Medium entropy metal oxide induced *OH species targeted transfer strategy for efficient polyethylene terephthalate plastic recycling

Increasing plastic waste is environmentally and biologically detrimental, and converting plastic waste into value-added chemicals and fuels by electrocatalytic methods is recognized as an up-cycling process that facilitates resource utilization. Here, we report a generalized medium entropy metal oxide Ni0.5Ce0.5Co2O4 induced *OH species targeted transfer strategy to selectively electrocatalytic upgrade various polyester plastics into value-added chemicals under alkaline conditions. Polyethylene terephthalate (PET) was upgraded to potassium diformate with high Faraday efficiency (95 %) and selectivity (>91 %) at a high current density of 343 mA cm(-2), generating both terephthalic acid and hydrogen. The synergistic interplay between Ni and Ce in Ni0.5Ce0.5Co2O4 facilitates the adsorption of ethylene glycol molecules and hydroxide ions, prompting the directionally oriented hydroxyl (*OH) to partake in the oxidation of ethylene glycol, thereby fostering the oxidation of hydrolyzed PET products. This work not only develops an excellent electrocatalyst for the upcycling of various polyester plastics but also guides the design of medium entropy metal oxides as electrocatalysts.

Automated summary

This study reports a strategy for upgrading polyester plastics into value-added chemicals using electrocatalytic methods. By inducing the targeted transfer of *OH species, polyethylene terephthalate was successfully upgraded into potassium diformate with high purity. This work not only develops an excellent electrocatalyst, but also provides guidance for the design of medium entropy metal oxides.