Inhibition of electric field on inception soot formation: A ReaxFF MD and DFT study

The attenuation of soot formation from polycyclic aromatic hydrocarbons during the fuel combustion process is important to human health and environmental pollution. This work studies the mechanism of inhibition soot formation process under electric field. The process of soot formation with the chemical bonding and physical stacking of PAHs nucleation was investigated under the influence of electric field by using ReaxFF molecular dynamics and density functional theory. MD simulation reveals that the electric field in 1 x 10(-5) -1 x 10(-4) V/angstrom induces an alternation in dispersion and stacking of PAH cluster to inhibit the PAH nucleation. The electric field inhibits the dehydrogenation and C-C bond cracking of the initial PAH during chemical growth of PAHs. Due to instability of the 5-7 membered rings, there are fewer bonding sites for large graphite lamella growth. The elucidation of reaction enthalpy of dehydrogenation, dimer growth, and the binding energy of pi-pi stacking with different direction field, are explored using DFT. The computational work discloses the inhibition mechanism of electric field on PAH development. The characterization results obtained by scanning electron microscopy and the temperatureprogrammed oxidation shows the coke content and particle size can be reduced under the influence of electric field which validates the computational result. The scientific insights gained here is useful for understanding soot inhabitation phenomenon. (c) 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

This study investigates the mechanism of soot formation inhibition under electric field during fuel combustion. The computational simulations reveal that the electric field alters the dispersion and stacking of polycyclic aromatic hydrocarbon (PAH) clusters, inhibiting PAH nucleation. The electric field also inhibits dehydrogenation and C-C bond cracking of PAHs, leading to reduced growth of large graphite lamella. The experimental validation using scanning electron microscopy and temperature-programmed oxidation confirms the inhibitory effect of electric field on soot formation.