Hydrogenolysis of glycerol over Cu0.4/Zn5.6-xMgxAl2O8.6 catalysts: The role of basicity and hydrogen spillover

A series of Cu-0.4/Zn5.6-xMgxAl2O8.6 catalysts with different Zn/Mg ratios were prepared and used in hydrogenolysis of glycerol in aqueous solution. This reaction proceeded more easily and efficiently over Cu-0.4/Zn0.6Mg5.0Al2O8.6 than Cu-0.4/Mg5.6Al2O8.6 and Cu-0.4/Zn5.6Al2O8.6. The selectivity of 1,2-propanediol is higher than 98.6% in all experiments over Cu-0.4/Zn0.6Mg5.0Al2O8.6, and the activity of surface Cu atoms reached 26.6 h(-1) at 200 degrees C. The structure, morphology, acidity (basicity), and adsorption ability of glycerol/hydrogen for these catalysts were characterized and discussed. It was concluded that the conversion of glycerol depended strongly on the basicity of these Cu-based catalysts and hydrogen spillover also enhanced its performance. (C) 2012 Elsevier Inc. All rights reserved.