Electrochemically mediated alkaline hydrolysis and methanolysis of poly(ethylene terephthalate) (PET)

Low-impact, closed-loop recycling of plastics is crucial to sustainably managing these pervasive and resource-intense materials. Our approach aimed to reinvent chemical recycling by integrating it with electrochemical processes to generate reactants electrochemically and depolymerize plastic in situ, with the objective of reducing both costs and environmental impacts. We investigated electrochemically mediated alkaline hydrolysis and methanolysis of poly(ethylene terephthalate) (PET) to achieve the following advantages over conventional methods: access to more extreme reactivity from applying an electrochemical driving force, process intensification, and application of more moderate operating conditions. Total PET conversion and product yields were measured to systematically investigate the performance effects of catholyte methanol content, anolyte buffering, and temperature. Leveraging these insights to improve experimental conditions, we achieved 45 mol% PET conversion in 5 hours at ambient pressure and relatively moderate temperature (50 °C) in 0.1 M NaClO4 (100 mol% methanol) catholyte and 0.1 M Na3PO4 anolyte.