Su Young Moon

Instantaneous hydrolysis of nerve-agent simulants with a six-connected zirconium-based metal-organic framework.

A nerve-agent simulant based on a phosphate ester is hydrolyzed using a MOF-based catalyst. Suspensions of MOF-808 (6-connected), a material featuring 6-connected zirconium nodes, display the highest hydrolysis rates among all MOFs that have been reported to date. A plug-flow reactor was also prepared with MOF-808 (6-connected) as the active layer. Deployed in a simple filtration scheme, the reactor displayed high hydrolysis efficiency and reusability.

Encapsulation of a Nerve Agent Detoxifying Enzyme by a Mesoporous Zirconium Metal–Organic Framework Engenders Thermal and Long-Term Stability

Immobilized enzymes typically have greater thermal and operational stability than their soluble form. Here we report that for the first time, a nerve agent detoxifying enzyme, organophosphorus acid anhydrolase (OPAA), has been successfully encapsulated into a water-stable zirconium metal-organic framework (MOF). This MOF features a hierarchical mesoporous channel structure and exhibits a 12 wt % loading capacity of OPAA. The thermal and long-term stabilities of OPAA are both significantly enhanced after immobilization.

Mechanochemical and solvent-free assembly of zirconium-based metal–organic frameworks

Mechanochemistry and accelerated aging are new routes to zirconium metal–organic frameworks, yielding UiO-66 and catalytically active UiO-66-NH2 accessible on the gram scale through mild solid-state self-assembly, without strong acids, high temperatures or excess reactants.

Effective, Facile, and Selective Hydrolysis of the Chemical Warfare Agent VX Using Zr6-Based Metal–Organic Frameworks

The nerve agent VX is among the most toxic chemicals known to mankind, and robust solutions are needed to rapidly and selectively deactivate it. Herein, we demonstrate that three Zr6-based metal-organic frameworks (MOFs), namely, UiO-67, UiO-67-NH2, and UiO-67-N(Me)2, are selective and highly active catalysts for the hydrolysis of VX. Utilizing UiO-67, UiO-67-NH2, and UiO-67-N(Me)2 in a pH 10 buffered solution of N-ethylmorpholine, selective hydrolysis of the P-S bond in VX was observed. In addition, UiO-67-N(Me)2 was found to catalyze VX hydrolysis with an initial half-life of 1.8 min. This half-life is nearly 3 orders of magnitude shorter than that of the only other MOF tested to date for hydrolysis of VX and rivals the activity of the best nonenzymatic materials. Hydrolysis utilizing Zr-based MOFs is also selective and facile in the absence of pH 10 buffer (just water) and for the destruction of the toxic byproduct EA-2192.

Tailoring the Pore Size and Functionality of UiO-Type Metal–Organic Frameworks for Optimal Nerve Agent Destruction

Evaluation of UiO-66 and UiO-67 metal-organic framework derivatives as catalysts for the degradation of soman, a chemical warfare agent, showed the importance of both the linker size and functionality. The best catalysts yielded half-lives of less than 1 min. Further testing with a nerve agent simulant established that different rate-assessment techniques yield similar values for degradation half-lives.

Synthesis of nanocrystals of Zr-based metal–organic frameworks with csq-net: significant enhancement in the degradation of a nerve agent simulant

The synthesis of nano-sized particles of NU-1000 (length from 75 nm to 1200 nm) and PCN-222/MOF-545 (length from 350 nm to 900 nm) is reported. The catalytic hydrolysis of methyl paraoxon was investigated as a function of NU-1000 crystallite size and a significant enhancement in the rate was observed for the nano-sized crystals compared to microcrystals.

Nanosizing a Metal–Organic Framework Enzyme Carrier for Accelerating Nerve Agent Hydrolysis

We report the synthesis and characterization of a water-stable zirconium metal-organic framework (MOF), NU-1003, featuring the largest mesoporous aperture known for a zirconium MOF. This material has been used to immobilize the nerve agent hydrolyzing enzyme, organophosphorus acid anhydrolase (OPAA). The catalytic efficiency of immobilized OPAA in nanosized NU-1003 is significantly increased compared to that of OPAA immobilized in microsized NU-1003 and even exceeds that of the free OPAA enzyme. This paper highlights a method for rapid and highly efficient hydrolysis of nerve agents using nanosized enzyme carriers.

Detoxification of Chemical Warfare Agents Using a Zr6 -Based Metal-Organic Framework/Polymer Mixture.

Owing to their high surface area, periodic distribution of metal sites, and water stability, zirconium-based metal-organic frameworks (Zr6 -MOFs) have shown promising activity for the hydrolysis of nerve agents GD and VX, as well as the simulant, dimethyl 4-nitrophenylphosphate (DMNP), in buffered solutions. A hurdle to using MOFs for this application is the current need for a buffer solution. Here the destruction of the simulant DMNP, as well as the chemical warfare agents (GD and VX) through hydrolysis using a MOF catalyst mixed with a non-volatile, water-insoluble, heterogeneous buffer is reported. The hydrolysis of the simulant and nerve agents in the presence of the heterogeneous buffer was fast and effective.