Investigation of thermodynamic, dynamic, and structural properties of H2 adsorption on a Ag-Au nanoalloy with a carbon nanotube support.

Abstract

We have performed MD simulations to investigate H(2) adsorption on Ag-Au nanoclusters with the different Au mole fractions supported on the carbon nanotubes with the different diameters. Our thermodynamic results shown that the saturation value of coverage and the enthalpy of adsorption increases as the mole fraction of Au is increased. Our structural results showed that the presence of the H(2) gas exerts a significant effect on the nanocluster surface atoms and tends to stabilize the surface atoms on the nanocluster. 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. We have also shown that the nanoclusters have smaller values of the self-diffusion coefficients in presence of H(2) molecules than those values in the initial state (vacuum), which is due to the increasing of the interface structure between the nanocluster and the nanotube.