TY - JOUR
T1 - A vacuum ultraviolet photoionization study on high-temperature decomposition of JP-10 (: Exo -tetrahydrodicyclopentadiene)
AU - Zhao, Long
AU - Yang, Tao
AU - Kaiser, Ralf I.
AU - Troy, Tyler P.
AU - Xu, Bo
AU - Ahmed, Musahid
AU - Alarcon, Juan
AU - Belisario-Lara, Daniel
AU - Mebel, Alexander M.
AU - Zhang, Yan
AU - Cao, Chuangchuang
AU - Zou, Jiabiao
N1 - Funding Information:
This project is supported by the Air Force Office of Scientific Research (AFOSR) under Grant Number FA9550-15-1-0011 (LZ, TY, AMM,RIK). Thework ofM. A., B. X., and T. P. at theAdvanced Light Source was supported by the Director, Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231, through the Chemical Sciences Division.
Publisher Copyright:
© the Owner Societies 2017.
PY - 2017
Y1 - 2017
N2 - Two sets of experiments were performed to unravel the high-temperature pyrolysis of tricyclo[5.2.1.02,6] decane (JP-10) exploiting high-temperature reactors over a temperature range of 1100 K to 1600 K, Advanced Light Source (ALS), and 927 K to 1083 K, National Synchrotron Radiation Laboratory (NSRL), with residence times of a few tens of microseconds (ALS) to typically 144 ms (NSRL). The products were identified in situ in supersonic molecular beams via single photon vacuum ultraviolet (VUV) photoionization coupled with mass spectroscopic detection in a reflectron time-of-flight mass spectrometer (ReTOF). These studies were designed to probe the initial (ALS) and also higher order reaction products (NSRL) formed in the decomposition of JP-10-including radicals and thermally labile closed-shell species. Altogether 43 products were detected and quantified including C1-C4 alkenes, dienes, C3-C4 cumulenes, alkynes, eneynes, diynes, cycloalkenes, cyclo-dienes, aromatic molecules, and most importantly, radicals such as ethyl, allyl, and methyl produced at shorter residence times. At longer residence times, the predominant fragments were molecular hydrogen (H2), ethylene (C2H4), propene (C3H6), cyclopentadiene (C5H6), cyclopentene (C5H8), fulvene (C6H6), and benzene (C6H6). Accompanied by electronic structure calculations, the initial JP-10 decomposition via C-H bond cleavages resulting in the formation of the initial six C10H15 radicals was found to explain the formation of all products detected in both sets of experiments. These radicals are not stable under the experimental conditions and further decompose via C-C bond β-scission processes. These pathways result in ring opening in the initial tricyclic carbon skeletons of JP-10. Intermediates accessed after the first β-scission can further isomerize or dissociate. Complex PAH products in the NRLS experiment (naphthalene, acenaphthylene, biphenyl) are likely formed via molecular growth reactions at elevated residence times.
AB - Two sets of experiments were performed to unravel the high-temperature pyrolysis of tricyclo[5.2.1.02,6] decane (JP-10) exploiting high-temperature reactors over a temperature range of 1100 K to 1600 K, Advanced Light Source (ALS), and 927 K to 1083 K, National Synchrotron Radiation Laboratory (NSRL), with residence times of a few tens of microseconds (ALS) to typically 144 ms (NSRL). The products were identified in situ in supersonic molecular beams via single photon vacuum ultraviolet (VUV) photoionization coupled with mass spectroscopic detection in a reflectron time-of-flight mass spectrometer (ReTOF). These studies were designed to probe the initial (ALS) and also higher order reaction products (NSRL) formed in the decomposition of JP-10-including radicals and thermally labile closed-shell species. Altogether 43 products were detected and quantified including C1-C4 alkenes, dienes, C3-C4 cumulenes, alkynes, eneynes, diynes, cycloalkenes, cyclo-dienes, aromatic molecules, and most importantly, radicals such as ethyl, allyl, and methyl produced at shorter residence times. At longer residence times, the predominant fragments were molecular hydrogen (H2), ethylene (C2H4), propene (C3H6), cyclopentadiene (C5H6), cyclopentene (C5H8), fulvene (C6H6), and benzene (C6H6). Accompanied by electronic structure calculations, the initial JP-10 decomposition via C-H bond cleavages resulting in the formation of the initial six C10H15 radicals was found to explain the formation of all products detected in both sets of experiments. These radicals are not stable under the experimental conditions and further decompose via C-C bond β-scission processes. These pathways result in ring opening in the initial tricyclic carbon skeletons of JP-10. Intermediates accessed after the first β-scission can further isomerize or dissociate. Complex PAH products in the NRLS experiment (naphthalene, acenaphthylene, biphenyl) are likely formed via molecular growth reactions at elevated residence times.
UR - http://www.scopus.com/inward/record.url?scp=85024113200&partnerID=8YFLogxK
U2 - 10.1039/c7cp01571b
DO - 10.1039/c7cp01571b
M3 - Article
C2 - 28504798
AN - SCOPUS:85024113200
SN - 1463-9076
VL - 19
SP - 15780
EP - 15807
JO - Physical Chemistry Chemical Physics
JF - Physical Chemistry Chemical Physics
IS - 24
ER -