Basic oxide-supported Ru catalysts for liquid phase glycerol hydrogenolysis in an additive-free system

• Ru/CeO2, Ru/La2O3 and Ru/MgO were efficient for the hydrogenolysis of glycerol.
• The method is convenient because no additives are required.
• The good performance of Ru/CeO2 is related to the weak surface basicity feature.
• Lactic acid is formed by a Cannizzaro reaction from pyruvaldehyde.

Several basic oxide-supported Ru catalysts (Ru/CeO2, Ru/La2O3 and Ru/MgO) were prepared and evaluated for the hydrogenolysis of glycerol. The Ru catalysts were characterized by inductively coupled plasma–atomic emission spectroscopy, nitrogen adsorption, powder X-ray diffraction, X-ray photoelectron spectroscopy, and transmission electron microscopy. Ru/CeO2 showed the best performance in the reaction, which is associated with its smaller metal particle size and the weak surface basicity feature of CeO2. 1,2-Propanediol is obtained as the main product through a dehydrogenation–dehydration–hydrogenation mechanism. The oxidation product lactic acid can be formed by a Cannizzaro reaction from the pyruvaldehyde intermediate.