Selective oxidation of 5-hydroxymethylfurfural over MnOx-CeO2 catalyst prepared with co-precipitation method

[Display omitted] •MnOx-CeO2 with uniform particle sizes prepared via homogeneous coprecipitation.•HMF conversion (98.8%) and FDCA yield (74.4%) was obtained at 115 ℃ weak base.•Reaction rate results confirmed high selectivity of FDCA from HMF oxidation.•The synergy mechanism of MnOx-CeO2 composite oxide catalysts was clearly revealed. The monomer 2,5-furan dicarboxylic acid (FDCA) derived by oxidation of 5-hydroxymethylfurfural (HMF) is expected to be a key platform chemical for producing bio-based polyesters. In this work, MnOx-CeO2 composite oxides were synthesized with homogeneous coprecipitation, coprecipitation, and mechanochemical methods for the purpose of developing sustainable oxidation catalysts for HMF. The influence of Mn/Ce ratios, temperature, reaction time, O2 pressure and catalyst loading showed that MnOx was the main active ingredient while the addition of CeO2 enhanced formation of high-valence Mn4+ and caused strong electronic interactions between Mn and Ce that facilitated migration of reactive oxygen species. Homogeneous coprecipitation gave materials with uniform particle sizes which lowered the catalyst activation temperature and improved catalyst redox capacity. Mn/Ce-H'6 could achieve 98.8 % HMF conversion and 74.4 % FDCA yield at 115 °C. A reaction model was developed for production of FDCA from HMF showed that the activation energy of 5-formyl-2-furancarboxylic acid (FFCA) ring-opening to form FDCA was lower than that of byproduct formation (75.3 to 82.6) kJ/mol.