CATALYTIC IGNITION AND EXTINCTION OF HYDROGEN - COMPARISON OF SIMULATIONS AND EXPERIMENTS

Surface ignition and extinction of hydrogen/air mixtures on platinum s urfaces are modeled using a detailed surface kinetic mechanism and tra nsport phenomena. It is shown that the platinum surface can be poisone d by different adsorbates, and the dynamic process of catalytic igniti on and extinction is associated with a phase transition from one poiso ning species to another. For certain temperatures, multiple poisoned s tates of the surface coexist. Comparison of simulations with experimen ts is conducted, and it is shown that the self-inhibition of hydrogen catalytic ignition is caused by poisoning of platinum by atomic hydrog en.