Catalytic ignition and extinction of hydrogen: Comparison of simulations and experiments

Surface ignition and extinction of hydrogen/air mixtures on platinum surfaces are modeled using a detailed surface kinetic mechanism and transport phenomena. It is shown that the platinum surface can be poisoned by different adsorbates, and the dynamic process of catalytic ignition and extinction is associated with a phase transition from one poisoning species to another. For certain temperatures, multiple poisoned states of the surface coexist. Comparison of simulations with experiments is conducted, and it is shown that the self-inhibition of hydrogen catalytic ignition is caused by poisoning of platinum by atomic hydrogen.