Short Communication

Abstract

Axial profiles of trace nitrogenous constituents formed and converted in an atmosphericpressure flat flame on a water-cooled burner were determined by direct molecular-beam, mass-spectrometer sampling. The premixed input composition was: 19% H₂, 9.5% O₂, 0.5% NH₃ and 71% Ar. This flame is free of both atmospheric N₂ and the oxides of carbon, so that the product N₂ and the intermediate N₂O were observed without major interferences at masses 28 and 44. A reaction zone, where NH₃ and NH₂ profiles decrease monotonically toward zero and NO and temperature profiles increase to maxima, extends 2mm above the burner. The measured terminal temperature is 1050 (± 5) K, and the yield of NO claims nearly half the available nitrogen and vastly exceeds the amount of oxidized nitrogen that would satisfy chemical equilibrium.