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

Published

November 1, 1999

Author(s)

C B. Kellogg, Karl Irikura

Abstract

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 (δ_rxnH_O ) and free energies (δ_rxnG ₁₅₀₀) of the reactions of several FeO_xH_y species in methane flames are reported. Heats of formation (δ_fH_O ) for the FeO_xH_y 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.

Citation

Journal of Physical Chemistry A

Volume

103

Issue

No. 8

Pub Type

Journals

Keywords

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

Citation

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 October 13, 2025)