Abstract
The free H atom existing in flame plays vital role in combustion chemistry. As a continuation of our previous study, the possibility of forming the first aromatic ring via the self recombination reaction of but-1-ene-3-yne (C4H4) with H-assistance was investigated in the present study. The potential energy surfaces were calculated with density functional theory and indicate that the C4H4 + C4H4(+H) reaction can generate 6-membered ring, ring opening and 5-membered ring structures. The zero point energies of the investigated molecules were obtained at CBS-QB3 level, and the reliability of energy calculation was checked with T1 diagnostic. The rate coefficients were calculated using conventional transition state theory (TST) and Rice-Ramsperger-Kassel-Marcus (RRKM) theory with solving master equation. By comparing the rate coefficients and branching ratio of product, we found that the CS10 + H, CS16, CS19 and CS38 are the dominant product of C4H4 + C4H4(+H) reaction in the temperature range of 500-2500 K, and the formation of other products can be ignored. The self-dehydrogenation reaction is the essential step in the formation of the main product CS10 + H. Similar to H-transfer reactions, the self dehydrogenation reactions are found to be sensitive to the molecular structure in terms of the energy barrier. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.