Gas Phase Oxidation of Hydrocarbons: Endothermic Nature of the Initial Stage of Reaction

Abstract

IT is generally agreed that the oxidation of hydrocarbons occurs by steps such as: The initial stage of oxidation as depicted by (1) is endothermic, while (2) and (3), and also many subsequent reactions, are exothermic. Experimentally, however, no evidence seems to have been furnished which would demonstrate the endothermic nature of the initial stage of hydrocarbon oxidation. What is well known is that the reactions are exothermic: cool flames readily appear in the early stages of oxidation of numerous hydrocarbons, particularly n-alkanes (excepting methane and ethane), and cause a considerable rise in the temperature of the reacting gases.