The hydrogenation of 5-hydroxymethylfurfural (HMF) to 2,5-dimethylfuran (DMF) with sol–gel Ru-Co/SiO2 catalyst

Abstract

Sol–gel Ru/SiO2, Co/SiO2, and Ru-Co/SiO2 catalysts were prepared for 5-hydroxymethylfurfural (HMF) hydrogenation to 2,5-dimethylfuran (DMF). Catalysts were characterized by BET, XRD, TPR, TEM, and XPS. Reactions were run with catalysts that were reduced at 500 °C for 1 h. Reaction time, temperature and hydrogen pressure effects were studied for hydrogenation. In the presence of both Ru and Co, the easier reduction was observed at Ru-Co/SiO2 catalyst. Although no DMF yield was observed with Ru/SiO2 and Co/SiO2, 96% DMF was obtained at 180 °C, under 15 bar H2 pressure for 2 h. Moreover >99.9% DMF yield was achieved with Ru-Co/SiO2 at 120 °C for 8 h and at 140 °C for 4 h, respectively. DMF yield did not change significantly after third use, however deactivation was observed after fifth use of catalyst. It may be attributed to oxidation of cobalt active sites during recycle runs.