TiO2-Al2O3 binary okides were prepared by gas-phase deposition of TiCly on r-Al2os support. It was found that TiO2 deposition is formd by the reaction of TiCl4 vapour with OH- group on A12O3 stirface. The TiO2 loading...TiO2-Al2O3 binary okides were prepared by gas-phase deposition of TiCly on r-Al2os support. It was found that TiO2 deposition is formd by the reaction of TiCl4 vapour with OH- group on A12O3 stirface. The TiO2 loading increases with the number of gas phase deposition operations and the tetrahedral sites of Al2O3 surface was first covered by TiO2. S1ightly decrease of surface area) pore value and average of pore diameter of TiOz-AlzO3 compared with Al2O3 was observed. In Mo/TiO2-Al2O3 catalysts Mo ealsts maally in the form of octalledla and polymer Mo7O2’ species, while no tetrahedral Mo species has been observed. The model of Mo/TiO2-Al2O3 catalyst could be imagined as a sandwich of MoO2-TiO2-Al2O3. Due to the weaker interaction between Mo species and A1zoa support in this case more Mo6+ ions in Mo/TiO2-Al2O3 sample are reduced to low valence state comparing with that of Mo/Al2O3 at 5o(f C in H2. The experimental results demonstrate that the HDS and HYD activities of Mo/TiO2-Al2O3 catalysts increase with Tioz content. It means that the full coverage of Al2o3 surface by TiO2 can driprove effectively the catalyst activity of molybdenum catalyst in hydrotreating process.展开更多
文摘TiO2-Al2O3 binary okides were prepared by gas-phase deposition of TiCly on r-Al2os support. It was found that TiO2 deposition is formd by the reaction of TiCl4 vapour with OH- group on A12O3 stirface. The TiO2 loading increases with the number of gas phase deposition operations and the tetrahedral sites of Al2O3 surface was first covered by TiO2. S1ightly decrease of surface area) pore value and average of pore diameter of TiOz-AlzO3 compared with Al2O3 was observed. In Mo/TiO2-Al2O3 catalysts Mo ealsts maally in the form of octalledla and polymer Mo7O2’ species, while no tetrahedral Mo species has been observed. The model of Mo/TiO2-Al2O3 catalyst could be imagined as a sandwich of MoO2-TiO2-Al2O3. Due to the weaker interaction between Mo species and A1zoa support in this case more Mo6+ ions in Mo/TiO2-Al2O3 sample are reduced to low valence state comparing with that of Mo/Al2O3 at 5o(f C in H2. The experimental results demonstrate that the HDS and HYD activities of Mo/TiO2-Al2O3 catalysts increase with Tioz content. It means that the full coverage of Al2o3 surface by TiO2 can driprove effectively the catalyst activity of molybdenum catalyst in hydrotreating process.
