Energy-efficient electrocatalytic upcycling of post-consumer PET plastics into valuable chemicals and hydrogen over MOF-derived NiCo hydroxide nanosheets

Jiang, M, Yang, Y, Wang, Y, Wang, Y, Ratova, M, Dai, W ORCID: https://orcid.org/0000-0002-9038-7207 and Wu, D ORCID: https://orcid.org/0000-0001-5272-6581 (2025) Energy-efficient electrocatalytic upcycling of post-consumer PET plastics into valuable chemicals and hydrogen over MOF-derived NiCo hydroxide nanosheets. Chemical Engineering Science, 317. 122101. ISSN 0009-2509

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Abstract

The rising accumulation of plastic waste, particularly polyethylene terephthalate (PET), poses a critical environmental threat, necessitating urgent and innovative recycling solutions. Current approaches to plastic upcycling lack efficiency, cost-effectiveness, and versatility, hindering the conversion of waste into high-value, easily separable chemicals. A transformative strategy is required to address these challenges and promote sustainable resource management. In this study, a MOF-derived NiCo hydroxide nanosheets electrode is designed for the electrocatalytic upcycling of waste PET plastics, while simultaneously producing energy-efficient H<inf>2</inf>. The synergistic interaction between Ni and Co in NiCo-OH dramatically enhances the adsorption of ethylene glycol (EG) and boosts electronic transfer capability, resulting in an impressive Faradaic efficiency of 96.5 % for formic acid production at 1.3 V vs. RHE. Comprehensive electrochemical measurements and real-time product analysis identify the Co³⁺/Co⁴⁺ species, generated during oxidation process, as the primary active sites for the selective cleavage of EG at C-C bonds. Notably, this electrocatalytic process efficiently valorizes real-life post-consumer PET bottles, yielding 12.74 g of potassium diformate and 3.28 g of terephthalic acid while co-producing 1.4 L of H<inf>2</inf>. This work introduces an efficient strategy for developing advanced catalysts for PET electro-upcycling while providing key insights into sustainable carbon cycle management.