A highly efficient and robust Cu/SiO2 catalyst prepared by the ammonia evaporation hydrothermal method for glycerol hydrogenolysis to 1,2-propanediol†
Abstract
A highly efficient and robust Cu/SiO2 catalyst from a pure-phase copper phyllosilicate precursor was successfully fabricated by the ammonia evaporation hydrothermal (AEH) method. The impregnation (IM) Cu/SiO2 catalyst was prepared for comparison. The structure, morphologies, thermal stability and surface chemical state of these catalysts were comprehensively characterized by ICP, BET, XRD (in situ XRD), N2O chemisorption, H2-TPR, IR and Raman spectroscopy, TEM and XPS. Compared to the IM sample, the AEH catalyst was exceedingly highly active and stable (300 h) for glycerol hydrogenolysis to 1,2-propanediol. The unprecedented catalytic performance was attributed to the strong interaction between Cu and SiO2 species derived from copper phyllosilicate, well-dispersed Cu nanoparticles and the cooperative effect of Cu0 and Cu+. Moreover, active Cu0 species were identified as the primary active sites for glycerol hydrogenolysis, as corroborated by the strong correlation between 1,2-propanediol yield and Cu surface area.