TY - JOUR
T1 - First-Principles Molecular Dynamics Study of the Thermal Decomposition Mechanism of TNT
AU - Shou, Liefeng
AU - Bi, Wenbo
AU - Zhang, Teng
AU - Wang, Hongliang
AU - Wang, Zhongqi
AU - Chen, Jun
AU - Zhu, Wenjun
N1 - Publisher Copyright:
© 2025 American Chemical Society.
PY - 2025/6/26
Y1 - 2025/6/26
N2 - The prolonged and widespread use of 2,4,6-trinitrotoluene (TNT, C7H5N3O6) has prompted in-depth investigations into its thermal decomposition mechanism. Although considerable research has been conducted on the thermodynamic properties of TNT and other polynitro organic compounds, their thermal stability remains a critical challenge in engineering applications. This study systematically investigates the sequential reaction mechanism of TNT thermal decomposition through first-principles molecular dynamics (FPMD) simulations, revealing three distinct stages: (1) initial solid-phase decomposition, (2) radical generation and carbon cluster formation, and (3) stabilization of final gaseous products, with 157 intermediate species identified. Systematic analysis of functional group evolution revealed three dominant reaction pathways: (i) methyl oxidation-carboxylation, (ii) nitro elimination, and (iii) dimer-mediated methyl elimination. Notably, we observed that nitro-to-nitrito isomerization (C―NO2 → C―ONO) occurs as a result of the continued oxidation of the benzene ring after C―NO2 bond cleavage. Kinetic and thermodynamic analyses showed that the direct attack of the oxygen atom on the aromatic ring in path b exhibited the best kinetic advantage in the functional group elimination reaction, while the choice of the initial oxidation site determined the overall decomposition rate.
AB - The prolonged and widespread use of 2,4,6-trinitrotoluene (TNT, C7H5N3O6) has prompted in-depth investigations into its thermal decomposition mechanism. Although considerable research has been conducted on the thermodynamic properties of TNT and other polynitro organic compounds, their thermal stability remains a critical challenge in engineering applications. This study systematically investigates the sequential reaction mechanism of TNT thermal decomposition through first-principles molecular dynamics (FPMD) simulations, revealing three distinct stages: (1) initial solid-phase decomposition, (2) radical generation and carbon cluster formation, and (3) stabilization of final gaseous products, with 157 intermediate species identified. Systematic analysis of functional group evolution revealed three dominant reaction pathways: (i) methyl oxidation-carboxylation, (ii) nitro elimination, and (iii) dimer-mediated methyl elimination. Notably, we observed that nitro-to-nitrito isomerization (C―NO2 → C―ONO) occurs as a result of the continued oxidation of the benzene ring after C―NO2 bond cleavage. Kinetic and thermodynamic analyses showed that the direct attack of the oxygen atom on the aromatic ring in path b exhibited the best kinetic advantage in the functional group elimination reaction, while the choice of the initial oxidation site determined the overall decomposition rate.
UR - https://www.scopus.com/pages/publications/105008484602
U2 - 10.1021/acs.jpca.5c01858
DO - 10.1021/acs.jpca.5c01858
M3 - Article
C2 - 40523829
AN - SCOPUS:105008484602
SN - 1089-5639
VL - 129
SP - 5628
EP - 5637
JO - Journal of Physical Chemistry A
JF - Journal of Physical Chemistry A
IS - 25
ER -