Diagnosing the Impact of External Electric Fields Chemical Kinetics: Application to Toluene Oxidation and Pyrolysis

In this study we utilize biased, reactive molecular dynamics (ReaxFF MD) simulations to quantitatively assess the impact of external electric fields on the kinetics of toluene oxidation and pyrolysis. We observe that the application of a strong external electric field significantly accelerates the kinetics of toluene oxidation, while having no effect on the pyrolysis reactions. When viewed through the lens of harmonic transition state theory, this phenomenon can be ascribed to the increase in the change of entropy between the transition state and reactants for the oxidation reactions. This conclusion is further verified with a model that relates the change in entropy as a function of field strength to predict the kinetics of toluene oxidation, which accounts for the total variance in the data recovered from simulation.