Supported Cu catalysts were synthesized and applied to convert glycerol, a renewable feedstock, to value-added propanediols. Among these catalysts, the gamma-Al2O3 supported Cu catalysts showed superior performance. Unlike most supported precious metal catalysts, the scission of C-C bonds was successfully suppressed on the Cu/Al2O3 catalysts without a sacrifice of glycerol conversion. The experimental results combined with the characterization studies using temperature programmed reduction (TPD) and X-ray diffraction (XRD) techniques revealed that the optimal Cu loading was 2.7 mmol of Cu metal/g of gamma-Al2O3 and that the suitable pre-reduction temperature was 300 degrees C. The Cu/Al2O3 catalyst with the optimized amount of Cu showed a selectivity to propanediols about 96.8% with a glycerol conversion about 49.6% under mild reaction conditions (220 degrees C, 1.5 MPa initial H-2 pressure, 10 h, Cu/glycerol molar ratio 3: 100). Compared with a commonly used commercial copper chromite catalyst, the Cu/Al2O3 Presented much higher activity, selectivity and Cu usage efficiency and is non-toxic. (C) 2009 Elsevier B.V. All rights reserved.