Tailoring the Ti coordination states in titanosilicate zeolites to simultaneously improve feedstock conversion and maximize the target product selectivity remains a challenge in the pursuit of high-performance catalysts for selective oxidation reactions. Herein, we provide a facile strategy to synthesize hierarchical anatase-free TS-1 (MFI-type) zeolites with tetrahedrally coordinated (TiO₄) and octahedrally coordinated Ti species (TiO₆). The TiO₄ species provide high epoxide selectivity, while the TiO₆ species afford improved alkene conversion. This strategy is achieved by synergistically using an L-lysine-assisted approach and a two-step crystallization; the two-step crystallization approach prevents the formation of anatase TiO₂, while L-lysine stabilizes the TiO₆ species and ensures efficient incorporation of TiO₆ into the anatase-free TS-1 zeolites. Compared with their conventional counterparts, which only contain TiO₄ species, the as-prepared TS-1 zeolites (Si/Ti = 36.9) result in a higher 1-hexene conversion (33%), higher TON value (153), and comparable epoxide selectivity (95%). This synthetic strategy provides avenues to tailor the amount and distribution of Ti species in titanosilicate zeolites to achieve high catalytic performances in various processes.

调整钛硅酸盐沸石中的 Ti 配位状态以同时提高原料转化率和最大化目标产物选择性仍然是寻求用于选择性氧化反应的高性能催化剂的挑战。在此，我们提供了一种简便的策略来合成具有四面体配位 (TiO ₄ ) 和八面体配位钛物质 (TiO ₆ ) 的分级无锐钛矿 TS-1（MFI型）沸石。TiO ₄物种提供高环氧化物选择性，而 TiO ₆物种提供改进的烯烃转化率。该策略是通过协同使用 L-赖氨酸辅助方法和两步结晶来实现的；两步结晶方法防止锐钛矿型 TiO ₂的形成，而 L-赖氨酸稳定了 TiO ₆种类并确保 TiO ₆有效结合到不含锐钛矿的 TS-1 沸石中。与仅含有 TiO ₄的传统同类产品相比对于物种，所制备的 TS-1 沸石 (Si/Ti = 36.9) 导致更高的 1-己烯转化率 (33%)、更高的 TON 值 (153) 和相当的环氧化物选择性 (95%)。这种合成策略为调整钛硅酸盐沸石中 Ti 种类的数量和分布提供了途径，以在各种工艺中实现高催化性能。