A Nanocatalyst‐Based Approach to Sustainable HMF Oxidation

In the urgent shift toward fossil‐free chemistry, 5‐hydroxymethylfurfural (HMF) stands out as a pivotal bio‐based platform molecule for producing high‐value furanic derivatives, including 2,5‐furandicarboxylic acid (FDCA), a key precursor for next‐generation bio‐plastics like polyethylene furanoate (PEF). However, conventional FDCA synthesis often relies on harsh conditions (high pressure, toxic oxidants, or complex catalytic systems), limiting scalability and/or sustainability. In this study, we demonstrated that colloidal Pd nanoparticles enable efficient HMF oxidation under mild conditions (atmospheric air, 80°C), achieving full HMF conversion with 80% FDCA selectivity, a competitive performance under milder conditions. Through detailed mechanistic investigations, we elucidated the catalytic cycle of Pd nanoparticles while demonstrating the critical role of the soluble base, which generates hydroxyl groups with water to drive the reaction. Our findings conclusively established that the base must be introduced stoichiometrically to achieve optimal performance. Colloidal Pd system overcomes the limitations of traditional heterogeneous catalysts by eliminating support interference, providing clear mechanistic insights. Its scalable and tunable nature allows for future immobilization to enhance recyclability and ensures a controlled oxidation reaction. These advantages, mild conditions, mechanistic insights, and tunability, position our system as a promising, sustainable alternative for FDCA production, paving the way for industrial high‐value‐added biobased chemicals production.