Reaction of Ketene with Atomic Hydrogen and Oxygen

Abstract

The reactions of atomic hydrogen and oxygen with ketene have been studied in a discharge-flow system coupled to a time-of-flight mass spectrometer. The principal products of the H-atom reaction are CH4 and CO, and a mechanism consistent with the kinetics of their formation is H + CH2CO = CH3 + CO, CH3 + H + wall = CH4 + wall. The bimolecular rate constant for addition of H to CH2CO was determined to be: k1 = 1.3 × 10−13cm3molecules−1·sec−1 at 298°K. The reaction of O atoms with ketene is quite complex. Considerable amounts of CO2, CO, H2O, and H2 are formed, and atomic H and H2CO were also detected. The data are consistent with an initial addition of O to ketene, O + CH2CO = CH2CO2, followed by rapid decomposition and the consumption of an additional O atom. The bimolecular rate constant was found to be k1 = 8.8 × 10−13cm3molecules−1·sec−1 at 298°K.