Trash to Treasure: Methanolysis of Postconsumer Polyethylene Terephthalate (PET) Using a Magnetically Retrievable Catalyst

The ever-increasing accumulation of plastic waste, specifically polyethylene terephthalate (PET), demands innovative upcycling strategies beyond conventional mechanical strategies. In this study, an efficient magnetically retrievable heterogeneous ZnFe 2 O 4 /TiO 2 nanocomposite catalyst was developed for the methanolysis of postconsumer PET into dimethyl terephthalate (DMT). The catalyst enabled complete conversion of PET and high DMT yields under mild and systematically optimized conditions. Recyclability tests demonstrated the catalyst’s robustness, retaining high activity over five cycles with trivial metal leaching. Control studies and comparative literature analysis further establish the supremacy of the ZnFe 2 O 4 /TiO 2 composite over its individual components and other reported catalysts. Comprehensive characterization ( 1 H-NMR, 13 C-NMR, FTIR, XRD, BET, SEM, HR-TEM, TGA, and VSM) validated the structural and functional integrity of the catalyst and product. Green metrics analysis confirmed the sustainability and low environmental impact of the process. Thus, this work establishes a sustainable and industrially viable “trash-to-treasure” green catalytic route for efficient PET upcycling via methanolysis.