Microscopic oxidation reaction mechanism of methanol in H2O/CO2 impurities: A ReaxFF molecular dynamics study

Abstract

In this study, the ReaxFF molecular dynamics (MD) simulations were performed to investigate the dynamic evolution of reactants and intermediates in the oxidation reaction of methanol, the oxidation reaction path was determined, and the effects of O2/methanol ratio and H2O/CO2 impurity on the oxidation were explored. The results indicate the consumption rate of methanol is significantly higher than that of O2, and the preferred product of the reaction are H2O, H2, CO and CO2. With the increase of reaction temperature, the consumption rate of reactants increases, which promotes the formation of intermediate products in advance, resulting in the increase of products. The amount of final products of H2O, H2, CO and CO2 at 3000 K under fuel rich condition is 1.59, 4.07, 4.36 and 3.20 times that at 2400 K, respectively. The presence of H2O/CO2 impurities promote the initial dissociation of methanol, and inhibits the consumption of O2 and the generation of H2O. The presence of CO2 impurities can promote the generation of CO. The activation energy is lowest in the CO2 impurity environment. This study provides a microscopic insight into the oxidation mechanism of methanol in various environment.