8wt%WO3/SiO2 metathesis （disproportionation） catalysts with different pore structures were prepared by the incipient-wetness-impregnation method. The as-synthesized catalysts were characterized by N2 adsorpfion-deso...8wt%WO3/SiO2 metathesis （disproportionation） catalysts with different pore structures were prepared by the incipient-wetness-impregnation method. The as-synthesized catalysts were characterized by N2 adsorpfion-desorption, scanning electron microscopy （SEM）, X-ray diffraction （XRD）, UV-visible diffuse reflectance spectroscopy （DRS） and scanning transmission electron microscopy-high-angle annular dark field （STEM HAADF）. The results of STEM HAADF showed that WO3 species were not uniformly distributed on the SiO2 support. The experimental results of 8wt%WO3/SiO2 performance in ethene/decene metathesis revealed that the catalytic effect of 8wt%WO3/SiO2 catalyst and coke formation over it were closely related to the support pore structure： The 8wt%WO3/SiO2 catalyst with a more complicated pore structure showed better catalytic performance but the coke deposition rate was also faster.展开更多
Supported loaded semiconductors （MoO3,ZnO）-TiO2/SiO2 were pre pared by an isovolumetric impregnation method from TiO2/SiO2 pre pared by chemical modification reaction. The chemisorption property and photon a bsorpti...Supported loaded semiconductors （MoO3,ZnO）-TiO2/SiO2 were pre pared by an isovolumetric impregnation method from TiO2/SiO2 pre pared by chemical modification reaction. The chemisorption property and photon a bsorption ability of MoO3-TiO2/SiO2 and ZnO-TiO2/SiO 2 were investigated by BET, UV-Vis DRS, IR and TPD-MS techniques. The gas -phase photocatalytic reaction of CH4 with H2O was performed at 150 ℃ in a fixed-bed annular reactor. The results show that the conversion of met hane and the selectivity of methanol reach to 5.1% and 87.3% respectively over MoO3-TiO2/SiO2, and MoO3-TiO2/SiO2 ex hibits higher photocatalytic acivity than ZnO-TiO2/SiO2.展开更多
文摘8wt%WO3/SiO2 metathesis （disproportionation） catalysts with different pore structures were prepared by the incipient-wetness-impregnation method. The as-synthesized catalysts were characterized by N2 adsorpfion-desorption, scanning electron microscopy （SEM）, X-ray diffraction （XRD）, UV-visible diffuse reflectance spectroscopy （DRS） and scanning transmission electron microscopy-high-angle annular dark field （STEM HAADF）. The results of STEM HAADF showed that WO3 species were not uniformly distributed on the SiO2 support. The experimental results of 8wt%WO3/SiO2 performance in ethene/decene metathesis revealed that the catalytic effect of 8wt%WO3/SiO2 catalyst and coke formation over it were closely related to the support pore structure： The 8wt%WO3/SiO2 catalyst with a more complicated pore structure showed better catalytic performance but the coke deposition rate was also faster.
文摘Supported loaded semiconductors （MoO3,ZnO）-TiO2/SiO2 were pre pared by an isovolumetric impregnation method from TiO2/SiO2 pre pared by chemical modification reaction. The chemisorption property and photon a bsorption ability of MoO3-TiO2/SiO2 and ZnO-TiO2/SiO 2 were investigated by BET, UV-Vis DRS, IR and TPD-MS techniques. The gas -phase photocatalytic reaction of CH4 with H2O was performed at 150 ℃ in a fixed-bed annular reactor. The results show that the conversion of met hane and the selectivity of methanol reach to 5.1% and 87.3% respectively over MoO3-TiO2/SiO2, and MoO3-TiO2/SiO2 ex hibits higher photocatalytic acivity than ZnO-TiO2/SiO2.
