Diatomite-dispersed NiMoW catalyst was prepared and characterized,and the activity of catalyst samples was tested during the HDS reaction of FCC diesel.Sulfur compounds in the feedstock and the hydrogenated products o...Diatomite-dispersed NiMoW catalyst was prepared and characterized,and the activity of catalyst samples was tested during the HDS reaction of FCC diesel.Sulfur compounds in the feedstock and the hydrogenated products obtained over different catalysts were determined by GC-PFPD.The test results showed that the diatomite-dispersed NiMoW catalyst had high hydrodesulfurization activity for FCC diesel,which could be contributed to the excellent hydrogenation performance of the said catalyst.Characterization of catalyst by TEM and XRD indicated that the diatomite-dispersed NiMoW catalyst possessed higher layer stacking,larger curvature of MoS2or WS2,and segregated Ni3S2crystals relative to the supported catalyst.This kind of structure leads to high hydrogenation activity of the diatomite-dispersed NiMoW catalyst.展开更多
Charged centers exist in the phosphor layer of the common thin film electroluminescent devices. In this article, electron scattering process due to these centers is studied through phase shift analysis. The scattering...Charged centers exist in the phosphor layer of the common thin film electroluminescent devices. In this article, electron scattering process due to these centers is studied through phase shift analysis. The scattering rates in different cases are obtained and compared with other important scattering processes. Electron transport processed under different charged centers conditions are simulated by means of Monte Carlo method. The quantitative results about the influence of charged centers on electron energy are obtained.展开更多
Silica-dispersed NiMo hydrodesulfurization catalysts were synthesized by the deposition-precipitation method. For comparative purposes, bulk NiMo catalysts were obtained by co-precipitation. The silica-dispersed NiMo ...Silica-dispersed NiMo hydrodesulfurization catalysts were synthesized by the deposition-precipitation method. For comparative purposes, bulk NiMo catalysts were obtained by co-precipitation. The silica-dispersed NiMo catalyst had highly active metals content. Silica was employed to disperse active metals for full utilization of active components. The BET analysis showed that the silica-dispersed NiMo catalysts had a high surface area （147.0 m2/g） and pore volume （0.27 mL/g）, whereas the bulk NiMo catalysts exhibited a very low surface area （87.5 m2/g）. Transmission electron microscopy results proved that the active components were dispersed on the SiO2 substrate. X-ray diffraction patterns of the silicadispersed NiMo catalyst and the bulk NiMo catalyst were indexed to NiMoO4. The hydrodesulfurization activity of silicadispersed NiMo catalysts was much higher than that of reference catalysts and could be up to twice greater than those of commercial NiMo alumina-supported systems per gram of catalyst. The activity testing results also demonstrated that the silica-dispersed NiMo catalyst was an effective hydrodesulflarization catalyst.展开更多
基金support of National Natural Science Foundation of China(Grant No.21306106)the Specialized Research Fund for the Doctoral Program of Higher Education of China(Grant No.2012371812012)China Postdoctoral Science Foundation(Grant No.2012M541941)
文摘Diatomite-dispersed NiMoW catalyst was prepared and characterized,and the activity of catalyst samples was tested during the HDS reaction of FCC diesel.Sulfur compounds in the feedstock and the hydrogenated products obtained over different catalysts were determined by GC-PFPD.The test results showed that the diatomite-dispersed NiMoW catalyst had high hydrodesulfurization activity for FCC diesel,which could be contributed to the excellent hydrogenation performance of the said catalyst.Characterization of catalyst by TEM and XRD indicated that the diatomite-dispersed NiMoW catalyst possessed higher layer stacking,larger curvature of MoS2or WS2,and segregated Ni3S2crystals relative to the supported catalyst.This kind of structure leads to high hydrogenation activity of the diatomite-dispersed NiMoW catalyst.
基金The 863 Project ,Doctoral Program Foundation of Education Departme
文摘Charged centers exist in the phosphor layer of the common thin film electroluminescent devices. In this article, electron scattering process due to these centers is studied through phase shift analysis. The scattering rates in different cases are obtained and compared with other important scattering processes. Electron transport processed under different charged centers conditions are simulated by means of Monte Carlo method. The quantitative results about the influence of charged centers on electron energy are obtained.
基金the financial support from the National Basic Research Program(No. 2010CB226905) of China.
文摘Silica-dispersed NiMo hydrodesulfurization catalysts were synthesized by the deposition-precipitation method. For comparative purposes, bulk NiMo catalysts were obtained by co-precipitation. The silica-dispersed NiMo catalyst had highly active metals content. Silica was employed to disperse active metals for full utilization of active components. The BET analysis showed that the silica-dispersed NiMo catalysts had a high surface area （147.0 m2/g） and pore volume （0.27 mL/g）, whereas the bulk NiMo catalysts exhibited a very low surface area （87.5 m2/g）. Transmission electron microscopy results proved that the active components were dispersed on the SiO2 substrate. X-ray diffraction patterns of the silicadispersed NiMo catalyst and the bulk NiMo catalyst were indexed to NiMoO4. The hydrodesulfurization activity of silicadispersed NiMo catalysts was much higher than that of reference catalysts and could be up to twice greater than those of commercial NiMo alumina-supported systems per gram of catalyst. The activity testing results also demonstrated that the silica-dispersed NiMo catalyst was an effective hydrodesulflarization catalyst.
