Continuous Flow Composite Membrane Catalysts for Efficient Decomposition of Chemical Warfare Agent Simulants

Abstract

Continuous and safe decomposition of chemical warfare agents (CWAs) is a critical requirement to protect both soldiers and citizens and to eliminate the stockpiles after the cold war. The Zr-based metal−organic framework (Zr-MOF) has been known as the most effective catalyst for decomposing CWAs, especially the most fatal nerve agents, however, its low processability due to the powder form limits its expansion to actual military applications. To this end, the composite membrane catalysts (CMCs) comprising the Zr-MOF (UiO-66 catalyst) and nylon 6 nanofiber (porous supporter) are developed by the simple integration of electrospray and electrospinning, resulting in selective immobilization of UiO-66 on the surface of the nylon 6 nanofibers. These strategical benefits of CMCs gave super catalytic durability including recyclability over five times without decreasing the catalytic activity for the decomposition of methyl paraoxon (MPO), a simulant of the nerve agent, in the presence of N-ethylmorpholine (N-EM), which was not achieved in the original particulate UiO-66. Because of the excellent physical and chemical stabilities of CMCs, the CMC with 56 wt % of UiO-66 (CMC56) decomposed 198 g of MPO within an hour in the continuous flow system with a flow rate of 21.6 mL h −1 . This study highlights the important strategies in designing the feasible membrane-type catalysts with superior catalytic activity and robust durability for decomposing CWAs in the continuous flow system.

Green MIP-202(Zr) Catalyst: Degradation and Thermally Robust Biomimetic Sensing of Nerve Agents

“…Zr-MOFs have displayed tremendous potential for the catalytic degradation of acutely toxic and potentially lethal OP biothreats, including OP pesticides such as MPOx ,,,,− and the highly toxic OP NAs, e.g., GA, GB, GD, and VX. − ,,, The underlying Zr-MOF-catalyzed OP compound hydrolysis ( i.e. , degradation) mechanism is well established to be initiated by nucleophilic substitution of an H 2 O defect (at a Lewis acidic Zr 4+ active site) on the Zr-cluster node by the PO moiety of the OP compound.…”

Synergetic effect of metal-organic framework UiO-66 and silver plasmonic nanoparticles on PET waste support in degradation of nerve agent simulant

“…3B, insert) [33]. Fourier-transform infrared spectroscopy (FTIR) spectra of PET@UiO-66-Ag25 contain characteristic signals of both PET at 1718 cm -1 , UiO-66 -1594 cm -1 and 1386 cm -1 are asymmetric and symmetric stretches of COO-Zr bonds [30] (Fig. 3C, S1A).…”

“…2A). The degradation of paraoxon-ethyl using UiO-66 is commonly hydrolytically degrading through the cleavage of phosphonate ester bonds [29] with the formation of pnitrophenol and diethyl phosphate [30,31]. Therefore, for the evaluation of adsorption/degradation efficiency of PET@UiO-66-Ag(5-100), we used the concentrations of paraoxon-ethyl and p-nitrophenol measured by HPLC-UV using standard calibration curves (Fig.…”

Utilizing Zirconium MOF‐functionalized Fiber Substrates Prepared by Molecular Layer Deposition for Toxic Gas Capture and Chemical Warfare Agent Degradation

“…Recently, it has protective layer in clothing requires some form of controlled immobilization of the MOFs on a carrier material. Therefore, a considerable effort has been put into immobilization of MOFs on different substrates, including fibers, [20,26,[34][35][36] woven and non-woven fabrics, [14,16,27,30,34] meshes, [37] and even as self-supporting structures. [18,38] Nonetheless, most techniques usually require a multi-step deposition process, where the MOF is either synthesized prior to the deposition, [14,27,29,35] or grown in situ by wet chemical techniques, often on a specially prepared seeding layer.…”