Dissociative adsorption of methane on Ni(1Â 1Â 1) surface with and without adatom: A theoretical study

The dissociative adsorption of methane on the flat and defective Ni(1 1 1) surfaces is studied by the plane-wave density functional theory (DFT) with the DACAPO program. The calculation results are presented as following: on flat Ni(1 1 1) surface, three distinct pathways were explored, differing by the initial adsorbed state of CH4. They converge readily to similar transition states corresponding to an activation energy value of 0.73 eV, in good agreement with the recent experimental value of 0.77 eV. On Ni(1 1 1) + adatom, two dissociation pathways have been studied, differing by the final coadsorbed states of the CH3 and H fragments. The activation energies are 0.72 and 0.55 eV. These results are discussed with respect to the literature.