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
A novel coprecipitation-reduction process has been proposed for preparing highly selective Cu/ZnO/Al 2O 3 catalysts for methanol synthesis from CO 2 hydrogenation. Compared to the catalysts prepared by the conventiona...A novel coprecipitation-reduction process has been proposed for preparing highly selective Cu/ZnO/Al 2O 3 catalysts for methanol synthesis from CO 2 hydrogenation. Compared to the catalysts prepared by the conventional method, the new catalysts prepared via the new method exhibit much higher BET surface area and pore size, much smaller crystallite size and higher catalytic activity and selectivity in CO 2 hydrogenation to methanol. It is also found that the molar ratio of Cu + to Cu 0 on the surface of the catalyst obtained by coprecipitation-reduction is much higher than that on the reduced catalyst obtained by the conventional method, which could be crucial for its high activity and selectivity for catalytic hydrogenation of CO 2 to methanol.展开更多
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.
文摘A novel coprecipitation-reduction process has been proposed for preparing highly selective Cu/ZnO/Al 2O 3 catalysts for methanol synthesis from CO 2 hydrogenation. Compared to the catalysts prepared by the conventional method, the new catalysts prepared via the new method exhibit much higher BET surface area and pore size, much smaller crystallite size and higher catalytic activity and selectivity in CO 2 hydrogenation to methanol. It is also found that the molar ratio of Cu + to Cu 0 on the surface of the catalyst obtained by coprecipitation-reduction is much higher than that on the reduced catalyst obtained by the conventional method, which could be crucial for its high activity and selectivity for catalytic hydrogenation of CO 2 to methanol.
