Simultaneous upcycling of PET plastic waste and CO2 reduction through Co-electrolysis: a novel approach for integrating CO2 reduction and PET hydrolysate oxidation

Abstract

Improper handling of polyethylene terephthalate (PET) plastic waste contributes to CO₂ emissions during incineration. This study proposes an innovative strategy for tackling PET waste and CO₂ emissions simultaneously. Integrating the CO₂ electrochemical reduction reaction (CO₂RR) with PET hydrolysate oxidation offers a promising avenue. Bismuth oxide carbonate (BOC) loaded on reduced graphene oxide (rGO) and CuCoO loaded on rGO (CuCoO@rGO) were employed for cathodic CO₂RR and anodic PET hydrolysate oxidation, respectively, for concurrent production of formate. The anodic CuCoO@rGO catalyst exhibited high electro-activity and a remarkable faradaic efficiency (FE) of 85.7% at 1.5 V vs. RHE. The cathodic BOC@rGO catalyst achieved a FE of 97.4% at −0.8 V vs. RHE, facilitating formate production from CO₂RR. Employing this approach in an electrolyzer allowed formic acid production at a low cell voltage of 1.9 V at 10 mA cm⁻² with a formate FE of 151.8%. This innovation offers a novel route for PET waste upcycling, CO₂ reduction, and environmental sustainability.