NiMo Dual-Atom Dimers on Pd Nanosheets for Selective C─H and C─C Bond Cleavage of Ethylene Glycol From Waste Plastics

Herein, we report the CO gas-mediated synthesis of palladium nanosheets (PdNS) as the first palladene support for atomically dispersed dimer catalysts. We further present the first report of NiMo dual-atom dimer immobilization on PdNS (NiMo-DA/PdNS) using rapid CO₂ laser irradiation within 10 min. The NiMo-DA/PdNS platform exhibits enhanced ethylene glycol (EG) oxidation reaction (EGOR) activity with potential-dependent product selectivity. At 1.0 V vs. RHE, glycolate (C2 product from selective C─H bond cleavage) was obtained with a Faradaic efficiency (FE) of 81% and a yield rate (YR) of 1.14 mmol h^-1 cm^-2. At 1.6 V vs. RHE, formate (C1 product from C─C bond cleavage) was selectively produced with an FE of 77.9% and a YR of 0.39 mmol h^-1 cm^-2. Theoretical calculations further corroborate these performance trends and elucidate the mechanism that C─C bond scission is facilitated by electron transfer to the catalyst surface at higher potentials, lowering the reaction free energy and enhancing C1 formation. This study demonstrates concurrent high selectivity toward both glycolate and formate while efficiently recovering high-purity terephthalic acid (TPA) monomers from polyethylene terephthalate (PET) hydrolysate electrolysis over 50 h, highlighting the practical potential of atomically engineered catalysts with real-world PET upcycling.