Initiation mechanisms of enhanced pyrolysis and oxidation of JP-10 (exo-tetrahydrodicyclopentadiene) on functionalized graphene sheets: Insights from ReaxFF molecular dynamics simulations

Functionalized graphene sheets (FGS) have proven to be an effective nanoparticle additive for jet fuels. In this study, the reactive force field (ReaxFF) molecular dynamics (MD) simulation is employed to investigate the initiation mechanisms of JP-10 pyrolysis and oxidation with FGS in comparison with normal JP-10 reactions. ReaxFF-nudged elastic band (NEB) calculations are performed to study the transition state and energy barrier for key initiation reactions in order to reveal the catalytic effect of FGS on JP-10 pyrolysis and oxidation. The results show that both pyrolysis and oxidation of JP-10 are advanced and enhanced in the presence of FGS, leading to earlier decomposition of JP-10 at a lower temperature and a faster reaction rate. It is found that the OH functional group on the FGS not only advances the initiation of JP-10 but also participates in various intermediate reactions to further enhance the pyrolysis and oxidation of JP-10. Moreover, the dehydrogenation of JP-10 without FGS is only observed at high temperatures. A deeper insight into the enhancement resulting from the FGS is provided through the analysis of the results of transition state and energy barrier for key initiation reactions. It is found that JP-10 decomposition initiated by OH or H on the FGS occurs at a lower energy barrier than unimolecular decomposition or through reaction with O-2 thereby changing and enhancing the JP-10 initiation. In summary, this research provides the scientific insight as to the potential use of FGS as a promising catalyst for JP-10 fuel systems.