SiO2 promoted Pt/WO_x/ZrO2 catalysts for the selective hydrogenolysis of glycerol to 1,3-propanediol

摘要

To improve 1,3-propanediol selectivity, a series of SiO2 modified Pt/WO_x/ZrO2 catalysts with various SiO2 content for glycerol hydrogenolysis were prepared via deposition-precipitation method followed by sequential impregnation. These catalysts were systematically characterized using BET, ICP, CO chemisorp-tion, XRD, H2-TPR, NH3-TPD, Raman, IR, TEM and XPS. The incorporation of suitable SiO2 into Pt/WO_x/ZrO2 catalysts had extremely favorable effects on the dispersion of WO_x and transformation from crystalline WO3 to active polytungstate, while superfluous SiO2 converted polytungstate to monotungstate. Among them, the 5PtW/ZrSi catalyst reached superior activity and maximum 1,3-propanediol selectivity, up to 52.0%. The structure-activity correlation indicated that glycerol hydrogenolysis conformed to dehydration-hydrogenation reaction mechanism and found that Pt and polytungstate were the most active species.