Electrooxidation of Ethylene Glycol to Glycolic Acid in a Neutral Electrolyte via Enhanced *OH Generation and Directional Spillover

Electrochemical upcycling of polyethylene terephthalate (PET)-derived ethylene glycol (EG) into glycolic acid (GA) presents a sustainable route toward circular plastic economy. While recent advances have improved EG oxidation reaction (EGOR) performance in alkaline media, the downstream separation of GA remains cumbersome and inevitably coproduces waste salts. Neutral media offer a promising alternative but are constrained by the difficulty in generating and utilizing *OH, a pivotal EGOR intermediate. Although Ir has been reported to promote H₂O dissociation into active *OH species, a major challenge lies in ensuring that the generated *OH effectively participates in EGOR, rather than undergoing self-dehydrogenation (*OH → *O). To address this, we designed an atomically isolated Ir decorated Pd alloy with high-density Ir-Pd interfaces, which establishes an *OH transfer network that promotes *OH-mediated EGOR while suppressing *OH self-dehydrogenation. In situ spectroscopic characterizations reveal that Ir₁Pd-SAA facilitates the efficient dissociation of H₂O into *OH at Ir single-atom sites, followed by *OH spillover to adjacent Pd sites within an atomic scale, thus triggering EGOR. Ir₁Pd-SAA delivers a peak current of 56.2 mA cm^-2 at 0.89 V vs RHE, outperforming pure Pd (10.7 mA cm^-2 at 0.95 V vs RHE) and Ir_NPPd (7.3 mA cm^-2 0.92 V vs RHE), along with high GA selectivity (80.1%), FE (76.3%), and stability over 330 h. Theoretical calculations confirm the Ir-Pd synergistic effect, where Ir promotes *OH generation and optimizes the electronic structure of Pd to initiate EGOR. This work provides fundamental insights for rational catalyst design for alcohol-to-organic acid conversion in neutral media.