Hybrid electrocatalysis for polyethylene terephthalate plastic upcycling via anodic depolymerization

초록

Plastic waste presents a main environmental issue because of its volume and persistent nature. Electrocatalytic upcycling has evolved as an assuring strategy for plastic transforming into value-added chemicals (VACs) over mild conditions, offering low carbon emissions and high selectivity. In particular, the electrochemical polyethylene terephthalate (PET) upcycling extends a sustainable strategy to mitigate plastic pollution while generating VACs. This process involves depolymerizing PET into monomers as terephthalic acid and ethylene glycol, followed by selective electro-oxidation of EG into C1/C2 products such as formate, glycolate, and carbonate. This review discusses current progress in integrated electrochemical systems that couple PET hydrolysate oxidation with cathodic reactions like the hydrogen evolution reaction, nitrate and CO2 reduction reaction. These hybrid systems enable the coproduction of valuable compounds including hydrogen, ammonia, and formate, effectively valorizing dual waste streams. Key focus areas include mechanistic insights into electrocatalytic pathways, catalyst development, and process integration. Despite the progress, challenges remain in catalyst stability, product separation, and scalability. This review also addresses current limitations and outlines future research directions toward scalable, sustainable, and carbon-circular technologies for plastic recycling.

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