Enhancing the Oxidation of Toluene with External Electric Fields: a Reactive Molecular Dynamics Study

The effects of external electric field (Efield) on chemical reactions were studied with the reactive molecular dynamics (ReaxFF MD) simulations by using the oxidation of toluene as a model system. We observed that Efields may greatly enhance the oxidation rate of toluene. The initial reaction time of toluene is also reduced remarkably in Efields. A stronger Efield leads to a faster oxidation rate of toluene. Further studies reveal that the applying of a Efield may result in the oxidation of toluene at 2100 K which is otherwise not able to happen when the Efield is not present. The oxidation rate of toluene at 2100 K in a Efield is comparable with the oxidation rate of toluene at 2900 K when the Efield is not applied. In addition, Efields were observed to significantly enhance the occurrence of the initial radical generation for different pathways of toluene oxidation but they do not seem to favor any of the pathways. Finally, Efields do not seem to enhance the polarization of toluene during its transition state, which suggests that a polarizable charge equilibration method (PQEq) method might be needed to take the effects of Efields into consideration.