Integrated process towards sustainable renewable plastics: Production of 2,5-furandicarboxylic acid from fructose in a base-free environment

We report an integrated approach to produce 2,5-furandicarboxylic acid (FDCA) using fructose as a feedstock in a base-free environment, thus providing a promising alternative to the current protocol. FDCA, an alternative molecule to terephthalic acid (obtained from the petroleum route), is used to synthesize poly(ethylene-2,5-furanoate) (PEF), a renewable plastic. In our approach, we produced 5-hydroxymethylfurfural (HMF; 84% yield) by fructose dehydration in an acetone (Ace)/H2O solvent system. The obtained HMF feed was subsequently oxidized over Ru/MnO2, producing FDCA in 92% yield under base-free conditions. The Ru/MnO2 catalyst outperformed conventional Pt/C and Ru/C catalysts under identical reaction conditions. Our novel approach for FDCA production via an integrated process using an Ace/H2O solvent mixture under base-free conditions is economically feasible and environmentally friendly. To the best of our knowledge, this work is the first to report the production of FDCA via this route. We postulate that the high catalytic efficiency of the sulfonated porous organic polymer and Ru/MnO2 in an Ace/H2O system renders them superior to existing homogeneous catalytic routes for HMF production and conversion into FDCA via a scalable process.