Inorganic/Organic Hybrid Magnetic Nanocatalysts for Effective PET Glycolysis

초록

Chemical recycling of polyethylene terephthalate (PET), particularly via glycolysis, has emerged as a promising approach to address global PET waste by converting it into valuable bis(2-hydroxyethyl)terephthalate monomers. Both homogeneous and heterogeneous catalysts have been investigated to mitigate the harsh conditions of PET glycolysis; however, homogeneous catalysts suffer from difficult separation and purification, whereas heterogeneous catalysts typically exhibit low reactivity. Here, ZnFe2O4@citrate inorganic/organic hybrid magnetic nanocatalysts were designed to operate at low reaction temperatures while enabling facile separation, thereby integrating the advantages of both catalyst types. The catalytic performance was demonstrated in PET glycolysis, achieving 83.7% conversion and 79.9% yield at 170 degrees C for 3 h, and 100% conversion and 94.1% yield at 180 degrees C for 2 h. The reduced reaction temperature was attributed to the cooperative action of inorganic Lewis acid and organic Lewis base catalysis. The nanocatalyst exhibited strong superparamagnetic properties, with a saturation magnetization of 77.5 emu/g, enabling efficient magnetic separation. These findings highlight the potential of an environmentally friendly closed-loop recycling approach that reduces the energy demand and operational cost of PET glycolysis.

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