5-Hydroxymethylfurfural Oxidation to 2,5-Furandicarboxylic Acid on Noble Metal-Free Nanocrystalline Mixed Oxide Catalysts

Noble metal-free catalysts based on earth-abundant and inexpensive mixed oxides are active of all steps the reaction cascade leading from 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA) using tert-butyl hydroperoxide (TBHP) as oxidation agent. Catalysts covering whole range composition in Cu-Mn Co-Fe series have been prepared characterised. The nature catalyst strongly affect conversion selectivity. distribution products indicates that radical-type oxygen species, deriving activation TBHP, play a determining role reaction. early mainly follow pattern expected for heterogeneous Fenton catalysts. Mixed oxide most effective further steps, formation FDCA, both systems. This behaviour can be related charge oxides, suggesting possible implication lattice last steps. results provide indications how optimize minimize byproducts (humins oligomers).