Shock wave kinetics of Fe plus NO based on Fe, O, and N atom measurements

摘要

The reaction of Fe atoms with NO was studied behind incident shock waves in the temperature range of 780 - 1,020 K at pressures between 0.3 and 1.2 bar. Atomic-resonance-absorption spectroscopy (ARAS) was applied for the time-resolved measurement of Fe, N, and O atoms in gas mixtures containing Fe(CO)(5) and NO, highly diluted in argon. The experiments showed a Fe-atom consumption without an associated O- or N-atom formation which can be explained by a recombination of Fe and NO: Fe + NO -->(k1) FeNO. The rate coefficient k(1) was obtained from pseudo-first-order analysis of the measured Fe-absorption profiles to be k(1) = 10(8.99 +/- 0.3) exp(7, 020 +/- 840 K/T) cm(3)/(mol s) with the uncertainty given at the 1 - sigma level. It showed an inverse temperature dependency. Variation of the experimental pressure does not have any effect on the rate coefficient.