摘要
以四丙基溴化铵为模板剂,硅溶胶为硅源,分别采用水热静态和动态合成法,制备出钛硅分子筛(TS-1)。采用高温氮化的方法,处理TS-1原粉,合成出含氮钛硅分子筛(N-TS-1),并对其进行了甲醇回流的预处理。通过X-射线粉末衍射和紫外可见漫反射光谱对样品进行了表征。优化了N-TS-1在丙烯环氧化反应中的反应条件,并在较优化的反应条件下,研究了动态合成参数对N-TS-1环氧化性能的影响,得出较优化的动态合成条件为晶化时间3d,晶种加入量2.5%(质量分数),Ti/Si摩尔比0.02。在较优化的合成条件下,将TS-1的合成逐步放大到2L和5L的高压釜,并考察了N-TS-1的丙烯环氧化性能。结果表明,N-TS-1在丙烯环氧化的反应中仍然保持着较高的催化稳定性和选择性,H2O2转化率可达95%以上,H2O2选择性和环氧丙烷选择性在80%以上。
Titanium silicalite-1(TS-1)is synthesized by static and dynamic hydrothermal synthesis methods using tetrapropylammonium bromide as template and silica sol as silica source.As-synthesized TS-1powder is used as precursors, the nitrogen-incorporated TS-1zeolite(N-TS-1)is successfully synthesized by the method of post-synthetic nitridation, and it is pretreated by methanol reflux.The samples are characterized by using X-ray diffraction and ultraviolet-visible spectroscopy.The effect of reaction conditions on the epoxidation of propylene over N-TS-1is investigated,and the optimal reaction conditions are obtained.Under the optimal reaction conditions,the effect of dynamic synthesis parameters on the epoxidation of propylene is investigated,and the appropriate synthesis conditions are as follows:crystallization period is 3d;amount of seeds adding is 2.5wt%(with respect to SiO2);Ti/Si molar ratio is 0.02.Under the optimal synthesis conditions,the amplified synthesis of TS-1in 2land 5lautoclaves is achieved,and catalytic properties of the resulting nitridized samples in the epoxidation of propylene are investigated.The results show that the nitridized samples still present high catalytic selectivity and stability,the conversion of H2O2reaches 95%,and selectivity of H2O2and propylene oxide are greater than 80%.
出处
《长江大学学报（自科版）（上旬）》
CAS
2013年第11期24-27,4-5,共6页
JOURNAL OF YANGTZE UNIVERSITY (NATURAL SCIENCE EDITION) SCI ＆ ENG
基金
湖北省自然科学基金项目(2012FFB00103)
关键词
钛硅分子筛
动态合成
氮化
丙烯环氧化
titanium silicalite-1
dynamic synthesis
nitridation
epoxidation of propylene
