Diverse promoters,including noble metals（such as Ru,Ir and Rh） and transition metal oxides（such as Re,La,Fe,Zr,Sn and Ce oxides） were introduced into Pt/WOx and Pt/WOx/Al2O3 catalysts to investigate the ability of...Diverse promoters,including noble metals（such as Ru,Ir and Rh） and transition metal oxides（such as Re,La,Fe,Zr,Sn and Ce oxides） were introduced into Pt/WOx and Pt/WOx/Al2O3 catalysts to investigate the ability of these promoters to modify activity and selectivity during glycerol hydrogenolysis to 1,3-propanediol.Among these,La exhibited the greatest promotional effect;the introduction of 0.1% La to the Pt/WOx improved activity,selectivity and stability,although the significant increase in selectivity came at the cost of a slight activity loss in the case of the Pt/WOx/Al2O3 catalyst.Transmission electron microscopy,high angle annular dark field scanning tunneling electron microscopy and NH3-temperature programmed desorption all demonstrated that the introduction of La generates a greater quantity of acidic sites on the catalyst surface,and that the majority of the La species are associated with Pt particles.Most of the other additives resulted in only minimal improvements or even detrimental effects with regard to both activity and selectivity,although some appear to improve the stability of the catalyst.展开更多
Pt/Au/WO_3 bimetallic catalysts were prepared by impregnation of Pt onto preformed Au/WO_3,obtained by a hexadecyl trmethyl ammonium bromide（CTAB）-assisted one-pot synthesis method.The resulting Pt/Au/WO_3 catalysts...Pt/Au/WO_3 bimetallic catalysts were prepared by impregnation of Pt onto preformed Au/WO_3,obtained by a hexadecyl trmethyl ammonium bromide（CTAB）-assisted one-pot synthesis method.The resulting Pt/Au/WO_3 catalysts exhibited remarkable synergistic effects for selective hydrogenolysis of glycerol to 1,3-propanediol. The characterization results showed that doping of Au promoted the reduction of both Pt and W at low temperatures and uniform dispersion of Pt on the WO_3 support. Furthermore, more low-valence Pt species were produced on the WO_3 surface after introduction of Au. These changes in electronic properties resulted in enhancement of both glycerol conversion and selectivity for 1,3-propanediol.展开更多
基金supported by the National Natural Science Foundation of China(21176235,21373206,21303187)~~
文摘Diverse promoters,including noble metals（such as Ru,Ir and Rh） and transition metal oxides（such as Re,La,Fe,Zr,Sn and Ce oxides） were introduced into Pt/WOx and Pt/WOx/Al2O3 catalysts to investigate the ability of these promoters to modify activity and selectivity during glycerol hydrogenolysis to 1,3-propanediol.Among these,La exhibited the greatest promotional effect;the introduction of 0.1% La to the Pt/WOx improved activity,selectivity and stability,although the significant increase in selectivity came at the cost of a slight activity loss in the case of the Pt/WOx/Al2O3 catalyst.Transmission electron microscopy,high angle annular dark field scanning tunneling electron microscopy and NH3-temperature programmed desorption all demonstrated that the introduction of La generates a greater quantity of acidic sites on the catalyst surface,and that the majority of the La species are associated with Pt particles.Most of the other additives resulted in only minimal improvements or even detrimental effects with regard to both activity and selectivity,although some appear to improve the stability of the catalyst.
基金supported by the National Natural Science Foundation of China(21690080,21690084,21721004,21673228)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB17020100)the National Key Projects for Fundamental Research and Development of China(2016YFA0202801)~~
文摘Pt/Au/WO_3 bimetallic catalysts were prepared by impregnation of Pt onto preformed Au/WO_3,obtained by a hexadecyl trmethyl ammonium bromide（CTAB）-assisted one-pot synthesis method.The resulting Pt/Au/WO_3 catalysts exhibited remarkable synergistic effects for selective hydrogenolysis of glycerol to 1,3-propanediol. The characterization results showed that doping of Au promoted the reduction of both Pt and W at low temperatures and uniform dispersion of Pt on the WO_3 support. Furthermore, more low-valence Pt species were produced on the WO_3 surface after introduction of Au. These changes in electronic properties resulted in enhancement of both glycerol conversion and selectivity for 1,3-propanediol.
