A Theoretical Study of PAH Growth by Phenylacetylene Addition

Although there were significant advancedment on PAH formation, current mechanisms are still limited in providing an integrated and accurate scheme of PAH yield in combustion conditions, thus more detailed and comprehensive understandings are necessary. This work provides a systematic investigation of polycyclic aromatic hydrocarbon (PAH) growth by phenylacetylene addition. A combination of the density functional theory (DFT/B3LYP/6-311+G(d,p)) and the complete basis set method (CBS-QB3) is performed to calculate the potential energy surfaces. The reaction system is initiated by the H elimination reaction of phenylacetylene + H → o-ethynylphenyl + H2, then the addition reaction of phenylacetylene and o-ethynylphenyl can produce PAHs with 1, 2, 3, and 4 rings. The temperature- and pressure-dependent reaction rate coefficients are calculated via a combination of conventional Transition State Theory (TST) and Rice-Ramsperger-Kassel-Marcus (RRKM) theory with solving Master Equation in the temperature range of ...