Abstract
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 CO(2) 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 CO(2) reducing cathode, a maximum combined FE of 156% was achieved for formate (anode) and syngas (cathode) at a cell voltage (E(cell)) of 1.6 V. Upon integration of the EGOR electrode in a CO(2)-fed flow cell, the coupled system required an E(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 CO(2) and plastic waste into valuable chemicals under cost-effective and energy-efficient conditions.