With
the expansion of the world’s ethylene industry, the
production of carbon five (C5) distillates has also gradually
increased. C5 can be used to produce a series of high-value-added
chemical products; however, it contains carbon disulfide (CS2), which is not conducive to subsequent processing. This requires
the use of highly efficient catalysts for the deep desulfurization
of C5 fractions. Analyzing the desulfurization mechanisms
from a microscopic perspective might be the key to prepare an efficient
catalyst. This work uses molecular dynamics (MD) and density functional
theory (DFT) to simulate and calculate the removal process of CS2. A reactive force field was used to simulate the kinetics
and explore possible reactions of the desulfurization process. It
is found that CS2 reacts with a hydroxyl group instead
of water, mainly including the C–O and S–O paths. The
main reaction is the C–O path two-step mechanism, and it is
also observed that few C atoms can adsorb two hydroxyl groups in the
one-step mechanism. Then, a DFT analysis at the B3PW91/Aug-cc-pVTZ
level of theory is performed to calculate the reaction paths and relative
energies of the one- and two-step mechanisms of the C–O and
S–O paths. It is found that the adsorption of CS2 and hydroxyl in the two-step mechanism of the C–O path is
an exothermic reaction with an activation energy of only 18.0 kcal
mol–1. However, the one-step mechanisms of the C–O
and S–O paths require more than 30 kcal mol–1 to obtain their corresponding products. Therefore, the two-step
mechanism of the C–O path is the most likely to occur, which
is consistent with the results from the MD simulations.