Coelectrolysis of PET and CO ₂ Using an Electrochemically Restructured Co-MOF-74 Anode and a Polymeric Co-Phthalocyanine Cathode

Mitigating carbon emissions and plastic waste is a pressing societal challenge due to the disruptive environmental impact of incremental accumulation. A promising strategy to address both issues is coelectrolysis of CO₂ and PET-plastic waste to high-value commodity chemicals. Here, we report electrocatalytic upcycling of polyethylene terephthalate (PET) plastic to formate and terephthalic acid using a cobalt-based metal-organic framework (Co-MOF-74). The electrocatalyst underwent oxidative restructuring to cobalt oxyhydroxide under operating conditions and exhibited near-unity faradaic efficiency (FE) for the ethylene glycol oxidation reaction (EGOR) to formate during short-term electrolysis. Notably, EGOR required 0.23 V lower potential compared to the conventional oxygen evolution reaction (OER) at a current density of 100 mA cm^-2. When coupled with a CO₂ reducing cathode, a maximum combined FE of 156% was achieved for formate (anode) and syngas (cathode) at a cell voltage (<i>E</i>_cell) of 1.6 V. Upon integration of the EGOR electrode in a CO₂-fed flow cell, the coupled system required an <i>E</i>_cell of ∼2.3 V to operate at 75 mA cm^-2. This work presents a promising integrated approach that offers a compelling solution for mitigating environmental pollution by enabling the electrochemical reforming of CO₂ and plastic waste into valuable chemicals under cost-effective and energy-efficient conditions.