Monte Carlo simulation of the oscillatory behavior in partial oxidation of methane on nickel catalyst

The Monte Carlo method is employed to study the kinetics of catalytic partial oxidation of methane to syngas on nickel catalyst. Using the Langmuir-Hinshelwood mechanism, self-sustained reaction rate oscillations can be observed under suitable conditions. Further analysis reveals that the rate oscillations are caused by the repetitive oxidation and reduction cycles of nickel surface, which result in a transformation of the formation mechanism of carbon monoxide from the reaction between C and O to the direct reduction of nickel oxide. The conditions for generating the self-sustained oscillations are investigated, and the regular oscillations are found for the diffusion parameter Ndif > 50 and the lattice size L ⩾ 90.