Nanostructured micro particles as a low-cost and sustainable catalyst in the recycling of PET fiber waste by the glycolysis method
Zengwei Guo, Erik Adolfsson, Pui Lam Tam
Abstract
Magnetic [email protected]3O4 micro particles were synthesized by coating nanosized Mg-Al double oxides onto Fe3O4 micro particles. The formed hierarchical structure gave [email protected]3O4 micro particles a high active surface area, which enabled these micro particles to work efficiently as a catalyst in the glycolysis of poly(ethylene terephthalate) (PET). The bis(hydroxyethyl) terephthalate (BHET) yield reached above 80 mol% in the presence of 0.5 wt% of [email protected]3O4 micro catalyst in the reaction system within 90 min at 240 °C. After the reaction, [email protected]3O4 micro catalyst was easily retrieved by a magnetic decantation and can be repetitively used for two times with a high catalytic efficiency. After that, the deactivated [email protected]3O4 micro catalyst can be regenerated by heat treatment. The regenerated [email protected]3O4 micro catalyst displays a comparable catalytic performance as that of the virgin catalyst. In addition, the Mg-Al double oxides and Fe3O4 micro particles are low-cost and environmentally benign. Therefore, the [email protected]3O4 micro catalyst may contribute to an economically and environmentally improved large-scale circular recycling of PET fiber waste.