Five types of KNO_3-NH_4VO_3-rare earth metal nitrate（K-V-rare earth metal） catalysts supported on a-porous alumina ceramic substrates were prepared by a coating method. All the catalysts were characterized by X-ray...Five types of KNO_3-NH_4VO_3-rare earth metal nitrate（K-V-rare earth metal） catalysts supported on a-porous alumina ceramic substrates were prepared by a coating method. All the catalysts were characterized by X-ray diffraction and thermogravimetry/differential scanning calorimetry. Catalytic activities were evaluated by a soot oxidation reaction using a temperature-programmed reaction system. The experimental results show that the addition of rare earth metal compound could obviously improve the catalytic activities of the K-V-based catalysts. The proper ratio of K-V-rare earth metal catalysts can not only lower the soot onset ignition temperature, but also quicken the soot oxidation rate. The crystalline phases formed by K, V, and rare earth metal are stable.展开更多
The effects of phosphorus on the structure and hydrofining performance of tri-metallic WMoNi/Al2O3 catalysts prepared with W/Mo-based hybrid precursor nanocrystals were investigated. The incorporation of phosphorus we...The effects of phosphorus on the structure and hydrofining performance of tri-metallic WMoNi/Al2O3 catalysts prepared with W/Mo-based hybrid precursor nanocrystals were investigated. The incorporation of phosphorus weakened the metal-support interactions （MSIs） and facilitated the formation of more synergetic NiWMoS phases with higher stacks. Catalytic tests using a fluid catalytic cracking diesel fuel showed that the changes in the MSIs and the morphology of the active phases had a more positive effect on the hydrodenitrogenation activity than on the hydrodesulfurization activity. In contrast, when phosphorus was incorporated into a tri-metallic WMoNiP/Al2O3 catalyst prepared by a conventional incipient impregnation method, the MSIs decreased causing aggregation of the metal species which resulted in poorer hydrofining performance of the catalyst. These results show that incorporating phosphorus into a WMoNi/Al2O3 catalyst can finely tune the structure of the active phase to enhance the hydrogenation and hydrodenitrogenation activity of the resulting tri-metallic catalyst.展开更多
基金Funded by the National Natural Science Foundation of China(Nos.21606140,21776147,and 51373086)the Science-Technology Program in Higher Education Institutions of Shandong Province,China(J11LD05)the Qingdao Municipal Science and Technology Commission,China(13-1-4-154-jch)
文摘Five types of KNO_3-NH_4VO_3-rare earth metal nitrate（K-V-rare earth metal） catalysts supported on a-porous alumina ceramic substrates were prepared by a coating method. All the catalysts were characterized by X-ray diffraction and thermogravimetry/differential scanning calorimetry. Catalytic activities were evaluated by a soot oxidation reaction using a temperature-programmed reaction system. The experimental results show that the addition of rare earth metal compound could obviously improve the catalytic activities of the K-V-based catalysts. The proper ratio of K-V-rare earth metal catalysts can not only lower the soot onset ignition temperature, but also quicken the soot oxidation rate. The crystalline phases formed by K, V, and rare earth metal are stable.
基金Acknowledgements We gratefully acknowledge the support from the National Natural Science Foundation of China （Grant Nos. U1462203 and 21106182）.
文摘The effects of phosphorus on the structure and hydrofining performance of tri-metallic WMoNi/Al2O3 catalysts prepared with W/Mo-based hybrid precursor nanocrystals were investigated. The incorporation of phosphorus weakened the metal-support interactions （MSIs） and facilitated the formation of more synergetic NiWMoS phases with higher stacks. Catalytic tests using a fluid catalytic cracking diesel fuel showed that the changes in the MSIs and the morphology of the active phases had a more positive effect on the hydrodenitrogenation activity than on the hydrodesulfurization activity. In contrast, when phosphorus was incorporated into a tri-metallic WMoNiP/Al2O3 catalyst prepared by a conventional incipient impregnation method, the MSIs decreased causing aggregation of the metal species which resulted in poorer hydrofining performance of the catalyst. These results show that incorporating phosphorus into a WMoNi/Al2O3 catalyst can finely tune the structure of the active phase to enhance the hydrogenation and hydrodenitrogenation activity of the resulting tri-metallic catalyst.
