Liquid phase hydrogenation of methyl levulinate over the mixture of supported ruthenium catalyst and zeolite in water

Liquid-phase hydrogenation of methyl levulinate was studied over graphite-supported ruthenium (Ru/graphite), zeolite-supported ruthenium, and a mixture of Ru/graphite and zeolites in water at 343 K. The final gamma-valerolactone yield over the mixture of Ru/graphite and ZSM-5 showed the highest activities between Ru/graphite, Ru/ZSM-5, and the mixture of Ru/graphite and several zeolites. Methyl levulinate was hydrogenated to methyl 4-hydroxyvalerate or directly to gamma-valerolactone over supported ruthenium metal sites and methyl 4-hydroxyvalerate was converted to gamma-valerolactone over acid sites. The mixture of Ru/graphite and ZSM-5 contained both highly dispersed ruthenium metal particles and a number of acid sites rather than those over zeolite-supported ruthenium catalysts, which led to the highest gamma-valerolactone yield. (C) 2013 Elsevier B.V. All rights reserved.