Flame photometric studies of reactions induced by nitric oxide in hydrogen-oxygen—nitrogen flames

Abstract

It has been found that nitric oxide is an effective homogeneous catalyst for the recombination of atomic hydrogen and hydroxyl radicals in fuel-rich flames of hydrogen, oxygen and nitrogen at atmospheric pressure. The results are consistent with the mechanism $ \mathrm{H} + \mathrm{NO} + \mathrm{M} \rightleftharpoons \mathrm{HNO} + \mathrm{M},$ $\mathrm{HNO} +\mathrm{H} \rightarrow \mathrm{H}_2 + \mathrm{NO} (k_4),$ $\mathrm{HNO} + \mathrm{HO} \rightarrow \mathrm{H}_2O + \mathrm{NO} \text{or} \mathrm{H}_2 + \mathrm{NO}_2 (k_5),$ and the following values for k$_4$ and k$_5$ are obtained: \begin{align*}k_4 = (1\cdot0 \pm 0\cdot5) &x 10^{-11} cm^3 \text{molecule}^{-1} s^{-1}, \\ k_5 = (1\cdot5 \pm 0\cdot5) &x 10^{-10} cm^3 \text{molecule}^{-1} s^{-1},\end{align*} with no significant temperature effect from 1600 to 2000 $^\circ$K. Alternative mechanisms are discussed.