A promising and new single-atom catalyst for CO oxidation: Si-embedded MoS2 monolayer

Abstract

Using dispersion-corrected density functional theory calculations, we introduce a silicon atom embedded MoS2 (Si–MoS2) as new and robust catalyst for oxidation of CO to CO2. According to our results, CO and O2 molecules are largely activated over Si–MoS2 due to considerable hybridization between the Si-3d and O2-2π* or CO-2π* states. The first step of CO oxidation (i.e., CO + O2 → CO2 + O*) preferably proceeds via the Langmuir-Hinshelwood (LH) mechanism. This includes the formation of a peroxo-type OOCO intermediate by overcoming an activation energy of 0.38 eV. The results show that the energy barrier for the removing the O* moiety left on the Si atom is only 0.32 eV. The calculated energy barriers are comparable with other theoretical reports of some noble metals. The results of the present study suggest that Si–MoS2 could be considered as a promising and low-cost catalyst for high performance oxidation of CO.