A Low-Cost and Easily Prepared Manganese Carbonate as an Efficient Catalyst for Aerobic Oxidation of 5-Hydroxymethylfurfural to 2,5-Diformylfuran

A low-cost and easily prepared manganese carbonate (MnCO3) has been synthesized for catalytic conversion of 5-hydroxymethylfurfural (5-HMF) to 2,5-diformylfuran (DFF). The properties and morphology of the manganese carbonate were measured by SEM, XRD, TGA, BET and XPS. In this method, no harsh reaction conditions were required, and it was a simple and green process for the oxidation of 5-HMF into DFF. To achieve an optimum DFF yield, different reaction conditions, including reaction temperature, reaction time, catalyst amount, and solvents were investigated. Results from the experiments indicated that the highest DFF yield of 86.9% was obtained at 120 °C under atmospheric oxygen pressure after 6 h. Finally, MnCO3 could be used at least five times with considerable stability.