Simulation of the Oxygen Dissociation Reaction under Thermally Nonequilibrium Conditions: Models, Trajectory Calculations, and the Experiment

Abstract

The aim of this work was to perform a comparative study of the well-known models of physicochemical processes based on the dissociation of oxygen as an example. The comparison was conducted with the use of the available results of calculations obtained by a method of quasi-classical trajectories. The principle of the information provision of models and the complexity of their computational implementation were taken into account in the study. The dissociation process was considered in the framework of one-temperature, two-temperature, and level approximations. The MD Trajectory software was used for the simulation of molecular reaction dynamics. Computer experiments with theoretical models were carried out using an Internet catalog of physical and chemical process models. A modification of the Marrone–Treanor level model was proposed for the approximation of the rate constant of oxygen dissociation obtained by the method of quasi-classical trajectories in the level approximation. The empirical parameter of this model was replaced by a new parameter, which took into account its possible dependence on translational temperature. For a two-temperature approximation, recommendations were formulated in terms of the applicability ranges of the models taking into account the vibrational temperature of dissociating molecules based on a comparison of the results of trajectory calculations and theoretical models. The results of trajectory calculations and theoretical models in a two-temperature approximation were also compared with the available experimental data on the dissociation of oxygen molecules.