jean-François [Auteur]
Unité de Catalyse et Chimie du Solide - UMR 8181 [UCCS]
Payen, Edmond [Auteur]
Unité de Catalyse et Chimie du Solide - UMR 8181 [UCCS]

Journal title :

Journal of the American Chemical Society

Abbreviated title :

J. Am. Chem. Soc.

Volume number :

124

Pages :

7084-7095

Publication date :

2002-05-24

ISSN :

0002-7863

HAL domain(s) :

Chimie

English abstract : [en]

Hydrogen adsorption on Mo−S, Co−Mo−S, and Ni−Mo−S (101̄0) surfaces has been modeled by means of periodic DFT calculations taking into account the gaseous surrounding of these catalysts in working conditions. On the stable ...
Show more >Hydrogen adsorption on Mo−S, Co−Mo−S, and Ni−Mo−S (101̄0) surfaces has been modeled by means of periodic DFT calculations taking into account the gaseous surrounding of these catalysts in working conditions. On the stable Mo−S surface, only six-fold coordinated Mo cations are present, whereas substitution by Co or Ni leads to the creation of stable coordinatively unsaturated sites. On the stable MoS2 surface, hydrogen dissociation is always endothermic and presents a high activation barrier. On Co−Mo−S surfaces, the ability to dissociate H2 depends on the nature of the metal atom and the sulfur coordination environment. As an adsorption center, Co strongly favors molecular hydrogen activation as compared to the Mo atoms. Co also increases the ability of its sulfur atom ligands to bind hydrogen. Investigation of surface acidity using ammonia as a probe molecule confirms the crucial role of sulfur basicity on hydrogen activation on these surfaces. As a result, Co−Mo−S surfaces present Co−S sites for which the dissociation of hydrogen is exothermic and weakly activated. On Ni−Mo−S surfaces, Ni−S pairs are not stable and do not provide for an efficient way for hydrogen activation. These theoretical results are in good agreement with recent experimental studies of H2−D2 exchange reactions.Show less >

Language :

Anglais

Audience :

Internationale

Popular science :

Non

Administrative institution(s) :

Université de Lille
CNRS
Centrale Lille
ENSCL
Univ. Artois

Collections :

• Unité de Catalyse et Chimie du Solide (UCCS) - UMR 8181

Research team(s) :

Catalyse pour l’énergie et la synthèse de molécules plateforme (CEMOP)
Modélisation et spectroscopies (MODSPEC)

Submission date :

2023-05-30T18:43:45Z
2024-04-26T11:32:43Z