Selective oxidation of biomass‐based 5‐hydroxymethylfurfural to 2,5‐diformylfuran catalyzed by multicomponent molybdenum‐based catalyst

BACKGROUND On the way to convert biomass-derived products as a renewable and environment-friendly source to high-value added chemicals, one great challenge is the effective control of selectivity in the reaction. Here, we contribute a heterogeneous catalysis method for selective transformation of biomass-based 5-hydroxymethylfurfural (HMF) into 2,5-diformylfuran (DFF) via multicomponent bismuth molybdate catalyst. The influence of the different pH value on the catalytic activity of the catalyst were investigated. In addition, to evaluate the catalytic performance of the catalyst in the selective oxidation of HMF, a variety of important reaction parameters such as the reaction temperature, catalyst amount, atmosphere, and solvent were examined. RESULTS The catalyst prepared with pH value in the range of 1-2 exhibits the optimal catalytic activity in the selective aerobic oxidation of the hydroxy group of HMF. As a result, the target compound of DFF could be obtained with excellent yield (99%) and high selectivity (> 99%) in the presence of 0.25 mg Co9Fe3BiMo12O51 (pH = 1-2) in DMSO at 130 degrees C under O-2 atmosphere. In addition, the catalyst Co9Fe3BiMo12O51 could be reused several times without a significant loss of its catalytic activity. CONCLUSION In this work, a heterogeneous catalytic approach to oxidizing HMF to DFF using Co9Fe3BiMo12O51 as catalyst and molecular oxygen as oxidant was established. The O-2 temperature-programmed desorption (O-2-TPD) characterization indicated that the pH value of co-precipitation obviously affected the oxygen mobility and storage capacities in the catalysts, which is related to the catalytic performance in the selective aerobic oxidation. (c) 2022 Society of Chemical Industry (SCI).