Dynamic redox reactivation of platinum sites for long-term glycolate electrosynthesis from polyethylene terephthalate wastes

Glycolates are indispensable in the health, chemical and pharmaceutical industries, whereas their mainstream production involve toxic chemicals and harsh operating condition. An alternative route for glycolate production is electrifying ethylene glycol (EG) that originates from polyethylene terephthalate (PET) but suffers from poor durability of active platinum site that tend to deactivate. Herein, we demonstrate a dynamic redox reactivation strategy, which alternates between working potential for oxidizing EG to glycolate and nonworking potential for reviving active platinum sites by the chemical reduction of adsorbed EG, realizing an unprecedented stability for over 3000 hours under average current density of ∼220 milliamperes per square centimeter. Upscaling this approach, the assembled electrolyzer drives a record current of 10 amperes at 1.18 volts for repeatable 40 batches of glycolates electrosynthesis, with each batch converting 48.0 grams of PET to 11.6 grams of glycolates (52.8% yield), 37.7 grams of p -phthalic acid (95.8% yield), 248.7 grams of NaHSO ₄ (95.2% yield) and ∼11.5 liters of hydrogen, showcasing a considerable revenue of ∼$1072 per ton glycolate.