Atomically dispersed Co atoms on MoS2 monolayer: A promising high-activity catalyst for CO oxidation

Abstract

We systematic investigated the CO oxidation reaction over a single Co atom supported by MoS2 monolayer (Co/MoS2) on the basis of density functional theory calculations and ab initio molecular dynamics simulations. The binding energy of a single Co atom onto MoS2 monolayer is up to 2.80eV, making the diffusion and aggregation of supported Co atom difficult. For CO oxidation reaction, both Eley–Rideal and Langmuir–Hinshelwood mechanisms are considered. The energy barriers of CO oxidation through the Langmuir–Hinshelwood mechanism for the rate-limiting step of formation the peroxide-like O-C-O-O intermediate is only 0.57eV. The relatively high CO oxidation activity of Co/MoS2 may be attributed to the strong electronic resonance among the 3d orbital of the Co atoms and the antibonding 2π* orbitals of adsorbed CO and O2. We proposal that the MoS2 monolayer can serve as a defect-free two dimensional single atom catalysts substrate for CO oxidation reaction. It provides not only a large surface ratio, but also a uniform distribution anchoring points for fixing metal atoms as activation sites. We hope that this work contributes to design more effective nonprecious-metal single-atom catalysts for CO oxidation and widen the applications of monolayer MoS2 materials.