A Bioinspired OH-Sponge Catalyst Enables Ultrawide-Voltage and Durable Electrosynthesis of Glycolic Acid from Plastic Waste

Abstract The electrochemical upcycling of plastic waste into high-value chemicals using renewable electricity is a promising route toward a circular economy. However, the electrocatalytic oxidation of polyethylene terephthalate (PET)-derived ethylene glycol (EG) to glycolic acid (GA) is severely limited by the narrow voltage window and rapid deactivation of noble-metal catalysts, primarily due to competitive hydroxyl adsorption and intermediate poisoning. Inspired by the spatial compartmentalization in enzymatic catalysis, we decouple reactant activation and oxygen species management through a spinel Co3O4-mediated OH-sponge effect, which buffers local OH– concentration, thus preventing Pt-oxidation and supplies active oxygen species enabling targeted conversion to GA. The resulting catalyst achieves an unprecedented GA selectivity of >95% over an ultrawide potential range of 0.5–1.5 V (vs RHE). It demonstrates exceptional durability, operating stably for over 2000 h in a half-cell and >650 h in a membrane electrode assembly. Techno-economic analysis indicates the process can yield a net profit of approximately $720 per ton of PET waste processed. This work provides a biomimetic design principle that simultaneously addresses the challenges of selectivity, stability, and operational flexibility, advancing the viability of electrochemical plastic upcycling.