First limit of the hydrogen + oxygen reaction in vessels coated with barium bromide

Abstract

The first explosion limit of the hydrogen + oxygen reaction has been determined over a wide range of mixture composition and vessel diameter for reaction vessels coated with barium bromide. The kinetic results suggest that only oxygen atoms and/or hydroxyl radicals are destroyed at the surface of the vessel, but a more detailed analysis shows that this cannot be the case. The magnitude of the observed explosion pressures is incompatible with the accepted values of the rate constants for the reactions of oxygen atoms and hydroxyl radicals with hydrogen. Hydrogen atoms must be destroyed at the surface, and the kinetics of the destruction are such that the characteristic kinetic features associated with this mode of chain termination disappear. The efficiency of the barium bromide surface for the destruction of hydrogen atoms is directly proportional to the partial pressure of oxygen in the reaction mixture, and possible reasons for this behaviour are discussed.