Hydrogenolysis of glycerol to monoalcohols over supported Mo and W Catalysts

MoO3 and WO3 were supported on γ-Al2O3 and SiO2 with nominal loadings of 10 wt % via wet impregnation. The catalysts were characterized using XRD, TPR, Pulse TPD, Raman, TEM, and BET surface area. The alumina supported catalysts were found to contain higher Brønsted acidity compared to those supported on silica. These catalysts were evaluated in the hydrogenolysis of glycerol in a continuous flow fixed bed reactor in a temperature range of 250–325 °C and a H2 pressure of 60 bar. All catalysts were active, with activity increasing with temperature as well as Brønsted acidity. The selectivity to ethylene glycol and 1,2-propanediol decreased with increase in temperature. In parallel, the selectivity to lower alcohols such as methanol, ethanol, 2-propanol, and 1-propanol increased with temperature as the ethylene glycol and 1,2-propanediol reacted further to these products due to C–C bond cleavage. The total selectivity to lower alcohols was 34.6, 64.8, 70.6, and 54.6% over Mo/Al2O3, Mo/SiO2, W/Al2O3, and W/SiO2 respectively. The total selectivity to lower alcohols increased to 73.6, 72.8, 85.3, and 66.1% over Mo/Al2O3, Mo/SiO2, W/Al2O3, and W/SiO2 respectively when the H2:glycerol ratio was doubled