Unlocking the Free Radical Evolution for Directed Conversion of Furoic Acid to 2,5‐Furandicarboxylic Acid Over Lattice‐Distorted MnO <i>x</i>

Developing the efficient C─H bond activation carboxylation processes for furoic acid (FA) represents a critical technological challenge in achieving atom-economical synthesis of 2,5-furandicarboxylic acid (FDCA). Despite notable advancements in this field, the inherent contradiction between the high reactivity of furan rings and the chemical inertness of C─H bonds poses substantial technical bottleneck for achieving controllable C─H carboxylation under mild conditions. Herein, we report a high lattice-distorted MnOx catalyst with surface trench-like structures, wherein the Mn^δ+-O_V-conjugated configurations and electron-rich Mn²⁺ cooperatively drive FA dehydrogenation and carbon radical reduction, inducing the free radical evolution process (FA→carbon-centered FA radical→FA carbanion), then coupled with solvent-polarized CO₂ to accelerate the carboxylation process. This approach achieved an FDCA selectivity of 95.82% under mild reaction conditions (≤390 K), providing novel insights into mild activation and conversion of biomass-derived inert chemical bonds.