Large Intermediates in Hydrazine Decomposition: A Theoretical Study of the N3H5 and N4H6 Potential Energy Surfaces
- Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Dept. of Chemical Engineering
- Argonne National Lab. (ANL), Argonne, IL (United States). Chemical Sciences and Engineering Division
Large complex formation involved in the thermal decomposition of hydrazine (N2H4) is studied using transition state theory-based theoretical kinetics. A comprehensive analysis of the N3H5 and N4H6 potential energy surfaces was performed at the CCSD(T)-F12a/aug-cc-pVTZ//omega B97x-D3/6-311++G(3df,3pd) level of theory, and pressure-dependent rate coefficients were determined. There are no low-barrier unimolecular decomposition pathways for triazane (n-N3H5), and its formation becomes more significant as the pressure increases; it is the primary product of N2H3 + NH2 below 550, 800, 1150, and 1600 K at 0.1, 1, 10, and 100 bar, respectively. The N4H6 surface has two important entry channels, N2H4 + H2NN and N2H3 + N2H3, each with different primary products. Interestingly, N2H4 + H2NN primarily forms N2H3 + N2H3, while disproportionation of N2H3 + N2H3 predominantly leads to the other N2H2 isomer, HNNH. Stabilized tetrazane (n-N4H6) formation from N2H3 + N2H3 becomes significant only at relatively high pressures and low temperatures because of fall-off back into N2H3 + N2H3. Pressure-dependent rate coefficients for all considered reactions as well as thermodynamic properties of triazane and tetrazane, which should be considered for kinetic modeling of chemical processes involving nitrogen-and hydrogen-containing species, are reported.
- Research Organization:
- Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Argonne National Lab. (ANL), Argonne, IL (United States)
- Sponsoring Organization:
- US Army Research Office (ARO); USDOE Office of Science (SC), Basic Energy Sciences (BES). Chemical Sciences, Geosciences, and Biosciences Division
- Grant/Contract Number:
- SC0014901; W911NF1710531; AC02-06CH11357
- OSTI ID:
- 1510335
- Alternate ID(s):
- OSTI ID: 1531171
- Journal Information:
- Journal of Physical Chemistry. A, Molecules, Spectroscopy, Kinetics, Environment, and General Theory, Vol. 123, Issue 22; ISSN 1089-5639
- Publisher:
- American Chemical SocietyCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
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