EMSI and Alloying Synergistically Enable Selective Electrooxidation of PET-Derived Ethylene Glycol to Glycolic Acid on PtAu-Ni(OH)2.

The electrocatalytic oxidation of ethylene glycol (EGOR) offers a promising route for upgrading polyethylene terephthalate (PET)-derived feedstocks into value-added chemicals. However, its practical implementation is hindered by sluggish hydroxyl activation and suboptimal adsorption configurations of key intermediates, leading to limited activity and C2 selectivity. Herein, a PtAu-Ni(OH)2 catalyst is constructed via a one-step hydrothermal strategy, in which PtAu alloy nanoparticles are uniformly anchored on Ni(OH)2 nanosheets. The prepared PtAu-Ni(OH)2 catalyst delivers current densities of 100 and 600 mA cm-2 at low potentials of 0.57 and 0.78 V vs. RHE, respectively, together with a glycolic acid Faradaic efficiency of up to 98%. Notably, the catalyst maintains negligible performance decay over 10 days under practical operating conditions. Mechanistic investigations reveal that the exceptional activity and C2 selectivity arise from the synergistic effects of Pt-Au alloying and electronic metal-support interactions (EMSI) between PtAu nanoparticles and Ni(OH)2. Alloying Pt with Au optimizes the adsorption configuration of EG-derived intermediates and enhances the oxidation resistance of Pt sites. Meanwhile, EMSI between PtAu and Ni(OH)2 induces interfacial charge redistribution, facilitating hydroxyl generation and optimizing OH adsorption. These effects stabilize key oxygenated intermediates, promote carbonyl oxidation, and suppress C─C bond cleavage, thereby enhancing C2 selectivity.