Ferrocene, an aromatic iron compound (C5H5)2, was tested for smoke emission effects in polystyrene sheets, using cone calorimeter, thermogravimetric analysis (TGA), Fourrier transform infrared (TGA-FTIR) and transmission electromicroscopy. 3% w/w ferrocene reduced both peak and total smoke emission by >55% but increased peak and total heat release rates by >25%. Ferrocene did not cause char formation, showing that the effects were gas phase. Ferrocene showed to accelerate removal by combustion of smoke precursors and intermediates, in particular oxidising both PAHs (benzene derivatives / polycyclic aromatic carbons) and CO (carbon monoxide). The effect is considered by the authors to be due to gas phase catalysis of oxidisation by γFe2O3.
“Insightful investigation of smoke suppression behavior and mechanism of polystyrene with ferrocene: An important role of intermediate smoke”, Z. Li et al., Fire and Materials. 2018;42:286–295 http://dx.doi.org/10.1002/fam.2491