Waste polyethylene terephthalate (PET) materials as sustainable precursors for the synthesis of nanoporous MOFs, MIL-47, MIL-53(Cr, Al, Ga) and MIL-101(Cr)

Abstract

In our novel green approach, the waste polyethylene terephthalate (PET) bottle material has effectively been used as the starting precursor instead of terephthalic acid for the synthesis of five terephthalate based nanoporous trivalent metal-organic frameworks (MOFs) namely MIL-47, MIL-53(Cr), MIL-53(Al), MIL-53(Ga), and MIL-101(Cr). The optimum reaction parameters to achieve the green synthesis were studied. These MOFs were structurally identified by using powder X-ray diffraction (PXRD) measurements. Scanning electron microscopy (SEM) images confirm the particle nature and size of the synthesized MOFs. Nitrogen gas sorption measurements have been done for some of the MOFs to check their porous properties. All the characterization techniques strongly supported that the synthesized MOFs using PET are similar to their literature reports. The gas adsorption studies for the synthesized MIL-53(Cr) and MIL-101(Cr) showed their significant gas uptake capability towards CO2 and H2 gases. Further, the synthesized MIL-47 and MIL-101(Cr) have been tested for their catalytic ability in chemical fixation of CO2 gas through the conversion of CO2 and epoxides to the corresponding cyclic carbonates which shows promising results to use them as catalysts.

Engineering Metal–Organic Framework Catalysts for C−C and C−X Coupling Reactions: Advances in Reticular Approaches from 2014–2018

“… Optimized crystal structure of MIL‐101(Cr) (reproduced with permission from ref. . Copyright 2016, The Royal Society of Chemistry).…”

Porous Nickel‐Alumina Derived from Metal‐Organic Framework (MIL‐53): A New Approach to Achieve Active and Stable Catalysts in Methane Dry Reforming

“…An additional benefit is the occurrence in this structure of aluminum bridging hydroxy groups lying along the inorganic chains that can interact with the nickel precursors and hence act as anchorage sites. Moreover, MIL‐53(Al) is made from the assembly of relatively inexpensive components, namely hydroxy‐aluminum species and terephthalate linkers, which can be extracted from natural or recycled feedstocks making this MOF‐derived strategy economically and ecologically viable.…”

Combining Organic and Inorganic Wastes to Form Metal–Organic Frameworks

“…The main issues of these materials remain their synthesis, generally at the gram scale, and the final price of the materials. Recently, these materials have been produced using commercial depolymerized PET as a source of organic ligands to build various MOFs, based on Zr [10,11], Cu [12], Zn [13], Cr [14,15], Al [14,16], Ga [14], and V [16], with a high purity. We have recently proposed the use of LiB waste as a source of metal ions for the synthesis of such materials [17][18][19].…”