Waste biomasses as precursors of catalytic supports in benzaldehyde hydrogenation

The optimization of Pd supported on activated biochars as innovative and sustainable catalysts was performed. Four different waste biomasses from vegetal (hazelnut shells (HS), broken rice grains (BR), rice husks (RH)) and animal origin (leather tannery shaving waste (LS)), were pyrolyzed and physically activated (by steam), and a commercial activated carbon was used as the reference support. 0.6 wt% Pd was impregnated onto the supports and all catalysts were characterized and tested for benzaldehyde hydrogenation. The catalytic test showed the highest activity (benzaldehyde conversion of 99%) and selectivity toward toluene (97% and 78%) for Pd/A-RH and Pd/A-HS, respectively. Characterizations of the supports and catalysts confirmed that physicochemical properties of the activated biochars, affected from the origin of initial biomasses, had fundamental influences on the final efficiency of the catalysts.