Selective hydrogenation of HMF to 1-hydroxy-2,5-hexanedione by biochar supported Ru catalysts

The development of sustainable and efficient catalysts namely Ru supported activated biochars was carried out for the selective hydrogenation of 5-hydroxymethylfurfural (HMF) to 1-hydroxy-2,5-hexanedione (HHD). In particular, the activated biochars (ALw and AHSw) obtained from pyrolysis and steam-based physical activation of two different biomasses from animal (leather tannery waste) and vegetal (hazelnut shells) origins showed completely different chemical, textural and morphological properties. Compared to ALw, after impregnation of 0.5 wt.% Ru, AHSw with inner micro-meso channels and cavities and higher layer stacking disorder led to a better tapping and anchorage of Ru nano particles on the catalyst and a suitable Ru single crystal dispersion. This led to a high activity of Ru/AHSw catalyst in the proposed reaction giving more than 80% selectivity to HHD and full HMF conversion at reaction conditions of 100 °C, 30 bar H2 and 3 h. Ru/AHSw also gave a promising performance compared to commercial Ru/C catalyst.