Guaiacol derivatives and inhibiting species adsorption over MoS2 and CoMoS catalysts under HDO conditions: A DFT study

We have investigated using DFT calculations the η1 adsorption of guaiacol, phenol, anisole and phenol over CoMoS and MoS2 phases under HDO conditions. This adsorption mode should lead to a direct deoxygenation (DDO) reaction, which is low hydrogen-consuming. The most stable mode is an adsorption through the OH group of the molecule. The calculation of adsorption Gibbs free energies of inhibiting compounds (H2O, H2S, and CO) which can be present under reaction conditions shows that these molecules adsorb more strongly than oxygenated compounds, which suggests that CO will be a major inhibitor of the HDO process of real feeds.

Graphical AbstractUsing DFT calculations, we have found that CO is more strongly adsorbed than oxygenated molecules like guaiacol or phenol. Therefore, CO will be a major inhibitor of the HDO process of real feeds.Figure optionsDownload full-size imageDownload as PowerPoint slideResearch Highlights► DFT calculations of Oxygenated compounds on (Co)MoS2 catalysts. ► Stronger adsorption of H2S, H2O and CO than phenol and guaiacol. ► Important inhibiting effect of CO in the reaction conditions.