Base-free aerobic oxidation of 5-hydroxymethylfurfural to 2,5-furandicarboxylic acid over a Pt/C–O–Mg catalyst†
Base-free aerobic oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA) was realized successfully based on the design of a novel Pt/C–O–Mg catalyst. The properties of this catalyst were characterized using TEM, XRD, XPS and temperature-programmed desorption of CO2. The catalyst had excellent activity and stability, the yield of FDCA reached 97% under optimal conditions (110 °C, O2 1.0 MPa) and the catalyst was used ten times with little loss of activity. The excellent activity and stability may come from the formation of a C–O–Mg bond, which created new, strong and stable basic sites. Further scaling up the reaction by 20 times, the yield of isolated FDCA reached 74.9% with very high purity (99.5%). This FDCA would be used as a substitute of the polymerization monomer for polyethylene terephthalate plastic (PET) synthesis after purification.