Role of Surface Reactions in Hydrogen–Oxygen Explosion Limits

In this paper, the role of surface reactions in the explosion limits of hydrogen–oxygen mixtures was investigated, which was found to substantially affect the limits. Specifically, we compared situations with and without surface reactions by considering various sticking coefficients, with the temperature exponents of the radicals varying simultaneously and individually, site density of surface and no surface reactions, dilutions of four gases, equivalence ratio of H2 and O2, reactor size (sphere radii), and residence time. The specific roles of these factors were identified, demonstrating that the existence of surface reactions can substantially modify the explosion limits and that the simulation can accurately predict the experimental data from both the closed vessel and flow reactor by accounting for the surface reactions.