CuO/SBA-16 catalysts were prepared by two different routes–the conventional impregnation method and the modified impregnation method with pH adjustment.These catalysts were characterized by X-ray diffraction(XRD),ato...CuO/SBA-16 catalysts were prepared by two different routes–the conventional impregnation method and the modified impregnation method with pH adjustment.These catalysts were characterized by X-ray diffraction(XRD),atomic absorption spectrometry(AAS),N2 physisorption and hydrogen temperature programmed reduction(H2-TPR)measurements which reveal that the cubic cagelike(Im3m)pore structure of the parent SBA-16 molecule sieves was well maintained throughout the synthesis.After introduction of Cu,a different CuO dispersion exists on these catalysts.The CuO/SBA-16 prepared by modified impregnation method has a single highly dispersed CuO which is considered as a highly efficient species for hydroxylation of phenol withH2O2.CuO/SBA-16 prepared by the conventional impregnation method shows the presence of bulk CuO species which is undesirable for this reaction.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the Science and Technology Foundation of Office of Education of Heilongjiang Province(Grant No.10551251).
文摘CuO/SBA-16 catalysts were prepared by two different routes–the conventional impregnation method and the modified impregnation method with pH adjustment.These catalysts were characterized by X-ray diffraction(XRD),atomic absorption spectrometry(AAS),N2 physisorption and hydrogen temperature programmed reduction(H2-TPR)measurements which reveal that the cubic cagelike(Im3m)pore structure of the parent SBA-16 molecule sieves was well maintained throughout the synthesis.After introduction of Cu,a different CuO dispersion exists on these catalysts.The CuO/SBA-16 prepared by modified impregnation method has a single highly dispersed CuO which is considered as a highly efficient species for hydroxylation of phenol withH2O2.CuO/SBA-16 prepared by the conventional impregnation method shows the presence of bulk CuO species which is undesirable for this reaction.
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.
