Construction of Cu-Ru bimetallic catalyst for the selective catalytic transfer hydrogenation of carbonyl (C--O) in biomass-derived compounds

The catalytic transfer hydrogenation (CTH) of levulinate ester to gamma-valerolactone is one of the important reactions for production of renewable fuels from biomass. An efficient and robust bimetallic Cu-Ru catalyst were developed for the hydrogenation of biomass-derived ethyl levulinate to gamma-valerolactone. A series of bimetallic catalysts were prepared and characterized in detail. Subsequently, the as-prepared catalysts were evaluated in the hydrogenation system of ethyl levulinate. The results showed that Cu-Ru/ZrO2-SO3-SiO2-450 catalyst provided 100 % GVL yield in 12 h at 180 degrees C. Meanwhile, it also exhibited high catalytic hydrogenation activity for the various biomass-derived carbonyl compounds. The structure-reactivity relationship of catalysts was investigated in detail, and the results show the interaction between support and metal sites played an important role in the hydrogenation activity. The sulfur species could tune the electronic states of metallic sites to gain optimal activity. Besides, the Cu-Ru/ZrO2-SO3-SiO2-450 catalyst performed excellent recyclability in five reaction runs without an obvious loss of activity.