# Coelectrolysis of PET and CO2 Using an Electrochemically Restructured Co-MOF-74 Anode and a Polymeric Co-Phthalocyanine Cathode

## TL;DR

This paper presents an electrochemical method to convert plastic waste and CO2 into valuable chemicals using a cobalt-based catalyst system.

## Contribution

The study introduces a novel electrocatalytic system using a restructured Co-MOF-74 anode and a polymeric co-phthalocyanine cathode for coelectrolysis.

## Key findings

- The Co-MOF-74 anode achieved near-unity faradaic efficiency for ethylene glycol oxidation to formate.
- The system achieved a combined faradaic efficiency of 156% for formate and syngas at 1.6 V cell voltage.
- The integrated system operated at 2.3 V in a CO2-fed flow cell at 75 mA cm–2.

## 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 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 (E
cell) of 1.6 V. Upon integration of the EGOR electrode in a CO2-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 CO2 and plastic waste
into valuable chemicals under cost-effective and energy-efficient
conditions.