Quantitative Electrocatalytic Upcycling of Polyethylene Terephthalate Plastic and Its Oligomer with a Cobalt-Based One-Dimensional Coordination Polymer Having Open Metal Sites along with Coproduction of Hydrogen
Snehanjali Behera, Soumitra Dinda, Rajat Saha, Biswajit Mondal
Abstract
Polyethylene terephthalate (PET) is the most used polymer, but its natural degradation kinetics is sluggish; therefore, its disposal poses an environmental threat. Here, we demonstrate electrocatalytic PET upcycling with full recyclability with a cobalt containing one-dimensional (1D) coordination polymer as an electrocatalyst that can operate at a low onset potential of 1.27 V vs. RHE, affording terephthalic acid (TPA) in 100% yield and potassium diformate (KDF) with ∼80% selectivity as isolated products, along with the coproduction of hydrogen. The mechanistic analysis, as obtained from systematic studies with PET, its oligomer, and monomer revealed a pathway for a side reaction generating carbonate (CO32–) that follows a formate oxidation instead of an oxalate oxidation pathway. The catalytic performance and the mechanistic insight gained from the study, are useful in developing the PET upcycling technologies with maximized formate/KDF production.