Direct synthesis of 2,5-furandicarboxylic acid from biomass-derived fructose using multifunctional Pd-Ru nanoparticles supported mesoporous organic polymers functionalized with sulfonic acid

The sustainable production of 2,5-furan dicarboxylic acid (FDCA) from biomass-derived fructose is crucial yet challenging for developing high-yield renewable alternatives to fossil-based polymers. Herein, a sulfonic acid-functionalized cross-linked porous organic polymer (S-CPOP) was synthesized via a facile Friedel–Crafts reaction, offering a high surface area (1050 m 2 g −1 ), mesoporosity, and abundant Brønsted acid sites (1.33 mmol g −1 ). The S-CPOP was employed both as a solid acid catalyst for fructose dehydration and as a support for monometallic (Pd and Ru) and bimetallic (Pd-Ru) nanoparticles (NPs) for subsequent oxidation processes. The Pd-Ru/S-CPOP exhibited outstanding catalytic performance in the direct, one-pot conversion of fructose to FDCA under base-free conditions, achieving a remarkably high FDCA yield of 95 % within a short reaction time. This exceptional activity is attributed to the synergistic effect between Pd and Ru NPs, the abundant sulfonic acid groups, and the mesoporous structure of the S-CPOP, which facilitates efficient mass transfer and reactant accessibility. The radical quenching, kinetic and thermodynamic experiments were also systematically evaluated, revealing key insights into the reaction mechanism. Notably, the catalyst demonstrated excellent stability and recyclability, retaining high activity over five consecutive runs without significant metal leaching or structural degradation. This work presents a cost-effective, environmentally benign, and multifunctional catalytic system for efficient FDCA production, offering a promising route for sustainable polymer precursor synthesis in bio-based industries.