Methane cracking on single-wall carbon nanotubes studied by semi-empirical tight binding simulations

The catalytic properties of thermally distorted single wall carbon nanotubes for the methane dissociation reaction have been investigated in the framework of semi-empirical tight-binding molecular dynamics, electronic structure and total energy calculations. It is shown that, if methane molecules and the nanotube are allowed to get closer than the equilibrium physi-sorption distance, the next dissociation reaction step is characterized by a small enthalpy change. Moreover the reactivity hierarchy of the various carbon nanotubes considered is related to the electronic density of states originating from the axial components of the atomic orbitals. (C) 2011 Elsevier Ltd. All rights reserved.