Inhibitory Action Research Of Pyrrole For Dibenzothiphene Hydrodesulfurization Reaction On NiMoS Catalyst

Dibenzothiophene and pyrrole, respectively, as one of the hardest removal ofsulfur-containing components and the most important nitride in the oil, whosehydrodesulfurization and hydrodenitrogenation process studies have great significance.In this paper, the method of density functional theory in quantum chemistry was used tocalculate the adsorption behavior of dibenzothiophene hydrodesulfurization and pyrrolehydrodenitrogenation process on NiMoS catalyst.Firstly, the surface adsorption of DBT and its hydrogenation sulfur compounds werestudied on NiMoS catalyst surface during hydrodesulfurization process. We focus on twodifferent adsorbed configurations as perpendicular and flat adsorptions. The results showthat it is an exothermic process for the adsorption process of DBT and its hydrogenationsulfur compounds on NiMoS catalyst surface. And then there are both perpendicular andflat adsorptions for DBT on the surface of NiMoS catalyst, but the others sulfurcompounds such as4H-DBT,6H-DBT and HY-DBT are easier perpendicular adsorbedon NiMoS catalyst surface, and their adsorption energies were grown up by increasing ofthe hydrogen atoms.Secondly, the adsorption behavior of pyrrole and the nitride in its hydrogenationprocess on the catalyst surface was simulated. The results show that pyrrole and itshydrogenation derivatives are easy absobed on NiMoS catalyst surface with paralleladsorption form. And compared with the various sulfide, nitride has a higher adsorptionenergy and more variable in the form of adsorption. At the same time, the study of H₂,H₂S and NH₃adsorption behavior of the catalyst surface show nitride has a higheradsorption energy on the catalyst surface is NiMoS and closer adsorption distance thansulfide, and the charge transfer between the catalyst is much more intense. A competitiveadsorption relationship exists between pyrrole and dibenzothiophene on NiMoS catalystsurface, and NiMoS catalyst has a stronger adsorption selectivity to pyrrole.