Branching Fraction of the NH2+ NO Reaction between 1210 and 1370 K

The branching fraction for the NH 2 + NO reaction has been determined in the temperature range 1210−1370 K from flow reactor experiments on the NH 3 /NO/O 2 and CO/NH 3 /NO/O 2 systems. The branching fraction is defined as α = k 1 /( k 1 + k 2 ), where NH 2 + NO → NNH + OH (1) and NH 2 + NO → N 2 + H 2 O (2). The experiments were performed at very low oxygen concentrations to minimize the impact of secondary reactions. The results show that α increases gradually from a value of 0.35 ± 0.04 at 1211 K to 0.45 ± 0.02 at 1369 K. The data blend smoothly with the most recent direct measurements and confirm the significant rise in branching fraction suggested by previous high-temperature determinations in static reactors and flames.