Electrochemical Upcycling of Polyethylene Terephthalate-Derived Ethylene Glycol into Commodity Chemicals

Abstract

Plastic pollution has emerged as a critical constraint on global ecological sustainability. As the most extensively produced petroleum-based thermoplastic polyester, polyethylene terephthalate (PET) suffers from inefficient recycling systems and widespread environmental accumulation. Although PET can be readily hydrolyzed to the ethylene glycol (EG) monomer, the lack of efficient EG valorization routes exacerbates carbon resource wastage and environmental pressure. Conventional PET plastics recycling technologies are plagued by inherent limitations such as downcycling and excessive energy consumption, rendering them misaligned with the resource circulation demands of the carbon neutrality agenda. In contrast, electrocatalysis, driven by renewable electricity, enables the selective upgrading of PET under ambient conditions, offering a promising route to high-value chemicals. This review provides a systematic and critical overview of recent advances in the electrocatalytic PET valorization. It begins with elucidating viable pathways for PET plastics depolymerization to EG, followed by a detailed analysis of the three core electrocatalytic mechanisms for EG transformation. The discussion then extends to rational design strategies for electrocatalysts, establishing clear relationships between structure and performance. Furthermore, the work critically examines integrated anodic-cathodic systems that couple PET plastics oxidation with value-added reduction reactions, alongside reactor design innovations for enhanced energy efficiency. The review concludes by assessing the technology's industrial potential while charting a course through persistent challenges toward future research directions.