Radicals and molecular products from the gas-phase pyrolysis of lignin model compounds. Cinnamyl alcohol.
The experimental results on detection and identification of intermediate radicals and molecular products from gas-phase pyrolysis of cinnamyl alcohol (CnA), the simplest non-phenolic lignin model compound, over the temperature range of 400-800 °C are reported. The low temperature matrix isolation - electron paramagnetic resonance (LTMI-EPR) experiments along with the theoretical calculations, provided evidences on the generation of the intermediate carbon and oxygen centered as well as oxygen-linked, conjugated radicals. A mechanistic analysis is performed based on density functional theory to explain formation of the major products from CnA pyrolysis; cinnamaldehyde, indene, styrene, benzaldehyde, 1-propynyl benzene, and 2-propenyl benzene. The evaluated bond dissociation patterns and unimolecular decomposition pathways involve dehydrogenation, dehydration, 1,3-sigmatropic H-migration, 1,2-hydrogen shift, C-O and C-C bond cleavage processes.
Department of Chemistry, Louisiana State University, Baton Rouge, LA 70803, USA.
Lavrent
L
Khachatryan
Department of Chemistry, Louisiana State University, Baton Rouge, LA 70803, USA.
Meng-Xia
MX
Xu
State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou 310027, China.
Ang-Jian
AJ
Wu
Department of Chemical and Biological Engineering, University at Buffalo, The State University of New York, Buffalo, NY 14260, USA.
Mikhail
M
Pechagin
Department of Chemical and Biological Engineering, University at Buffalo, The State University of New York, Buffalo, NY 14260, USA.
Rubik
R
Asatryan
Biomass; EPR; Renewable fuel; Spin trapping; Theoretical calculations