Electrooxidation of PET alkaline hydrolysate to formate and glycolate enabled by the synergistic interaction of Ag and NiFe-LDH

Waste plastics present a significant threat to ecosystems and human health, necessitating efficient and cost-effective solutions for their conversion into high-value products. This study introduces a novel electrochemical reforming strategy to upgrade polyethylene terephthalate (PET) into valuable chemicals, primarily formic acid, while simultaneously generating hydrogen. A highly efficient electrocatalyst composed of nano-arrays of silver and NiFe layered double hydroxide (LDH) is synthesized via a hydrothermal and photo-precipitation process on a nickel foam substrate. This advanced catalyst achieves selective electrochemical conversion of ethylene glycol (EG) as PET hydrolysate to formate and glycolate with Faradaic efficiencies of 85% and 13% at 1.5 V vs . the reversible hydrogen electrode, with a stable and high current density. Density functional theory calculations reveal that the synergistic interaction between Ag and NiFe-LDH optimizes the adsorption and desorption of key intermediates on the catalytic sites, resulting in superior activity, selectivity, and stability for the electrochemical EG oxidation reaction. These findings highlight the potential of this catalyst for sustainable plastic waste valorization and renewable hydrogen production.