Effect of Oxygen Bulk Diffusion in Nickel on Self-Sustained Oscillations in the Catalytic Oxidation of Methane
The model of methane oxidation over nickel was amended with a step of diffusion of oxygen from the nickel surface into its volume, and the influence of this step on the characteristics of the oscillatory regime was studied. Solutions obtained in the models with and without diffusion of oxygen into nickel were compared. In the self-oscillatory regime of the reaction, the concentration of subsurface oxygen was found to oscillate synchronously with concentrations of reaction products. The addition of the oxygen diffusion into the model leads to the appearance of an induction period, which is consistent with experimental data.