CoO_x‑MC (MC = Mesoporous Carbon) for Highly Efficient Oxidation of 5‑Hydroxymethylfurfural (5-HMF) to 2,5-Furandicarboxylic Acid (FDCA)

CoO_x-MC (MC = mesoporous carbon), with CoO_x nanoparticles of ca. 25 nm well distributed on mesoporous carbon, was synthesized by calcination of a Co/polymer framework precursor prepared via ion exchange between Co²⁺ in [Co­(NH₃)₆]²⁺ and H⁺ in the polymeric gel. The as-synthesized CoO_x-MC exhibited superior performance for the selective oxidation of 5-hydroxymethylfurfural (5-HMF) to produce 2,5-furandicarboxylic acid (FDCA) in water using O₂ as the oxidant at 80 °C, with 98.3% of 5-HMF converted in 30 h and a yield of 95.3% to desirable FDCA. The turnover frequency (TOF) for the formation of FDCA over CoO_x-MC was determined to be 2.22 h^–1, a performance superior to those non-noble metal catalysts ever reported for the selective oxidation of 5-HMF to produce FDCA. This study not only provides an efficient, cost-saving, and environmentally friendly catalytic system for the production of FDCA from 5-HMF but also highlights the great potential of mesoporous carbon as the support in fabricating highly active catalytic systems.