Hydrogenolysis of glycerol over homogenously dispersed copper on solid base catalysts

摘要

Homogenously dispersed copper on layered solid base (Cuo.4/Mg_(5.6)Al2O_(8.6)-CP, with 80.1% dispersion of copper) was synthesized via thermal decomposition of the as-synthesized Cu_(0.4)Mg_(5.6)Al2(OH)_(16)CO3 layered double hydroxides. This bi-functional highly dispersed Cu-solid base catalyst is extremely effective for hydrogenolysis of aqueous glycerol. The detected conversion of glycerol reached 80.0% with a 98.2% selectivity of 1,2-propanediol at 180°C, 3.0 MPa H2 and 20 h. But copper dispersed poorly in those catalysts prepared via impregnation and ion-exchange, and their activities were lower. These precursors and catalysts were characterized by N2-adsorption, X-ray diffraction, scanning electronic microscope, transmission electronic microscope, thermo-gravimetry, temperature-programmed reduction with H2, in-situ XRD, dissociative N2O adsorption and CO2 temperature-programmed desorption. It was confirmed that the as-synthesized Cu_(0.4)Mg_(5.6)Al2(OH)_(16)CO3 showed a well crystallized layer-structure of hydrotalcite and copper dispersed homogenously on the layer-structure of hydrotalcite after thermal decomposition and H2 reduction.