Hydrogenolysis of biodiesel derived glycerol to 1,2-propanediol (1,2-PDO) has attracted much attention in recent years In this work, glycerol hydrogenolysis to 1,2-PDO was performed over CuO/MgO catalysts prepared by impregnation and coprecipitation at 180 degrees C and 3.0 MPa H(2) It was found that the Cu(15)/MgO catalyst prepared by coprecipitation had the best activity. The conversion of glycerol and the selectivity of 1,2-PDO over Cu(15)/MgO reached 720% and 97.6%, respectively And the conversion of glycerol was further increased to 82.0% when small amount of NaOH was added in the reaction mixture Those highly active catalysts were characterized by X-ray diffraction, transmission electron microscopy, N(2)-adsorption and temperature-programmed reduction with H(2). Characterization results revealed that the activity of the prepared catalysts depended strongly on the particle sizes of both Cu and MgO Catalysts that have smaller sized Cu and MgO particles are more active for glycerol hydrogenolysis (C) 2010 Elsevier Ltd All rights reserved.