Tuning *OH adsorption strength via alloy structural engineering for electrochemical ethylene glycol synthesis

The industrial synthesis of ethylene glycol (EG) via ethylene oxide hydration is energy-intensive and environmentally harmful due to high greenhouse gas emissions. Although electrochemical oxidation presents a more sustainable route for the direct synthesis of EG from ethylene, existing technologies are hampered by limited catalytic performance stemming from inadequate regulation of the key intermediate, adsorbed hydroxyl radicals (*OH). Herein, we employ a structural engineering strategy to fabricate a PdPtRh trimetallic alloy catalyst by introducing highly electronegative platinum (Pt) and rhodium (Rh) into a palladium (Pd) matrix. By precisely tuning the catalyst’s electronic structure, we effectively optimize the adsorption strength of *OH. Benefiting from this alloying effect, the developed PdPtRh catalyst demonstrates exceptional performance in the ethylene-to-EG conversion, achieving a peak Faradaic efficiency of 52 % and a production rate of 7.61 μmol/cm 2 /h-markedly superior to conventional monometallic Pd catalysts. Density Functional Theory (DFT) calculations further reveal that the alloy structure facilitates charge redistribution among the metals, effectively lowering key energy barriers in the reaction process. This work not only offers a novel design paradigm for developing efficient, eco-friendly catalysts for EG electrosynthesis but also highlights the immense potential of harnessing multimetallic synergistic effects to optimize performance in the field of electrocatalysis.