Multimodal Characterization of Materials and Decontamination Processes for Chemical Warfare Protection

Abstract

This Review summarizes the recent progress made in the field of chemical threat reduction by utilizing new in situ analytical techniques and combinations thereof to study multifunctional materials designed for capture and decomposition of nerve gases and their simulants. The emphasis is on the use of in situ experiments that simulate realistic operating conditions (solid–gas interface, ambient pressures and temperatures, time-resolved measurements) and advanced synchrotron methods, such as in situ X-ray absorption and scattering methods, a combination thereof with other complementary measurements (e.g., XPS, Raman, DRIFTS, NMR), and theoretical modeling. The examples presented in this Review range from studies of the adsorption and decomposition of nerve agents and their simulants on Zr-based metal organic frameworks to Nb and Zr-based polyoxometalates and metal (hydro)­oxide materials. The approaches employed in these studies ultimately demonstrate how advanced synchrotron-based in situ X-ray absorption spectroscopy and diffraction can be exploited to develop an atomic- level understanding of interfacial binding and reaction of chemical warfare agents, which impacts the development of novel filtration media and other protective materials.

A computational study of water in UiO‐66 Zr‐MOFs: Diffusion, hydrogen bonding network, and confinement effect

“…2,3 However, significant drawbacks of those filters, such as low adsorption capacities, deactivation of the active sites and slow degradation kinetics, present an urgent need to develop improved materials capable of fast adsorption and decontamination of CWAs under ambient conditions. 4 These challenges have motivated research into a new category of catalytically active materials for CWAs decontamination, including metal oxides, 5 polyoxometalates, 6 and metal organic frameworks. 7,8 Metal organic frameworks (MOFs) are a novel class of materials, formed by inorganic cores connected by organic linkers to extended networks with high porosities and ultrahigh surface areas.…”

“…The current state‐of‐the‐art technologies for filtration and decomposition of CWAs mainly use activated carbons in pure or impregnated forms for the detoxification of these toxic chemicals 2,3 . However, significant drawbacks of those filters, such as low adsorption capacities, deactivation of the active sites and slow degradation kinetics, present an urgent need to develop improved materials capable of fast adsorption and decontamination of CWAs under ambient conditions 4 . These challenges have motivated research into a new category of catalytically active materials for CWAs decontamination, including metal oxides, 5 polyoxometalates, 6 and metal organic frameworks 7,8 …”

Two Polymorphic Polyoxometalate-Based Metal–Organic Frameworks for the Efficient Synthesis of Functionalized Sulfoxides and Detoxification of Mustard Gas Simulants

“…The transformation of sulfides to the corresponding sulfoxides is a significant issue for economic and environmental considerations, not only because such processes can synthesize intermediates with pharmaceutical and chemical activity but also because the transformation can purify toxic chemicals, such as oxidative detoxification of the sulfur mustard simulant and oxidative desulfurization of petroleum . Although many traditional stoichiometric oxidants (e.g., nitric acid, hypervalent iodine, oxone, K 2 FeO 4 , and so forth) have been proved to be effective for the oxidation of sulfide, most systems usually suffer from numerous defects in terms of low sulfoxide selectivity, extreme reaction conditions, complex handling procedures, as well as generating environmentally harmful toxic pollutants. − As an alternative solution, therefore, a wide variety of catalytic oxidation systems using metal–organic frameworks (MOFs), ionic liquid, covalent–organic frameworks (COFs), or modified zeolites as catalysts, and molecular oxygen, hydrogen peroxide, or tert -butyl hydroperoxide as environmentally benign oxidants have gradually attracted extensive attention from researchers. − Nevertheless, it is frustrating that some above systems remain displaying low sulfoxide yield and lack versatility and economic applicability.…”

Polyniobate Nanothreads for Decomposition of the Nerve Agent Simulant Dimethyl Chlorophosphate

“…1,2 In particular, organophosphorus (OP) nerve agents, one class of CWAs, are generally detoxified via hydrolysis. Several types of materials for hydrolysis of OP nerve agents and simulants have been proposed, 3,4 notably metal−organic frameworks (MOFs) and polyoxometalates (POMs).…”