Microscopic mechanism study of nitromethane oxidation: based on ReaxFF molecular dynamics simulation

This study conducted a ReaxFF-MD simulation to investigate the oxidation reaction of nitromethane at temperatures ranging from 2400 to 3000 K. Both temperature and oxygen concentration had significant effects on the reaction process. As the temperature increased, the consumption of reactants accelerated, and the conversion of intermediates became more rapid, resulting in an increase in the reaction rate. CH₃ and CH₂O were identified as key intermediates, among which the accumulation of CH₂O was much higher than that of other carbon-containing species. The increase in initial oxygen content promoted the generation of CO₂ and H₂O, while the yields of H₂ and N₂ decreased. The concentrations of OH, HO₂, and H₂O₂ were influenced by both temperature and oxygen availability, among which HO₂ and H₂O₂ responded more significantly to changes in oxygen content. According to Arrhenius analysis, the activation energy of nitromethane thermal decomposition was 35.87 kcal mol^-1, while the activation energies for fuel enrichment, stoichiometric, and fuel deficient oxidation systems were 32.20, 48.15, and 41.74 kcal mol^-1, respectively.