Selective Hydrogenolysis of Glycerol to 1,2-Propanediol over Highly Active and Stable Cu/MgO Catalyst in the Vapor Phase

Highly active, selective, and stable Cu/MgO catalyst was developed for hydrogenolysis of glycerol to 1,2-propanediol (1,2-PDO) in vapor phase. The effect of metal loading, temperature, pressure and weight hourly space velocity (WHSV) on glycerol conversion and 1,2-PDO yield was investigated in a down flow fixed bed tubular reactor. Catalytic results demonstrated that Cu/MgO catalyst promoted the selective hydrogebolysis of C-O bond and limited the cleavage of C-C bond which significantly reduced the selectivity of undesirable products. Very high yield (95.5%) of 1,2-PDO was obtained with 100% conversion of glycerol over 10 wt % Cu/MgO catalyst at very low WHSV of 1.2 h(-1), 220 degrees C, and 0.75 MPa pressure. The superior performance of 10 wt % Cu/MgO catalyst was attributed to the presence of bifunctional acidic-basic sites, small particle size, and synergetic interaction between copper nanoparticles and MgO support. Time-on-stream study and the characterization results of fresh and used catalyst confirmed the stability of the catalyst after prolonged contact under hydrogen environment, and the carbon deposition rate was almost negligible (similar to 0.6 mmol carbon g cat(-1) h(-1)).