Mesoporous Ru/Sn-SBA-15 catalysts: synthesis, characterization and catalytic activity towards hydrogenation of levulinic acid

Among the various biomass-derived platform chemicals, levulinic acid (LA) has been identified as one of the top-10 important molecules by Department of Energy, United States of America because value-added chemicals such as gamma-Valerolactone (GVL), derivatives of valeric acid (VA) can directly be obtained from it. The bare SBA-15 and Sn-SBA-15 mesoporous catalysts with different Si/Sn (25 and 50) molar ratios were prepared by hydrothermal in-situ method and different amounts of Ru loaded samples (x% Ru/Sn-SBA-15 with Si/Sn = 25 where x =1, 3, 5 and 7% of Ru) were prepared by impregnation method. The structure, phase composition, morphology and surface elemental analysis of as-prepared catalysts were analyzed by various instrumental techniques. The synthesized Ru/Sn-SBA-15 catalysts were subjected to hydrogenation of LA into GVL. Among the different catalysts synthesized, 5% Ru/Sn-SBA-15 catalyst was identified as the most efficient catalyst (99% LA conversion and 98% selectivity towards GVL). The outstanding catalytic performance of the catalyst is attributed to the mesoporous structure, the acidic properties of the support and the interactive effect between Ru and Sn. The recyclability test revealed that the 5% Ru/Sn-SBA-15 catalyst exhibit good stability and reusability.