Selective aerobic oxidation of 5-hydroxymethylfurfural to 2,5-dimethylfuran over heteroatom-doped ordered carbon supported Ru catalysts

Heteroatom (N, B or P)-doped ordered mesoporous carbons (OMCs) supported Ru catalysts was utilized in the aerobic oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-diformylfuran (DFF). The characterization data showed that the heteroatom-doping of OMC promoted the dispersion of Ru nanoparticles on catalysts, which further improved their catalytic activities for the selective aerobic oxidation of HMF into DFF. Among the three kinds of heteroatom-doped Ru catalysts, the P-doped one displayed the best activity for the selective aerobic oxidation of HMF into DFF. From Ru/OMC-P0.56, 100% of HMF conversion, 88% of DFF yield with a high activity of 68.7 h−1 were achieved at 90 °C for 4 h under 2 MPa O2 in toluene. Partial inactivation of catalyst was observed in the recycling runs, which might be attributed to the deposition of humins on catalyst and the agglomeration of Ru particles.