Low-loaded Pd（0.05 wt.%）/Al2O3 catalysts modified by ceria were prepared by impregnation method.Gas phase hydrogenation of acrylonitrile to propionitrile was selected as probe reaction to study the effect of the lig...Low-loaded Pd（0.05 wt.%）/Al2O3 catalysts modified by ceria were prepared by impregnation method.Gas phase hydrogenation of acrylonitrile to propionitrile was selected as probe reaction to study the effect of the light rare earth element cerium on the cataltic activity and stability.Experimental results indicated that addition of a small mount of ceria improved the catalytic activity and stability greatly.The best content of ceria was 3 wt.%,and consecutive impregnation method was prior to co-impregnation method.展开更多
The catalytic activity measurement for the NO+CO reaction over CuO/CeO\-2/\%γ\%\|Al\-2O\-3 catalysts at a low\|temperature(200 ℃) shows that the activity is strongly related to ceria loading amount, and both surface...The catalytic activity measurement for the NO+CO reaction over CuO/CeO\-2/\%γ\%\|Al\-2O\-3 catalysts at a low\|temperature(200 ℃) shows that the activity is strongly related to ceria loading amount, and both surface dispersed ceria species and crystalline CeO\-2 shows a significant enhancement on the activity. The effect of ceria species is contributed to their promoting the reduction of copper oxide species.展开更多
A series of sulfided PtMo/ γ Al 2O 3 catalysts[ w (Mo)=9.0%] with different contents of Pt were characterized by using low temperature FTIR spectroscopy of adsorbed CO, while their HDS activity was investigated with ...A series of sulfided PtMo/ γ Al 2O 3 catalysts[ w (Mo)=9.0%] with different contents of Pt were characterized by using low temperature FTIR spectroscopy of adsorbed CO, while their HDS activity was investigated with thiophene as a model substrate. Experimentally, it was found that no existence of the bands related to the surface complexes of Al 3+ ←CO and Pt 0←CO→Pt 0 was observed at 77 K and that the rate of the thiophene HDS reaction(573 K) is well linearly proportional to the area of the Pt 0←CO band at 2 093 cm -1 with a higher extrapolated HDS rate compared to that of sulfided Mo/ γ Al 2O 3 catalyst at the zero content of platinum. On the basis of the results here, the conclusion may be made that the active monolayer phase of Pt Mo S may be formed over sulfided PtMo/ γ Al 2O 3 catalysts during the sulfidation process and that both Mo 2+ and Pt 0 sites for CO adsorption should be the active reaction centers of thiophene HDS.展开更多
文摘Low-loaded Pd（0.05 wt.%）/Al2O3 catalysts modified by ceria were prepared by impregnation method.Gas phase hydrogenation of acrylonitrile to propionitrile was selected as probe reaction to study the effect of the light rare earth element cerium on the cataltic activity and stability.Experimental results indicated that addition of a small mount of ceria improved the catalytic activity and stability greatly.The best content of ceria was 3 wt.%,and consecutive impregnation method was prior to co-impregnation method.
文摘The catalytic activity measurement for the NO+CO reaction over CuO/CeO\-2/\%γ\%\|Al\-2O\-3 catalysts at a low\|temperature(200 ℃) shows that the activity is strongly related to ceria loading amount, and both surface dispersed ceria species and crystalline CeO\-2 shows a significant enhancement on the activity. The effect of ceria species is contributed to their promoting the reduction of copper oxide species.
文摘A series of sulfided PtMo/ γ Al 2O 3 catalysts[ w (Mo)=9.0%] with different contents of Pt were characterized by using low temperature FTIR spectroscopy of adsorbed CO, while their HDS activity was investigated with thiophene as a model substrate. Experimentally, it was found that no existence of the bands related to the surface complexes of Al 3+ ←CO and Pt 0←CO→Pt 0 was observed at 77 K and that the rate of the thiophene HDS reaction(573 K) is well linearly proportional to the area of the Pt 0←CO band at 2 093 cm -1 with a higher extrapolated HDS rate compared to that of sulfided Mo/ γ Al 2O 3 catalyst at the zero content of platinum. On the basis of the results here, the conclusion may be made that the active monolayer phase of Pt Mo S may be formed over sulfided PtMo/ γ Al 2O 3 catalysts during the sulfidation process and that both Mo 2+ and Pt 0 sites for CO adsorption should be the active reaction centers of thiophene HDS.
