Stacking height effect and hydrogen activation calculations on the Co9S8/MoS2 catalyst via computational transition states

G. A. Gonzalez , M. Alvarado , M. A. Ramos , G. Berhault (1) , R. R. Chianelli

1 CATREN - IRCELYON-Catalyse Hétérogène pour la Transition Energétique

We carried out computational transition states calculations for the hydrogen activation to study the catalytic dependence on the stacking height with different number of layers (n), 1 < n < 4 for unsupported Co9S8/MoS2 catalyst with three possible activation sites, the sulfur-sulfur (S, S) site, molybdenum-sulfur (Mo, S) site, and molybdenum-molybdenum (Mo, Mo) site. The hydrogen activation is considered the rate determining step for the overall hydrodesulfurization (HDS) reaction. Understanding the hydrogen activation thermodynamically is important to determine the energy required for the hydrogen activation on the Co9S8/MoS2 catalyst interface. The stacking height dependency and catalytic activity on the catalyst sites were found by calculating the transition states and energy of barrier for the hydrogen activation via linear synchronous transit and quadratic synchronous transit (LST/QST) methods integrated in a density functional theory (DFT) program such as DMol(3). This study showed that catalytic activity was dependent on the stacking height revealing that the Co9S8/MoS2 structure at the (Mo, Mo) site was the most efficient catalytically structure requiring less energy for the hydrogen activation. (C) 2016 Elsevier B.V. All rights reserved.

Domaines: Catalyse; Environnement et Société

G. A. Gonzalez, M. Alvarado, M. A. Ramos, G. Berhault, R. R. Chianelli. Stacking height effect and hydrogen activation calculations on the Co9S8/MoS2 catalyst via computational transition states. Computational Materials Science, 2016, 123, pp.93-105. ⟨10.1016/j.commatsci.2016.06.002⟩. ⟨hal-01367610⟩