Adsorption and dissociation of the methanethiol (CH₃SH) molecule on the Fe(100) surface

Abstract

These contributions explore interaction modes between the methanethoil (CH3SH) molecule and the Fe(100) surface via implementing accurate density functional theory (DFT) calculations with the inclusion of van der Waals corrections. We consider three adsorption sites over the Fe(100) surface, namely, top(T), bridge (B), and hollow (H) sites as potential catalytic active sites for the molecular and dissociative adsorption of the CH3SH molecule. The molecular adsorption structures are found to occupy either B or T sites with former sites holding higher stability by 0.17 eV. The inclusion of van der Waals corrections refound to slightly alter adsorption energies. For instance, adsorption energies increased by ~0.18 and ~0.21 eV for B and T structure, respectively, in reference to values obtained by the plain generalized gradient approximation (GGA) functional. A stability ordering of the dissociation products was found to follow the sequence (CH4, S) > (CH3, S, H) > (─SCH3, H) > (─CH3, SH). The differential charge density distributions were examined to underpin prominent electronic contributing factors. Direct fission of C─S bond in the CH3SH molecule attains exothermic values in the range 2.0 to 2.1 eV. The most energetically favorable sites for the surface‐mediated fission of the thiol's S─H bond correspond to the structure where the ─SCH3 and H are both situated on hollow sites with an adsorption energy of −2.43 eV. Overall, we found that inclusion of van der Waals functional to change the binding energies more noticeably in case of dissociative adsorption structures. The results presented herein should be instrumental in efforts that aim to design stand‐alone Fe desulfurization catalysts.

Single-atom Fe with Fe1N3 structure showing superior performances for both hydrogenation and transfer hydrogenation of nitrobenzene

“…In order to understand the excellent catalytic performance of Fe 1 /N-C in the hydrogenation of nitrobenzene to aniline, the reaction energies on Fe 1 /N-C and Fe (100), which is the commonly active surface for the Fe-based catalyst [49][50][51], were explored by DFT calculations. In addition, Fe (100) facet was selected for our calculations because the Fe (100) facet is often used as the representative facet of Fe nanoparticles to discuss calculation-related issues qualitatively [52][53][54]. At the same time, the formation energies of the Fe (100), (111), and (211) planes were calculated (Fig.…”

Adsorption and Separation of Ethyl Mercaptan from Methane by Hydroxyl Groups on the Surface of HTiNbO5-Nanosheets

“…Light mercaptans (R-SH, R = C 1 -C 4 ) are considered pollutants in low-molecular alkane gases such as natural gas and biogas − because of the causticity and toxicity. − However, pure R-SH is an important chemical synthetic raw material. − Therefore, the separation of R-SH from methane gas is of great significance for the purification of methane gas and the resource utilization of sulfide.…”