DFT Computations on the CH4 Formation on the CNT-Co Nanocatalyst

The structures of armchair (4,4) carbon nanotube-Co nanocatalyst (1) and CNT-Co-CH4 (2) were optimized using Gaussian 98 program at B3LYP/LANL2DZ level of theory. The binding energies were measured from the equation E(bind) = E(complex) –  E(molecule). The biding energy of CNT-Co nanocatalyst was somewhat greater than that of the compound (2) on which the methane molecule has been formed. However, the difference in the binding energies of compounds 1 and 2 was not very high indicating the CNT-Co catalyst is favorable for the hydrocarbon synthesis.Also, the dipole moment values of both CNT and CH4 (~0 Debye) were considerably enhanced by impregnation of Co catalyst on the CNT and by adsorption of methane on the CNT-Co surface. Therefore, the CNT supported Co catalyst is considered as an active and appropriate nanocatalyst for the Fischer-Tropsch synthesis of hydrocarbons in the GTL process.

کلیدواژه ها:

DFT computation ، CNT-Co Nanocatalyst ، Fischer-Tropsch synthesis ، Hydrocarbon