Reactant‐Sustained Dynamically Stable Interfacial Hydrogen‐Bond Network for Highly Selective, Ampere‐Level Ethylene Glycol Electrooxidation

ABSTRACT The catalyst‐electrolyte interfacial microenvironment fundamentally governs the activity and selectivity of electrochemical reactions. However, engineering a dynamically stable interface capable of sustaining continuous reactant delivery and facilitating proton‐coupled electron transfer remains challenging, particularly under ampere‐level current densities. Herein, a reactant‐enhanced hydrogen‐bond network constructed on an ultrathin metal‐organic framework (MOF)‐derived electrocatalyst (Co‐PET@NF) enables highly selective ethylene glycol electrooxidation (EGOR). Mechanistic investigations reveal that abundant exposed unsaturated Co sites promote preferential EG adsorption for increased EG surface coverage and accelerated replenishment dynamics, ensuring the connectivity and integrity of the interfacial hydrogen‐bond network. This dynamically reinforced network facilitates rapid proton transfer from the catalyst surface into the bulk electrolyte, stabilizing the dehydrogenated active sites while preserving a localized alkaline surface microenvironment. Consequently, Co‑PET@NF achieves a high Faradaic efficiency for formate (FE FA ) of 92.8% at 1.0 A cm −2 . In a coupled hydrogen co‑production system, the cell voltage is reduced by 260 mV at 1.0 A cm −2 compared to water electrolysis, with stable operation over 120 h while delivering an FE FA of 96.9%. Moreover, this mechanism can be extended to other alcohol‐based substances (e.g., methanol and glycerol), elucidating the importance of reactant‐catalyst interfacial hydrogen‐bond interactions in steering alcohol oxidation selectivity and providing a sustainable strategy for biomass and plastic upgrading.