Decomposing Chemical Warfare Agents Utilizing Metal-Organic Frameworks

Mondloch, J. E.; Katz, M. J.; Isley, W. C., III; Ghosh, P.; Liao, P.; Bury, W.; Wagner, G. W.; Hall, M. G.; DeCoste, J. B.; Peterson, G. W.; Snurr, R. Q.; Cramer, C. J.; Hupp, J. T.; Farha, O. K.
Nature Mater. 2015, 14, 512 (doi:10.1038/nmat4238).

Chemical warfare agents containing phosphate ester bonds are among the most toxic chemicals known to mankind. Recent global military events, such as the conflict and disarmament in Syria, have brought into sharp focus the need to find effective strategies for the rapid destruction of these banned chemicals. Solutions are needed for immediate personal protection (e.g., the filtration and catalytic destruction of air borne versions of agents), bulk destruction of chemical weapon stockpiles, protection (via coating) of clothing, equipment and buildings, and containment of agent spills. Solid heterogeneous materials such as modified activated carbon or metal oxides exhibit many desirable characteristics for the destruction of chemical warfare agents. Unfortunately, low sorptive capacities, low effective active site loadings, deactivation of the active site, slow degradation kinetics, and/or a lack of tailorability offer significant room for improvement in these materials. Here we report a carefully chosen metal-organic framework (MOF) material featuring high porosity and exceptional chemical stability that is extraordinarily effective for the degradation of nerve agents and their simulants. Experimental and computational evidence point to Lewis-acidic Zr^IV ions as the active site and to their superb accessibility as a defining element of their efficacy.