Swell and Destroy: A MOF-Containing Polymer Sponge that Immobilizes and Catalytically Degrades Nerve Agents.

Organophosphorus chemical warfare agents function as potent neurotoxins. Whilst the destruction of nerve agents is most readily achieved by hydrolysis, their storage and transport is hazardous; lethal in milligram doses with any spillage resulting in fatalities. Furthermore, current decontamination and remediation measures are limited by the need for stoichiometric reagents, solvents and buffered solutions, complicating the process for the treatment of bulk contaminants. Herein, we report a composite polymer material capable of rendering bulk VX unusable by immobilisation within a porous polymer until a MOF catalyst fully hydrolyses the neurotoxin. This is an all-in-one capability that minimizes the use of multiple reagents, facilitated by a porous high-internal phase emulsion-based polystyrene monolith housing an active zirconia MOF catalyst (MOF-808); the porous polymer absorbs and immobilises the liquid agents, while the MOF enables hydrolysis. The dichotomous hierarchy of porous materials facilitates the containment and rapid hydrolysis of VX (> 80% degradation in 8 hours) in the presence of excess of H2O. This composite can further enable the hydrolysis of neat VX with a reliance on ambient humidity (>95% in 11 days). Potentially, 4.5 kg of the composite can absorb, immobilise and degrade the contents of a standard chemical drum/barrel (208 litres, 55 gallons) of chemical warfare agent. We believe that this composite is the first example of what will be the go-to approach for CWA immobilisation and degradation in the future. Furthermore, we believe that this demonstration of a catalytically reusable absorbent sponge provides a signpost for the development of similar materials where immobilisation of a substrate in a catalytically active environment is desirable.