气固相同晶取代法制备Ti-ZSM-5及其催化性能的研究

Preparation of Ti\|ZSM\|5 Zeolites by Gas\|Solid Isomorphous Replacement and Their Catalytic Performance

以Ｂ－ＺＳＭ－５沸石为母体，经过盐酸洗涤脱硼后，采用气固相同晶取代法制备了Ｔｉ－ＺＳＭ－５沸石．考察了制备条件如反应温度、反应时间和载气流速等对产品沸石中钛物种的配位状态和含量的影响．发现进入Ｔｉ－ＺＳＭ－５骨架中的钛含量存在一个极限值．ＦＴ－ＩＲ、ＵＶ－Ｖｉｓ表征技术和丙烯环氧化反应结果表明：不同气固相反应条件下制备的Ｔｉ－ＺＳＭ－５沸石具有不同的物化性质．骨架钛含量高而非骨架钛含量低的钛沸石具有较高的丙烯环氧化催化活性．

Ti\|ZSM\|5 zeolites have been prepared by gas\|solid isomorphous replacement, using B\|ZSM\|5 zeolites as precursors which were pretreated with diluted HCL solution to remove boron and sodium ions. The effects of preparing conditions such as reaction temperature, reaction time and flowing speed of carrying gas on the coordinating state and amount of titanium atoms in the Ti\|ZSM\|5 zeolites have been investigated. The results show that there exists a saturate amount of titanium incorporated into the framework. The results of FT\|IR, UV\|Vis and epoxidation of propylene with dilute hydrogen peroxide solution show that the physicochemical properties of Ti\|ZSM\|5 zeolites prepared at different reaction conditions are interrelated with the catalytic performance.