Selective Hydrogenation of 5‐Hydroxymethylfurfural to 1‐Hydroxy‐2,5‐hexanedione by Biochar‐Supported Ru Catalysts

The development of sustainable and efficient catalysts -namely Ru supported on activated biochars- is carried out for the selective hydrogenation of 5-hydroxymethylfurfural (HMF) to 1-hydroxy-2,5-hexanedione (HHD). Activated biochars obtained from pyrolysis and steam-based physical activation of two different biomasses from animal (leather tannery waste; A(Lw)) and vegetal (hazelnut shells; A(HSw)) origins show completely different chemical, textural, and morphological properties. Compared to A(Lw), after impregnation with 0.5 wt % Ru, A(HSw), with inner micro-mesochannels and cavities and higher layer stacking disorder, leads to better trapping and anchoring of Ru nanoparticles on the catalyst and a suitable Ru single crystal dispersion. This leads to a highly active Ru/A(HSw) catalyst in the proposed reaction, giving more than 80 % selectivity to HHD and full HMF conversion at 100 degrees C with 30 bar H-2 for 3 h. Ru/A(HSw) also shows promising performance compared to a commercial Ru/C catalyst.