Thermal Unimolecular Decomposition of Nitrous Oxide at Low Pressures

Article abstract of DOI:10.1021/j100267a035

The thermal decomposition of nitrous oxide, pure and in mixtures with N2 and CO2, was studied in a quartz vessel in the temperature range from 1080 to 1227 K at concentrations ranging from 10^-7 to 1.5 * 10^-6 mol/cm³, the lowest of which represents a concentration almost two orders of magnitude lower than in most previous studies.It is found that the activation energy, based on both the raw experimental data and data corrected for heterogeneity, shows continued falloff with pressure with no indication of reaching a limit at the lowest pressure studied.This in accord with the prediction of the theory of Lorquet, Lorquet, and Forst (LLF), and in considerable disagreement with the recommended values of Baulch et al.The LLF theory reproduces fairly well the experimental concentration dependence of both the rate constant and activation energy, but experiment seems to indicate that activation energy may fall off with pressure somewhat faster than predicted by theory.