Synthesis of high performance Silicalite-1 zeolite membranes on silica tubes was first reported in this paper.After two-step in-situ hydrothermal synthesis,well intergrown Silicalite-1 zeolite membranes were synthesiz...Synthesis of high performance Silicalite-1 zeolite membranes on silica tubes was first reported in this paper.After two-step in-situ hydrothermal synthesis,well intergrown Silicalite-1 zeolite membranes were synthesized on silica tubes after aging at 75 ℃ for 12 h.The Silicalite-1 zeolite membranes were characterized by SEM.The separation performance towards ethanol/water mixtures was evaluated by pervaporation.With temperature increasing,the flux of S-1 membrane,increased from 0.2 kg·m-2·h-1 at 30 ℃ to ca. 1.0 kg·m-2·h-1 at 80 ℃, while the separation factor decreased from 110 to 89.These results showed that silica supports may be more suitable for preparing high performance Silicalite-1 membranes.展开更多
The growth and orientation of zeolite crystals on a glass substrate was investigated by changing the roughness and setting of the substrate surface.The orientation control of crystals on the glass substrate was achiev...The growth and orientation of zeolite crystals on a glass substrate was investigated by changing the roughness and setting of the substrate surface.The orientation control of crystals on the glass substrate was achieved.It was found that the setting and treatment of the glass substrate had a substantial effect on crystal orientation.When the substrate surface was upward, the preferential growth of crystal was along the a-axis.However, the preferential growth of crystal was along b-axis when the substrate surface was downward.According to experimental results, a film formation mechanism was proposed to account for the growth and orientation of crystals on the glass substrate.展开更多
以正硅酸乙酯为硅源,合成了具有MFI结构的球形和六方片状silicalite-1全硅分子筛,并将其作为载体制备了负载型催化剂用于丙烷脱氢制丙烯反应;采用SEM、XRD、TEM、N_(2)吸附-脱附、Py-FTIR、NH_(3)-TPD、^(29)Si MAS NMR和H_(2)-TPR等方...以正硅酸乙酯为硅源,合成了具有MFI结构的球形和六方片状silicalite-1全硅分子筛,并将其作为载体制备了负载型催化剂用于丙烷脱氢制丙烯反应;采用SEM、XRD、TEM、N_(2)吸附-脱附、Py-FTIR、NH_(3)-TPD、^(29)Si MAS NMR和H_(2)-TPR等方法对两种分子筛载体及负载型催化剂的结构和表面性质进行表征,研究了不同形貌silicalite-1载体对催化剂性能的影响机制。实验结果表明,球形silicalite-1分子筛载体具有更大的外比表面积和更多的表面硅羟基,进而增强了活性组分与载体间的相互作用,提高了活性金属在载体表面的分散度,因此在丙烷脱氢制丙烯反应中球形silicalite-1载体负载的催化剂具有更高的活性。展开更多
文摘Synthesis of high performance Silicalite-1 zeolite membranes on silica tubes was first reported in this paper.After two-step in-situ hydrothermal synthesis,well intergrown Silicalite-1 zeolite membranes were synthesized on silica tubes after aging at 75 ℃ for 12 h.The Silicalite-1 zeolite membranes were characterized by SEM.The separation performance towards ethanol/water mixtures was evaluated by pervaporation.With temperature increasing,the flux of S-1 membrane,increased from 0.2 kg·m-2·h-1 at 30 ℃ to ca. 1.0 kg·m-2·h-1 at 80 ℃, while the separation factor decreased from 110 to 89.These results showed that silica supports may be more suitable for preparing high performance Silicalite-1 membranes.
文摘The growth and orientation of zeolite crystals on a glass substrate was investigated by changing the roughness and setting of the substrate surface.The orientation control of crystals on the glass substrate was achieved.It was found that the setting and treatment of the glass substrate had a substantial effect on crystal orientation.When the substrate surface was upward, the preferential growth of crystal was along the a-axis.However, the preferential growth of crystal was along b-axis when the substrate surface was downward.According to experimental results, a film formation mechanism was proposed to account for the growth and orientation of crystals on the glass substrate.
文摘以正硅酸乙酯为硅源,合成了具有MFI结构的球形和六方片状silicalite-1全硅分子筛,并将其作为载体制备了负载型催化剂用于丙烷脱氢制丙烯反应;采用SEM、XRD、TEM、N_(2)吸附-脱附、Py-FTIR、NH_(3)-TPD、^(29)Si MAS NMR和H_(2)-TPR等方法对两种分子筛载体及负载型催化剂的结构和表面性质进行表征,研究了不同形貌silicalite-1载体对催化剂性能的影响机制。实验结果表明,球形silicalite-1分子筛载体具有更大的外比表面积和更多的表面硅羟基,进而增强了活性组分与载体间的相互作用,提高了活性金属在载体表面的分散度,因此在丙烷脱氢制丙烯反应中球形silicalite-1载体负载的催化剂具有更高的活性。
