Growth of Polycyclic Aromatic Hydrocarbon and Soot Inception by in silico Simulation

Soot is formed resulting from incomplete combustion processes of fossil fuels and is one of the most abundant specie in the space. The early stages of soot formation are central to many ongoing studies in combustion research, but its inception and growth are still elusive and highly debated. Herein, molecular dynamic simulations with ab initio based neural network potentials were carried out to simulate the reaction process leading to the growth of PAHs and soot inception from small hydrocarbon reactants. The in silico simulation provided detailed information of reaction paths that revealed critical steps leading to the formation and growth of large PAHs. And the simulation results clearly showed that the formation and growth of possible soot inceptions are achieved through a series of reactions with small PAH radicals, particularly the two-ring PAH radicals rather than by direct combination of large polynuclear hydrocarbons.