LAMMPS molecular dynamics simulation of methane decomposition on nickel thin films at high temperatures

摘要

The activation energy of methane decomposition by nickel was calculated using models of nickel thin films, a large-scale atomic/molecular massively parallel simulator (LAMMPS) and a ReaxFF potential. The rate constants of the first-order chemical reaction of methane decomposition were obtained by analyzing the number of un-decomposed methane molecules in individual movie frames. The obtained activation energies of methane decomposition on the Ni (111) surfaces showed values close to those reported in the literature. The structural change of a Ni thin film with (111) surfaces was simulated to investigate how carbon and hydrogen atoms are deposited on the Ni thin film upon the decomposition of methane molecules at a high temperature. The catalytic activity of the (111) Ni thin film was found to decrease from the time point of critical supersaturation of carbon in the Ni thin film.