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

We have investigated using DFT calculations the eta(1) 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. (C) 2011 Elsevier B.V. All rights reserved.