Study on physical properties of ethylbenzene under external electric field

[Display omitted] •The study of ethylbenzene under electric fields has been carried out for the first time.•The calculation of tunneling ionization was conducted to do further research on dissociation property of ethylbenzene.•The degradation of ethylbenzene under a certain electric field was achieved for the first time.•Concerted dissociation in ethylbenzene molecule was found and calculated for the first time. External electric field dissociation is an effective means of hazardous substance degradation. As a volatile hazardous substance, there is no corresponding research on ethylbenzene (EB). In this work, calculations of EB were conducted under an external electric field (0 V·mm−1–2570 V·mm−1) and density functional theory (DFT) with 6–31 G+ (d, p) basis set. All results agree closely at that when the electric field increases along a certain direction, energy of EB increases and the barrier of potential energy for dissociation decreases. When the voltage reached a certain level, the barrier of dissociation disappears, indicating that EB is under an extremely unstable state and can be easily degraded. Then, the tunnel ionization was studied to have a more comprehensive view about this research. Above conclusions provide a reference for the study of the characteristics of EB molecules or mixtures containing it under an external electric field.