(385ad) Electrochemically Enhanced Hydrolysis and Upcycling of Polyethylene Terephthalate (PET)

The broad commercial use of polyethylene terephthalate (PET) is due to its attractive physical and chemical properties, including high transparency, crystallization rate, high thermal stability, and high mechanical properties, leading to a massive annual production of 70 million tons—making up 10% of all plastics [1]. However, these robust physicochemical properties of PET contribute to slow degradation in nature and the formation of environmentally damaging microplastics, which pose risks to the environment and human health. Therefore, emphasizing the necessity for its recycling. Besides mechanical recycling methods, extensive study has been conducted on chemical hydrolysis in breaking down PET into its monomers (ethylene glycol and terephthalic acid). Recently, electrochemical methods have gained attention as a promising alternative to convert PET hydrolysate (ethylene glycol) into valuable chemicals [2].

Botte's group is investigating electrochemical approaches to convert polyethylene terephthalate into valuable chemicals such as formic acid, formate etc. This novel approach integrates the hydrolysis of PET with the concurrent electrochemical oxidation of ethylene glycol. Our studies indicate that the electrochemical approach enhanced PET hydrolysis in comparison to traditional chemical hydrolysis [3] along with the oxidation of ethylene glycol into formic acid/formate in a single process, eliminating the need for separate hydrolysis. In this presentation, we will cover the outcomes of enhancing the hydrolysis of PET through electrochemical means, employing transition metals as catalysts, and using a low potential under mild temperature conditions. Optimization of this process could be a sustainable approach for upcycling of PET into valuable products.

1.Liu, K., et al., Selective electrocatalytic reforming of PET-derived ethylene glycol to formate with a Faraday efficiency of 93.2% at industrial-level current densities. Chemical Engineering Journal, 2023. 473: p. 145292.

2.Li, Y., et al., Alcohol–alkali hydrolysis for high-throughput PET waste electroreforming-assisted green hydrogen generation. Journal of Materials Chemistry A, 2024. 12(4): p. 2121-2128.

3.Lu, F. and G.G. Botte, Understanding the Electrochemically Induced Conversion of Urea to Ammonia Using Nickel Based Catalysts. Electrochimica Acta, 2017. 246: p. 564-571.