Single atom transition metals on MoS2 monolayer and their use as catalysts for CO2 activation

The properties of single metal atoms adsorbed on MoS2 monolayer surface as well as the behaviour of CO2 molecules on these active sites are studied by using density functional theory methods. Eleven different transition metals (Au, Co, Cr, Cu, Fe, Ir, Mn, Ni, Pd, Pt or Sn) were considered as well as the main adsorption sites on the surface. Reported results show adsorption on top of Mo atoms and hollow sites on the hexagonal ring centres leading to very large adsorption energies. The adsorption is characterized by deep interaction wells and adsorbed metal to surface charge transfer in most of the studied atoms. The low surface coverage upon single atom adsorption hinders in plane metal diffusion and thus once atoms are adsorbed, they remain on top on each site as showed by Ab initio molecular dynamics simulations. The behaviour of CO2 molecules on top of active sites formed by metal atoms adsorbed on the monolayer is characterized by strong chemisorption, leading to large bending of gas molecules, thus showing how CO2 molecules can react on these metal sites. This work reports for the first time a systematic evaluation of transition metal atoms adsorbed on MoS2 monolayers, including their dynamic properties, as well as their properties as active sites for CO2 reactions.