Role of Nitric Oxide in the Thermal Decomposition of Nitrous Oxide

The rates of decomposition of N₂O and of formation of NO were measured simultaneously in a static system. NO yields at the beginning of reaction are as high as 50 to 60%, but NO quickly inhibits its own further formation. From initial NO yields, information about the reaction of oxygen atoms with N₂O and about wall recombination was obtained. Limiting NO pressures for complete N₂O decomposition were interpreted in terms of the reaction NO+O+M→NO₂+M, and its rate constant was calculated. The effect of increased surface area and of added gases was studied. The halogens were found to be efficient inhibitors of NO formation. The chemiluminescence of reacting N₂O was observed and its dependence on temperature, pressure, and added gases studied. All evidence points to the reaction $$\mathrm{O}+\mathrm{NO}\to {\mathrm{NO}}_2\mathrm{+h\nu }$$ as its origin. Inhibition of NO formation and of chemiluminescence is shown to be closely related.