Advanced catalyst design and mechanistic insights in electrocatalytic upcycling of PET-derived ethylene glycol and coupled electrolysis systems

Abstract

Polyethylene terephthalate (PET) is a major contributor to plastic pollution and a promising feedstock for circular chemical manufacturing. Electrocatalytic upcycling has emerged as a scalable strategy that couples mild PET depolymerization with electricity driven reforming of PET derived ethylene glycol (EG) into value added C1/C2 oxygenates. We first summarize PET valorization routes and the electrochemical fundamentals underlying this process. We then analyze the mechanistic landscape of the ethylene glycol oxidation reaction (EGOR), contrasting C–C cleavage pathways leading to formate with selectivity steering toward glycolate or glycolic acid. Building on these insights, we survey state-of-the-art noble metal and Earth abundant catalysts and distill unifying design principles. Finally, we discuss coupled electrolysis platforms that pair the EGOR with the hydrogen evolution reaction, CO₂ reduction, or nitrate reduction to co-produce fuels and chemicals at reduced cell voltages. We conclude by outlining priorities in catalyst durability, rigorous product quantification, mechanistic validation, product separation, and system level design to accelerate practical PET electro-upcycling.