Advances and Insights in Electrocatalytic Upcycling of Polyethylene Terephthalate Plastic Wastes

Polyethylene terephthalate (PET) is one of the most commonly used polyester plastics; however, its still-low recycling rate results in large amounts of waste emissions that pose a great threat to the ecosystem and human health. Electrocatalysis provides an effective strategy to convert waste PET plastics into high-value-added chemicals under mild conditions, which can achieve enhanced recycling efficiency. Especially, when coupled with cathode reduction reactions such as hydrogen evolution, carbon dioxide reduction, nitrate reduction, etc., valuable chemicals can be concurrently produced at both anode and cathode. The corresponding coupling systems and their applicable electrocatalysts in the recycling process of PET waste have yet to be comprehensively reviewed. This review first describes the mechanisms of electrocatalytic PET upcycling in detail, and summarizes the electrochemical reforming strategies by emphasizing various anode-cathode reaction coupling pathways and related intermediates. Then, the most recent advances in developing highly active electrocatalysts in different-coupled systems, as well as typical product separation approaches of PET hydrolysate, are discussed to provide insights into innovative design principles. Finally, perspectives and outlooks are presented for electrocatalytic recycling of PET wastes, which is expected to benefit future developments of related fields, especially the electrocatalyst design toward practical application.