Decomposition of 2,4,6-trinitrotoluene (TNT) and 5-nitro-2,4-dihydro-3H-1,2,4-triazol-3-one (NTO) by Fe13O13 nanoparticle: density functional theory study

To obtain more insight into the mechanisms of the decomposition of energetic compounds, we performed a computational study of the interaction of Fe13O13 nanoparticles with two energetic molecules such as 2,4,6-trinitrotoluene (TNT) and 5-nitro-2,4-dihydro-3H-1,2,4-triazol-3-one (NTO). The density functional theory using M06-2X, B3LYP, and BLYP density functionals was applied. We found that the reactivity of these molecules strongly depends on the place of adsorption (so-called top and bottom planes of Fe13O13). Namely, only the interaction with the bottom plane results in the thermodynamic characteristics of the decomposition that provide a medium reaction rate for the studied processes. Several pathways for such decomposition were found. One of them is the inter-complex oxygen transfer of nitro-group oxygen to Fe13O13. This pathway results in the formation of adsorbed nitroso compounds. The second pathway describes a more complex decomposition that includes the transfer of the nitro-group oxygen accompanied by the hydrogen transfer. In all cases, the interaction of energetic molecules with Fe13O13 nanoparticles takes place along with a barrier-less electron transfer from Fe13O13 to TNT or NTO species.

Automated summary

Through computational study, we found that the decomposition mechanisms of energetic compounds depend on the adsorption position of Fe13O13 nanoparticles. Different adsorption positions affect the reactivity and thermodynamic characteristics of the molecules. Two decomposition pathways were identified, involving inter-complex oxygen transfer of the nitro-group oxygen and transfer of nitro-group oxygen along with hydrogen transfer. Furthermore, the interaction between energetic molecules and Fe13O13 nanoparticles is accompanied by barrier-less electron transfer.