A DFT and HRTEM Study on MoS₂/Co: Locating Promoters in Catalytic Nanostructures

Abstract

Locating cobalt promoters on catalytically MoS₂ structures is a challenging task to achieve; this is due to the size on those MoS₂ nanostructures. Previous reports in the literature indicate that specific locations for Co in MoS₂ slabs are (1010)-plane creating either a sulfur-Co or Molybdenum-Co termination edge, due to lower energy required for the permutation Mo, S and Co to occur. We present results obtained from Density Functional Theory study done on the interface between MoS₂ and Co₉S₈ crystal structures; the interface show an interesting thiocubane cluster and it is suspected to be the responsible for Mo-S-Co bonding to exist, along with HDS reaction. In order to understand electronic properties on thiocubane Density of States and Mulliken Population Analysis calculations were implemented using Cambridge Serial Total Energy Package (CASTEP). Results indicate a strong electron donation from Co to Mo through intermediate sulfur atom bonded to both metals while an enhanced metallic character is also found.