Hierarchically porous Beta/SBA-16(BS)composite materials,combining the characteristics of the acidity from the Beta zeolite and the three-dimensional structure from SBA-16,were synthesized successfully through a two-s...Hierarchically porous Beta/SBA-16(BS)composite materials,combining the characteristics of the acidity from the Beta zeolite and the three-dimensional structure from SBA-16,were synthesized successfully through a two-step in-situ assembly hydrothermal crystallization method.A series of Ni Mo catalysts supported on BS with different silica-alumina ratios were prepared.The supports and the corresponding catalysts were characterized by XRD,N_(2) physisorption,^(27)Al MAS NMR,TEM,pyridine-FTIR,Raman,XPS and HRTEM.The activities of series catalysts were evaluated by the hydrodesulfurization(HDS)performances of dibenzothiophene(DBT)and 4,6-dimethyldibenzothiophene(4,6-DMDBT).It was found that the Beta crystallites were embedded into SBA-16 through silanols accompanied by dealumination on the T3-T9 sites of Beta crystallites.Ni Mo/BS-3 with a silica-alumina ratio of 100 exhibited the highest DBT and 4,6-DMDBT HDS activities at the WHSV value of 10 h^(-1),with the conversions of 95.9%and 86.9%respectively,due to the synergistic effects of the suitable specific surface areas,the relatively large pore size,appropriate acidity,the relatively high sulfidation degree,moderate dispersity and good stacking degree of Mo S;active phases.展开更多
A SBA-16-type mesoporous silica material was synthesized under a moderately acidic condition of 0.5 mol·L -1 HCl solution.These mesoporous materials were characterized with X-ray diffraction(XRD)pattern,scanning ...A SBA-16-type mesoporous silica material was synthesized under a moderately acidic condition of 0.5 mol·L -1 HCl solution.These mesoporous materials were characterized with X-ray diffraction(XRD)pattern,scanning electron microscopy(SEM),transmission electron microscopy(TEM),and nitrogen adsorption-desorption measurements.The three-dimensional microporosity of the prepared mesoporous silica having ordered hexagonal mesoporous structure was evidenced by the well-defined XRD patterns combined with TEM photographs.SEM observation showed a highly ordered cubic crystal structure for the prepared mesoporous silica.The size of these crystallites was maintained within the range of 4—6 μm,which is fairly important for the application to the stationary phase for separation.The nitrogen adsorption-desorption analysis revealed that the prepared mesoporous silica possessed a small pore diameter of 3.68 nm,a total surface area of 363.65 m2·g -1 ,a total pore volume of 0.38 cm3·g -1 ,and a pore-wall thickness of 6.63 nm.These features may lead to higher thermal and hydrothermal stability,excellent microporosity,and good connectivity.The mesoporous silica prepared in this study exhibited potential applications to catalysis,sensoring,and separation.展开更多
基金supported by the National Natural Science Foundation of China(No.21878330,21676298)the National Science and Technology Major Project(No.2019YFC1907700)+1 种基金the CNPC Key Research Project(2016E-0707)the King Abdullah University of Science and Technology(KAUST)。
文摘Hierarchically porous Beta/SBA-16(BS)composite materials,combining the characteristics of the acidity from the Beta zeolite and the three-dimensional structure from SBA-16,were synthesized successfully through a two-step in-situ assembly hydrothermal crystallization method.A series of Ni Mo catalysts supported on BS with different silica-alumina ratios were prepared.The supports and the corresponding catalysts were characterized by XRD,N_(2) physisorption,^(27)Al MAS NMR,TEM,pyridine-FTIR,Raman,XPS and HRTEM.The activities of series catalysts were evaluated by the hydrodesulfurization(HDS)performances of dibenzothiophene(DBT)and 4,6-dimethyldibenzothiophene(4,6-DMDBT).It was found that the Beta crystallites were embedded into SBA-16 through silanols accompanied by dealumination on the T3-T9 sites of Beta crystallites.Ni Mo/BS-3 with a silica-alumina ratio of 100 exhibited the highest DBT and 4,6-DMDBT HDS activities at the WHSV value of 10 h^(-1),with the conversions of 95.9%and 86.9%respectively,due to the synergistic effects of the suitable specific surface areas,the relatively large pore size,appropriate acidity,the relatively high sulfidation degree,moderate dispersity and good stacking degree of Mo S;active phases.
文摘A SBA-16-type mesoporous silica material was synthesized under a moderately acidic condition of 0.5 mol·L -1 HCl solution.These mesoporous materials were characterized with X-ray diffraction(XRD)pattern,scanning electron microscopy(SEM),transmission electron microscopy(TEM),and nitrogen adsorption-desorption measurements.The three-dimensional microporosity of the prepared mesoporous silica having ordered hexagonal mesoporous structure was evidenced by the well-defined XRD patterns combined with TEM photographs.SEM observation showed a highly ordered cubic crystal structure for the prepared mesoporous silica.The size of these crystallites was maintained within the range of 4—6 μm,which is fairly important for the application to the stationary phase for separation.The nitrogen adsorption-desorption analysis revealed that the prepared mesoporous silica possessed a small pore diameter of 3.68 nm,a total surface area of 363.65 m2·g -1 ,a total pore volume of 0.38 cm3·g -1 ,and a pore-wall thickness of 6.63 nm.These features may lead to higher thermal and hydrothermal stability,excellent microporosity,and good connectivity.The mesoporous silica prepared in this study exhibited potential applications to catalysis,sensoring,and separation.
