Adsorption of Organo Sulphur Compounds through MoS2/G Nanohybrids for Hydrodesulphurization: A Computational Approach

Abstract

The refining of fossil fuels is one example of an industrial process that releases sulfurcontaining chemicals, which are harmful to both humans and the environment. Computational modelling, Quantum Mechanics, Monte Carlo, and Molecular Dynamics simulations were used to study the adsorption of four organosulfur compounds (CH3SH, C2H5SH, C2H5SC2H5, and DBT) on MoS2/Graphene (MoS2/G) nanohybrids for HDS. Through molecular level studies of adsorption energetics, the goal is to effectively desulfurize by synthesising and engineering the nanohybrid. This study investigated the adsorption behavior and catalytic efficiency of organosulfur compounds on MoS₂/graphene (MoS₂/G) nanohybrids, focusing on hydrodesulfurization (HDS) processes. Geometry optimization of the nanohybrid and adsorbates was performed using the Forcite module with the UNIVERSAL forcefield. Adsorption energies and stable geometries were determined via Monte Carlo simulations employing the Adsorption Locator Tool (ALT) and the COMPASS force field. Molecular dynamics simulations using the NPT ensemble at 300 K revealed insights into the dynamic adsorption processes. Among the tested organosulfur compounds, dibenzothiophene (DBT) demonstrated the highest adsorption efficiency. Furthermore, cobalt doping significantly enhanced the binding capacity of the MoS₂/G system, attributed to improved adsorption and catalytic performance. The findings highlight the superior potential of Co-doped MoS₂/G nanohybrids in facilitating HDS processes, offering an efficient pathway for sulfur removal in industrial applications. According to these results, Co-doped MoS2/G shows great potential as an efficient adsorbent of all organosulfur compounds. Nevertheless, dibenzothiophene (DBT) exhibited the best adsorptive removal efficiency, with the Co-doped MoS2/G displaying an even greater negative adsorption energy of -13.24 kcal/mol. Comparatively less adsorption energy of -11.54 kcal/mol was observed in the pristine structure of MoS2/G, which quantitatively indicates that the Co-doped