Nanosized inorganic metal oxides as heterogeneous catalysts for the degradation of chemical warfare agents

tNanosized inorganic metal oxides, such as TiO2, ZnO, a-Al2O3, are proposed as heterogeneous cata-lysts for the oxidative degradation of chemical warfare agents (CWA), particularly of organosulfur toxicagents, into oxidised products with reduced toxicity. The morphology, structural and textural propertiesof the catalysts were investigated. Furthermore, their catalytic properties were evaluated in the oxida-tive abatement of (2-chloroethyl)ethylsulfide, CEES, a simulant of sulfur mustard (blistering CWA). Theirperformance was also compared to a conventional decontamination powder and a commercial Nb2O5sample. The metal oxides powders were then employed in the active oxidative decontamination of CEESfrom a cotton textile substrate, mimicking a real contamination occurrence. Remarkable results in termsof abatement and degradation into desired products were recorded, achieving good conversions anddecontamination efficiency with Nb2O5, TiO2and a-Al2O3, under very mild conditions, with hydrogenperoxide (as aqueous solution or as urea-hydrogen peroxide adduct), at room temperature and ambientpressure. In the aim of a real on-field use, the potential environmental impact of these solids was alsoevaluated by bioluminescence toxicity tests on reference bacteria (Photobacterium leiognathi Sh1), show-ing a negligible negative impact for TiO2, a-Al2O3, and Nb2O5. A major biotoxic effect was only found forZnO.