Regensburg 2019 – wissenschaftliches Programm
DY 51.8: Poster
Donnerstag, 4. April 2019, 15:00–18:00, Poster B2
A Theoretical Investigation of Hydrocarbon Decomposition at High Temperature and High Pressure — •Nehzat Safaei, Kurt Kremer, and Omar Valsson — Max Planck Institute for Polymer Research, Ackerman- nweg 10, 55128, Mainz, German
We have studied reaction kinetics of hydrocarbon decomposition at high pressures and temperatures using variationally enhanced sampling method. Investigation of hydrocarbons decomposition witch provides valuable information about the rate of radical creation and subsequent reactions, specially at extreme conditions where there is a serious lack of both thermodynamic and kinetic data, can reveals new insights to the synthesis of most interesting carbon-based compounds such as graphene and nanodiamond which are the promising materials for a variety of applications. In order to calculate the decomposition rate of hydrocarbons in different thermodynamics conditions, we have performed molecular dynamics simulation to explore the phase space of different systems of hydrocarbons with different chain lengths. Variationally enhanced sampling method along with metadynamics is employed to calculate the rate of decomposition reactions. In this approach, an effective bias potential is constructed and implemented as a fixed bias which speeds up the molecular dynamics time by facilitating escape over dissociation barrier. We employed metadynamics with an infrequent deposition stride to ensure that the trajectory does not stuck in any regions. We have measured the validity of the rare event assumption by the p-value test of cumulative distribution function of the data fitted to the Poisson expression.