Kinetics of the reaction between methane and iodine from 830 to 1150 K in the presence and absence of oxygen



The formation of methyl iodide was determined by radiochemical methods and by massspectroscopic analyses in mixtures of Ar–CH4–I2 and Ar[BOND]CH4[BOND]I2[BOND]O2, heated by a reflected shock wave to temperatures of 830–1150 K. The rate of formation of CH3I was consistent with the chain mechanism

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where the indicated rate constant for reaction between I and CH4 is given by k2(cm3/mol · s) = 1014.17 exp(−32.9 ± 0.8 kcal/mol/RT). No effect on the reaction rate by the presence of O2 was detected. However, in one experiment at 1097 K with 3.86 mol % O2 the formation of CH2O was indicated by the mass-spectroscopic analysis, presumably from the reaction of O2 with CH3.