Fast Catalytic Hydrogenation of 2,5-Hydroxymethylfurfural to 2,5-Dimethylfuran with Ruthenium on Carbon Nanotubes

We have found that the utilization of carbon nanotubes as support for ruthenium nanoparticles increases hydrogenation activity over 40 times in terms of turnover frequency (TOF) when compared to activated carbon in the transformation of hydroxymethylfurfural to dimethylfuran. Catalysts based on carbon nanotubes produced 83.5% yield of dimethylfuran (TOF 819.7 h –1 ) in under 1 h at 150 °C and less than 20 bar hydrogen pressure, whereas the activated carbon catalyst required more than 3 h to give an 80% yield of dimethylfuran (TOF 36 h –1 ). The superior accessibility of pores in carbon nanotubes, plus an electronic promotional effect in the carbon nanotubes, appear to be responsible for the superior activity of the catalysts supported on carbon nanotubes. The catalysts were synthesized by impregnation and characterized by X-ray diffraction, X-ray photoelectron spectroscopy, nitrogen physisorption, temperature-programmed reduction, electron microscopy and pulse CO chemisorption to propose the structure–activity relationships. This work highlights the importance of the support in hydrogenating reactions with ruthenium and the potential applicability of carbon nanotubes as supports for the hydrogenation of other bioderivatives.