Mixed-matrix membrane reactors for the destruction of toxic chemicals

Abstract

The extremely toxic synthetic organophosphates used as pesticides and chemical warfare agents (CWA) are capable of not only directly disrupting biological functions but also causing secondary contamination of water and soil. Among the proposed detoxifying materials, zirconium-based metal-organic frameworks (MOFs) have emerged as promising catalysts for CWA degradation. However, the practical application of MOFs is limited by their intractable powdery form, and requires complex instrumental settings. To address this issue, mixed-matrix membrane reactors (MMR) are developed based on Zr-based MOFs embedded in the porous polymer matrix. Such configurations also enable CWAs flowing through the nanochannels of MMR to easily access the catalysts, which is beneficial for enhancing the CWA degradation. A series of flat MMRs and hollow fiber MMRs containing UiO-66, UiO-66-NH2, and MOF-808 were evaluated. MMRs containing MOF-808 provided an extremely high conversion of 95% despite short residence times (<10 s) under continuous operation reflecting their promise for practical applications.