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

Abstract

The paper reports on the concurrent electrochemical generation of formate through CO2 reduction (cathode) and polyethylene terephthalate (PET) hydrolysate oxidation (anode).

Sustainable Formate Synthesis: Integrating Ethylene Glycol Oxidation with Carbon Dioxide Electrocatalysis Using Redox-Stabilized Earth-Abundant Electrodes

“…33 Likewise, Kilaparthi et al also reported a 200 mV lower anodic potential for PET-hydrolysate-derived EGO compared to OER at 20 mA/cm 2 by employing CuCoO@rGO as an anode. 49 1 H NMR analysis (Figure S18a) of the PET hydrolysate before electrolysis indicates the complete alkaline hydrolysis of PET to its monomers, namely EG and terephthalic acid (TPA). Controlled potential electrolysis of the PET hydrolysate shows a decrease in the current density expected from EG consumption (Figure S18b).…”

Upcycling of Plastic Waste Using Photo-, Electro-, and Photoelectrocatalytic Approaches: A Way toward Circular Economy

“…Further, the oxidation products were analyzed using 1 H and 13 C NMR, and it was found that the highest FE of 85.7% was obtained at a potential of 1.5 V at the anode whereas 97.4% at the cathode. 329 Further, two-electrode electrolyzer (CuCoO@r-GO∥BOC@rGO) was utilized for the coproduction of formic acid by the CO 2 RR and EG oxidation. Also, a very low potential of 1.9 V was required to achieve a current density of 10 mA cm −2 .…”

“…Meanwhile, FE greater than 130% was obtained over a potential ranging from 1.7 to 2.1 V. As a result, this integrated strategy not only provides an effective solution for valuing PET plastic trash but also it may open the way for the cost-effective and long-term manufacturing of value-added commodity chemicals from plastic waste while also reducing CO 2 emissions. 329 Due to its harmful impact on the ecosystem and ecology, microplastic contamination has become a critical environmental issue of global concern. It is extremely difficult to suggest a more economical strategy to achieve highly selective conversion of microplastic into add-value products due to their characteristics of complicated composition.…”

“…308 An excellent strategy to increase the selectivity, FE, conversion, and profit of this process is to substitute H 2 evolution cathodic reaction to another reaction like CO 2 reduction to yield the same product HCOOH in both electrodes. 329,373 This strategy eliminates the complexities in this system and the TEA of this system shows an increase in the overall profit from USD 355 per ton to USD 550 per ton PET upcycled. 308 In conclusion, the conversion of EG to formic acid or formate can be made economically viable and profitable with high operating current density or by replacing the H 2 evolution reaction with reactions like CO 2 reduction to achieve the same product at both the electrodes.…”

“…At this potential, a faradic efficiency of 151.8% was achieved for formate production. Meanwhile, FE greater than 130% was obtained over a potential ranging from 1.7 to 2.1 V. As a result, this integrated strategy not only provides an effective solution for valuing PET plastic trash but also it may open the way for the cost-effective and long-term manufacturing of value-added commodity chemicals from plastic waste while also reducing CO 2 emissions …”