The thermal decomposition of ethyl formate diluted in argon has been investigated behind reflected shock waves over the temperature range 1220-1710 K, with a total density of ～ 1.2×10[-5] mol/㎤. Production and decay processes of formic acid were monitored by means of the time-resolved IR emission at 5.7 μm. The emission profiles were analyzed by utilizing the integrated profiles method developed by Yamasaki et al. The resultant first-order decay rate constant is expressed as k=10[9.10] exp (-40.7 Kcal mol[-1]/RT) s[-1], which is in proper agreement with that for the pyrolysis of formic acid obtained by Blades at lawer temperatures, but slightly lower than the estimated expression suggested by Benson and O'Neal. The formation rate for carbon dioxide, however, is found to be greatly accelerated compared to that with formic acid as a starting material, which attributes to the chemical activation of the intermediary produces formic acid
