Adsorption and dissociation mechanism of hydrogen sulfide on layered FeS surfaces: A dispersion-corrected DFT study

摘要

The surface properties of various layered FeS surfaces were calculated using dispersion-corrected density functional theory (DFT-D2). The calculations indicated that FeS(0 0 1) was the most surface. The most stable adsorption sites of H2S and its dissociation products on the different layered FeS surfaces were determined, and the activation energy (E-a) and reaction heat (AE) of H2S dissociation were calculated. Our results showed that the adsorption energy (E-ads) of H2S on the investigated surfaces increased in the order FeS(111) FeS (100) FeS(011) FeS(001). The complete dissociation of H2S was most favorable on the FeS(011) surface with an E-a and Delta E of 0.10 and 0.26 eV, respectively. The dissociation reaction of H2S essentially did not occur on the (001) surface, while partial dissociation was observed on the (111) surface. These calculations demonstrated that the different dissociation behavior of H2S on the different surfaces was related not only to the electronic properties of the surfaces, but also to the adsorption configurations of the transition states. These findings increase our understanding of the electronic structure, relative stability, and surface bonding of various FeS surfaces, and also have reference value for related processes such as friction lubrication, heterogeneous catalysis, and biological systems.