Facile production of 2,5-diformylfuran from base-free oxidation of 5-hydroxymethyl furfural over manganese–cobalt spinels supported ruthenium nanoparticles

This work reports manganese–cobalt spinels (MnCo2O4) supported ruthenium (Ru) nanoparticles, Ru/MnCo2O4, efficiently catalyzed 5-hydroxymethyl furfural (HMF) oxidation to 2,5-diformylfuran (DFF) with high yield 98.3% at 130 °C and 1.0 MPa of O2 pressure in toluene used as solvent under base-free conditions. A new class of spinels MnCo2O4 having multiple valence states of Mn and Co was synthesized by using simple co-precipitation method and used as support with ruthenium nanoparticles as heterogeneous catalyst. The reusability tests of catalyst Ru/MnCo2O4 were also carried out and was found to be recyclable up to several consecutive cycles without significance loss of original activity.