A QUANTUM CHEMISTRY STUDY OF THE FORMATION OF PAH AND SOOT PRECURSORS THROUGH BUTADIENE REACTIONS

Abstract

Density functional theory was used to investigate the kinetics of the reaction of addition of C₂H₃ and C₆H₅ to 1,3-C₄H₆. Kinetic constants for each elementary reaction involved in the reactive processes were calculated at the B3LYP/6-31g(d,p) level with conventional transition state theory, while overall rate constants for the formation of the different products were determined with Quantum Rice Ramsperger Kassel theory. The main result of this study is that, once provided a significant amount of 1,3-C₄H₆ in the flame environment (such as in butadiene flames), a significant contribution to the rate of formation of benzene, cyclopentadiene, and naphthalene can be ascribed to the investigated reactions.

Keywords:

• polyaromatic hydrocarbons
• soot
• quantum chemistry

The authors are indebted to Prof. E. Ranzi and T. Faravelli for continuous and fruitful discussions.

Notes

k = AT  ^αexp(−E _a/(RT)); preexponential factor and activation energies are reported in units consistent with kcal, s, mol, and cm.

k = AT  ^αexp(−E _a/(RT)); preexponential factor and activation energies are reported in units consistent with kcal, s, mol, and cm.