Promoted *OH Adsorption Facilitates C–C Bond\nCleavage for Efficient Electrochemical Upcycling of Polyethylene Terephthalate

The\nelectrochemical oxidation of ethylene glycol (EG) derived from\npolyethylene terephthalate (PET) plastic into value-added chemicals,\ncoupled with hydrogen evolution, offers a promising approach to addressing\nplastic pollution. However, the mechanisms by which the adsorption\nof key reaction intermediates affects the EG oxidation reaction (EGOR)\nare not well understood. To investigate this, we synthesized two model\ncatalysts: amorphous-phase CoNiOOH/NF and CoNiOOH–Ni<sub>3</sub>S<sub>2</sub>/NF with an amorphous/crystalline interface. Detailed\ncharacterizations and theoretical calculations demonstrate that the\namorphous/crystalline interface in CoNiOOH–Ni<sub>3</sub>S<sub>2</sub>/NF shifts the d-band center upward, enhancing the adsorption\nof EG and *OH compared to amorphous CoNiOOH/NF. Enhanced *OH adsorption\nis crucial for promoting C–C bond cleavage and subsequent dehydrogenation.\nIn situ electrochemical infrared absorption spectroscopy (IRAS) and\ntheoretical calculations reveal that formate (FA) is primarily formed\nthrough cleavage of the C–C bond in glycolic acid, followed\nby oxidation. Notably, CoNiOOH–Ni<sub>3</sub>S<sub>2</sub>/NF\nachieves industrial-level current densities of 500 mA cm<sup>–2</sup> at an ultralow potential of 1.45 V vs RHE, with a Faradaic efficiency\n(FE) of 96.6% and FA productivity of 3.14 mmol cm<sup>–2</sup> h<sup>–1</sup> at 1.70 V vs RHE. This study offers valuable\ninsights for designing efficient heterojunction catalysts for the\nelectrochemical upcycling of PET plastics.