摘要
通过 12 0 0h模拟实验 ,考察了CH3 OH H2 O2 丙烯环氧化水热环境对廉价法合成的大晶粒钛硅沸石TS 1(1μm× 2 μm× 6 μm ,n(Si) /n(Ti) =5 3 6 )结构的影响 .通过XRF ,XRD ,FT IR ,UV Vis,NH3 TPD ,SEM ,N2 物理吸附和丙烯环氧化探针反应等表征手段发现 ,在丙烯环氧化反应的水热环境中 ,TS 1沸石的晶体结构和骨架钛较稳定 ,TS 1沸石长时间与H2 O2 作用 ,其表面也不会被酸化 ;处理后的TS 1样品的催化活性和选择性不变 .这些结果表明 ,用廉价法合成的大晶粒钛硅沸石TS 1与H2 O2 的作用是可逆的 .这可能与TS
The effect of the hydrothermal environment of propylene epoxidation on framework of TS 1 zeolite during its long period of service was studied by simulated experiments lasting for 1?200 h. The TS 1 zeolite has crystal size of 1 μm×2 μm×6 μm and SiO 2/TiO 2 mole ratio of 53 6. The experiments were carried out in a glass tube fixed bed reactor placed in a water bath. The hydrothermal environment was simulated by methanol solution ( c (H 2O 2)=0 8 and 1 6 mol/L) at 50～70 ℃. During the experiments, sampling was made at intervals and the samples were characterized by XRF, XRD, FT IR, UV Vis, NH 3 TPD, SEM and probe reaction of propylene epoxidation. There is no detectable change in the crystal structure and the framework Ti of TS 1 zeolite within 1?200 h. Moreover, no evident increase in acidity on the zeolite surface occurs. The treated TS 1 sample exhibits the same activity and selectivity in propylene epoxidation as the fresh TS 1 zeolite. The treated TS 1 zeolite can react with H 2O 2 reversibly. Therefore, whether TS 1 zeolite reacts with H 2O 2 reversibly or not may depend largely on the process and the condition of hydrothermal synthesis.
出处
《催化学报》
SCIE
CAS
CSCD
北大核心
2003年第6期437-440,共4页
基金
国家重点基础研究发展规划项目 (G2 0 0 0 0 480 0 9)
关键词
钛硅沸石
丙烯
环氧化反应
TS-1
晶体结构
水热稳定性
骨架钛
环氧丙烷
催化剂
过氧化氢
titanium silicate 1 zeolite, crystal structure, framework titanium, hydrothermostability, propylene, epoxidation, hydrogen peroxide, propylene oxide
