Kinetics of gas phase electron–ion recombination by NO++ e–→ N + O from measurements in flames
Abstract
Mass spectrometric measurements of ion concentrations in the burnt gases of flames of either C2H2+ O2+ N2+ occasionally trace amounts of NO or H2+ O2+ N2 with small additions of C2H2 and NO have enabled the rate coefficient, k1, for electron–ion recombination in reaction (I) NO++ e–→ N + O (I) to be determined. Such measurements have been made for a wide variety of flame conditions over the temperature range 1820 to 2650 K and indicate that k1 changes from 2.3 × 10–7 to 1.4 × 10–7 ion–1 cm3 s–1. At the lower temperatures k1 varies as T–0.7, but as T–1.5 at the hotter ones. There is evidence that circumstances can be devised in flames, when charged species are produced by chemi-inoization in the reverse of reaction (I), whose rate coefficient is found to be 6.7 × 10–12 exp (–31 900/T) atom–1 cm3 s–1 from 1820 to 2650 K.