Hydrogenolysis of glycerol to propanediols over nano-Ru/C catalyst with ionic liquid addition

Abstract

Supported ruthenium catalyst on nano-activated carbon (2% Ru/C) and titania (2%Ru/TiO2) were prepared by wet impregnation technique with addition of ionic liquid and without ionic liquid (1-decyl-3-methylimidazolium and choline chloride with different Lewis acid). Mole ratio of choline chloride and Lewis acid were fixed at 1:3. Catalysts evaluation was performed by glycerol hydrogenolysis reaction at 100ºC with initial hydrogen pressure 20 bars for 7 hours reaction. The result showed that supported ruthenium catalyst on activated carbon acetylene black with addition of choline chloride/zinc (II) chloride indicated 30.7% of glycerol converted to 20.6% propylene glycol and 11.4% ethylene glycol. Catalysts profile of XRD showed graphitic phase which can reduce catalyst poisoning effect. XPS analysis showed that Ru/CC-ZnCl2/C catalyst spesies was in Ru4+ state before reaction Meanwhile, mapping analysis using FE-SEM showed well dispersion of ruthenium metal on nano-activated carbon acetylene black with addition of choline chloride/zinc (II) chloride gave the highest selectivity to propanediol. Furthermore, smaller size of nano activated carbon (30-60nm) than titania (90-120nm) analyzed by TEM may the main course in increased the conversion of glycerol.