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Gas Phase Thermochemistry of Iron Oxides and Hydroxides: Portrait of a Super-Efficient Flame Suppressant



C B. Kellogg, Karl Irikura


In the search for non-ozone depleting Halon (CF3Br) replacements, several metals, including iron, have been identified as super-efficient flame suppressants. Although some thermochemical data exist for the species that are thought to be most important in iron's flame chemistry, a more complete and accurate characterization of the thermochemistry of iron oxides, hydrides and hydroxides is required to improve kinetic flame models. In this investigation predicted enthalpies (δrxnHO ) and free energies (δrxnG 1500) of the reactions of several FeOxHy species in methane flames are reported. Heats of formation (δfHO ) for the FeOxHy species of interest are also recommended. The hybrid B3LYP density-functional method and the CCSD(T) coupled-cluster method are employed in conjunction with a relativistic effective core potential on the iron center and a valence triple-zeta basis on all atoms in order to characterize the relative energetics of the important species.
Journal of Physical Chemistry A
No. 8


Ab initio, B3LYP, ECP, flame suppressant, iron, thermochemistry, transition metal


Kellogg, C. and Irikura, K. (1999), Gas Phase Thermochemistry of Iron Oxides and Hydroxides: Portrait of a Super-Efficient Flame Suppressant, Journal of Physical Chemistry A (Accessed June 20, 2024)


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Created October 31, 1999, Updated October 12, 2021