Aqueous-phase Hydrogenation of Levulinic Acid over Carbon Layer Protected Silica-supported Cobalt-Ruthenium Catalysts

Abstract The hydrogenation of levulinic acid (LA) to γ-valerolactone (GVL) by using water as solvent is a crucial process in the production of fine chemicals from biomass. An ultrathin carbon layer coating CoRu bimetallic catalyst supported on silica (CoRu@C/SiO2) is prepared by using tannis-ligated cobalt-ruthenium complex on silica as precursors, and applied for catalyzed synthesis of GVL from LA. Because of the synergistic effect between cobalt and ruthenium, the addition of small amounts of Ru to Co catalysts can increase the catalytic activity in the aqueous hydrogenation of LA. The ultrathin carbon layer covered on the CoRu bimetallic catalyst can greatly reduce the leaching of active metals. The CoRu@C/SiO2 catalyst achieves high stability and is reused up to 5 runs without significant loss of performance in aqueous hydrogenation of levulinic acid.