Efficient oxidation of biomass derived 5-hydroxymethylfurfural into 2,5-furandicarboxylic acid catalyzed by Merrifield resin supported cobalt porphyrin

In this study, a new method was developed for the oxidation of 5-hydroxymethylfurfural (HMF) into 2,5-furandicarboxylic acid (FDCA) over Merrifield resin supported Co(II)–meso-tetra(4-pyridyl)-porphyrin (abbreviated as Merrifield resin-Co-Py). Diffuse reflectance spectra showed that Co(II)–meso-tetra(4-pyridyl)-porphyrin was successfully bonded on the Merrifield resin. The Merrifield resin-Co-Py catalyst was used for the oxidation of HMF into FDCA, and several parameters were studied. Tert-butyl hydroperoxide was the best oxidant among other common oxidants. The reaction solvent greatly affected both HMF conversion and product selectivity. High HMF conversion of 95.6% and FDCA yield of 90.4% were obtained at 100   °C after 24   h. Time course of HMF conversion over Merrifield resin-Co-Py showed that 2,5-diformylfuran was the intermediate for the conversion of HMF into FDCA. The catalyst could be reused without the significant loss of its catalytic activity.