Single‐Atom Barium‐Mediated Hydrogen‐Bonding Interaction via Mortise‐and‐Tenon Interlock for Rechargeable Biomass Electrooxidation in Pure Water

-O to undergo deprotonation into FDCA (∼100% conversion and selectivity) in pure water without electricity (discharging). Hydrogen-bonding interaction between surficial sulfate and hydroxide of HMF can accelerate the substrate migration toward solid-liquid interface with enhanced conversion. Theoretical calculations expound that hydrogen-bonding interaction decreases the hybridization degree between O-2p and H-1s orbitals in O─H bond of HMF to heighten its H removability, thereby fostering complete HMF oxidation into FDCA. Various biomass derivatives are also amenable to this decoupling system, affording >96.3% yields for acids. Techno-economic analysis illustrates that replacing strong alkali with pure water can reduce the production cost of FDCA by 50.5%, underlining the wide prospect of this decoupling strategy and endowing an attractive route for biomass valorization.