Near-instantaneous catalytic hydrolysis of organophosphorus nerve agents with zirconium-based MOF/hydrogel composites

Abstract

Zirconium-based metal-organic frameworks (Zr-MOFs) with Lewis-acidic sites are potent catalysts for degrading organophosphorus nerve agents. However, a volatile basic solution must regenerate the Zr-MOF catalysts, challenging its real-world implementation. By crosslinking polyethylene imine with an epoxide in the presence of selected Zr-MOFs, we prepared Zr-MOF/hydrogel composite catalysts for the rapid degradation of organophosphorus chemicals under atmospheric conditions. We developed a series of Zr-MOF hydrogel powder composites varying in Zr-node connectivity, linker functionality, and topology. The MOF-808 hydrogel powder was the highest-performing MOF-based composite for the hydrolysis of organophosphorus nerve-agent simulants. We coated the MOF-808 hydrogel onto a textile, and the composite rapidly detoxified nerve-agent simulants and actual nerve agents. The resulting half-lives are the fastest reaction rates to date among MOF-based composite materials, representing a critical step toward the production of protective gear for the instantaneous detoxification of nerve agents in practical conditions. • An amine-based hydrogel integrated with Zr-MOFs forms active detoxification catalysts • The MOF/hydrogel composites detoxify two organophosphorus nerve-agent simulants • The MOF/hydrogel composites integrated onto fiber detoxify GD and VX under ambient conditions Chemical warfare agents (CWAs) threaten the health and security of the global population, which motivates the development of protective wear that can rapidly detoxify CWAs into less-toxic species. Metal-organic frameworks (MOFs) are hybrid materials offering exceptional porosity and rich structural chemical diversity. The incorporation of Lewis-acidic sites into MOFs, specifically zirconium-based building blocks, forms highly active catalysts for the hydrolysis of organophosphorus nerve agents. However, a regenerating base and a source of water are needed, limiting the practical incorporation of Zr-MOFs in protective gear. To date, the subsequent incorporation of the active MOF onto a fiber composite has resulted in slow kinetics. Herein, we have designed a MOF/hydrogel powder and fibrous composites for the ultrafast solid-state catalytic detoxification of the phosphoester agents under ambient conditions. This scalable methodology is critical for realizing MOF-based protective masks and clothing. The development of heterogeneous catalyst composites that can detoxify organophosphorus chemical nerve agents through hydrolysis reactions is limited by slow kinetics and the need for water, as well as a base to regenerate the catalyst. We report the incorporation of an amine-based hydrogel integrated with Zr-MOFs onto a fibrous composite that results in the ultrafast solid-state catalytic detoxification of the phosphoester nerve agents (GD and VX) and their less-toxic chemical simulants under ambient conditions.