CO Adsorption on Ag Nanoclusters Supported on Carbon Nanotube: A Molecular Dynamics Study

Molecular dynamics simulations are used to study CO adsorption on Ag nanoclusters ranging from 38 to 500 Ag atoms, supported on carbon nanotube. Each nanocluster was simulated under various-pressures of CO gas at different temperatures. The absolute value of enthalpy of adsorption was calculated for all of the nanoclusters in constant coverage which is increased sharply by decreasing cluster size. This increasing trend with coverage reaches a maximum around 0.75 ML for Ag-108. Also, the structural changes are irreversible in such a way that by gradually decreasing the pressure to zero, the nanocluster geometry is not reversed to its initial structure in vacuum conditions. It was found that structural irreversibility increases with the size. Also, the difference between diffusivity of Ag nanoclusters in vacuum and CO atmosphere increases with the size.