Low-cost and earth abundant zirconium hydroxide (Zr(OH)4) has demonstrated high filtration capacity and rapid decomposition kinetics for many families of chemical warfare agents (CWAs) and CWA simulants, with chemical reactivity attributed to various surface hydroxyl species (terminal, bridging, etc.) and under-coordinated Zr. Unfortunately, these promising results are usually obtained under unrealistic operating environments such as high vacuum or pristine and contaminant-free conditions. Previous work suggests that carbonates and other surface species form on the Zr(OH)4 surface under ambient conditions (specifically in the presence of CO2), potentially diminishing the material’s filtration capacity and decontamination kinetics. To evaluate Zr(OH)4 for use in operando, ambient surface chemistry must be performed in the presence of various environmental factors such as light, humidity and trace atmospheric contaminants. This talk focuses on the reactivity of CO2 with the Zr(OH)4 surface, particularly the surface hydroxyl species implicated in CWA decomposition chemistry. The impact of carbonate on the surface reaction chemistry and the CWA (both live agent and simulants) decomposition rates and mechanisms is elucidated using a combination of IR methods, predominantly ATR and DRIFTS, XPS, and NMR.

Role of CO2 on the reactivity of Zr(OH)4 nanopowders in real-world conditions: Towards in operando chemical warfare agent decomposition

251st National Meeting (2016)

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