Stable Glycerol Electrooxidation to Glycerate Over 1000 Hours on a Hydroxyl-Modulated PdNiMo Alloy

The electrochemical upgrading of glycerol into a single, valuable C₃ product remains a long-standing challenge, constrained by the limitations of insufficient activity, low selectivity, and poor stability. Here, we report a ternary PdNiMo alloy catalyst that synergistically modulates the electronic structure and optimizes the surface *OH coverage for efficient and stable glycerol-to-glycerate conversion. Combined experimental and theoretical studies reveal that Mo incorporation downshifts the d-band center and weakens *OH binding, while Ni introduction optimizes the balance between *OH-covered and free Pd sites. The resulting PdNiMo catalyst exhibits exceptional GEOR performance, achieving a high current density of 171 mA cm^-2 at 0.8 V vs. RHE and a superior glycerate selectivity of 67.5%. More impressively, in a membrane electrode assembly electrolyzer, the catalyst demonstrates outstanding durability, maintaining a current density of over 50 mA cm^-2 for more than 1000 h at a cell voltage of 1.2 V_cell. This work elucidates the critical role of tailored hydroxyl coverage in selective oxidation and provides a design principle for advanced electrocatalysts in renewable energy-powered electrosynthesis.