Adsorption and dissociation of H2S on Mo2C(001) surface-A first-principle study

• DOI: 10.1016/j.apsusc.2015.05.115
• Publication Date: 2015-05-30T00:17:34Z
• Authors: Dianling Fu; Wenyue Guo; Yunjie Liu; Yuhua Chi
• Keywords: Mulliken population analysis; Lone pair; HOMO/LUMO

Abstract The adsorption and decomposition reaction mechanisms of H 2 S on Mo 2 C(001) has been systematically studied using self-consistent periodic density functional theory. Results show that the molecular of H 2 S is adsorbed either on the Mo top site or bridge site. Mulliken population analysis and density of states for H 2 S/Mo-terminated Mo 2 C(001) adsorption system are examined to confirm the adsorption mechanism of H 2 S with the Mo 2 C(001) surface, which can involve the donation of charge from the “s lone pair electrons” that are LUMO orbitals into the surface and the back donation of electrons from the surface into the HOMO orbital. The optimal pathway for the dissociation of H 2 S on the Mo 2 C(001) surface can be H 2 S top → SH fcc + H fcc → S fcc + H fcc + H fcc . The first step is the rate-determining step because it has the smallest rate constant among the possible reactions pathways.