A Catalytically Accessible Polyoxometalate in a Porous Fiber for Degradation of a Mustard Gas Simulant

ACS Appl Mater Interfaces. 2022 Apr 13;14(14):16687-16693. doi: 10.1021/acsami.2c01584. Epub 2022 Mar 30.

Abstract

Polyoxometalates (POMs) are versatile materials for chemical catalysis due to their tunable acidity and rich redox properties. While POMs have attracted significant attention in homogeneous catalysis, challenges regarding aggregation and instability in solvents often prevent the wide implementation of POMs as heterogeneous catalysts. Therefore, the successful incorporation of a POM into a solid support, such as a polymer, is desirable for practical applications where unique functionalities of the POM combine with the advantages of the polymer. In this work, we showcase how polymers of intrinsic microporosity (PIMs) can serve as matrices for anchoring a pure inorganic Keggin-type POM (H3PW12O40) to fabricate PIM-based composite materials. Specifically, we found that PIMs installed with amidoxime functionalities could successfully attach POMs (PW12@PIM-1-AO) without self-segregation. Furthermore, we fabricated porous fibrous mats via electrospinning of the PIM-POM composites. Comprehensive characterization confirmed the integrity of the POM in the composite material. Following this, we demonstrated that the incorporated POMs in the composite fibers maintained their innate catalytic activity for the oxidative degradation of 2-chloroethyl ethyl sulfide, a sulfur mustard simulant, in the presence of hydrogen peroxide as the oxidant. Ultimately, our work highlights that PIM-based hybrid materials provide a potential route for implementing these reactive fiber mats into protective equipment.

Keywords: chemical warfare agents; composite fibers; polymers of intrinsic microporosity (PIMs); polyoxometalates (POMs); porous polymers.